Modeling nutrient retention at the watershed scale: Does small stream research apply to the whole river network?

NASA Astrophysics Data System (ADS)

Aguilera, Rosana; Marcé, Rafael; Sabater, Sergi

2013-06-01

are conveyed from terrestrial and upstream sources through drainage networks. Streams and rivers contribute to regulate the material exported downstream by means of transformation, storage, and removal of nutrients. It has been recently suggested that the efficiency of process rates relative to available nutrient concentration in streams eventually declines, following an efficiency loss (EL) dynamics. However, most of these predictions are based at the reach scale in pristine streams, failing to describe the role of entire river networks. Models provide the means to study nutrient cycling from the stream network perspective via upscaling to the watershed the key mechanisms occurring at the reach scale. We applied a hybrid process-based and statistical model (SPARROW, Spatially Referenced Regression on Watershed Attributes) as a heuristic approach to describe in-stream nutrient processes in a highly impaired, high stream order watershed (the Llobregat River Basin, NE Spain). The in-stream decay specifications of the model were modified to include a partial saturation effect in uptake efficiency (expressed as a power law) and better capture biological nutrient retention in river systems under high anthropogenic stress. The stream decay coefficients were statistically significant in both nitrate and phosphate models, indicating the potential role of in-stream processing in limiting nutrient export. However, the EL concept did not reliably describe the patterns of nutrient uptake efficiency for the concentration gradient and streamflow values found in the Llobregat River basin, posing in doubt its complete applicability to explain nutrient retention processes in stream networks comprising highly impaired rivers.

Nutrient processes at the stream-lake interface for a channelized versus unmodified stream mouth

USGS Publications Warehouse

Niswonger, Richard G.; Naranjo, Ramon C.; Smith, David; Constantz, James E.; Allander, Kip K.; Rosenberry, Donald O.; Neilson, Bethany; Rosen, Michael R.; Stonestrom, David A.

2017-01-01

Inorganic forms of nitrogen and phosphorous impact freshwater lakes by stimulating primary production and affecting water quality and ecosystem health. Communities around the world are motivated to sustain and restore freshwater resources and are interested in processes controlling nutrient inputs. We studied the environment where streams flow into lakes, referred to as the stream-lake interface (SLI), for a channelized and unmodified stream outlet. Channelization is done to protect infrastructure or recreational beach areas. We collected hydraulic and nutrient data for surface water and shallow groundwater in two SLIs to develop conceptual models that describe characteristics that are representative of these hydrologic features. Water, heat, and solute transport models were used to evaluate hydrologic conceptualizations and estimate mean residence times of water in the sediment. A nutrient mass balance model is developed to estimate net rates of adsorption and desorption, mineralization, and nitrification along subsurface flow paths. Results indicate that SLIs are dynamic sources of nutrients to lakes and that the common practice of channelizing the stream at the SLI decreases nutrient concentrations in pore water discharging along the lakeshore. This is in contrast to the unmodified SLI that forms a barrier beach that disconnects the stream from the lake and results in higher nutrient concentrations in pore water discharging to the lake. These results are significant because nutrient delivery through pore water seepage at the lakebed from the natural SLI contributes to nearshore algal communities and produces elevated concentrations of inorganic nutrients in the benthic zone where attached algae grow.

Salmon carcasses increase stream productivity more than inorganic fertilizer pellets: A test on multiple trophic levels in streamside experimental channels

USGS Publications Warehouse

Wipfli, Mark S.; Hudson, John P.; Caouette, John P.; Mitchell, N.L.; Lessard, Joanna L.; Heintz, Ron A.; Chaloner, D.T.

2010-01-01

Inorganic nutrient amendments to streams are viewed as possible restoration strategies for re-establishing nutrients and stream productivity throughout the western coast of North America, where salmon runs and associated marine-derived nutrient subsidies have declined. In a mesocosm experiment, we examined the short-term (6 weeks) comparative effects of artificial nutrient pellets and salmon carcasses, alone (low and high amounts) and in combination, on stream food webs. Response variables included dissolved nutrient concentrations, biofilm ash-free dry mass (AFDM) and chlorophyll-alevels, macroinvertebrate density, growth and body condition of juvenile coho salmon Oncorhynchus kisutch, and whole-body lipid content of invertebrates and juvenile coho salmon. Most of the response variables were significantly influenced by carcass treatment; the only response variable significantly influenced by fertilizer pellet treatment was soluble reactive phosphorus (SRP) concentration. Ammonium-nitrogen concentration was the only response variable affected by both (low and high) levels of carcass treatment; all others showed no significant response to the two carcass treatment levels. Significant treatment × time interactions were observed for all responses except nitrate; for most responses, significant treatment effects were detected at certain time periods and not others. For example, significantly higher SRP concentrations were recorded earlier in the experiment, whereas significant fish responses were observed later. These results provide evidence that inorganic nutrient additions do not have the same ecological effects in streams as do salmon carcasses, potentially because inorganic nutrient additions lack carbon-based biochemicals and macromolecules that are sequestered directly or indirectly by consumers. Salmon carcasses, preferably deposited naturally during spawning migrations, appear to be far superior to inorganic nutrient amendments for sustaining and restoring stream productivity, including fish production, and should be chosen over artificial nutrient additions when feasible and practical.

Bioavailability of Dissolved Organic Carbon and Nitrogen From Tropical Montane Rainforest Streams Across a Geologic age Gradient

NASA Astrophysics Data System (ADS)

Wiegner, T. N.

2005-05-01

Dissolved organic matter (DOM) is metabolically important in streams. Its bioavailability is influenced by organic matter sources to streams and inorganic nutrient availability. As forest canopies and soils develop over time, organic matter inputs to streams should switch from algal to watershed sources. Across this succession gradient, nutrient limitation should also change. This study examines how chemical composition and bioavailability of DOM from tropical montane rainforest streams on Hawaii change across a geologic age gradient from 4 ky to 150 ky. Dissolved organic C (DOC) and N (DON) concentrations, chemical characteristics, and bioavailability varied with site age. With increasing stream age, DOC and DON concentrations, DOM aromaticity, and the C:N of the stream DOM increased. Changes in stream DOM chemistry and inorganic nutrient availability affected DOM bioavailability. Fifty percent of the DOC from the 4 ky site was bioavailable, where little to none was bioavailable from the older streams. Inorganic nutrient availability did not affect DOC bioavailability. In contrast, DON bioavailability was similar (12%) across sites and was affected by inorganic nutrient availability. This study demonstrates that the chemistry and metabolism of streams draining forests change with ecosystem age and development.

Stream Communities Along a Catchment Land-Use Gradient: Subsidy-Stress Responses to Pastoral Development

NASA Astrophysics Data System (ADS)

Niyogi, Dev K.; Koren, Mark; Arbuckle, Chris J.; Townsend, Colin R.

2007-02-01

When native grassland catchments are converted to pasture, the main effects on stream physicochemistry are usually related to increased nutrient concentrations and fine-sediment input. We predicted that increasing nutrient concentrations would produce a subsidy-stress response (where several ecological metrics first increase and then decrease at higher concentrations) and that increasing sediment cover of the streambed would produce a linear decline in stream health. We predicted that the net effect of agricultural development, estimated as percentage pastoral land cover, would have a nonlinear subsidy-stress or threshold pattern. In our suite of 21 New Zealand streams, epilithic algal biomass and invertebrate density and biomass were higher in catchments with a higher proportion of pastoral land cover, responding mainly to increased nutrient concentration. Invertebrate species richness had a linear, negative relationship with fine-sediment cover but was unrelated to nutrients or pastoral land cover. In accord with our predictions, several invertebrate stream health metrics (Ephemeroptera-Plecoptera-Trichoptera density and richness, New Zealand Macroinvertebrate Community Index, and percent abundance of noninsect taxa) had nonlinear relationships with pastoral land cover and nutrients. Most invertebrate health metrics usually had linear negative relationships with fine-sediment cover. In this region, stream health, as indicated by macroinvertebrates, primarily followed a subsidy-stress pattern with increasing pastoral development; management of these streams should focus on limiting development beyond the point where negative effects are seen.

Nutrient variation in an urban lake chain and its consequences for phytoplankton production.

PubMed

Roach, W John; Grimm, Nancy B

2009-01-01

In the Central Arizona-Phoenix (CAP) ecosystem, managers divert mixed stream water and groundwater to maintain an artificial lake chain in Indian Bend Wash (IBW), a historically flashy, ephemeral, desert stream. Nutrient concentrations in the CAP ecosystem's groundwater, stream water, and floodwater differ: stream water has low concentrations of both inorganic N and P, while groundwater is low in inorganic P but rich in nitrate (NO(3)(-)). Consequently, groundwater contribution drives inorganic N concentrations in the lake chain. In contrast, floodwater typically has high P concentrations while remaining low in N. Thus we expected N and P concentrations in IBW lakes to vary with the mix of water flowing through them. Elevated NO(3)(-) and low inorganic P concentrations were predicted when groundwater pumping was pronounced and this prediction was supported. We hypothesized that these predictable changes in water chemistry would affect nutrient limitation of phytoplankton. Laboratory nutrient-addition bioassays demonstrated that phytoplankton growth was P-limited throughout the summer of 2003 when N/P was high. However, after a late-season flood drove N/P below 31:1, the expected threshold between N and P limitation, N limitation was observed. Our results indicate that effects of floods, the preeminent historic drivers of Sonoran Desert stream biogeochemistry, are mitigated in urban ecosystems by decisions about which spigots to turn. Consequently, nutrient limitation of urban streams is driven as much by management decisions as by natural hydrologic variation.

Tracing Nitrogen Sources in Forested Catchments Under Varying Flow Conditions: Seasonal and Event Scale Patterns

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Kendall, C.

2004-12-01

Our ability to assess how stream nutrient concentrations respond to biogeochemical transformations and stream flow dynamics is often limited by datasets that do not include all flow conditions that occur over event, monthly, seasonal, and yearly time scales. At the Sleepers River Research Watershed in northeastern Vermont, USA, nitrate, DOC (dissolved organic carbon), and major ion concentrations were measured on samples collected over a wide range of flow conditions from summer 2002 through summer 2004. Nutrient flushing occurred at the W-9 catchment and high-frequency sampling revealed critical insights into seasonal and event-scale controls on nutrient concentrations. In this seasonally snow-covered catchment, the earliest stage of snowmelt introduced nitrogen directly to the stream from the snowpack. As snowmelt progressed, the source of stream nitrate shifted to flushing of soil nitrate along shallow subsurface flow paths. In the growing season, nitrogen flushing to streams varied with antecedent moisture conditions. More nitrogen was available to flush to streams when antecedent moisture was lowest, and mobile nitrogen stores in the landscape regenerated under baseflow conditions on times scales as short as 7 days. Leaf fall was another critical time when coupled hydrological and biogeochemical processes controlled nutrient fluxes. With the input of labile organic carbon from freshly decomposing leaves, nitrate concentrations declined sharply in response to in-stream immobilization or denitrification. These high-resolution hydrochemical data from multiple flow regimes are identifying "hot spots" and "hot moments" of biogeochemical and hydrological processes that control nutrient fluxes in streams.

Can uptake length in strams be determined by nutrient addition experiments? Results from an interbiome comparison study

Treesearch

P. J Mulholland; J. L. Tanks; J. R. Webster; W. B. Bowden; W. K Dodds; S. V. Gregory; N. B Grimm; J. L. Meriam; J. L. Meyer; B. J. Peterson; H. M. Valett; W. M. Wollheim

2002-01-01

Nutrient uptake length is an important parnmeter tor quantifying nutrient cycling in streams. Although nutrient tracer additions are the preierred method for measuring uptake length under ambient nutrient concentrations, short-term nutrient addition experiments have more irequently been used to estimate uptake length in streams. Theoretical analysis of the relationship...

Effects of whole-stream nutrient enrichment on the concentration and abundance of aquatic hyphomycete conidia in transport

Treesearch

Vol. 96(1): 57-65 Mycologia

2004-01-01

The concentrations and relative abundances of aquatic hyphomycete conidia in water were followed during a three-year study in two headwater streams at Coweeta Hydrologic Laboratory, North Carolina, using the membrane-filtration technique. After a one-ye& pretreatment period, one of the streams was enriched continuously with inorganic nutrients (N+P) for two years...

Relationships Between Land Use and Stream Nutrient Concentrations in a Highly Urbanized Tropical Region of Brazil: Thresholds and Riparian Zones.

PubMed

Tromboni, F; Dodds, W K

2017-07-01

Nutrient enrichment in streams due to land use is increasing globally, reducing water quality and causing eutrophication of downstream fresh and coastal waters. In temperate developed countries, the intensive use of fertilizers in agriculture is a main driver of increasing nutrient concentrations, but high levels and fast rates of urbanization can be a predominant issue in some areas of the developing world. We investigated land use in the highly urbanized tropical State of Rio de Janeiro, Brazil. We collected total nitrogen, total phosphorus, and inorganic nutrient data from 35 independent watersheds distributed across the State and characterized land use at a riparian and entire watershed scales upstream from each sample station, using ArcGIS. We used regression models to explain land use influences on nutrient concentrations and to assess riparian protection relationships to water quality. We found that urban land use was the primary driver of nutrient concentration increases, independent of the scale of analyses and that urban land use was more concentrated in the riparian buffer of streams than in the entire watersheds. We also found significant thresholds that indicated strong increases in nutrient concentrations with modest increases in urbanization reaching maximum nutrient concentrations between 10 and 46% urban cover. These thresholds influenced calculation of reference nutrient concentrations, and ignoring them led to higher estimates of these concentrations. Lack of sewage treatment in concert with urban development in riparian zones apparently leads to the observation that modest increases in urban land use can cause large increases in nutrient concentrations.

The Influence of Shredder Feeding on Fungal Activity in a Nutrient-Enriched Stream and an Unaltered Stream

NASA Astrophysics Data System (ADS)

Chung, N.; Suberkopp, K.

2005-05-01

The effect of shredder feeding on aquatic hyphomycete communities associated with submerged leaves was studied in two southern Appalachian headwater streams in North Carolina. Coarse and fine mesh litter bags containing red maple (Acer rubrum) leaves were placed in the nutrient-enriched stream and in the reference stream and were retrieved monthly. Both shredder feeding and nutrient enrichment enhanced breakdown rates. The breakdown rates of leaves in coarse mesh bags in the reference stream (k = 0.0275) and fine mesh bags in the nutrient enriched stream (k = 0.0272) were not significantly different, suggesting that the shredding effect on litter breakdown was offset by higher fungal activity as a result of nutrient enrichment. Fungal sporulation rates and biomass (based on ergosterol concentrations) were higher in the nutrient enriched than in the reference stream, but neither fungal biomass nor sporulation rate was affected by shredder feeding. Species richness was higher in the nutrient-enriched than in the reference stream. The enrichment with nutrients altered fungal community composition more than shredder feeding.

Effects of watershed densities of animal feeding operations on nutrient concentrations and estrogenic activity in agricultural streams.

PubMed

Ciparis, Serena; Iwanowicz, Luke R; Voshell, J Reese

2012-01-01

Application of manures from animal feeding operations (AFOs) as fertilizer on agricultural land can introduce nutrients and hormones (e.g. estrogens) to streams. A landscape-scale study was conducted in the Shenandoah River watershed (Virginia, USA) in order to assess the relationship between densities of AFOs in watersheds of agricultural streams and in-stream nutrient concentrations and estrogenic activity. The effect of wastewater treatment plants (WWTPs) on nutrients and estrogenic activity was also evaluated. During periods of high and low flow, dissolved inorganic nitrogen (DIN) and orthophosphate (PO(4)-P) concentrations were analyzed and estrogens/estrogenic compounds were extracted and quantified as17β-estradiol equivalents (E2Eq) using a bioluminescent yeast estrogen screen. Estrogenic activity was measurable in the majority of collected samples, and 20% had E2Eq concentrations >1 ng/L. Relatively high concentrations of DIN (>1000 μg/L) were also frequently detected. During all sampling periods, there were strong relationships between watershed densities of AFOs and in-stream concentrations of DIN (R(2) = 0.56-0.81) and E2Eq (R(2) = 0.39-0.75). Relationships between watershed densities of AFOs and PO(4)-P were weaker, but were also significant (R(2) = 0.27-0.57). When combined with the effect of watershed AFO density, streams receiving WWTP effluent had higher concentrations of PO(4)-P than streams without WWTP discharges, and PO(4)-P was the only analyte with a consistent relationship to WWTPs. The results of this study suggest that as the watershed density of AFOs increases, there is a proportional increase in the potential for nonpoint source pollution of agricultural streams and their receiving waters by nutrients, particularly DIN, and compounds that can cause endocrine disruption in aquatic organisms. Copyright © 2011 Elsevier B.V. All rights reserved.

Long-Term Data Reveal Patterns and Controls on Stream Water Chemistry in a Forested Stream: Walker Branch, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lutz, Brian D; Mulholland, Patrick J; Bernhardt, Emily

2012-01-01

We present 20 years of weekly stream water chemistry, hydrology, and climate data for the Walker Branch watershed in eastern Tennessee, USA. Since 1989, the watershed has experienced a similar to 1.08 degrees C increase in mean annual temperature, a similar to 20% decline in precipitation, and a similar to 30% increase in forest evapotranspiration rates. As a result, stream runoff has declined by similar to 34%. We evaluate long-term trends in stream water concentrations and fluxes for nine solutes and use wet deposition data to calculate approximate watershed input-output budgets. Dissolved constituents were classified as geochemical solutes (Ca2+, Mg2+,more » and SO42-) or nutrients (NH4+, NO3-, soluble reactive phosphorus [SRP], total soluble nitrogen [TSN], total soluble phosphorus [TSP], and dissolved organic carbon [DOC]). Geochemical solutes are predominantly controlled by discharge, and the long-term changes in catchment hydrology have led to significant trends in the concentrations and fluxes of these solutes. Further, the trends in geochemical solute concentrations indicate shifting soil flowpath contributions to streamflow generation through time, with deep groundwater having a greater proportional contribution in recent years. Despite dramatic changes in watershed runoff, there were no trends in inorganic nutrient concentrations (NH4+, NO3-, and SRP). While most nutrients entering the watershed are retained, stream fluxes of nutrient solutes have declined significantly as a result of decreasing runoff. Nutrient concentrations in the stream exhibit large seasonality controlled by in-stream biological uptake. Stream benthic communities are sensitive to hydrologic disturbance, and changes in the frequency or intensity of storm events through time can affect nutrient fluxes. Stream NO3- concentrations are also sensitive to drought, with concentrations decreasing (increasing) if conditions during the three years prior to the time of sampling were drier (wetter) than the long-term mean. Future changes in the incidence of storm events, as well as the number and duration of droughts, have the potential to significantly alter watershed nutrient losses. Our analysis indicates that changing climates can differentially affect watershed element cycles either through changes in biogeochemical process rates or through changes in catchment hydrology. Furthermore, climate change can include both long-term trending in mean climate variables, as well as changes in the frequency and intensity of storms and droughts, with each of these types of change having distinct effects on the biological and geochemical processes governing different solutes.« less

National Aquatic Resource Surveys (NARS) N/P Values for Streams - Wadeable Streams Assessment

EPA Pesticide Factsheets

The National Aquatic Resource Survey (NARS) findings for nutrients in streams and lakes highlight that nutrient pollution is widespread across the United States and impacts biological communities. The NARS analysis examined the range of values for nutrients in least-disturbed sites in a WSA region [WSA regions are modified Level III ecoregions from Omernik (1987)] and used this distribution for nitrogen (N) and phosphorus (P) to separate sites into those having high, medium, or low concentrations of nutrients. Sites identified as high were worse (i.e., had higher nutrient concentrations) than 95% of the sites used to define least-disturbed condition. Similarly, the 75th percentile of the least-disturbed distribution was used to distinguish between sites in medium and low condition. This means that sites reported as being as low were as good as or better than 75% of the sites used to define least-disturbed condition. A relative risk analysis of the data from this survey found that nationally streams and lakes have more than two times greater risk of having degraded biological communities when nutrient concentrations are high than when they are low. For more information, please consult the National Wadeable Streams Assessment (WSA) Report available online at: https://www.epa.gov/national-aquatic-resource-surveys/nrsa:

Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

PubMed

Mykrä, Heikki; Sarremejane, Romain; Laamanen, Tiina; Karjalainen, Satu Maaria; Markkola, Annamari; Lehtinen, Sirkku; Lehosmaa, Kaisa; Muotka, Timo

2018-04-16

We examined how short-term (19 days) nutrient enrichment influences stream fungal and diatom communities, and rates of leaf decomposition and algal biomass accrual. We conducted a field experiment using slow-releasing nutrient pellets to increase nitrate (NO 3 -N) and phosphate (PO 4 -P) concentrations in a riffle section of six naturally acidic (naturally low pH due to catchment geology) and six circumneutral streams. Nutrient enrichment increased microbial decomposition rate on average by 14%, but the effect was significant only in naturally acidic streams. Nutrient enrichment also decreased richness and increased compositional variability of fungal communities in naturally acidic streams. Algal biomass increased in both stream types, but algal growth was overall very low. Diatom richness increased in response to nutrient addition by, but only in circumneutral streams. Our results suggest that primary producers and decomposers are differentially affected by nutrient enrichment and that their responses to excess nutrients are context dependent, with a potentially stronger response of detrital processes and fungal communities in naturally acidic streams than in less selective environments.

Response of non-added solutes during nutrient addition experiments in streams

NASA Astrophysics Data System (ADS)

Rodriguez-Cardona, B.; Wymore, A.; Koenig, L.; Coble, A. A.; McDowell, W. H.

2015-12-01

Nutrient addition experiments, such as Tracer Additions for Spiraling Curve Characterization (TASCC), have become widely popular as a means to study nutrient uptake dynamics in stream ecosystems. However, the impact of these additions on ambient concentrations of non-added solutes is often overlooked. TASCC addition experiments are ideal for assessing interactions among solutes because it allows for the characterization of multiple solute concentrations across a broad range of added nutrient concentrations. TASCC additions also require the addition of a conservative tracer (NaCl) to track changes in conductivity during the experimental manipulation. Despite its use as a conservative tracer, chloride (Cl) and its associated sodium (Na) might change the concentrations of other ions and non-added nutrients through ion exchange or other processes. Similarly, additions of biologically active solutes might change the concentrations of other non-added solutes. These methodological issues in nutrient addition experiments have been poorly addressed in the literature. Here we examine the response of non-added solutes to pulse additions (i.e. TASCC) of NaCl plus nitrate (NO3-), ammonium, and phosphate across biomes including temperate and tropical forests, and arctic taiga. Preliminary results demonstrate that non-added solutes respond to changes in the concentration of these added nutrients. For example, concentrations of dissolved organic nitrogen (DON) in suburban headwater streams of New Hampshire both increase and decrease in response to NO3- additions, apparently due to biotic processes. Similarly, cations such as potassium, magnesium, and calcium also increase during TASCC experiments, likely due to cation exchange processes associated with Na addition. The response of non-added solutes to short-term pulses of added nutrients and tracers needs to be carefully assessed to ensure that nutrient uptake metrics are accurate, and to detect biotic interactions that may provide insights into fundamental aspects of stream nutrient cycling.

Stressor-Response Models Relating Nutrient Enrichment to Algal Communities in Pacific Northwest Streams and Rivers

NASA Astrophysics Data System (ADS)

Sobota, D. J.; Hubler, S.; Paul, M. J.; Labiosa, R.

2015-12-01

Excessive algal growth in streams and rivers from nutrient enrichment can cause costly human health and environmental problems. As part of the US Environmental Protection Agency's Nutrient Scientific Technical Exchange Partnership and Support (N-STEPS) program, we have been developing stressor-response (S-R) models relating nutrients to attached algal (periphyton) communities to help prioritize monitoring for water quality impairments in Oregon (Pacific Northwest, USA) streams and rivers. Existing data from the state and neighboring states were compiled and standardized from the Oregon Department of Environmental Quality, US Environmental Protection Agency, and the US Geological Survey. To develop S-R models, algal community and biomass metrics were compared with nitrogen (N) and phosphorus (P) concentration data, including total, dissolved, and inorganic forms of these nutrients. In total, 928 paired algal-nutrient samples were compiled from the 8 Level-III Ecoregions occurring in Oregon. Relationships between algal biomass metrics and nutrient concentrations were weak, with only ash-free dry mass and standing stock of chlorophyll a showing slight positive relationships across gradients of total N and soluble reactive P concentrations, respectively. In contrast, metrics describing algal community composition, including percent diatoms and abundance of nutrient-sensitive species, showed very strong nonlinear relationships with total N or P concentrations. This suggests that data describing algal community composition can help identify specific nutrient stressors across environmentally-diverse streams and rivers in the Pacific Northwest. Future analyses will examine if nutrient-algal S-R models vary across different hydrological, physiographical, and ecological settings in the region.

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

NASA Astrophysics Data System (ADS)

Ford, William I.; King, Kevin; Williams, Mark R.

2018-01-01

In landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can contribute to deleterious environmental conditions downstream. This study assessed upland and in-stream controls on baseflow nutrient concentrations in a low-gradient, tile-drained agroecosystem watershed. We conducted time-series analysis using Empirical mode decomposition of seven decade-long nutrient concentration time-series in the agricultural Upper Big Walnut Creek watershed (Ohio, USA). Four tributaries of varying drainage areas and three main-stem sites were monitored, and nutrient grab samples were collected weekly from 2006 to 2016 and analyzed for dissolved reactive phosphorus (DRP), nitrate-nitrogen (NO3-N), total nitrogen (TN), and total phosphorus (TP). Statistically significant seasonal fluctuations were compared with seasonality of baseflow, watershed characteristics (e.g., tile-drain density), and in-stream water quality parameters (pH, DO, temperature). Findings point to statistically significant seasonality of all parameters with peak P concentrations in summer and peak N in late winter-early spring. Results suggest that upland processes exert strong control on DRP concentrations in the winter and spring months, while coupled upland and in-stream conditions control watershed baseflow DRP concentrations during summer and early fall. Conversely, upland flow sources driving streamflow exert strong control on baseflow NO3-N, and in-stream attenuation through transient and permanent pathways impacts the magnitude of removal. Regarding TN and TP, we found that TN was governed by NO3-N, while TP was governed by DRP in summer and fluvial erosion of P-rich benthic sediments during higher baseflow conditions. Findings of the study highlight the importance of coupled in-stream and upland management for mitigating eutrophic conditions during environmentally sensitive timeframes.

Water-quality assessment of the Lower Grand River Basin, Missouri and Iowa, USA, in support of integrated conservation practices

USGS Publications Warehouse

Wilkison, Donald H.; Armstrong, Daniel J.

2016-01-01

The effectiveness of agricultural conservation programmes to adequately reduce nutrient exports to receiving streams and to help limit downstream hypoxia issues remains a concern. Quantifying programme success can be difficult given that short-term basin changes may be masked by long-term water-quality shifts. We evaluated nutrient export at stream sites in the 44 months that followed a period of increased, integrated conservation implementation within the Lower Grand River Basin. These short-term responses were then compared with export that occurred in the main stem and adjacent rivers in northern Missouri over a 22-year period to better contextualize any recent changes. Results indicate that short-term (October 2010 through May 2014) total nitrogen (TN) concentrations in the Grand River were 20% less than the long-term average, and total phosphorus (TP) concentrations were 23% less. Nutrient reductions in the short term were primarily the result of the less-than-average precipitation and, consequently, streamflow that was 36% below normal. Therefore, nutrient concentrations measured in tributary streams were likely less than normal during the implementation period. Northern Missouri streamflow-normalized TN concentrations remained relatively flat or declined over the period 1991 through 2013 likely because available sources of nitrogen, determined as the sum of commercial fertilizers, available animal manures and atmospheric inputs, were typically less than crop requirement for much of that time frame. Conversely, flow-normalized stream TP concentrations increased over the past 22 years in northern Missouri streams, likely in response to many years of phosphorus inputs in excess of crop requirements. Stream nutrient changes were most pronounced during periods that coincided with the major tillage, planting and growth phases of row crops and increased streamflow. Nutrient reduction strategies targeted at the period February through June would likely have the greatest impact on reducing nutrient export from the basin. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

Using Algal Metrics and Biomass to Evaluate Multiple Ways of Defining Concentration-Based Nutrient Criteria in Streams and their Ecological Relevance

EPA Science Inventory

We examined the utility of nutrient criteria derived solely from total phosphorus (TP) concentrations in streams (regression models and percentile distributions) and evaluated their ecological relevance to diatom and algal biomass responses. We used a variety of statistics to cha...

Nutrients versus emerging contaminants-Or a dynamic match between subsidy and stress effects on stream biofilms.

PubMed

Aristi, I; Casellas, M; Elosegi, A; Insa, S; Petrovic, M; Sabater, S; Acuña, V

2016-05-01

Freshwater ecosystems are threatened by multiple anthropogenic stressors, which might be differentiated into two types: those that reduce biological activity at all concentrations (toxic contaminants), and those that subsidize biological activity at low concentrations and reduce it at high concentrations (assimilable contaminants). When occurring in mixtures, these contaminants can have either antagonistic, neutral or synergistic effects; but little is known on their joint effects. We assessed the interaction effects of a mixture of assimilable and toxic contaminants on stream biofilms in a manipulative experiment using artificial streams, and following a factorial design with three nutrient levels (low, medium or high) and either presence or absence of a mixture of emerging contaminants (ciprofloxacin, erythromycin, diclofenac, methylparaben, and sulfamethoxazole). We measured biofilm biomass, basal fluorescence, gross primary production and community respiration. Our initial hypotheses were that biofilm biomass and activity would: increase with medium nutrient concentrations (subsidy effect), but decrease with high nutrient concentrations (stress effect) (i); decrease with emerging contaminants, with the minimum decrease at medium nutrient concentrations (antagonistic interaction between nutrients subsidy and stress by emerging contaminants) and the maximum decrease at high nutrient concentrations (synergistic interaction between nutrients and emerging contaminants stress) (ii). All the measured variables responded linearly to the available nutrients, with no toxic effect at high nutrient concentrations. Emerging contaminants only caused weak toxic effects in some of the measured variables, and only after 3-4 weeks of exposure. Therefore, only antagonistic interactions were observed between nutrients and emerging contaminants, as medium and high nutrient concentrations partly compensated the harmful effects of emerging contaminants during the first weeks of the experiment. Our results show that contaminants with a subsidy effect can alleviate the effects of toxic contaminants, and that long-term experiments are required to detect stress effects of emerging contaminants at environmentally relevant concentrations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

In-stream biotic control on nutrient biogeochemistry in a forested sheadwater tream, West Fork of Walker Branch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roberts, Brian J; Mulholland, Patrick J

2007-01-01

A growing body of evidence demonstrates the importance of in-stream processing in regulating nutrient export, yet the influence of temporal variability in stream metabolism on net nutrient uptake has not been explicitly addressed. Streamwater DIN and SRP concentrations in Walker Branch, a first-order deciduous forest stream in eastern Tennessee, show a repeated pattern of annual maxima in summer and biannual minima in spring and autumn. Temporal variations in catchment hydrologic flowpaths result in lower winter and higher summer nutrient concentrations, but do not explain the spring and autumn nutrient minima. Ambient nutrient uptake rates were measured 2-3 times per weekmore » over an 18-mo period and compared to daily rates of gross primary production (GPP) and ecosystem respiration (ER) to examine the influence of in-stream biotic activity on nutrient export. GPP and ER rates explained 85% of the variation in net DIN retention with high net NO3- uptake (and lower net NH4+ release) rates occurring during spring and autumn and net DIN release in summer. Diel nutrient concentration patterns were examined several times throughout the year to determine the relative importance of autotrophic and heterotrophic activity on net nutrient uptake. High spring GPP corresponded to daily decreases in NO3- over the illuminated hours resulting in high diel NO3- amplitude which dampened as the canopy closed. GPP explained 91% of the variance in diel NO3- amplitude. In contrast, the autumn nutrient minima was largely explained by heterotrophic respiration since GPP remained low and little diel NO3- variation was observed during the autumn.« less

Seasonal patterns in nutrients, carbon, and algal responses in wadeable streams within three geographically distinct areas of the United States, 2007-08

USGS Publications Warehouse

Lee, Kathy E.; Lorenz, David L.; Petersen, James C.; Greene, John B.

2012-01-01

The U.S. Geological Survey determined seasonal variability in nutrients, carbon, and algal biomass in 22 wadeable streams over a 1-year period during 2007 or 2008 within three geographically distinct areas in the United States. The three areas are the Upper Mississippi River Basin (UMIS) in Minnesota, the Ozark Plateaus (ORZK) in southern Missouri and northern Arkansas, and the Upper Snake River Basin (USNK) in southern Idaho. Seasonal patterns in some constituent concentrations and algal responses were distinct. Nitrate concentrations were greatest during the winter in all study areas potentially because of a reduction in denitrification rates and algal uptake during the winter, along with reduced surface runoff. Decreases in nitrate concentrations during the spring and summer at most stream sites coincided with increased streamflow during the snowmelt runoff or spring storms indicating dilution. The continued decrease in nitrate concentrations during summer potentially is because of a reduction in nitrate inputs (from decreased surface runoff) or increases in biological uptake. In contrast to nitrate concentrations, ammonia concentrations varied among study areas. Ammonia concentration trends were similar at UMIS and USNK sampling sites with winter peak concentrations and rapid decreases in ammonia concentrations by spring or early summer. In contrast, ammonia concentrations at OZRK sampling sites were more variable with peak concentrations later in the year. Ammonia may accumulate in stream water in the winter under ice and snow cover at the UMIS and USNK sites because of limited algal metabolism and increased mineralization of decaying organic matter under reducing conditions within stream bottom sediments. Phosphorus concentration patterns and the type of phosphorus present changes with changing hydrologic conditions and seasons and varied among study areas. Orthophosphate concentrations tended to be greater in the summer at UMIS sites, whereas total phosphorus concentrations at most UMIS and USNK sites peaked in the spring during runoff and then decreased through the remainder of the sampling period. Total phosphorus and orthophosphate concentrations in OZRK streams peaked during summer indicating a runoff-based source of both nutrients. Orthophosphate concentrations may increase in streams in the late summer when surface runoff composes less of total streamflow, and when groundwater containing orthophosphate becomes a more dominant source in streams during lower flows. Seston chlorophyll a concentrations were greatest early in the growing season (spring), whereas the spring runoff events coincided with reductions in benthic algal chlorophyll a biomass likely because of scour of benthic algae from the channel bottom that are entrained in the water column during that period. Nitrate, ammonia, and orthophosphate concentrations also decreased during that same period, indicating dilution in the spring during runoff events. The data from this study indicate that the source of water (surface runoff or groundwater) to a stream and the intensity of major runoff events are important factors controlling instream concentrations. Biological processes appear to affect nutrient concentrations during more stable lower flow periods in later summer, fall, and winter when residence time of water in a channel is longer, which allows more time for biological uptake and transformations. Management of nutrient conditions in streams is challenging and requires an understanding of multiple factors that affect in-stream nutrient concentrations and biological uptake and growth.

Use of Weighted Regressions on Time, Discharge, and Season to Assess Effectiveness of Agricultural and Environmental Best Management Practices in California and Nevada, USA

NASA Astrophysics Data System (ADS)

Domagalski, J. L.; Schlegel, B.; Hutchins, J.

2014-12-01

Long-term data sets on stream-water quality and discharge can be used to assess whether best management practices (BMPs) are restoring beneficial uses of impaired water as required under the Clean Water Act. In this study, we evaluated a greater than 20-year record of water quality from selected streams in the Central Valley (CV) of California and Lake Tahoe (California and Nevada, USA). The CV contains a mix of agricultural and urbanized land, while the Lake Tahoe area is mostly forested, with seasonal residents and tourism. Because nutrients and fine sediments cause a reduction in water clarity that impair Lake Tahoe, BMPs were implemented in the early 1990's, to reduce nitrogen and phosphorus loads. The CV does not have a current nutrient management plan, but numerous BMPs exist to reduce pesticide loads, and it was hypothesized that these programs could also reduce nutrient levels. In the CV and Lake Tahoe areas, nutrient concentrations, loads, and trends were estimated by using the recently developed Weighted Regressions on Time, Discharge, and Season (WRTDS) model. Sufficient data were available to compare trends during a voluntary and enforcement period for seven CV sites within the lower Sacramento and San Joaquin Basins. For six of the seven sites, flow-normalized mean annual concentrations of total phosphorus and nitrate decreased at a faster rate during the enforcement period than during the earlier voluntary period. Concentration changes during similar years and ranges of flow conditions suggest that BMPs designed for pesticides also reduced nutrient loads in the CV. A trend analysis using WRTDS was completed for six streams that enter Lake Tahoe during the late 1980's through 2008. The results of the model confirm that nutrient loading is influenced strongly by season, such as by spring runoff from snowmelt. The highest nutrient concentrations in the late 1980's and early 1990's correlate with high flows, followed by statistically significant decreases in loading from most streams under different flow conditions. The results of the WRTDS model indicate a clear reduction in nutrient loading of nitrogen and phosphorus in all six streams. However, some streams show an increase in nutrient concentrations after 2000, suggesting the possible need for changes to the nutrient reduction management practices.

Water-quality assessment of the Trinity River Basin, Texas - Nutrients in streams draining an agricultural and an urban area, 1993-95

USGS Publications Warehouse

Land, Larry F.; Shipp, Allison A.

1996-01-01

Water samples collected from streams draining an agricultural area in the west-central part of the Trinity River Basin upstream from the Richland-Chambers Reservoir and from streams draining an urban area in the Dallas-Fort Worth metropolitan area during March 1993 - September 1995 were analyzed for nutrients (nitrogen and phosphorus compounds). A comparison of the data for agricultural and urban streams shows the maximum concentration of total nitrogen is from an urban stream and the maximum concentration of total phosphorus is from an agricultural stream. One-half of the samples have total nitrogen concentrations equal to or less than 1.1 and 1.0 milligrams per liter in the agricultural and urban streams, respectively; and one-half of the samples have total phosphorous concentrations equal to or less than 0.04 and 0.05 milligram per liter in the agricultural and urban streams, respectively. The highest concentrations of total nitrogen in both types of streams are in the spring. The minimum concentrations of total nitrogen are during the summer in the agricultural streams and during the winter in the urban streams. Concentrations of total phosphorus in agricultural streams show negligible seasonal variability. The highest concentrations of total phosphorus are in spring and possibly late summer in the urban streams. In the midrange of streamflow in the urban streams and throughout the range of streamflow in the agricultural streams, concentrations of total nitrogen increase. Concentrations of total phosphorus increase with streamflow in the middle and upper ranges of streamflow in both agricultural and urban streams.

Using Bacterial Growth on Insects to Assess Nutrient Impacts in Streams

Treesearch

A. Dennis Lemly

2000-01-01

A combination field and laboratory study was conducted to evaluate the ability of a recently developed bioindicator to detect detrimental nutrient conditions in streams. The method utilizes bacterial growth on aquatic insects to determine nutrient impacts. Field investigations indicated that elevated concentrations of nitrate and phosphate were associated with growth...

LINKING NUTRIENTS TO ALTERATIONS IN AQUATIC LIFE IN CALIFORNIA WADEABLE STREAMS

EPA Science Inventory

This report estimates the natural background and ambient concentrations of primary producer abundance indicators in California wadeable streams, identifies thresholds of adverse effects of nutrient-stimulated primary producer abundance on benthic macroinvertebrate and algal commu...

Stream-subsurface nutrient dynamics in a groundwater-fed stream

NASA Astrophysics Data System (ADS)

Rezanezhad, F.; Niederkorn, A.; Parsons, C. T.; Van Cappellen, P.

2015-12-01

The stream-riparian-aquifer interface plays a major role in the regional flow of nutrients and contaminants due to a strong physical-chemical gradient that promotes the transformation, retention, elimination or release of biogenic elements. To better understand the effect of the near-stream zones on stream biogeochemistry, we conducted a field study on a groundwater-fed stream located in the rare Charitable Research Reserve, Cambridge, Ontario, Canada. This study focused on monitoring the spatial and temporal distributions of nutrient elements within the riparian and hyporheic zones of the stream. Several piezometer nests and a series of passive (diffusion) water samplers, known as peepers, were installed along longitudinal and lateral transects centered on the stream to obtain data on the groundwater chemistry. Groundwater upwelling along the stream resulted in distinctly different groundwater types and associated nitrate concentrations between small distances in the riparian zone (<4m). After the upstream source of the stream surface water, concentrations of nutrients (NO3-, NH4+, SO42- and carbon) did not significantly change before the downstream outlet. Although reduction of nitrate and sulphate were found in the riparian zone of the stream, this did not significantly influence the chemistry of the adjacent stream water. Also, minimal retention in the hyporheic zones limited reduction of reactive compounds (NO3- and SO42-) within the stream channel. The results showed that the dissolved organic carbon (DOC) and residence time of water in the hyporheic zone and in surface water limited denitrification.

Two tales of legacy effects on stream nutrient behaviour

NASA Astrophysics Data System (ADS)

Bieroza, M.; Heathwaite, A. L.

2017-12-01

Intensive agriculture has led to large-scale land use conversion, shortening of flow pathways and increased loads of nutrients in streams. This legacy results in gradual build-up of nutrients in agricultural catchments: in soil for phosphorus (biogeochemical legacy) and in the unsaturated zone for nitrate (hydrologic legacy), controlling the water quality in the long-term. Here we investigate these effects on phosphorus and nitrate stream concentrations using high-frequency (10-5 - 100 Hz) sampling with in situ wet-chemistry analysers and optical sensors. Based on our 5 year study, we observe that storm flow responses differ for both nutrients: phosphorus shows rapid increases (up to 3 orders of magnitude) in concentrations with stream flow, whereas nitrate shows both dilution and concentration effects with increasing flow. However, the range of nitrate concentrations change is narrow (up to 2 times the mean) and reflects chemostatic behaviour. We link these nutrient responses with their dominant sources and flow pathways in the catchment. Nitrate from agriculture (with the peak loading in 1983) is stored in the unsaturated zone of the Penrith Sandstone, which can reach up to 70 m depth. Thus nitrate legacy is related to a hydrologic time lag with long travel times in the unsaturated zone. Phosphorus is mainly sorbed to soil particles, therefore it is mobilised rapidly during rainfall events (biogeochemical legacy). The phosphorus stream response will however depend on how well connected is the stream to the catchment sources (driven by soil moisture distribution) and biogeochemical activity (driven by temperature), leading to both chemostatic and non-chemostatic responses, alternating on a storm-to-storm and seasonal basis. Our results also show that transient within-channel storage is playing an important role in delivery of phosphorus, providing an additional time lag component. These results show, that consistent agricultural legacy in the catchment (high historical loads of nutrients) has different effects on nutrients stream responses, depending on their dominant sources and pathways. Both types of time lags, biogeochemical for phosphorus and hydrologic for nitrate, need to be taken into account when designing and evaluating the effectiveness of the agri-environmental mitigation measures.

Identifying pathways and processes affecting nitrate and orthophosphate inputs to streams in agricultural watersheds

USGS Publications Warehouse

Tesoriero, A.J.; Duff, J.H.; Wolock, D.M.; Spahr, N.E.; Almendinger, J.E.

2009-01-01

Understanding nutrient pathways to streams will improve nutrient management strategies and estimates of the time lag between when changes in land use practices occur and when water quality effects that result from these changes are observed. Nitrate and orthophosphate (OP) concentrations in several environmental compartments were examined in watersheds having a range of base flow index (BFI) values across the continental United States to determine the dominant pathways for water and nutrient inputs to streams. Estimates of the proportion of stream nitrate that was derived from groundwater increased as BFI increased. Nitrate concentration gradients between groundwater and surface water further supported the groundwater source of nitrate in these high BFI streams. However, nitrate concentrations in stream-bed pore water in all settings were typically lower than stream or upland groundwater concentrations, suggesting that nitrate discharge to streams was not uniform through the bed. Rather, preferential pathways (e.g., springs, seeps) may allow high nitrate groundwater to bypass sites of high biogeochemical transformation. Rapid pathway compartments (e.g., overland flow, tile drains) had OP concentrations that were typically higher than in streams and were important OP conveyers in most of these watersheds. In contrast to nitrate, the proportion of stream OP that is derived from ground water did not systematically increase as BFI increased. While typically not the dominant source of OP, groundwater discharge was an important pathway of OP transport to streams when BFI values were very high and when geochemical conditions favored OP mobility in groundwater. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

Drivers of Microbial Metabolic Activity, Biogeochemical Cycling and Associated Greenhouse Gas Production in Streambed Sediments

NASA Astrophysics Data System (ADS)

Comer-Warner, S.; Krause, S.; Gooddy, D.; Blaen, P.; Brekenfeld, N.; Wexler, S.; Kaiser, J.

2017-12-01

Hotspots of enhanced biogeochemical reactivity are produced where groundwater and surface water mixes in streambed sediments. This enhanced reactivity is due to elevated residence times and nutrient concentrations found in these areas, leading to increased rates of microbial metabolic activity. Streambed sediments, therefore, may be important in reducing catchment-wide nutrient concentrations through increased cycling. However, they also have the potential to produce high concentrations of greenhouse gases (CO2, CH4 and N2O), as end-products of respiration and intermediate products of denitrification. The hydrological and biogeochemical drivers of streambed C and N cycling, are still insufficiently understood. Here we present results from biogeochemical sampling and tracer experiments in an agricultural sandstone stream in the UK. Nutrient, DOC and greenhouse gas concentrations, as well as d13CCO2, were measured in the streambed sediment in multilevel piezometers, and nutrient concentrations, as well as d15NNO3 and d18ONO3, were measured in Diffusive Equilibrium in Thin-film Gels. Tracer experiments using both conservative (Fluorescein and NaCl) and smart (Resazurin-Resorufin) tracers were performed to determine in-stream metabolism, transient storage and solute transport times in sub-reaches of the stream. Our results show large differences in nutrient and greenhouse gas concentrations between sub-reaches dominated by gravel sediments and those dominated by sandy sediments, as well as seasonally. This suggests temperature, sediment type and residence time are key controls on streambed nutrient cycling and greenhouse gas production. The results of this study have important implications for future greenhouse gas estimates from streams and rivers, particularly as the contribution of sediment greenhouse gas production is recognised as increasingly significant.

Quantifying nutrient sources in an upland catchment using multiple chemical and isotopic tracers

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Boyer, E. W.; Shanley, J. B.; Doctor, D. H.; Kendall, C.; Aiken, G. R.

2006-12-01

To explore processes that control the temporal variation of nutrients in surface waters, we measured multiple environmental tracers at the Sleepers River Research Watershed, an upland catchment in northeastern Vermont, USA. Using a set of high-frequency stream water samples, we quantified the variation of nutrients over a range of stream flow conditions with chemical and isotopic tracers of water, nitrate, and dissolved organic carbon (DOC). Stream water concentrations of nitrogen (predominantly in the forms of nitrate and dissolved organic nitrogen) and DOC reflected mixing of water contributed from distinct sources in the forested landscape. Water isotopic signatures and end-member mixing analysis revealed when solutes entered the stream from these sources and that the sources were linked to the stream by preferential shallow subsurface and overland flow paths. Results from the tracers indicated that freshly-leached, terrestrial organic matter was the overwhelming source of high DOC concentrations in stream water. In contrast, in this region where atmospheric nitrogen deposition is chronically elevated, the highest concentrations of stream nitrate were attributable to atmospheric sources that were transported via melting snow and rain fall. These findings are consistent with a conceptual model of the landscape in which coupled hydrological and biogeochemical processes interact to control stream solute variability over time.

Urban Effects on Microbial Processes and Food Webs in Coastal Watershed Streams

EPA Science Inventory

We conducted a stream survey in the Narragansett Bay Watershed that targeted a gradient of development intensity and examined how associated changes in nutrients, carbon, and stressors affected periphyton and macroinvertebrates. Concentrations of nutrients, cations, and anions we...

Spatio-temporal variation in stream water chemistry in a tropical urban watershed

Treesearch

A. Ramirez; K.G. Rosas; A.E. Lugo; O.M. Ramos-Gonzalez

2014-01-01

Urban activities and related infrastructure alter the natural patterns of stream physical and chemical conditions. According to the Urban Stream Syndrome, streams draining urban landscapes are characterized by high concentrations of nutrients and ions, and might have elevated water temperatures and variable oxygen concentrations. Here, we report temporal and spatial...

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

USDA-ARS?s Scientific Manuscript database

Controls on baseflow nutrient concentrations in agroecosystems are poorly characterized in comparison with storm events. However, in landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can drive deleterious environm...

The relative influence of nutrients and habitat on stream metabolism in agricultural streams

USGS Publications Warehouse

Frankforter, J.D.; Weyers, H.S.; Bales, J.D.; Moran, P.W.; Calhoun, D.L.

2010-01-01

Stream metabolism was measured in 33 streams across a gradient of nutrient concentrations in four agricultural areas of the USA to determine the relative influence of nutrient concentrations and habitat on primary production (GPP) and respiration (CR-24). In conjunction with the stream metabolism estimates, water quality and algal biomass samples were collected, as was an assessment of habitat in the sampling reach. When data for all study areas were combined, there were no statistically significant relations between gross primary production or community respiration and any of the independent variables. However, significant regression models were developed for three study areas for GPP (r 2 = 0.79-0.91) and CR-24 (r 2 = 0.76-0.77). Various forms of nutrients (total phosphorus and area-weighted total nitrogen loading) were significant for predicting GPP in two study areas, with habitat variables important in seven significant models. Important physical variables included light availability, precipitation, basin area, and in-stream habitat cover. Both benthic and seston chlorophyll were not found to be important explanatory variables in any of the models; however, benthic ash-free dry weight was important in two models for GPP. ?? 2009 The Author(s).

Seasonal and event-scale controls on dissolved organic carbon and nitrate flushing from catchments

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Boyer, E. W.; Shanley, J. B.; Doctor, D. H.

2005-05-01

To explore terrestrial and aquatic linkages controlling nutrient dynamics in forested catchments, we collected high-frequency samples from 2002 to 2004 at the Sleepers River Research Watershed in northeastern Vermont USA. We measured DOC (dissolved organic carbon), SUVA (specific UV absorbance), nitrate, and major ion concentrations over a wide range of flow conditions. In addition, weekly samples since 1991 provide a longer term record of stream nutrient fluxes. During events, DOC concentrations increased with flow consistent with the flushing of a large reservoir of mobile organic carbon from forest soils. Higher concentrations of DOC and SUVA in the growing versus dormant season illustrated seasonal variation in sources, characteristics (i.e. reactivity), availability, and controls on the flushing response of organic matter from the landscape to streams. In contrast, stream nitrate concentrations increased with flow but only when catchments "wetted-up" after baseflow periods. Growing season stream nitrate responses were dependent on short-term antecedent moisture conditions indicating rapid depletion of the soil nitrate reservoir when source areas became hydrologically connected to streams. While the different response patterns emphasized variable source and biogeochemical controls in relation to flow patterns, coupled carbon and nitrogen biogeochemical processes were also important controls on stream nutrient fluxes. In particular, leaf fall was a critical time when reactive DOC from freshly decomposing litter fueled in-stream consumption of nitrate leading to sharp declines of stream nitrate concentrations. Our measurements highlight the importance of "hot spots" and "hot moments" of biogeochemical and hydrological processes that control stream responses. Furthermore, our work illustrates how carbon, nitrogen, and water cycles are coupled in catchments, and provides a conceptual model for future work aimed at modeling forest stream hydrochemistry at the catchment scale.

Siletz River nutrients: Effects of biosolids application

EPA Science Inventory

Stream water nutrients were measured in the Siletz River, Oregon, with the goal of comparing dissolved nutrient concentrations, primarily the nitrogenous nutrients nitrate and ammonium, with previously collected data for the Yaquina and Alsea Rivers for the nutrient criteria prog...

Marine-derived nutrients, bioturbation, and ecosystem metabolism: reconsidering the role of salmon in streams.

PubMed

Holtgrieve, Gordon W; Schindler, Daniel E

2011-02-01

In coastal areas of the North Pacific Ocean, annual returns of spawning salmon provide a substantial influx of nutrients and organic matter to streams and are generally believed to enhance the productivity of recipient ecosystems. Loss of this subsidy from areas with diminished salmon runs has been hypothesized to limit ecosystem productivity in juvenile salmon rearing habitats (lakes and streams), thereby reinforcing population declines. Using five to seven years of data from an Alaskan stream supporting moderate salmon densities, we show that salmon predictably increased stream water nutrient concentrations, which were on average 190% (nitrogen) and 390% (phosphorus) pre-salmon values, and that primary producers incorporated some of these nutrients into tissues. However, benthic algal biomass declined by an order of magnitude despite increased nutrients. We also measured changes in stream ecosystem metabolic properties, including gross primary productivity (GPP) and ecosystem respiration (ER), from three salmon streams by analyzing diel measurements of oxygen concentrations and stable isotopic ratios (delta O-O2) within a Bayesian statistical model of oxygen dynamics. Our results do not support a shift toward higher primary productivity with the return of salmon, as is expected from a nutrient fertilization mechanism. Rather, net ecosystem metabolism switched from approximately net autotrophic (GPP > or = ER) to a strongly net heterotrophic state (GPP < ER) in response to bioturbation of benthic habitats by salmon. Following the seasonal arrival of salmon, GPP declined to <12% of pre-salmon rates, while ER increased by over threefold. Metabolism by live salmon could not account for the observed increase in ER early in the salmon run, suggesting salmon nutrients and disturbance enhanced in situ heterotrophic respiration. Salmon also changed the physical properties of the stream, increasing air-water gas exchange by nearly 10-fold during peak spawning. We suggest that management efforts to restore salmon ecosystems should consider effects on ecosystem metabolic properties and how salmon disturbance affects the incorporation of marine-derived nutrients into food webs.

The role of DOM in nitrogen processing in streams across arctic regions affected by fire

NASA Astrophysics Data System (ADS)

Rodriguez-Cardona, B.; Schade, J. D.; Holmes, R. M.; Natali, S.; Mann, P. J.; Wymore, A.; Coble, A. A.; Prokishkin, A. S.; Zito, P.; Podgorski, D. C.; Spencer, R. G.; McDowell, W. H.

2017-12-01

In stream ecosystems, inputs of dissolved organic carbon (DOC) have a strong influence on nitrogen (N) processing. Previous studies have demonstrated that increases in DOC concentrations can promote greater N removal in many stream ecosystems. Most of what we know about C and N coupling comes from studies of temperate streams; less is known about this relationship in the Arctic. Streams in Arctic ecosystems are facing rapid changes in climate and disturbance regimes, in particular increasing fire frequencies that are likely to alter biogeochemical cycles. Although fires can lead to increases in NO3 concentrations in streams, the effects of fire on DOC (concentration and composition) have been difficult to generalize. We studied the relationships between DOC and N in two locations; the Central Siberian Plateau, Russia and the Yukon-Kuskokwim (YK) River Delta, Alaska. Streams in both regions show increases in NO3 concentrations after fire, while DOC concentrations decrease in Siberia but increase in streams within the YK-Delta. These patterns in DOC and NO3 create a gradient in DOC and nutrient concentrations, allowing us to study this coupling in a wider Pan-Arctic scope. In order to assess the role of DOC in Arctic N processing, we conducted NO3 and NH4 additions to stream microcosms at the Alaskan site as well as whole-stream additions in Siberia. We hypothesized that nutrient uptake would be high in older burn sites of Siberia and recently burned sites in the YK-Delta, due to greater DOC concentrations and availability. Our results suggest that nitrogen dynamics in the Alaskan sites is strongly responsive to C availability, but is less so in Siberian sites. The potential impacts of permafrost thawing and fires on DOM and nutrient dynamics thus appear to not be consistent across the Arctic suggesting that different regions of the Arctic have unique biogeochemical controls.

Sources, transformations, and hydrological processes that control stream nitrate and dissolved organic matter concentrations during snowmelt in an upland forest

USGS Publications Warehouse

Sebestyen, Stephen D.; Boyer, Elizabeth W.; Shanley, James B.; Kendall, Carol; Doctor, Daniel H.; Aiken, George R.; Ohte, Nobuhito

2008-01-01

We explored catchment processes that control stream nutrient concentrations at an upland forest in northeastern Vermont, USA, where inputs of nitrogen via atmospheric deposition are among the highest in the nation and affect ecosystem functioning. We traced sources of water, nitrate, and dissolved organic matter (DOM) using stream water samples collected at high frequency during spring snowmelt. Hydrochemistry, isotopic tracers, and end‐member mixing analyses suggested the timing, sources, and source areas from which water and nutrients entered the stream. Although stream‐dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) both originated from leaching of soluble organic matter, flushing responses between these two DOM components varied because of dynamic shifts of hydrological flow paths and sources that supply the highest concentrations of DOC and DON. High concentrations of stream water nitrate originated from atmospheric sources as well as nitrified sources from catchment soils. We detected nitrification in surficial soils during late snowmelt which affected the nitrate supply that was available to be transported to streams. However, isotopic tracers showed that the majority of nitrate in upslope surficial soil waters after the onset of snowmelt originated from atmospheric sources. A fraction of the atmospheric nitrogen was directly delivered to the stream, and this finding highlights the importance of quick flow pathways during snowmelt events. These findings indicate that interactions among sources, transformations, and hydrologic transport processes must be deciphered to understand why concentrations vary over time and over space as well as to elucidate the direct effects of human activities on nutrient dynamics in upland forest streams.

A comparison of algal, macroinvertebrate, and fish assemblage indices for assessing low-level nutrient enrichment in wadeable Ozark streams

USGS Publications Warehouse

Justus, B.G.; Petersen, J.C.; Femmer, S.R.; Davis, J.V.; Wallace, J.E.

2010-01-01

Biotic indices for algae, macroinvertebrates, and fish assemblages can be effective for monitoring stream enrichment, but little is known regarding the value of the three assemblages for detecting perturbance as a consequence of low-level nutrient enrichment. In the summer of 2006, we collected nutrient and biotic samples from 30 wadeable Ozark streams that spanned a nutrient-concentration gradient from reference to moderately enriched conditions. Seventy-three algal metrics, 62 macroinvertebrate metrics, and 60 fish metrics were evaluated for each of the three biotic indices. After a group of candidate metrics had been identified with multivariate analysis, correlation procedures and scatter plots were used to identify the four metrics having strongest relations to a nutrient index calculated from log transformed and normalized total nitrogen and total phosphorus concentrations. The four metrics selected for each of the three biotic indices were: algae-the relative abundance of most tolerant diatoms, the combined relative abundance of three species of Cymbella, mesosaprobic algae percent taxa richness, and the relative abundance of diatoms that are obligate nitrogen heterotrophs; macroinvertebrate-the relative abundance of intolerant organisms, Baetidae relative abundance, moderately tolerant taxa richness, and insect biomass; fish-herbivore and detritivore taxa richness, pool species relative abundance, fish catch per unit effort, and black bass (Micropterus spp.) relative abundance. All three biotic indices were negatively correlated to nutrient concentrations but the algal index had a higher correlation (rho = -0.89) than did the macroinvertebrate and fish indices (rho = -0.63 and -0.58, respectively). Biotic index scores were lowest and nutrient concentrations were highest for streams with basins having the highest poultry and cattle production. Because of the availability of litter for fertilizer and associated increases in grass and hay production, cattle feeding capacity increases with poultry production. Studies are needed that address the synergistic effect of poultry and cattle production on Ozark streams in high production areas before ecological risks can be adequately addressed.

Relation of water quality to land use in the drainage basins of six tributaries to the lower Delaware River, New Jersey, 2002-07

USGS Publications Warehouse

Baker, Ronald J.; Esralew, Rachel A.

2010-01-01

Concentrations and loads of water-quality constituents in six streams in the lower Delaware River Basin of New Jersey were determined in a multi-year study conducted by the U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection. Two streams receive water from relatively undeveloped basins, two from largely agricultural basins, and two from heavily urbanized basins. Each stream was monitored during eight storms and at least eight times during base flow during 2002-07. Sampling was conducted during base flow before each storm, when stage was first observed to rise, and several times during the rising limb of the hydrographs. Agricultural and urban land use has resulted in statistically significant increases in loads of nitrogen and phosphorus species relative to loads in undeveloped basins. For example, during the growing season, median storm flow concentrations of total nitrogen in the two streams in agricultural areas were 6,290 and 1,760 mg/L, compared to 988 and 823 mg/L for streams in urban areas, and 719 and 333 mg/L in undeveloped areas. Although nutrient concentrations and loads were clearly related to land useurban, agricultural, and undeveloped within the drainage basins, other basin characteristics were found to be important. Residual nutrients entrapped in lake sediments from streams that received effluent from recently removed sewage-treatment plants are hypothesized to be the cause of extremely high levels of nutrient loads to one urban stream, whereas another urban stream with similar land-use percentages (but without the legacy of sewage-treatment plants) had much lower levels of nutrients. One of the two agricultural streams studied had higher nutrient loads than the other, especially for total phosphorous and organic nitrogen. This difference appears to be related to the presence (or absence) of livestock (cattle).

Targeting Urban Watershed Stressor Gradients: Stream Survey Design, Ecological Responses, and Implications of Land Cover Resolution

EPA Science Inventory

We conducted a stream survey in the Narragansett Bay Watershed designed to target a gradient of development intensity, and to examine how associated changes in nutrients, carbon, and stressors affect periphyton and macroinvertebrates. Concentrations of nutrients, cations, and ani...

A comparison of algal, macroinvertebrate, and fish assemblage indices for assessing low-level nutrient enrichment in wadeable Ozark streams

USGS Publications Warehouse

Justus, B.G.; Femmer, Suzanne R.; Davis, Jerri V.; Petersen, James C.; Wallace, J.E.

2010-01-01

All three biotic indices were negatively correlated to nutrient concentrations but the algal index had a higher correlation (rho = −0.89) than did the macroinvertebrate and fish indices (rho = −0.63 and −0.58, respectively). Biotic index scores were lowest and nutrient concentrations were highest for streams with basins having the highest poultry and cattle production. Because of the availability of litter for fertilizer and associated increases in grass and hay production, cattle feeding capacity increases with poultry production. Studies are needed that address the synergistic effect of poultry and cattle production on Ozark streams in high production areas before ecological risks can be adequately addressed.

Nutrient Distribution and Tree Development Through Age 8 of Four Oaks Planted at Five Spacings in a Minor Stream Bottom

Treesearch

Harvey E. Kennedy; Bryce E. Schlaegel; Roger M. Krinard

1986-01-01

Eight hardwood species were planted at five spacings in a minor stream bottom in southeast Arkansas. Because of inherent differences in nutrient requirements and tree development, only four oak species are covered in this paper. Spacing generally did not affect nutrient concentrations, but differences did exist among species. Leaves constituted only 10-15 percent of...

Assessment of water chemistry, habitat, and benthic macroinvertebrates at selected stream-quality monitoring sites in Chester County, Pennsylvania, 1998-2000

USGS Publications Warehouse

Reif, Andrew G.

2004-01-01

Biological, chemical, and habitat data have been collected from a network of sites in Chester County, Pa., from 1970 to 2003 to assess stream quality. Forty sites in 6 major stream basins were sampled between 1998 and 2000. Biological data were used to determine levels of impairment in the benthic-macroinvertebrate community in Chester County streams and relate the impairment, in conjunction with chemical and habitat data, to overall stream quality. Biological data consisted of benthic-macroinvertebrate samples that were collected annually in the fall. Water-chemistry samples were collected and instream habitat was assessed in support of the biological sampling.Most sites in the network were designated as nonimpacted or slightly impacted by human activities or extreme climatic conditions on the basis of biological-metric analysis of benthic-macroinvertebrate data. Impacted sites were affected by factors, such as nutrient enrichment, erosion and sedimentation, point discharges, and droughts and floods. Streams in the Schuylkill River, Delaware River, and East Branch Brandywine Creek Basins in Chester County generally had low nutrient concentrations, except in areas affected by wastewater-treatment discharges, and stream habitat that was affected by erosion. Streams in the West Branch Brandywine, Christina, Big Elk, and Octoraro Creek Basins in Chester County generally had elevated nutrient concentrations and streambottom habitat that was affected by sediment deposition.Macroinvertebrate communities identified in samples from French Creek, Pigeon Creek (Schuylkill River Basin), and East Branch Brandywine Creek at Glenmoore consistently indicate good stream conditions and were the best conditions measured in the network. Macroinvertebrate communities identified in samples from Trout Creek (site 61), West Branch Red Clay Creek (site 55) (Christina River Basin), and Valley Creek near Atglen (site 34) (Octoraro Creek Basin) indicated fair to poor stream conditions and were the worst conditions measured in the network. Trout Creek is heavily impacted due to erosion, and Valley Creek near Atglen and West Branch Red Clay Creek are influenced by wastewater discharges. Hydrologic conditions in 1999, including a prolonged drought and a flood, influenced chemical concentrations and macroinvertebrate community structure throughout the county. Concentrations of nutrients and ions were lower in 1999 when compared to 1998 and 2000 concentrations. Macroinvertebrate communities identified in samples from 1999 contained lower numbers of individuals when compared to 1998 and 2000 but had similar community structure. Results from chemical and biological sampling in 2000 indicated that the benthic-macroinvertebrate community structure and the concentrations of nutrients and ions recovered to pre-1999 levels.

Temporal variation in the importance of a dominant consumer to stream nutrient cycling

DOE PAGES

Griffiths, Natalie A.; Hill, Walter

2014-06-19

Animal excretion can be a significant nutrient flux within ecosystems, where it supports primary production and facilitates microbial decomposition of organic matter. The effects of excretory products on nutrient cycling have been documented for various species and ecosystems, but temporal variation in these processes is poorly understood. We examined variation in excretion rates of a dominant grazing snail, Elimia clavaeformis, and its contribution to nutrient cycling, over the course of 14 months in a well-studied, low-nutrient stream (Walker Branch, east Tennessee, USA). Biomass-specific excretion rates of ammonium varied over twofold during the study, coinciding with seasonal changes in food availabilitymore » (measured as gross primary production) and water temperature (multiple linear regression, R 2 = 0.57, P = 0.053). The contribution of ammonium excretion to nutrient cycling varied with seasonal changes in both biological (that is, nutrient uptake rate) and physical (that is, stream flow) variables. On average, ammonium excretion accounted for 58% of stream water ammonium concentrations, 26% of whole-stream nitrogen demand, and 66% of autotrophic nitrogen uptake. Phosphorus excretion by Elimia was contrastingly low throughout the year, supplying only 1% of total dissolved phosphorus concentrations. The high average N:P ratio (89:1) of snail excretion likely exacerbated phosphorus limitation in Walker Branch. To fully characterize animal excretion rates and effects on ecosystem processes, multiple measurements through time are necessary, especially in ecosystems that experience strong seasonality.« less

Temporal variation in the importance of a dominant consumer to stream nutrient cycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Griffiths, Natalie A.; Hill, Walter

Animal excretion can be a significant nutrient flux within ecosystems, where it supports primary production and facilitates microbial decomposition of organic matter. The effects of excretory products on nutrient cycling have been documented for various species and ecosystems, but temporal variation in these processes is poorly understood. We examined variation in excretion rates of a dominant grazing snail, Elimia clavaeformis, and its contribution to nutrient cycling, over the course of 14 months in a well-studied, low-nutrient stream (Walker Branch, east Tennessee, USA). Biomass-specific excretion rates of ammonium varied over twofold during the study, coinciding with seasonal changes in food availabilitymore » (measured as gross primary production) and water temperature (multiple linear regression, R 2 = 0.57, P = 0.053). The contribution of ammonium excretion to nutrient cycling varied with seasonal changes in both biological (that is, nutrient uptake rate) and physical (that is, stream flow) variables. On average, ammonium excretion accounted for 58% of stream water ammonium concentrations, 26% of whole-stream nitrogen demand, and 66% of autotrophic nitrogen uptake. Phosphorus excretion by Elimia was contrastingly low throughout the year, supplying only 1% of total dissolved phosphorus concentrations. The high average N:P ratio (89:1) of snail excretion likely exacerbated phosphorus limitation in Walker Branch. To fully characterize animal excretion rates and effects on ecosystem processes, multiple measurements through time are necessary, especially in ecosystems that experience strong seasonality.« less

Nutrient and chlorophyll relations in selected streams of the New England Coastal Basins in Massachusetts and New Hampshire, June-September 2001

USGS Publications Warehouse

Riskin, Melissa L.; Deacon, J.R.; Liebman, M.L.; Robinson, K.W.

2003-01-01

The U.S. Environmental Protection Agency is developing guidance to assist states with defining nutrient criteria for rivers and streams and to better describe nutrient-algal relations. As part of this effort, 13 wadeable stream sites were selected, primarily in eastern Massachusetts, for a nutrient-assessment study during the summer of 2001. The sites represent a range of water-quality impairment conditions (reference, moderately impaired, impaired) based on state regulatory agency assessments and previously assessed nitrogen, phosphorus, and dissolved-oxygen data. In addition, a combination of open- and closed-canopy locations were sampled at six of the sites to investigate the effect of sunlight on algal growth. Samples for nutrients and for chlorophyll I from phytoplankton and periphyton were collected at all stream sites. Total nitrogen (dissolved nitrite + nitrate + total ammonia + organic nitrogen) and total phosphorus (phosphorus in an unfiltered water sample) concentrations were lowest at reference sites and highest at impaired sites. There were statistically significant differences (p < 0.05) among reference, moderately impaired, and impaired sites for total nitrogen and total phosphorus. Chlorophyll a concentrations from phytoplankton were not significantly different among site impairment designations. Concentrations of chlorophyll a from periphyton were highest at nutrient-impaired open-canopy sites. Chlorophyll a concentrations from periphyton samples were positively correlated with total nitrogen and total phosphorus at the open- and closed-canopy sites. Correlations were higher at open-canopy sites (p < 0.05, rho = 0.64 to 0.71) than at closed-canopy sites (p < 0.05, rho = 0.36 to 0.40). Statistically significant differences in the median concentrations of chlorophyll a from periphyton samples were observed between the open- and closed-canopy sites (p < 0.05). Total nitrogen and total phosphorus data from moderately impaired and impaired sites in this study exceeded the preliminary U.S. Environmental Protection Agency nutrient criteria values for the coastal region of New England. In an effort to establish more appropriate nutrient and chlorophyll criteria for streams in the New England coastal region, relations between total nitrogen and total phosphorus to periphyton chlorophyll a in wadeable streams from this study were quantified to present potential techniques for determining nutrient concentrations. Linear regression was used to estimate the total nitrogen and total phosphorus concentrations that corresponded to various chlorophyll a concentrations. On the basis of this relation, a median concentration for moderately enriched streams of 21 milligrams per square meter (mg/m2) of periphyton chlorophyll a from the literature corresponded to estimated concentrations of 1.3 milligrams per liter (mg/L) for total nitrogen and 0.12 mg/L for total phosphorus. The median concentration for periphyton chlorophyll a from the literature is similar to the 50th-percentile concentration of periphyton chlorophyll a (17 mg/m2) calculated with the data from open-canopy sites in this study. The 25th-percentile concentration for periphyton chlorophyll a of all open-canopy sites (5.2 mg/m2) and the 75th-percentile concentration for periphyton chlorophyll a of open-canopy reference sites (16 mg/m2) also were plotted to provide additional estimates and methods for developing total nitrogen and total phosphorus criteria. The 25th-percentile concentrations of total nitrogen and total phosphorus were calculated based on all sites in this study and were used as another potential criteria estimation. A concentration of 0.64 mg/L for total nitrogen and 0.030 mg/L for total phosphorus were calculated. As another possible method to develop threshold concentrations, the 10th-percentile concentrations of total nitrogen and total phosphorus were calculated based on all the impaired sites in this study. A concentration threshold of 0

Characterization of Water Quality in Unmonitored Streams in the Mississippi Alluvial Plain, Northwestern Mississippi, May-June 2006

USGS Publications Warehouse

Bryson, Jeannie R.; Coupe, Richard H.; Manning, Michael A.

2007-01-01

The Mississippi Department of Environmental Quality is required to develop restoration and remediation plans for water bodies not meeting their designated uses, as stated in the U.S. Environmental Protection Agency's Clean Water Act section 303(d). The majority of streams in northwestern Mississippi are on the 303(d) list of water-quality limited waters. Agricultural effects on streams in northwestern Mississippi have reduced the number of unimpaired streams (reference streams) for water-quality comparisons. As part of an effort to develop an index to assess impairment, the U.S. Geological Survey collected water samples from 52 stream sites on the 303(d) list during May-June 2006, and analyzed the samples for nutrients and chlorophyll. The data were analyzed by trophic group as determined by total nitrogen concentrations. Seven constituents (nitrite plus nitrate, total Kjeldhal nitrogen, total phosphorus, orthophosphorus, total organic carbon, chlorophyll a, and pheophytina) and four physical property measurements (specific conductance, pH, turbidity, and dissolved oxygen) were determined to be significantly different (p < 0.05) between trophic groups. Total Kjeldhal nitrogen, turbidity, and dissolved oxygen were used as indicators of stream productivity with which to infer stream health. Streams having high total Kjeldhal nitrogen values and high turbidity values along with low dissolved oxygen concentrations were typically eutrophic abundant in nutrients), whereas streams having low total Kjeldhal nitrogen values and low turbidity values along with high dissolved oxygen concentrations were typically oligotrophic (deficient in nutrients).

Inorganic N and P dynamics of Antarctic glacial meltwater streams as controlled by hyporheic exchange and benthic autotrophic communities

USGS Publications Warehouse

McKnight, Diane M.; Runkel, R.L.; Tate, C.M.; Duff, J.H.; Moorhead, D.L.

2004-01-01

The McMurdo Dry Valleys of South Victoria Land, Antarctica, contain numerous glacial meltwater streams that drain into lakes on the valley floors. Many of the streams have abundant perennial mats of filamentous cyanobacteria. The algal mats grow during streamflow in the austral summer and are in a dormant freeze-dried state during the rest of the year. NO3 and soluble reactive P (SRP) concentrations were lower in streams with abundant algal mats than in streams with sparse algal mats. NO3 and SRP concentrations were higher in the hyporheic zone of a stream with abundant algal mats than in the stream itself. An experimental injection of LiCl, NaNO3, and K3PO4 was conducted in Green Creek, which has abundant algal mats. Substantial hyporheic exchange occurred. The NO3 and PO4 concentrations at 50 m below the injection were 55 ??M and 18 ??M, respectively, during the experiment. NO3 and PO4 concentrations were below the detection limit of 1 to 2 ??M at a site 497 m below the injection during the Cl tracer arrival, indicating a high capacity for nutrient uptake by algal communities. NO2 and NH4 were present at sites 226 and 327 m below the injection, indicating that, in addition to denitrification and algal uptake, dissimilatory NO3 reduction to NO2 and NH4 may be a NO3 sink during transport. Transport modelling with nutrient uptake represented as a 1st-order process yielded reach-scale parameters of 4.3 ?? 10-5 to 3.9 ?? 10-4/s and 1.4 ?? 10-4 to 3.8 ?? 10 -4/s for uptake of NO3 and PO4, respectively. The best match with the observed data was a model in which PO4 uptake occurred only in the main channel and NO3 uptake occurred in the main channel and in the hyporheic zone. Hyporheic NO3 uptake was 7 to 16% of the total uptake for the different stream reaches. These results demonstrate that nutrient flux to the lakes is controlled by hyporheic exchange and nutrient uptake by algal mats in dry valley streams. Streams without algal mats contribute more nutrients to the lakes than streams with algal mats.

Periphyton response to long-term nutrient enrichment in a shaded headwater stream

Treesearch

Jennifer L. Greenwood; Amy D. Rosemond

2009-01-01

We maintained elevated but moderate concentrations of nitrogen and phosphorus continuously for 2 years in a heavily shaded headwater stream and compared effects on stream periphyton with a reference...

Environmental Characteristics and Geographic Information System Applications for the Development of Nutrient Thresholds in Oklahoma Streams

USGS Publications Warehouse

Masoner, Jason R.; Haggard, Brian E.; Rea, Alan

2002-01-01

The U.S.Environmental Protection Agency has developed nutrient criteria using ecoregions to manage and protect rivers and streams in the United States. Individual states and tribes are encouraged by the U.S. Environmental Protection Agency to modify or improve upon the ecoregion approach. The Oklahoma Water Resources Board uses a dichotomous process that stratifies streams using environmental characteristics such as stream order and stream slope. This process is called the Use Support Assessment Protocols, subchapter15. The Use Support Assessment Protocols can be used to identify streams threatened by excessive amounts of nutrients, dependant upon a beneficial use designation for each stream. The Use Support Assessment Protocols, subchapter 15 uses nutrient and environmental characteristic thresholds developed from a study conducted in the Netherlands, but the Oklahoma Water Resources Board wants to modify the thresholds to reflect hydrologic and ecological conditions relevant to Oklahoma streams and rivers. Environmental characteristics thought to affect impairment from nutrient concentrations in Oklahoma streams and rivers were determined for 798 water-quality sites in Oklahoma. Nutrient, chlorophyll, water-properties, and location data were retrieved from the U.S. Environmental Protection Agency STORET database including data from the U.S. Geological Survey, Oklahoma Conservation Commission, and Oklahoma Water Resources Board. Drainage-basin area, stream order, stream slope, and land-use proportions were determined for each site using a Geographic Information System. The methods, procedures, and data sets used to determine the environmental characteristics are described.

Data for a regional approach to the development of an effects-based nutrient criterion for wadable streams

USGS Publications Warehouse

Crawford, J. Kent; Loper, Connie A.; Beaman, Joseph R.; Soehl, Anna G.; Brown, Will S.

2007-01-01

States are required by the U.S. Environmental Protection Agency to establish nutrient criteria (concentrations of nutrients above which water quality is deteriorated) as part of their water-quality regulations. A study of wadable streams in the Mid-Atlantic Region was undertaken by the U.S. Geological Survey, the U.S. Environmental Protection Agency, and the Maryland Department of the Environment, with assistance from the Pennsylvania Department of Environmental Protection, to help define current concentrations of nutrients in streams with the goal of associating different nutrient-concentration levels with their effects on water quality. During the summers of 2004 and 2005, diel concentrations of dissolved oxygen, nutrient concentrations, concentrations of chlorophyll a in attached algae, and algal-community structure were measured at 46 stream sites in Maryland, Pennsylvania, Virginia, and West Virginia. Data from this work can be used by individual state agencies to define nutrient criteria. Quality-control measures for the study included submitting blank samples, duplicate samples, and reference samples for analysis of nutrients, total organic carbon, chlorophyll a, and algal biomass. Duplicate and split samples were submitted for periphyton identifications. Three periphyton split samples were sent to an independent lab for a check on periphyton identifications. Neither total organic carbon nor nutrients were detected in blank samples. Concentrations of nutrients and total organic carbon were similar for most duplicate sample pairs, with the exception of a duplicate pair from Western Run. Concentrations of ammonia plus organic nitrogen for this duplicate pair differed by as much as 34 percent. Total organic carbon for the duplicate pair from Western Run differed by 102 percent. The U.S. Geological Survey National Water Quality Laboratory performance on the only valid reference sample submitted was excellent; the relative percent difference values were no larger than 5 percent for any constituent analyzed. For periphyton identifications, duplicate samples had Jaccard Coefficient of Community values slightly greater than 0.5. This indicates the periphyton sampling protocol used provided a sample that was only moderately reproducible. Jaccard Coefficients for three periphyton samples split between two independent labs were 0.2, 0.11, and 0.08. These very low values suggest a poor concurrence on species identifications performed by the two labs. As a result of these quality-control samples, the slides prepared for diatom identifications were sent to the Academy of Natural Sciences for re-identification. Caution is urged when interpreting periphyton-community information from this study. This report and the raw data from the study are available online at http://pubs.usgs.gov/ds257

Bacterial growth on stream insects: potential for use in bioassessment

Treesearch

A. Dennis Lemly

1998-01-01

Growth of filamentous bacteria (Sphaerotilus sp., Leptothrix sp.) on aquatic insects was evaluated for its usefulness as a bioindicator of detrimental nutrient levels in streams. Field measurements of insect abundance, nutrient concentrations, and incidence/ degree of bacterial growth on insects upstream and downstream of livestock pastures were made in 2 Virginia, USA...

Riparian and Associated Habitat Characteristics Related to Nutrient Concentrations and Biological Responses of Small Streams in Selected Agricultural Areas, United States, 2003-04

USGS Publications Warehouse

Zelt, Ronald B.; Munn, Mark D.

2009-01-01

Physical factors, including both in-stream and riparian habitat characteristics that limit biomass or otherwise regulate aquatic biological condition, have been identified by previous studies. However, linking the ecological significance of nutrient enrichment to habitat or landscape factors that could allow for improved management of streams has proved to be a challenge in many regions, including agricultural landscapes, where many ecological stressors are strong and the variability among watersheds typically is large. Riparian and associated habitat characteristics were sampled once during 2003-04 for an intensive ecological and nutrients study of small perennial streams in five contrasting agricultural landscapes across the United States to determine how biological communities and ecosystem processes respond to varying levels of nutrient enrichment. Nutrient concentrations were determined in stream water at two different sampling times per site and biological samples were collected once per site near the time of habitat characterization. Data for 141 sampling sites were compiled, representing five study areas, located in parts of the Delmarva Peninsula (Delaware and Maryland), Georgia, Indiana, Ohio, Nebraska, and Washington. This report examines the available data for riparian and associated habitat characteristics to address questions related to study-unit contrasts, spatial scale-related differences, multivariate correlation structure, and bivariate relations between selected habitat characteristics and either stream nutrient conditions or biological responses. Riparian and associated habitat characteristics were summarized and categorized into 22 groups of habitat variables, with 11 groups representing land-use and land-cover characteristics and 11 groups representing other riparian or in-stream habitat characteristics. Principal components analysis was used to identify a reduced set of habitat variables that describe most of the variability among the sampled sites. The habitat characteristics sampled within the five study units were compared statistically. Bivariate correlations between riparian habitat variables and either nutrient-chemistry or biological-response variables were examined for all sites combined, and for sites within each study area. Nutrient concentrations were correlated with the extent of riparian cropland. For nitrogen species, these correlations were more frequently at the basin scale, whereas for phosphorus, they were about equally frequent at the segment and basin scales. Basin-level extents of riparian cropland and reach-level bank vegetative cover were correlated strongly with both total nitrogen and dissolved inorganic nitrogen (DIN) among multiple study areas, reflecting the importance of agricultural land-management and conservation practices for reducing nitrogen delivery from near-stream sources. When sites lacking segment-level wetlands were excluded, the negative correlation of riparian wetland extent with DIN among 49 sites was strong at the reach and segment levels. Riparian wetland vegetation thus may be removing dissolved nutrients from soil water and shallow groundwater passing through riparian zones. Other habitat variables that correlated strongly with nitrogen and phosphorus species included suspended sediment, light availability, and antecedent water temperature. Chlorophyll concentrations in seston were positively correlated with phosphorus concentrations for all sites combined. Benthic chlorophyll was correlated strongly with nutrient concentrations in only the Delmarva study area and only in fine-grained habitats. Current velocity or hydraulic scour could explain correlation patterns for benthic chlorophyll among Georgia sites, whereas chlorophyll in seston was correlated with antecedent water temperature among Washington and Delmarva sites. The lack of any consistent correlation pattern between habitat characteristics and organic material density (ash-free dry mass)

Quantifying the impact of septic tank systems on eutrophication risk in rural headwaters.

PubMed

Withers, P J A; Jarvie, H P; Stoate, C

2011-04-01

Septic tank systems (STS) are a potential source of nutrient emissions to surface waters but few data exist in the UK to quantify their significance for eutrophication. We monitored the impact of STS on nutrient concentrations in a stream network around a typical English village over a 1-year period. Septic tank effluent discharging via a pipe directly into one stream was highly concentrated in soluble N (8-63mgL(-1)) and P (<1-14mgL(-1)) and other nutrients (Na, K, Cl, B and Mn) typical of detergent and household inputs. Ammonium-N (NH(4)N) and soluble reactive P (SRP) fractions were dominant (70-85% of total) and average concentrations of nitrite-N (NO(2)N) were above levels considered harmful to fish (0.1mgL(-1)). Lower nutrient concentrations were recorded at a ditch and a stream site, but range and average values downstream of rural habitation were still 4 to 10-fold greater than those in upstream sections. At the ditch site, where flow volumes were low, annual flow-weighted concentrations of NH(4)N and SRP increased from 0.04 and 0.07mgL(-1), respectively upstream to 0.55 and 0.21mgL(-1) downstream. At the stream site, flow volumes were twice as large and flow-weighted concentrations increased much less; from 0.04 to 0.21mgL(-1) for NH(4)N and from 0.06 to 0.08mgL(-1) for SRP. At all sites, largest nutrient concentrations were recorded under low flow and stream discharge was the most important factor determining the eutrophication impact of septic tank systems. The very high concentrations, intercorrelation and dilution patterns of SRP, NH(4)-N and the effluent markers Na and B suggested that soakaways in the heavy clay catchment soils were not retaining and treating the septic tank effluents efficiently, with profound implications for stream biodiversity. Water companies, water regulators and rural communities therefore need to be made more aware of the potential impacts of STS on water quality so that their management can be optimised to reduce the risk of potential eutrophication and toxicity to aquatic ecosystems during summer low flow periods. Copyright © 2011 Elsevier Ltd. All rights reserved.

Assessment of nutrient enrichment by use of algal-, invertebrate-, and fish-community attributes in wadeable streams in ecoregions surrounding the Great Lakes

USGS Publications Warehouse

Frey, Jeffrey W.; Bell, Amanda H.; Hambrook Berkman, Julie A.; Lorenz, David L.

2011-01-01

The algal, invertebrate, and fish taxa and community attributes that best reflect the effects of nutrients along a gradient of low to high nutrient concentrations in wadeable, primarily midwestern streams were determined as part of the U.S. Geological Suvey's National Water-Quality Assessment (NAWQA) Program. Nutrient data collected from 64 sampling sites that reflected reference, agricultural, and urban influences between 1993 and 2006 were used to represent the nutrient gradient within Nutrient Ecoregion VI (Cornbelt and Northern Great Plains), VII (Mostly Glaciated Dairy Region), and VIII (Nutrient Poor Largely Glaciated Upper Midwest and Northeast). Nutrient Ecoregions VII and VIII comprise the Glacial North diatom ecoregion (GNE) and Nutrient Ecoregion VI represents the Central and Western Plains diatom ecoregion (CWPE). The diatom-ecoregion groupings were used chiefly for data analysis. The total nitrogen (TN) and total phosphorus (TP) data from 64 sites, where at least 6 nutrient samples were collected within a year at each site, were used to classify the sites into low-, medium-, and high-nutrient categories based upon the 10th and 75th percentiles of for sites within each Nutrient Ecoregion. In general, TN and TP concentrations were 3-5 times greater in Nutrient Ecoregion VI than in Nutrient Ecoregions VII and VIII. A subgroup of 54 of these 64 sites had algal-, invertebrate-, and fish-community data that were collected within the same year as the nutrients; these sites were used to assess the effects of nutrients on the biological communities. Multidimensional scaling was used to determine whether the entire region could be assessed together or whether there were regional differences between the algal, invertebrate, and fish communities. The biological communities were significantly different between the northern sites, primarily in the GNE and the southern sites, primarily in the CWPE. In the higher nutrient concentration gradient in the streams of the CWPE, algae exhibited greater differences than invertebrates and fish between all of the nutrient categories for both TN and TP; however, in the lower nutrient gradient in the streams of the GNE, invertebrates exhibited greater differences between the nutrient categories. Certain species of algae, invertebrates, and fish were more prevalent in low- and high-nutrient categories within each of the diatom ecoregions. Breakpoint analysis was used to identify the concentration at which the relations between the response variable (biological attribute) and the stressor variable (TN and TP) change. There were significant breakpoints for nutrients (TN and TP) and multiple attributes for algae, invertebrates, and fish communities within the CWPE and GNE diatom ecoregions. In general, more significant breakpoints, with lower concentrations, were found in the GNE than the more nutrient-rich CWPE. The breakpoints from all biological communities were generally about 3-5 times higher in the south (CWPE) than the north (GNE). In the north, breakpoints with similar lower concentrations were found for TN from all biological communities (around 0.60 milligram per liter) and for TP (between 0.02 and 0.03 milligram per liter) for the algae and invertebrate communities. The findings from our study suggest that the range in breakpoints for TN and TP from the GNE can be used as oligotrophic and eutrophic boundaries derived from biological response based on this ecoregion having (1) a gradient with sufficiently low to high nutrient concentrations, (2) distinctive differences in the biological communities in the low- to high-nutrient streams, (3) similarity of breakpoints within algal, invertebrate, and fish communities, (4) significant attributes with either direct relations to nutrients or traditional changes in community structure (that is, decreases in sensitive species or increases in tolerant species), and (5) similar breakpoints in other studies in this and other regions. In nutrie

Stream microbial diversity in response to environmental changes: review and synthesis of existing research

PubMed Central

Zeglin, Lydia H.

2015-01-01

The importance of microbial activity to ecosystem function in aquatic ecosystems is well established, but microbial diversity has been less frequently addressed. This review and synthesis of 100s of published studies on stream microbial diversity shows that factors known to drive ecosystem processes, such as nutrient availability, hydrology, metal contamination, contrasting land-use and temperature, also cause heterogeneity in bacterial diversity. Temporal heterogeneity in stream bacterial diversity was frequently observed, reflecting the dynamic nature of both stream ecosystems and microbial community composition. However, within-stream spatial differences in stream bacterial diversity were more commonly observed, driven specifically by different organic matter (OM) compartments. Bacterial phyla showed similar patterns in relative abundance with regard to compartment type across different streams. For example, surface water contained the highest relative abundance of Actinobacteria, while epilithon contained the highest relative abundance of Cyanobacteria and Bacteroidetes. This suggests that contrasting physical and/or nutritional habitats characterized by different stream OM compartment types may select for certain bacterial lineages. When comparing the prevalence of physicochemical effects on stream bacterial diversity, effects of changing metal concentrations were most, while effects of differences in nutrient concentrations were least frequently observed. This may indicate that although changing nutrient concentrations do tend to affect microbial diversity, other environmental factors are more likely to alter stream microbial diversity and function. The common observation of connections between ecosystem process drivers and microbial diversity suggests that microbial taxonomic turnover could mediate ecosystem-scale responses to changing environmental conditions, including both microbial habitat distribution and physicochemical factors. PMID:26042102

Influence of Soils, Riparian Zones, and Hydrology on Nutrients, Herbicides, and Biological Relations in Midwestern Agricultural Streams

NASA Astrophysics Data System (ADS)

Porter, S.

2001-12-01

Chemical, biological, and habitat conditions were characterized in 70 streams in the upper Mississippi River basin during August 1997, as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. The study was designed to evaluate algal and macroinvertebrate responses to high agricultural intensity in relation to nonpoint sources of nutrients and herbicides, characteristics of basin soils, wooded-riparian vegetation, and hydrology. Concentrations and forms of nutrients, herbicides and their metabolites, and seston constituents varied significantly with regional differences in soil properties, ground and surface water relations, density of riparian trees, and precedent rainfall-runoff conditions. Dissolved nitrate concentrations were relatively low in streams with high algal productivity; however, nitrate concentrations increased with basin water yield, which was associated with the regional distribution of rainfall during the month prior to the study. Stream productivity and respiration were positively correlated with seston (phytoplankton) chlorophyll concentrations, which were significantly larger in streams in areas with poorly drained soils and low riparian-tree density. Concentrations of dissolved phosphorus were low in streams where periphyton biomass was high. Periphyton biomass was relatively larger in streams with clear water and low abundance of macroinvertebrates that consume algae. Periphyton biomass decreased rapidly with modest increases in the abundance of scrapers such as snails and certain mayfly taxa. Differences in dissolved oxygen, organic carbon, stream velocity, and precedent hydrologic conditions explained much of the variance in macroinvertebrate community structure. The overall number of macroinvertebrate species and number of mayfly, caddisfly, and stonefly (EPT) taxa that are sensitive to organic enrichment were largest in streams with moderate periphyton biomass, in areas with moderately-well drained soils and high riparian-tree density. Regional differences in hydrologic processes can account for significant differences or gradients in chemical and biological conditions in streams that drain a relatively homogeneous landscape.

Stream-water chemistry, nutrients, and pesticides in Town Brook, a headwater stream of the Cannonsville Reservoir Watershed, Delaware County, New York, 1999

USGS Publications Warehouse

McHale, Michael R.; Phillips, Patrick J.

2001-01-01

Stream-water chemistry was monitored from January 1 through December 31, 1999, in the Town Brook watershed (TBW) in Delaware County, N.Y. to provide a basis for future evaluation of the effectiveness of Best Management Practices (BMPs) in decreasing agricultural nutrient and pesticide leaching to receiving waters. Total runoff from the watershed during 1999 was 664 millimeters (mm). Annual nutrient export (in kilograms per hectare) values were: ammonia (NH3), 0.25; nitrate (NO3-), 4.3; total nitrogen (TN), 10.6; orthophosphate (OP), 0.26; total dissolved phosphorus (TDP), 0.30; and total phosphorus (TP), 1.2 during 1999. Streamwater samples were collected during baseflow, elevated baseflow, and stormflow conditions. Stormflow, which produced the greatest flowweighted mean nutrient concentrations, represented only 41 percent of the annual runoff but accounted from 49 to 68 percent of the annual nutrient export. The highest seasonal flow-weighted mean concentrations were measured during the summer; the highest concentrations occurred during a large storm on July 4, 1999 with a recurrence interval greater than 100 years. The greatest seasonal export of dissolved nutrients (NH3, NO3-, OP, and TDP) occurred during the winter, whereas the greatest export of TN and TP was during the summer. Most of the TN and TP export during the summer occurred during the July 4 storm. That storm, together with a second large storm on September 16, 1999, accounted for the following percentages of annual export: ammonia, 17 percent; NO3-, 21 percent; TN, 45 percent; OP, 21 percent; TDP, 21 percent; and TP, 56 percent. Although these results provide information on the quantity and timing of nutrient export, they do not indicate the nutrient source nor the transport mechanisms by which nutrients are delivered to the stream.Baseflow and stormflow samples were collected for pesticide analyses at the Town Brook watershed outlet from January through July 1999. Eight pesticides and pesticide metabolites (degradation products) were detected in the samples. Four compounds (metolachlor, atrazine, metolachlor ESA, and metolachlor OA) were detected in concentrations greater than 1 micrograms per liter (μg/L) in one or more samples. Two of these compounds.the herbicide metabolites metalochlor ESA and metalochlor OA.were detected in concentrations higher than those of the parent compound metolachlor. Only one sample, collected during the July 4 storm, exceeded New York State surface-water-quality standards for any pesticide (simazine); its concentration of 0.53 μg/L was 0.03 μg/L higher than the New York State standard (0.50 μg/L). No concentrations exceeded Federal water-quality standards. Pesticide and metabolite concentrations were as much as 25 times greater during stormflow than during baseflow. Stormflow pesticide concentrations were indicative of a spring 'flushing', in which stream pesticide concentrations are elevated from concentrations typical during the rest of the year during the first few storms after pesticide application. Pesticides and pesticide metabolites were detected in all stormflow samples. These results illustrate the need to include baseflow and stormflow in pesticide sampling routines.The results of this study emphasize the need for (1) baseflow and stormflow sampling to capture the range of nutrient and pesticide concentrations from agricultural watersheds, and (2) research to define the mechanisms of nutrient and pesticide export in agriculutral watersheds.

ESTIMATING THE LIKELIHOOD OF OCCURRENCE OF SELECTED PESTICIDES AND NUTRIENTS EXCEEDING SPECIFIC CONCENTRATIONS IN COASTAL PLAIN STREAMS BASED ON LANDSCAPE CHARACTERISTICS

EPA Science Inventory

The occurrence of selected pesticides and nutrient compounds in nontidal headwater streams of the Mid-Atlantic Coastal Plain (North Carolina through New Jersey) during winter and spring base flow is related to land use, soils, and other geographic variables that reflect sources a...

New studies initiated by the U.S. Geological Survey - Effects of nutrient enrichment on stream ecosystems

USGS Publications Warehouse

Munn, Mark D.; Hamilton, Pixie A.

2003-01-01

In 2001, the U.S. Geological Survey’s National Water-Quality Assessment (NAWQA) Program began an intensive study of nutrient enrichment elevated concentrations of nitrogen and phosphorus in streams in five agricultural basins across the Nation (see map, p. 2). This study is providing nationally consistent and comparable data and analyses of nutrient conditions, including how these conditions vary as a result of natural and human-related factors, and how nutrient conditions affect algae and other biological communities. This information will benefit stakeholders, including the U.S. Environmental Protection Agency (USEPA) and its partners, who are developing nutrient criteria to protect the aquatic health of streams in different geographic regions.Nutrient enrichment is one of five national priority topics addressed by NAWQA in its second decade of studies, which began in 2001. During its first round of assessments in 51 major river basins (referred to as “Study Units”), NAWQA scientists collected data on water chemistry, stream hydrology and habitat, and biological communities; currently, NAWQA is revisiting selected basins and focusing on (1) trends, (2) factors that affect water quality and aquatic health, and (3) national priority water issues related to, for example, the development of nutrient criteria, source-water protection strategies, and stream restoration plans.The nutrient enrichment study has four major objectives that address nutrient conditions, dissolved oxygen, aquatic communities, and geographic and landscape features in agricultural basins (see inset). The focus on agricultural streams is a starting point. As the study progresses, streams draining other land uses, such as those in residential and urban areas, will likely be added.

Nutrient concentrations and loads in the northeastern United States - Status and trends, 1975-2003

USGS Publications Warehouse

Trench, Elaine C. Todd; Moore, Richard B.; Ahearn, Elizabeth A.; Mullaney, John R.; Hickman, R. Edward; Schwarz, Gregory E.

2012-01-01

The U.S. Geological Survey (USGS) National Water-Quality Assessment Program (NAWQA) began regional studies in 2003 to synthesize information on nutrient concentrations, trends, stream loads, and sources. In the northeastern United States, a study area that extends from Maine to central Virginia, nutrient data were evaluated for 130 USGS water-quality monitoring stations. Nutrient data were analyzed for trends in flow-adjusted concentrations, modeled instream (non-flow-adjusted) concentrations, and stream loads for 32 stations with 22 to 29 years of water-quality and daily mean streamflow record during 1975-2003 (termed the long-term period), and for 46 stations during 1993-2003 (termed the recent period), by using a coupled statistical model of streamflow and water quality developed by the USGS. Recent trends in flow-adjusted concentrations of one or more nutrients also were analyzed for 90 stations by using Tobit regression. Annual stream nutrient loads were estimated, and annual nutrient yields were calculated, for 47 stations for the long-term and recent periods, and for 37 additional stations that did not have a complete streamflow and water-quality record for 1993-2003. Nutrient yield information was incorporated for 9 drainage basins evaluated in a national NAWQA study, for a total of 93 stations evaluated for nutrient yields. Long-term downward trends in flow-adjusted concentrations of total nitrogen and total phosphorus (18 and 19 of 32 stations, respectively) indicate regional improvements in nutrient-related water-quality conditions. Most of the recent trends detected for total phosphorus were upward (17 of 83 stations), indicating possible reversals to the long-term improvements. Concentrations of nutrients in many streams persist at levels that are likely to affect aquatic habitat adversely and promote freshwater or coastal eutrophication. Recent trends for modeled instream concentrations, and modeled reference concentrations, were evaluated relative to ecoregion-based nutrient criteria proposed by the U.S. Environmental Protection Agency. Instream concentrations of total nitrogen and total phosphorus persist at levels higher than proposed criteria at more than one-third and about one-half, respectively, of the 46 stations analyzed. Long-term trends in nutrient loads were primarily downward, with downward trends in total nitrogen and total phosphorus loads detected at 12 and 17 of 32 stations, respectively. Upward trends were rare, with one upward trend for total nitrogen loads and none for total phosphorus. Trends in loads of nitrite-plus-nitrate nitrogen included 7 upward and 8 downward trends among 32 stations. Downward trends in loads of ammonia nitrogen and total Kjeldahl nitrogen were detected at all six stations evaluated. Long-term downward trends detected in four of the five largest drainage basins evaluated include: total nitrogen loads for the Connecticut, Delaware, and James Rivers; total Kjeldahl nitrogen and ammonia nitrogen loads for the Susquehanna River; ammonia nitrogen and nitrite-plus-nitrate nitrogen loads for the James River; and total phosphorus loads for the Connecticut and Delaware Rivers. No trends in load were detected for the Potomac River. Nutrient yields were evaluated relative to the extent of land development in 93 drainage basins. The undeveloped land-use category included forested drainage basins with undeveloped land ranging from 75 to 100 percent of basin area. Median total nitrogen yields for the 27 undeveloped drainage basins evaluated, including 9 basins evaluated in a national NAWQA study, ranged from 290 to 4,800 pounds per square mile per year (lb/mi2/yr). Total nitrogen yields even in the most pristine drainage basins may be elevated relative to natural conditions, because of high rates of atmospheric deposition of nitrogen in parts of the northeastern United States. Median total phosphorus yields ranged from 12 to 330 lb/mi2/yr for the 26 undeveloped basins evaluated. The undeveloped category includes some large drainage basins with point-source discharges and small percentages of developed land; in these basins, streamflow from undeveloped headwater areas dilutes streamflow in more urbanized reaches, and dampens but does not eliminate the point-source "signal" of higher nutrient loads. Median total nitrogen yields generally do not exceed 1,700 lb/mi2/yr, and median total phosphorus yields generally do not exceed 100 lb/mi2/yr, in the drainage basins that are least affected by human land-use and waste-disposal practices. Agricultural and urban land use has increased nutrient yields substantially relative to undeveloped drainage basins. Median total nitrogen yields for 24 agricultural basins ranged from 1,700 to 26,000 lb/mi2/yr, and median total phosphorus yields ranged from 94 to 1,000 lb/mi2/yr. The maximum estimated total nitrogen and total phosphorus yields, 32,000 and 16,000 lb/mi2/yr, respectively, for all stations in the region were in small (less than 50 square miles (mi2)) agricultural drainage basins. Median total nitrogen yields ranged from 1,400 to 17,000 lb/mi2/yr in 26 urbanized drainage basins, and median total phosphorus yields ranged from 43 to 1,900 lb/mi2/yr. Urbanized drainage basins with the highest nutrient yields are generally small (less than 300 mi2) and are drained by streams that receive major point-source discharges. Instream nutrient loads were evaluated relative to loads from point-source discharges in four drainage basins: the Quinebaug River Basin in Connecticut, Massachusetts, and Rhode Island; the Raritan River Basin in New Jersey; the Patuxent River Basin in Maryland; and the James River Basin in Virginia. Long-term downward trends in nutrient loads, coupled with similar trends in flow-adjusted nutrient concentrations, indicate long-term reductions in the delivery of most nutrients to these streams. However, the absence of recent downward trends in load for most nutrients, coupled with instream concentrations that exceed proposed nutrient criteria in several of these waste-receiving streams, indicates that challenges remain in reducing delivery of nutrients to streams from point sources. During dry years, the total nutrient load from point sources in some of the drainage basins approached or equaled the nutrient load transported by the stream.

Water-quality assessment of the Kentucky River basin, Kentucky; nutrients, sediments, and pesticides in streams, 1987-90

USGS Publications Warehouse

Haag, K.H.; Porter, S.D.

1995-01-01

The U.S. Geological Survey investigated the water quality of the Kentucky River Basin in Kentucky as part of the National Water Quality Assessment program. Data collected during 1987-90 were used to describe the spatial and temporal variability of nutrients, suspended sediment, and pesticides in streams. Concentrations of phosphorus were signifi- cantly correlated with urban and agricultural land use. The high phosphorus content of Bluegrass Region soils was an important source of phosphorus in streams. At many sites in urban areas, all of the stream nitrogen load was attributable to wastewater- treatment-plant effluent. Tributary streams affected by agricultural sources of nutrients contained higher densities of phytoplankton than streams that drained forested areas. Data indicate that a consid- erable percentage of total nitrogen was transported as algal biomass during periods of low discharge. Average suspended-sediment concentrations for the study period were positively correlated with dis- charge. There was a downward trend in suspended- sediment concentrations downstream in the Kentucky River main stem during the study. Although a large amount of suspended sediment originates in the Eastern Coal Field Region, contributions of suspended sediment from the Red River and other tributary streams of the Knobs Region also are important. The most frequently detected herbicides in water samples were atrazine, 2,4-D, alachlor, metolachlor, and dicamba. Diazinon, malathion, and parathion were the most frequently detected organo- phosphate insecticides in water samples. Detectable concentrations of aldrin, chlordane, DDT, DDE, dieldrin, endrin, endosulfan, heptachlor, heptachlor epoxide, and lindane were found in streambed- sediment samples.

Effects of stock use and backpackers on water quality in wilderness in Sequoia and Kings Canyon National Parks, USA.

PubMed

Clow, David W; Forrester, Harrison; Miller, Benjamin; Roop, Heidi; Sickman, James O; Ryu, Hodon; Domingo, Jorge Santo

2013-12-01

During 2010-2011, a study was conducted in Sequoia and Kings Canyon National Parks (SEKI) to evaluate the influence of pack animals (stock) and backpackers on water quality in wilderness lakes and streams. The study had three main components: (1) a synoptic survey of water quality in wilderness areas of the parks, (2) paired water quality sampling above and below several areas with differing types and amounts of visitor use, and (3) intensive monitoring at six sites to document temporal variations in water quality. Data from the synoptic water quality survey indicated that wilderness lakes and streams are dilute and have low nutrient and Escherichia coli concentrations. The synoptic survey sites were categorized as minimal use, backpacker-use, or mixed use (stock and backpackers), depending on the most prevalent type of use upstream from the sampling locations. Sites with mixed use tended to have higher concentrations of most constituents (including E. coli) than those categorized as minimal-use (P ≤ 0.05); concentrations at backpacker-use sites were intermediate. Data from paired-site sampling indicated that E. coli, total coliform, and particulate phosphorus concentrations were greater in streams downstream from mixed-use areas than upstream from those areas (P ≤ 0.05). Paired-site data also indicated few statistically significant differences in nutrient, E. coli, or total coliform concentrations in streams upstream and downstream from backpacker-use areas. The intensive-monitoring data indicated that nutrient and E. coli concentrations normally were low, except during storms, when notable increases in concentrations of E. coli, nutrients, dissolved organic carbon, and turbidity occurred. In summary, results from this study indicate that water quality in SEKI wilderness generally is good, except during storms; and visitor use appears to have a small, but statistically significant influence on stream water quality.

Effects of Stock Use and Backpackers on Water Quality in Wilderness in Sequoia and Kings Canyon National Parks, USA

NASA Astrophysics Data System (ADS)

Clow, David W.; Forrester, Harrison; Miller, Benjamin; Roop, Heidi; Sickman, James O.; Ryu, Hodon; Domingo, Jorge Santo

2013-12-01

During 2010-2011, a study was conducted in Sequoia and Kings Canyon National Parks (SEKI) to evaluate the influence of pack animals (stock) and backpackers on water quality in wilderness lakes and streams. The study had three main components: (1) a synoptic survey of water quality in wilderness areas of the parks, (2) paired water quality sampling above and below several areas with differing types and amounts of visitor use, and (3) intensive monitoring at six sites to document temporal variations in water quality. Data from the synoptic water quality survey indicated that wilderness lakes and streams are dilute and have low nutrient and Escherichia coli concentrations. The synoptic survey sites were categorized as minimal use, backpacker-use, or mixed use (stock and backpackers), depending on the most prevalent type of use upstream from the sampling locations. Sites with mixed use tended to have higher concentrations of most constituents (including E. coli) than those categorized as minimal-use ( P ≤ 0.05); concentrations at backpacker-use sites were intermediate. Data from paired-site sampling indicated that E. coli, total coliform, and particulate phosphorus concentrations were greater in streams downstream from mixed-use areas than upstream from those areas ( P ≤ 0.05). Paired-site data also indicated few statistically significant differences in nutrient, E. coli, or total coliform concentrations in streams upstream and downstream from backpacker-use areas. The intensive-monitoring data indicated that nutrient and E. coli concentrations normally were low, except during storms, when notable increases in concentrations of E. coli, nutrients, dissolved organic carbon, and turbidity occurred. In summary, results from this study indicate that water quality in SEKI wilderness generally is good, except during storms; and visitor use appears to have a small, but statistically significant influence on stream water quality.

Effects of stock use and backpackers on water quality in wilderness in Sequoia and Kings Canyon National Parks, USA

USGS Publications Warehouse

Clow, David W.; Forrester, Harrison; Miller, Benjamin; Roop, Heidi; Sickman, James O.; Ryu, Hodon; Santo Domingo, Jorge

2013-01-01

During 2010-2011, a study was conducted in Sequoia and Kings Canyon National Parks (SEKI) to evaluate the influence of pack animals (stock) and backpackers on water quality in wilderness lakes and streams. The study had three main components: (1) a synoptic survey of water quality in wilderness areas of the parks, (2) paired water-quality sampling above and below several areas with differing types and amounts of visitor use, and (3) intensive monitoring at six sites to document temporal variations in water quality. Data from the synoptic water-quality survey indicated that wilderness lakes and streams are dilute and have low nutrient and Escherichia coli (E. coli) concentrations. The synoptic survey sites were categorized as minimal use, backpacker use, or mixed use (stock and backpackers), depending on the most prevalent type of use upstream from the sampling locations. Sites with mixed use tended to have higher concentrations of most constituents (including E.coli) than those categorized as minimal-use (p≤0.05); concentrations at backpacker-use sites were intermediate. Data from paired-site sampling indicated that E.coli, total coliform, and particulate phosphorus concentrations were greater in streams downstream from mixed-use areas than upstream from those areas (p≤0.05). Paired-site data also indicated few statistically significant differences in nutrient, E. coli, or total coliform concentrations in streams upstream and downstream from backpacker-use areas. The intensive-monitoring data indicated that nutrient and E. coli concentrations normally were low, except during storms, when notable increases in concentrations of E.coli, nutrients, dissolved organic carbon, and turbidity occurred. In summary, results from this study indicate that water quality in SEKI wilderness generally is good, except during storms; and visitor use appears to have a small, but statistically significant influence on stream water quality.

Water-quality assessment of the Lower Susquehanna River Basin, Pennsylvania and Maryland; sources, characteristics, analysis and limitations of nutrient and suspended-sediment data, 1975-90

USGS Publications Warehouse

Hainly, R.A.; Loper, C.A.

1997-01-01

This report describes analyses of available information on nutrients and suspended sediment collected in the Lower Susquehanna River Basin during water years 1975-90. Most of the analyses were applied to data collected during water years 1980-89. The report describes the spatial and temporal availability of nutrient and suspended-sediment data and presents a preliminary concept of the spatial and temporal patterns of concentrations and loads within the basin. Where data were available, total and dissolved forms of nitrogen and phosphorus species from precipitation, surface water, ground water, and springwater, and bottom material from streams and reservoirs were evaluated. Suspended-sediment data from streams also were evaluated. The U.S. Geological Survey National Water Information System (NWIS) database was selected as the primary database for the analyses. Precipitation-quality data from the National Atmospheric Deposition Program (NADP) and bottom-material-quality data from the National Uranium Resource Evaluation (NURE) were used to supplement the water-quality data from NWIS. Concentrations of nutrients were available from 3 precipitation sites established for longterm monitoring purposes, 883 wells (854 synoptic areal survey sites and 29 project and research sites), 23 springs (17 synoptic areal survey sites and 6 project and research sites), and 894 bottom-material sites (840 synoptic areal survey sites and 54 project and research sites). Concentrations of nutrients and (or) suspended sediment were available from 128 streams (36 long-term monitoring sites, 51 synoptic areal survey sites, and 41 project and research sites). Concentrations of nutrients and suspended sediment in streams varied temporally and spatially and were related to land use, agricultural practices, and streamflow. A general north-to-south pattern of increasing median nitrate concentrations, from 2 to 5 mg/L, was detected in samples collected in study unit streams. In streams that drain areas dominated by agriculture, concentrations of nutrients and suspended sediment tend to be elevated with respect to those found in areas of other land-use types and are related to the amount of commercial fertilizer and animal manure applied to the area drained by the streams. Animal manure is the dominant source of nitrogen for the streams in the lower, agricultural part of the basin. Concentrations of nutrients in samples from wells varied with season and well depth and were related to hydrogeologic setting. Median concentrations of nitrate were 2.5 and 3.5 mg/L for wells drawing water at depths of 0 to 100 ft and 101 to 200 ft, respectively. The lowest median concentrations for nitrate in ground water from wells were generally found in siliciclastic-bedrock, forested settings of the Ridge and Valley Physiographic Province, and the highest were found in carbonate-bedrock agricultural settings of the Piedmont Physiographic Province. Twenty-five percent of the measurements from wells in carbonate rocks in the Piedmont Physiographic Province exceeded the Pennsylvania drinking-water standard. An estimate of mass balance of nutrient loads within the Lower Susquehanna River Basin was produced by combining the available information on stream loads, atmosphericdeposition loads, commercial-fertilizer applications, animal-manure production, privateseptic-system nonpoint-source loads, and municipal and industrial point-source loads. The percentage of the average annual nitrate load carried in base flow of streams in the study unit ranged from 45 to 76 percent, and the average annual phosphorus load carried in base flow ranged from 20 to 33 percent. Average annual yields of nutrients and suspended sediment from tributary basins are directly related to percentage of drainage area in agriculture and inversely to drainage area. Information required to compute loads of nitrogen and phosphorus were available for all sources except atmospheric deposition, for which only nitrogen data were available. Atmospheric deposition is the dominant source of nitrogen for the mostly forested basins draining the upper half of the study unit. The estimate of total annual nitrogen load to the study unit from precipitation is 98.8 million pounds. Nonpoint and point sources of nutrients were estimated. Nonpoint and point sources combined, including atmospheric deposition, provide a potential annual load of 390 million pounds of nitrogen and 79.5 million pounds of phosphorus. The range of percentages of the estimated nonpoint and point sources that were measured in the stream was 20 to 47 percent for nitrogen and 6 to 14 percent for phosphorus. On the average, the Susquehanna River discharges 141,000 pounds of nitrogen and 7,920 pounds of phosphorus to the Lower Susquehanna River reservoir system each year. About 98 percent of the nitrogen and 60 percent of the phosphorus passes through the reservoir system. Interpretations of available water-quality data and conclusions about the water quality of the Lower Susquehanna River Basin were limited by the scarcity of certain types of water-quality data and current ancillary data. A more complete assessment of the water quality of the basin with respect to nutrients and suspended sediment would be enhanced by the availability of additional data for multiple samples over time from all water environments; samples from streams in the northern and western part of the basin; samples from streams and springs throughout the basin during high base-flow or stormflow conditions; and information on current land-use, and nutrient loading from all types of land-use settings.

Recent (2008-10) water quality in the Barton Springs segment of the Edwards aquifer and its contributing zone, central Texas, with emphasis on factors affecting nutrients and bacteria

USGS Publications Warehouse

Mahler, Barbara J.; Musgrove, MaryLynn; Sample, Thomas L.; Wong, Corinne I.

2011-01-01

The Barton Springs zone, which comprises the Barton Springs segment of the Edwards aquifer and the watersheds to the west that contribute to its recharge, is in south-central Texas, an area with rapid growth in population and increasing amounts of land area affected by development. During November 2008-March 2010, an investigation of factors affecting the fate and transport of nutrients and bacteria in the Barton Springs zone was conducted by the U.S. Geological Survey (USGS), in cooperation with the Texas Commission on Environmental Quality. The primary objectives of the study were to characterize occurrence of nutrients and bacteria in the Barton Springs zone under a range of flow conditions; to improve understanding of the interaction between surface-water quality and groundwater quality; and to evaluate how factors such as streamflow variability and dilution affect the fate and transport of nutrients and bacteria in the Barton Springs zone. The USGS collected and analyzed water samples from five streams (Barton, Williamson, Slaughter, Bear, and Onion Creeks), two groundwater wells (Marbridge and Buda), and the main orifice of Barton Springs in Austin, Texas. During the period of the study, during which the hydrologic conditions transitioned from exceptional drought to wetter than normal, water samples were collected routinely (every 3 to 4 weeks) from the streams, wells, and spring and, in response to storms, from the streams and spring. All samples were analyzed for major ions, nutrients, the bacterium Escherichia coli, and suspended sediment. During the dry period, the geochemistry of groundwater at the two wells and at Barton Springs was dominated by flow from the aquifer matrix and was relatively similar and unchanging at the three sites. At the onset of the wet period, when the streams began to flow, the geochemistry of groundwater samples from the Marbridge well and Barton Springs changed rapidly, and concentrations of most major ions and nutrients and densities of Escherichia coli became more similar to those of samples from the streams relative to concentrations and densities during the dry period. Geochemical modeling indicated that the proportion of Barton Springs discharge composed of stream recharge increased from about 0-8 percent during the dry period to about 80 percent during the wet period. The transition from exceptional drought to wetter-than-normal conditions resulted in a number of marked changes that highlight factors affecting the fate and transport of nutrients and bacteria and the strong influence of stream recharge on water quality in the Barton Springs segment of the Edwards aquifer and had a pronounced effect on the fate of nitrogen species. Organic nitrogen loaded to and stored in soils during the dry period was nitrified to nitrate when the soils were rewetted, resulting in elevated concentrations of nitrate plus nitrite in streams as these constituents were progressively leached during continued wet weather. Estimated mean monthly loads of organic nitrogen and nitrate plus nitrite in stream recharge and Barton Springs discharge, which were relatively low and constant during the dry period, increased during the wet period. Loads of organic nitrogen, on average, were about six times greater in stream recharge than in Barton Springs discharge, indicating that organic nitrogen likely was being converted to nitrate within the aquifer. Loads of total nitrogen (organic nitrogen plus ammonia and nitrate plus nitrite) in stream recharge (162 kilograms per day) and in Barton Springs discharge (157 kilograms per day) for the period of the investigation were not significantly different. Dilution was not an important factor affecting concentrations of nitrate plus nitrite in the streams or in Barton Springs during the period of this investigation: Concentrations of nitrate plus nitrite did not decrease in streams with increasing stream discharge, and nitrate plus nitrite concentrations measured at Barton

Assessment of total nitrogen and total phosphorus in selected surface water of the National Park Service Northern Colorado Plateau Network, Colorado, Utah, and Wyoming, from 1972 through 2007

USGS Publications Warehouse

Brown, Juliane B.; Thoma, David P.

2012-01-01

Nutrients are a nationally recognized concern for water quality of streams, rivers, groundwater, and water bodies. Nutrient impairment is documented by the U.S. Environmental Protection Agency as a primary cause of degradation in lakes and reservoirs, and nutrients are related to organic enrichment and oxygen depletion, which is an important cause of degradation in streams. Recently (2011), an effort to develop State-based numeric nutrient criteria has resulted in renewed emphasis on nutrients in surface water throughout the Nation. In response to this renewed emphasis and to investigate nutrient water quality for Northern Colorado Plateau Network streams, the U.S. Geological Survey, in cooperation with the National Park Service, assessed total nitrogen and total phosphorus concentration data for 93 sites in or near 14 National Park units for the time period 1972 through 2007.

Effects of livestock grazing on nutrient retention in a headwater stream of the Rio Puerco Basin

Treesearch

Mark A. Sewards; H. Maurice Valett

1996-01-01

Sediment and nutrient loss from headwater streams of sedimentary basins in the semi-arid Southwest have been attributed to both over-grazing by livestock and to climatic cycles that influence arroyo formation. Considerable effort has been directed toward the influence of livestock grazing on riparian species abundance and diversity. Less work has concentrated on the...

The impact of solar radiation on the use of dissolved organic matter in two Ozark Streams: Possible role of photo-enhanced humification

NASA Astrophysics Data System (ADS)

Townsend, S. L.; Ziegler, S. E.

2005-05-01

The effect of solar radiation on dissolved organic matter (DOM) utilization was studied in two contrasting streams from June 2002 through October 2004. Moores Creek is an agricultural stream with elevated nutrient and dissolved organic carbon (DOC) concentrations. Huey Hollow is a forested stream with low nutrient and DOC concentrations. A series of experiments were conducted seasonally to assess how solar radiation influenced DOM utilization. Exposure of DOM to solar radiation significantly decreased its utilization during most seasons in both streams. Each stream experienced one seasonal period when exposure of DOM significantly increased bacterial production; during these periods, DOM appeared to be the least bioavailable and most photochemically reactive. Interestingly, in spring when bioavailability of DOM was lowest in Moores Creek solar radiation exposure further reduced DOM bioavailability. Elevated ammonium concentrations during this spring experiment suggest photochemically-enhanced humification may have been an important mechanism influencing DOM cycling. Bioassays using 15N-labeled ammonium indicated no significant effect of elevated ammonium on the utilization of DOM in either stream in fall 2004. Detection of elevated 15N in the DOM fractions, however, would reveal light stimulated humification under elevated ammonium concentrations not detected with the bioassay.

Low transient storage and uptake efficiencies in seven agricultural streams: implications for nutrient demand

USGS Publications Warehouse

Sheibley, Rich W.; Duff, John H.; Tesoriero, Anthony J.

2014-01-01

We used mass load budgets, transient storage modeling, and nutrient spiraling metrics to characterize nitrate (NO3−), ammonium (NH4+), and inorganic phosphorus (SRP) demand in seven agricultural streams across the United States and to identify in-stream services that may control these conditions. Retention of one or all nutrients was observed in all but one stream, but demand for all nutrients was low relative to the mass in transport. Transient storage metrics (As/A, Fmed200, Tstr, and qs) correlated with NO3− retention but not NH4+ or SRP retention, suggesting in-stream services associated with transient storage and stream water residence time could influence reach-scale NO3− demand. However, because the fraction of median reach-scale travel time due to transient storage (Fmed200) was ≤1.2% across the sites, only a relatively small demand for NO3− could be generated by transient storage. In contrast, net uptake of nutrients from the water column calculated from nutrient spiraling metrics were not significant at any site because uptake lengths calculated from background nutrient concentrations were statistically insignificant and therefore much longer than the study reaches. These results suggest that low transient storage coupled with high surface water NO3− inputs have resulted in uptake efficiencies that are not sufficient to offset groundwater inputs of N. Nutrient retention has been linked to physical and hydrogeologic elements that drive flow through transient storage areas where residence time and biotic contact are maximized; however, our findings indicate that similar mechanisms are unable to generate a significant nutrient demand in these streams relative to the loads.

Nutrients in Streams and Rivers Across the Nation -- 1992-2001

USGS Publications Warehouse

Mueller, David K.; Spahr, Norman E.

2006-01-01

Nutrient compounds of nitrogen and phosphorus were investigated in streams and rivers sampled as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. Nutrient data were collected in 20 NAWQA study units during 1992-95, 16 study units during 1996-98, and 15 study units during 1999-2001. To facilitate comparisons among sampling sites with variable sampling frequency, daily loads were determined by using regression models that relate constituent transport to streamflow and time. Model results were used to compute mean annual loads, yields, and concentrations of ammonia, nitrate, total nitrogen, orthophosphate, and total phosphorus, which were compared among stream and river sampling sites. Variations in the occurrence and distribution of nutrients in streams and rivers on a broad national scale reflect differences in the sources of nutrient inputs to the upstream watersheds and in watershed characteristics that affect movement of those nutrients. Sites were classified by watershed size and by land use in the upstream watershed: agriculture, urban, and undeveloped (forest or rangeland). Selection of NAWQA urban sites was intended to avoid effects of major wastewater-treatment plants and other point sources, but in some locations this was not feasible. Nutrient concentrations and yields generally increased with anthropogenic development in the watershed. Median concentrations and yields for all constituents at sites downstream from undeveloped areas were less than at sites downstream from agricultural or urban areas. Concentrations of ammonia, orthophosphate, and total phosphorus at agricultural and urban sites were not significantly different; however, concentrations of nitrate and total nitrogen were higher at agricultural than at urban sites. Total nitrogen concentrations at agricultural sites were higher in areas of high nitrogen input or enhanced transport, such as irrigation or artificial drainage that can rapidly move water from cropland to streams (Midwest, Northern Plains, and western areas of the United States). Concentrations were lower in the Southeast, where more denitrification occurs during transport of nitrogen compounds in shallow ground water. At urban sites, high concentrations of ammonia and orthophosphate were more prevalent downstream from wastewater-treatment plants. At sites with large watersheds and high mean-annual streamflow ('large-watershed' sites), concentrations of most nutrients were significantly less than at sites downstream from agricultural or urban areas. Total nitrogen concentrations at large-watershed sites were higher in Midwest agricultural areas and lower in the Western United States, where agricultural and urban development is less extensive. Total phosphorus concentrations at large-watershed sites were higher in areas of greater potential erosion and low overall runoff such as the arid areas in the West. Although not as distinct as seasonal patterns of streamflow, geographic patterns of seasonally high and low concentrations of total nitrogen and total phosphorus were identified in the data. Seasonal patterns in concentrations of total nitrogen generally mirror seasonal patterns in streamflow in the humid Eastern United States but are inverse to seasonal patterns in streamflow in the semiarid interior West. Total phosphorus concentrations typically have the opposite regional relation with streamflow; high concentrations coincide with high streamflows in the interior West. In the NAWQA Program, sites downstream from relatively undeveloped areas were selected to provide a baseline for comparison to sites with potential effects of urban development and agriculture. Concentrations of nitrate, total nitrogen, and total phosphorus at NAWQA undeveloped sites were found to be greater than values reported by other studies for conditions of essentially no development (background conditions). Concentrations at NAWQA undeveloped sites represent conditions

Relationships between nutrient enrichment, pleurocerid snail density and trematode infection rate in streams

USGS Publications Warehouse

Ciparis, Serena; Iwanowicz, Deborah D.; Voshell, J. Reese

2013-01-01

Summary 1. Nutrient enrichment is a widespread environmental problem in freshwater ecosystems. Eutrophic conditions caused by nutrient enrichment may result in a higher prevalence of infection by trematode parasites in host populations, due to greater resource availability for the molluscan first intermediate hosts. 2. This study examined relationships among land use, environmental variables indicating eutrophication, population density of the pleurocerid snail, Leptoxis carinata, and trematode infections. Fifteen study sites were located in streams within the Shenandoah River catchment (Virginia, U.S.A.), where widespread nutrient enrichment has occurred. 3. Snail population density had a weak positive relationship with stream water nutrient concentration. Snail population density also increased as human activities within stream catchments increased, but density did not continue to increase in catchments where anthropogenic disturbance was greatest. 4. Cercariae from five families of trematodes were identified in L. carinata, and infection rate was generally low (<10%). Neither total infection rate nor the infection rate of individual trematode types showed a positive relationship with snail population density, nutrients or land use. 5. There were statistically significant but weak relationships between the prevalence of infection by two trematode families and physical and biological variables. The prevalence of Notocotylidae was positively related to water depth, which may be related to habitat use by definitive hosts. Prevalence of Opecoelidae had a negative relationship with orthophosphate concentration and a polynomial relationship with chlorophyll a concentration. Transmission of Opecoelid trematodes between hosts may be inhibited by eutrophic conditions. 6. Leptoxis carinata appears to be a useful species for monitoring the biological effects of eutrophication and investigating trematode transmission dynamics in lotic systems.

Sources, transformations, and hydrological processes that control stream nitrate and dissolved organic matter concentrations during snowmelt in an upland forest

Treesearch

Stephen D. Sebestyen; Elizabeth W. Boyer; James B. Shanley; Carol Kendall; Daniel H. Doctor; George R. Aiken; Nobuhito Ohte

2008-01-01

We explored catchment processes that control stream nutrient concentrations at an upland forest in northeastern Vermont, USA, where inputs of nitrogen via atmospheric deposition are among the highest in the nation and affect ecosystem functioning. We traced sources of water, nitrate, and dissolved organic matter (DOM) using stream water samples collected at high...

NUTRIENT CONCENTRATIONS IN FLOWING WATERS OF THE SOUTH FORK BROAD RIVER, GEORGIA WATERSHED

EPA Science Inventory

We monitored concentrations of nutrients, dissolved organic matter (DOM) and other parameters in 17 headwater streams, at three sites on the main stem, and in three major tributaries near their confluence with the South Fork Broad River on a monthly basis for over a year. Concent...

Quantifying the Urban and Rural Nutrient Fluxes to Lake Erie Using a Paired Watershed Approach

NASA Astrophysics Data System (ADS)

Hopkins, M.; Beck, M.; Rossi, E.; Luh, N.; Allen-King, R. M.; Lowry, C.

2016-12-01

Excess nutrients have a detrimental impact on the water quality of Lake Erie, specifically nitrate and phosphate, which can lead to toxic algae blooms. Algae blooms have negatively impacted Lake Erie, which is the main source of drinking water for many coastal Great Lake communities. In 2014 the city of Toledo, Ohio was forced to shut down its water treatment plant due to these toxic algae blooms. The objective of this research is to quantify surface water nutrient fluxes to the eastern basin of Lake Erie using a paired watershed approach. Three different western New York watersheds that feed Lake Erie were chosen based on land use and areal extent: one small urban, one small rural, and one large rural. These paired watersheds were chosen to represent a range of sources of potential nutrient loading to the lake. Biweekly water samples were taken from the streams during the 2015-2016 winter to summer seasonal transition to quantify springtime snow melt effects on nutrient fluxes. These results were compared to the previous year samples, collected over the summer of 2015, which represented wetter conditions. Phosphorous levels were assessed using the ascorbic acid colorimetric assay, while nitrate was analyzed by anion-exchange chromatography. Stream gaging was used to obtain flow measurements and establish a rating curve, which was incorporated to quantify seasonal nutrient fluxes entering the lake. Patterns in the nutrient levels show higher level of nutrients in the rural watersheds with a decrease in concentration over the winter to spring transition. However, nutrient patterns in the urban stream show relatively constant patters of nutrient flux, which is independent of seasonal transition or stream discharge. A comparison of wet and dry seasons shows higher nutrient concentrations during summers with greater rainfall. By identifying the largest contributors of each nutrient, we can better allocate limited attenuation resources.

Spatial and temporal shifts in gross primary productivity, respiration, and nutrient concentrations in urban streams impacted by wastewater treatment plant effluent

NASA Astrophysics Data System (ADS)

Ledford, S. H.; Toran, L.

2017-12-01

Impacts of wastewater treatment plant effluent on nutrient retention and stream productivity are highly varied. The working theory has been that large pulses of nutrients from plants may hinder in-stream nutrient retention. We evaluated nitrate, total dissolved phosphorus, and dissolved oxygen in Wissahickon Creek, an urban third-order stream in Montgomery and Philadelphia counties, PA, that receives effluent from four wastewater treatment plants. Wastewater treatment plant effluent had nitrate concentrations of 15-30 mg N/L and total dissolved phosphorus of 0.3 to 1.8 mg/L. Seasonal longitudinal water quality samples showed nitrate concentrations were highest in the fall, peaking at 22 mg N/L, due to low baseflow, but total dissolved phosphorous concentrations were highest in the spring, reaching 0.6 mg/L. Diurnal dissolved oxygen patterns above and below one of the treatment plants provided estimates of gross primary productivity (GPP) and ecosystem respiration (ER). A site 1 km below effluent discharge had higher GPP in April (80 g O2 m-2 d-1) than the site above the plant (28 g O2 m-2 d-1). The pulse in productivity did not continue downstream, as the site 3 km below the plant had GPP of only 12 g O2 m-2 d-1. Productivity fell in June to 1-2 g O2 m-2 d-1 and the differences in productivity above and below plants were minimal. Ecosystem respiration followed a similar pattern in April, increasing from -17 g O2 m-2 d-1 above the plant to -47 g O2 m-2 d-1 1 km below the plant, then decreasing to -8 g O2 m-2 d-1 3 km below the plant. Respiration dropped to -3 g O2 m-2 d-1 above the plant in June but only fell to -9 to -10 g O2 m-2 d-1 at the two downstream sites. These findings indicate that large nutrient pulses from wastewater treatment plants spur productivity and respiration, but that these increases may be strongly seasonally dependent. Examining in-stream productivity and respiration is critical in wastewater impacted streams to understanding the seasonal and spatial variability of nutrient stresses so that limitations on discharge can be better targeted.

Nutrient attenuation in rivers and streams, Puget Sound Basin, Washington

USGS Publications Warehouse

Sheibley, Rich W.; Konrad, Christopher P.; Black, Robert W.

2015-01-01

From a management perspective, preservation and improvement of instream nutrient attenuation should focus on increasing the travel time through a reach and contact time of water sediment (reactive) surfaces and lowering nutrient concentrations (and loads) to avoid saturation of instream attenuation and increase attenuation efficiency. These goals can be reached by maintaining and restoring channel-flood plain connectivity, maintaining and restoring healthy riparian zones along streams, managing point and nonpoint nutrient loads to streams and rivers, and restoring channel features that promote attenuation such as the addition of woody debris and maintaining pool-riffle morphologies. Many of these management approaches are already being undertaken during projects aimed to restore quality salmon habitat. Therefore, there is a dual benefit to these projects that also may lead to enhanced potential for nitrogen and phosphorus attenuation.

Characterizing the Effects of Stormwater Mitigation on Nutrient Export and Stream Concentrations

NASA Astrophysics Data System (ADS)

Bell, Colin D.; McMillan, Sara K.; Clinton, Sandra M.; Jefferson, Anne J.

2017-04-01

Urbanization increases nutrient loading and lowers residence times for processing of reactive solutes, including nitrate, total dissolved nitrogen, orthophosphate, and dissolved organic carbon), which leads to increased stream concentrations and mass export. Stormwater control measures mitigate the impacts of urbanization, and have the potential to improve stream water quality, however the net effect instream is not well understood. We monitored two urban and two suburban watersheds in Charlotte, NC to determine if mitigation controlled the fraction of total mass export during storm, if development classification as either urban or suburban (defined by the age, density and distribution of urban development) controlled storm nutrient and carbon dynamics, and if stormwater control measures were able to change stream water chemistry. While average concentrations during stormflow were generally greater than baseflow, indicating that storms are important times of solute export, the fraction of storm-derived export was unrelated to mitigation by stormwater control measures. Development classification was generally not an important control on export of N and dissolved organic carbon. However, event mean concentrations of orthophosphate were higher at the suburban sites, possibly from greater fertilizer application. Stormwater control measures influenced instream water chemistry at only one site, which also had the greatest mitigated area, but differences between stormwater control measure outflow and stream water suggest the potential for water quality improvements. Together, results suggest stormwater control measures have the potential to decrease solute concentrations from urban runoff, but the type, location, and extent of urban development in the watershed may influence the magnitude of this effect.

Trends in the nutrient enrichment of U.S. rivers during the late 20th century and their relation to changes in probable stream trophic conditions

USGS Publications Warehouse

Alexander, R.B.; Smith, R.A.

2006-01-01

We estimated trends in concentrations of total phosphorus (TP) and total nitrogen (TN) and the related change in the probabilities of trophic conditions from 1975 to 1994 at 250 nationally representative riverine monitoring locations in the U.S. with drainage areas larger than about 1,000 km2. Statistically significant (p < 0.05) declines were detected in TP and TN concentrations at 44% and 37% of the monitoring sites, and significant increases were detected at 3% and 9% of the sites, respectively. We used a statistical model to assess changes in the probable trophic-state classification of the sites after adjusting for climate-related variability in nutrient concentrations. The probabilistic assessment accounts for current knowledge of the trophic response of streams to nutrient enrichment, based on a recently proposed definition of "eutrophic," "mesotrophic," and "oligotrophic" conditions in relation to total nutrient concentrations. Based on these trophic definitions, we found that the trophic state improved at 25% of the monitoring sites and worsened at fewer than 5% of the sites; about 70% of the sites were unchanged. Improvements in trophic-state related to declines in TP were more common in predominantly forested and shrub-grassland watersheds, whereas the trophic state of predominantly agricultural sites was unchanged. Despite the declines in TP concentrations at many sites, about 50% of all monitoring sites, and more than 60% of the sites in predominantly agricultural and urban watersheds, were classified as eutrophic in 1994 based on TP concentrations. Contemporaneous reductions in major nutrient sources to streams, related to wastewater treatment upgrades, phosphate detergent bans, and declines in some agricultural sources, may have contributed to the declines in riverine nutrient concentrations and associated improvements in trophic conditions. ?? 2006, by the American Society of Limnology and Oceanography, Inc.

Hydrological Controls on Nutrient Concentrations and Fluxes in Agricultural Catchments

NASA Astrophysics Data System (ADS)

Petry, J.; Soulsby, C.

2002-12-01

This investigation into diffuse agricultural pollution and the hydrological controls that exert a strong influence on both nutrient concentrations and fluxes, was conducted in an intensively farmed lowland catchment in north-east Scotland. The study focuses on spatial and seasonal variations in nutrient concentrations and fluxes at the catchment scale, over a 15-month period. The water quality of the 14.5 km2 Newmills Burn catchment has relatively high nutrient levels with mean concentrations of NO3-N and NH3-N at 6.09 mg/l and 0.28 mg/l respectively. Average PO4-P concentrations are 0.06 mg/l. Over short timescales nutrient concentrations and fluxes are greatest during storm events when PO4-P and NH3-N are mobilised by overland flow in riparian areas, where soils have been compacted by livestock or machinery. Delivery of deeper soil water in subsurface storm flow, facilitated by agricultural under-drainage, produces a marked increase in NO3-N (6.9 mg/l) concentrations on the hydrograph recession limb. A more detailed insight into the catchment response to storm events, and in particular the response of the hydrological pathways which provide the main sources of runoff during storm events, was gained by sampling stream water at 2-hourly intervals during 5 events. End Member Mixing Analysis (EMMA) was carried out using event specific end-member chemistries to differentiate three catchment-scale hydrological pathways (overland flow, subsurface storm flow, groundwater flow) on the basis of observed Si and NO3-N concentrations in sampled source waters. Results show that overland flow generally dominates the storm peak and provides the main flow path by which P is transferred to stream channels during storm events, whilst subsurface storm flows usually dominate the storm hydrograph volumetrically and route NO3-rich soil water to the stream. The study shows that altering hydrological pathways in a catchment can have implications for nutrient management. Whilst buffer strips can reduce the delivery of NH3-N and PO4-P by overland flow to stream channels during storm events, the management of N-rich storm runoff as NO3 via sub-surface drains would require significant interference with the drainage network. This could have a negative impact on agricultural production in the catchment.

Long-Term Trends in Nutrient Concentrations and Fluxes in Streams Draining to Lake Tahoe, California

NASA Astrophysics Data System (ADS)

Domagalski, J. L.

2017-12-01

Lake Tahoe, situated in the rain shadow of the eastern Sierra Nevada at an elevation of 1,897 meters, has numerous small to medium sized tributaries that are sources of nutrients and fine sediment. The Tahoe watershed is relatively small and the surface area of the lake occupies about 38% of the total watershed area (1,313 km2). Each stream contributing water to the lake therefore also occupies a small watershed, mostly forested, with typical trees being Jeffrey, Ponderosa, or Sugar Pine and White Fir. Outflow from the lake contributes to downstream uses such as water supply and ecological resources. Only about 6% of the watershed is urbanized or residential land, and wastewater is exported to adjacent basins and not discharged to the lake as part of a plan to maintain water clarity. The lake's exceptional clarity has been diminishing due to phytoplankton and fine sediment, prompting development of management plans to improve water quality. Much of the annual discharge and flux of nutrients to the lake results from snowmelt in the spring and summer months, and climatic changes have begun to shift this melt to earlier time frames. Winter rains on urbanized land also contribute to nutrient loads. To understand the relative importance of land use, climate, and other factors affecting stream concentrations and fluxes, a Weighted Regression on Time Discharge and Season (WRTDS) model documented trends over a time frame of greater than 25 years. Ten streams have records of discharge, nutrient (NO3, NH3, OP, TP, TKN) and sediment data to complete this analysis. Both urbanized and non-urbanized locations generally show NO3 trending down in the 1980s. Some locations show initially decreasing orthophosphate trends, followed by small significant increases in concentration and fluxes starting around 2000 to 2005. Although no wastewater enters the streams, ammonia concentrations mimic those of orthophosphate, with initially negative trends in concentration and flux followed by positive trends after 2005 through 2015. Those trends in ammonia are observed at most sites irrespective of the degree of urbanization and may be related to atmospheric transport of ammonia from outside of the basin. Continued monitoring of these streams is necessary to understand the implications of various management options on the lake.

Wastewater treatment plant effluent introduces recoverable shifts in microbial community composition in urban streams

NASA Astrophysics Data System (ADS)

Ledford, S. H.; Price, J. R.; Ryan, M. O.; Toran, L.; Sales, C. M.

2017-12-01

New technologies are allowing for intense scrutiny of the impact of land use on microbial communities in stream networks. We used a combination of analytical chemistry, real-time polymerase chain reaction (qPCR) and targeted amplicon sequencing for a preliminary study on the impact of wastewater treatment plant effluent discharge on urban streams. Samples were collected on two dates above and below treatment plants on the Wissahickon Creek, and its tributary, Sandy Run, in Montgomery County, PA, USA. As expected, effluent was observed to be a significant source of nutrients and human and non-specific fecal associated taxa. There was an observed increase in the alpha diversity at locations immediately below effluent outflows, which contributed many taxa involved in wastewater treatment processes and nutrient cycling to the stream's microbial community. Unexpectedly, modeling of microbial community shifts along the stream was not controlled by concentrations of measured nutrients. Furthermore, partial recovery, in the form of decreasing abundances of bacteria and nutrients associated with wastewater treatment plant processes, nutrient cycling bacteria, and taxa associated with fecal and sewage sources, was observed between effluent sources. Antecedent moisture conditions impacted overall microbial community diversity, with higher diversity occurring after rainfall. These findings hint at resilience in stream microbial communities to recover from wastewater treatment plant effluent and are vital to understanding the impacts of urbanization on microbial stream communities.

Sediment and solute transport in a mountainous watershed in Valle del Cauca, Colombia

NASA Astrophysics Data System (ADS)

Guzman, C. D.; Castro, A.; Morales, A.; Hoyos, F.; Moreno, P.; Steenhuis, T. S.

2014-12-01

A main goal of this study was to improve prediction of sediment and solute transport using soil surface and soil nutrient changes, based on field measurements, within small watersheds receiving conservation measures. Sediment samples and solute concentrations were measured from two streams in the southwestern region of the Colombian Andes. Two modeling approaches for stream discharge and sediment transport predicted were used with one of these being used for nutrient transport prediction. These streams are a part of a recent initiative from a water fund established by Asobolo, Asocaña, and Cenicaña in collaboration with the Natural Capital Project to improve conservation efforts and monitor their effects. On-site soil depth changes, groundwater depth measurements, and soil nutrient concentrations were also monitored to provide more information about changes within this mountainous watershed during one part of the yearly rainy season. This information is being coupled closely with the outlet sediment concentration and solute concentration patterns to discern correlations. Lateral transects in the upper, middle, and lower part of the hillsides in the Aguaclara watershed of the Rio Bolo watershed network showed differences in soil nutrient status and soil surface depth changes. The model based on semi-distributed hydrology was able to reproduce discharge and sediment transport rates as well as the initially used model indicating available options for comparison of conservation changes in the future.

LANDSCAPE CHARACTERISTICS AND HIGH STREAM NITROGEN IN THE OREGON COAST RANGE: RED ALDER COMPLICATES USE OF NUTRIENT CRITERIA

EPA Science Inventory

Stream nitrogen concentrations are variable and often high in the Oregon Coast Range, uncharacteristic for a predominantly forested region. We compiled stream nitrogen data and GIS-derived landscape characteristics in order to examine variation in nitrogen across the region. In s...

Using Stream Discharge as a Predictor of Biotic Health in the Upper Oconee Watershed

EPA Science Inventory

Drought is viewed typically as an issue of water quantity, but drought also likely has strong effects on water quality in streams. These effects may occur via increased pollutant and nutrient concentrations and stream water temperature, as well as reductions in instream habitat. ...

Linking landscape characteristics and stream nitrogen in the Oregon Coast Range: Empirical modeling of water quality monitoring data

EPA Science Inventory

Background sources of nitrogen (N) provide a challenge for setting stream nutrient criteria in the Pacific Northwest US. Red alder (Alnus rubra), an early successional nitrogen fixing tree, and sea salt inputs can strongly influence stream N concentrations observed in individual...

Variation in responses to spawning Pacific salmon among three south-eastern Alaska streams

USGS Publications Warehouse

Chaloner, D.T.; Lamberti, G.A.; Merritt, R.W.; Mitchell, N.L.; Ostrom, P.H.; Wipfli, M.S.

2004-01-01

1. Pacific salmon are thought to stimulate the productivity of the fresh waters in which they spawn by fertilising them with marine-derived nutrients (MDN). We compared the influence of salmon spawners on surface streamwater chemistry and benthic biota among three southeastern Alaska streams. Within each stream, reaches up- and downstream of barriers to salmon migration were sampled during or soon after spawners entered the streams. 2. Within streams, concentrations of dissolved ammonium and soluble reactive phosphorus (SRP), abundance of epilithon (chlorophyll a and ash-free dry mass) and biomass of chironomids were significantly higher in reaches with salmon spawners. In contrast, biomass of the mayflies Epeorus spp. and Rhithrogena spp. was significantly higher in reaches lacking spawners. 3. Among streams, significant differences were found in concentrations of dissolved ammonium, dissolved organic carbon, nitrate and SRP, abundance of epilithon, and the biomass of chironomids and Rhithrogena. These differences did not appear to reflect differences among streams in spawner density, nor the changes in water chemistry resulting from salmon spawners. 4. Our results suggest that the 'enrichment' effect of salmon spawners (e.g. increased streamwater nutrient concentrations) was balanced by other concurrent effects of spawners on streams (e.g. sediment disturbance). Furthermore, the collective effect of spawners on lotic ecosystems is likely to be constrained by conditions unique to individual streams, such as temperature, background water chemistry and light attenuation.

Comparison of Hydrologic and Water-Quality Characteristics of Two Native Tallgrass Prairie Streams with Agricultural Streams in Missouri and Kansas

USGS Publications Warehouse

Heimann, David C.

2009-01-01

This report presents the results of a study by the U.S. Geological Survey, in cooperation with the Missouri Department of Natural Resources, to analyze and compare hydrologic and water-quality characteristics of tallgrass prairie and agricultural basins located within the historical distribution of tallgrass prairie in Missouri and Kansas. Streamflow and water-quality data from two remnant, tallgrass prairie basins (East Drywood Creek at Prairie State Park, Missouri, and Kings Creek near Manhattan, Kansas) were compared to similar data from agricultural basins in Missouri and Kansas. Prairie streams, especially Kings Creek in eastern Kansas, received a higher percentage of base flow and a lower percentage of direct runoff than similar-sized agricultural streams in the region. A larger contribution of direct runoff from the agricultural streams made them much flashier than prairie streams. During 22 years of record, the Kings Creek base-flow component averaged 66 percent of total flow, but base flow was only 16 to 26 percent of flows at agricultural sites of various record periods. The large base-flow component likely is the result of greater infiltration of precipitation in prairie soils and the resulting greater contribution of groundwater to streamflow. The 1- and 3-day annual maximum flows were significantly greater at three agricultural sites than at Kings Creek. The effects of flashier agricultural streams on native aquatic biota are unknown, but may be an important factor in the sustainability of some native aquatic species. There were no significant differences in the distribution of dissolved-oxygen concentrations at prairie and agricultural sites, and some samples from most sites fell below the 5 milligrams per liter Missouri and Kansas standard for the protection of aquatic life. More than 10 percent of samples from the East Drywood Creek prairie stream were less than this standard. These data indicate low dissolved-oxygen concentrations during summer low-flow periods may be a natural phenomenon for small prairie streams in the Osage Plains. Nutrient concentrations including total nitrogen, ammonia, nitrate, and total phosphorus were significantly less in base-flow and runoff samples from prairie streams than from agricultural streams. The total nitrogen concentration at all sites other than one of two prairie sampling sites were, on occasion, above the U.S. Environmental Protection Agency recommended criterion for total nitrogen for the prevention of nutrient enrichment, and typically were above this recommended criterion in runoff samples at all sites. Nitrate and total phosphorus concentrations in samples from the prairie streams generally were below the U.S. Environmental Protection Agency recommended nutrient criteria in base-flow and runoff samples, whereas samples from agricultural sites generally were below the criteria in base-flow samples and generally above in runoff samples. The lower concentrations of nutrient species in prairie streams is likely because prairies are not fertilized like agricultural basins and prairie basins are able to retain nutrients better than agricultural basins. This retention is enhanced by increased infiltration of precipitation into the prairie soils, decreased surface runoff, and likely less erosion than in agricultural basins. Streamflow in the small native prairie streams had more days of zero flow and lower streamflow yields than similar-sized agricultural streams. The prairie streams were at zero flow about 50 percent of the time, and the agricultural streams were at zero flow 25 to 35 percent of the time. Characteristics of the prairie basins that could account for the greater periods of zero flow and lower yields when compared to agricultural streams include greater infiltration, greater interception and evapotranspiration, shallower soils, and possible greater seepage losses in the prairie basins. Another difference between the prairie and agricultural strea

Influence of Environmental Factors on Biotic Responses to Nutrient Enrichment in Agricultural Streams1

PubMed Central

Maret, Terry R; Konrad, Christopher P; Tranmer, Andrew W

2010-01-01

The influence of environmental factors on biotic responses to nutrients was examined in three diverse agricultural regions of the United States. Seventy wadeable sites were selected along an agricultural land use gradient while minimizing natural variation within each region. Nutrients, habitat, algae, macroinvertebrates, and macrophyte cover were sampled during a single summer low-flow period in 2006 or 2007. Continuous stream stage and water temperature were collected at each site for 30 days prior to sampling. Wide ranges of concentrations were found for total nitrogen (TN) (0.07-9.61 mg/l) and total phosphorus (TP) (<0.004-0.361 mg/l), but biotic responses including periphytic and sestonic chlorophyll a (RCHL and SCHL, respectively), and percent of stream bed with aquatic macrophyte (AQM) growth were not strongly related to concentrations of TN or TP. Pearson’s coefficient of determination (R2) for nutrients and biotic measures across all sites ranged from 0.08 to 0.32 and generally were not higher within each region. The biotic measures (RCHL, SCHL, and AQM) were combined in an index to evaluate eutrophic status across sites that could have different biotic responses to nutrient enrichment. Stepwise multiple regression identified TN, percent canopy, median riffle depth, and daily percent change in stage as significant factors for the eutrophic index (R2 = 0.50, p < 0.001). A TN threshold of 0.48 mg/l was identified where eutrophic index scores became less responsive to increasing TN concentrations, for all sites. Multiple plant growth indicators should be used when evaluating eutrophication, especially when streams contain an abundance of macrophytes. PMID:22457568

Impacts of sewage effluent on tree survival, water quality and nutrient removal in coastal plain swamps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuenzler, E.J.

1987-09-01

An investigation was conducted of the impacts of sprayed municipal sewage on swamp tree survival and the effects of the swamp system on nutrient concentrations below the outfalls on two streams on the coastal plain of North Carolina. Effluent was discharged to one swamp stream by aerial spraying and to the other stream by way of a small ditch. Ninety-eight percent of the trees struck directly by the spray were dead within 18 months of the date spraying began. Both swamp systems removed sufficient quantities of nitrogen and phosphorus within a few kilometers to account for virtually all of themore » sewage nutrient load to the swamps.« less

The spatial structure and temporal synchrony of water quality in stream networks

NASA Astrophysics Data System (ADS)

Abbott, Benjamin; Gruau, Gerard; Zarneske, Jay; Barbe, Lou; Gu, Sen; Kolbe, Tamara; Thomas, Zahra; Jaffrezic, Anne; Moatar, Florentina; Pinay, Gilles

2017-04-01

To feed nine billion people in 2050 while maintaining viable aquatic ecosystems will require an understanding of nutrient pollution dynamics throughout stream networks. Most regulatory frameworks such as the European Water Framework Directive and U.S. Clean Water Act, focus on nutrient concentrations in medium to large rivers. This strategy is appealing because large rivers integrate many small catchments and total nutrient loads drive eutrophication in estuarine and oceanic ecosystems. However, there is growing evidence that to understand and reduce downstream nutrient fluxes we need to look upstream. While headwater streams receive the bulk of nutrients in river networks, the relationship between land cover and nutrient flux often breaks down for small catchments, representing an important ecological unknown since 90% of global stream length occurs in catchments smaller than 15 km2. Though continuous monitoring of thousands of small streams is not feasible, what if we could learn what we needed about where and when to implement monitoring and conservation efforts with periodic sampling of headwater catchments? To address this question we performed repeat synoptic sampling of 56 nested catchments ranging in size from 1 to 370 km2 in western France. Spatial variability in carbon and nutrient concentrations decreased non-linearly as catchment size increased, with thresholds in variance for organic carbon and nutrients occurring between 36 and 68 km2. While it is widely held that temporal variance is higher in smaller streams, we observed consistent temporal variance across spatial scales and the ranking of catchments based on water quality showed strong synchrony in the water chemistry response to seasonal variation and hydrological events. We used these observations to develop two simple management frameworks. The subcatchment leverage concept proposes that mitigation and restoration efforts are more likely to succeed when implemented at spatial scales expressing high variability in the target parameter, which indicates decreased system inertia and demonstrates that alternative system responses are possible. The subcatchment synchrony concept suggests that periodic sampling of headwaters can provide valuable information about pollutant sources and inherent resilience in subcatchments and that if agricultural activity were redistributed based on this assessment of catchment vulnerability to nutrient loading, water quality could be improved while maintaining crop yields.

Nutrient loss from disturbed forest watersheds in Oregon's Coast Range

Treesearch

James H. Miller; M. Newton

1983-01-01

Dissolved nutrients were monitored bi-weekly in stream water draining 14 upland watetzhcds in Oregon's Coast Range after sprayin g with 2,4,5-T + 2,4-D, clearcut harvesting and slash burning. Anion generation and leaching were primarily studied. The nitrate concentrations fell and the bicarbonate concentrations rose during summer low-flows from treated watersheds...

Consequences of variation in stream-landscape connections for stream nitrate retention and export

NASA Astrophysics Data System (ADS)

Handler, A. M.; Helton, A. M.; Grimm, N. B.

2017-12-01

Hydrologic and material connections among streams, the surrounding terrestrial landscape, and groundwater systems fluctuate between extremes in dryland watersheds, yet the consequences of this variation for stream nutrient retention and export remain uncertain. We explored how seasonal variation in hydrologic connection among streams, landscapes, and groundwater affect nitrate and ammonium concentrations across a dryland stream network and how this variation mediates in-stream nitrate uptake and watershed export. We conducted spatial surveys of stream nitrate and ammonium concentration across the 1200 km2 Oak Creek watershed in central Arizona (USA). In addition, we conducted pulse releases of a solution containing biologically reactive sodium nitrate, with sodium chloride as a conservative hydrologic tracer, to estimate nitrate uptake rates in the mainstem (Q>1000 L/s) and two tributaries. Nitrate and ammonium concentrations generally increased from headwaters to mouth in the mainstem. Locally elevated concentrations occurred in spring-fed tributaries draining fish hatcheries and larger irrigation ditches, but did not have a substantial effect on the mainstem nitrogen load. Ambient nitrate concentration (as N) ranged from below the analytical detection limit of 0.005 mg/L to 0.43 mg/L across all uptake experiments. Uptake length—average stream distance traveled for a nutrient atom from the point of release to its uptake—at ambient concentration ranged from 250 to 704 m and increased significantly with higher discharge, both across streams and within the same stream on different experiment dates. Vertical uptake velocity and aerial uptake rate ranged from 6.6-10.6 mm min-1 and 0.03 to 1.4 mg N m-2 min-1, respectively. Preliminary analyses indicate potentially elevated nitrogen loading to the lower portion of the watershed during seasonal precipitation events, but overall, the capacity for nitrate uptake is high in the mainstem and tributaries. Ongoing work focuses on how seasonal variability in connections between the stream and sources of nitrogen affect in-stream nitrate and ammonium uptake rates and watershed export. Episodic connections between dryland streams and the surrounding landscape can have a strong effect on stream nitrogen loads, uptake, and export.

Nutrient concentrations in Upper and Lower Echo, Fallen Leaf, Spooner, and Marlette Lakes and associated outlet streams, California and Nevada, 2002-03

USGS Publications Warehouse

Lico, Michael S.

2004-01-01

Five lakes and their outlet streams in the Lake Tahoe Basin were sampled for nutrients during 2002-03. The lakes and streams sampled included Upper Echo, Lower Echo, Fallen Leaf, Spooner, and Marlette Lakes and Echo, Taylor, and Marlette Creeks. Water samples were collected to determine seasonal and spatial concentrations of dissolved nitrite plus nitrate, dissolved ammonia, total Kjeldahl nitrogen, dissolved orthophosphate, total phosphorus, and total bioreactive iron. These data will be used by Tahoe Regional Planning Agency in revising threshold values for waters within the Lake Tahoe Basin. Standard U.S. Geological Survey methods of sample collection and analysis were used and are detailed herein. Data collected during this study and summary statistics are presented in graphical and tabular form.

Nutrients stimulate leaf breakdown rates and detritivore biomass: Bottom-up effects via heterotrophic pathways

USGS Publications Warehouse

Greenwood, J.L.; Rosemond, A.D.; Wallace, J.B.; Cross, W.F.; Weyers, H.S.

2007-01-01

Most nutrient enrichment studies in aquatic systems have focused on autotrophic food webs in systems where primary producers dominate the resource base. We tested the heterotrophic response to long-term nutrient enrichment in a forested, headwater stream. Our study design consisted of 2 years of pretreatment data in a reference and treatment stream and 2 years of continuous nitrogen (N) + phosphorus addition to the treatment stream. Studies were conducted with two leaf species that differed in initial C:N, Rhododendron maximum (rhododendron) and Acer rubrum (red maple). We determined the effects of nutrient addition on detrital resources (leaf breakdown rates, litter C:N and microbial activity) and tested whether nutrient enrichment affected macroinvertebrate consumers via increased biomass. Leaf breakdown rates were ca. 1.5 and 3?? faster during the first and second years of enrichment, respectively, in the treatment stream for both leaf types. Microbial respiration rates of both leaf types were 3?? higher with enrichment, and macroinvertebrate biomass associated with leaves increased ca. 2-3?? with enrichment. The mass of N in macroinvertebrate biomass relative to leaves tended to increase with enrichment up to 6?? for red maple and up to 44?? for rhododendron leaves. Lower quality (higher C:N) rhododendron leaves exhibited greater changes in leaf nutrient content and macroinvertebrate response to nutrient enrichment than red maple leaves, suggesting a unique response by different leaf species to nutrient enrichment. Nutrient concentrations used in this study were moderate and equivalent to those in streams draining watersheds with altered land use. Thus, our results suggest that similarly moderate levels of enrichment may affect detrital resource quality and subsequently lead to altered energy and nutrient flow in detrital food webs. ?? 2006 Springer-Verlag.

El-Niño/Southern Oscillation (ENSO) influences on monthly NO 3 load and concentration, stream flow and precipitation in the Little River Watershed, Tifton, Georgia (GA)

NASA Astrophysics Data System (ADS)

Keener, V. W.; Feyereisen, G. W.; Lall, U.; Jones, J. W.; Bosch, D. D.; Lowrance, R.

2010-02-01

SummaryAs climate variability increases, it is becoming increasingly critical to find predictable patterns that can still be identified despite overall uncertainty. The El-Niño/Southern Oscillation is the best known pattern. Its global effects on weather, hydrology, ecology and human health have been well documented. Climate variability manifested through ENSO has strong effects in the southeast United States, seen in precipitation and stream flow data. However, climate variability may also affect water quality in nutrient concentrations and loads, and have impacts on ecosystems, health, and food availability in the southeast. In this research, we establish a teleconnection between ENSO and the Little River Watershed (LRW), GA., as seen in a shared 3-7 year mode of variability for precipitation, stream flow, and nutrient load time series. Univariate wavelet analysis of the NINO 3.4 index of sea surface temperature (SST) and of precipitation, stream flow, NO 3 concentration and load time series from the watershed was used to identify common signals. Shared 3-7 year modes of variability were seen in all variables, most strongly in precipitation, stream flow and nutrient load in strong El Niño years. The significance of shared 3-7 year periodicity over red noise with 95% confidence in SST and precipitation, stream flow, and NO 3 load time series was confirmed through cross-wavelet and wavelet-coherence transforms, in which common high power and co-variance were computed for each set of data. The strongest 3-7 year shared power was seen in SST and stream flow data, while the strongest co-variance was seen in SST and NO 3 load data. The strongest cross-correlation was seen as a positive value between the NINO 3.4 and NO 3 load with a three-month lag. The teleconnection seen in the LRW between the NINO 3.4 index and precipitation, stream flow, and NO 3 load can be utilized in a model to predict monthly nutrient loads based on short-term climate variability, facilitating management in high risk seasons.

Linking Landscape Characteristics and High Stream Nitrogen in the Oregon Coast Range: Red Alder Complicates Use of Nutrient Criteria

EPA Science Inventory

Red alder (a nitrogen-fixing tree) and sea salt inputs can strongly influence stream nitrogen concentrations in western Oregon and Washington. We compiled a database of stream nitrogen and landscape characteristics in the Oregon Coast Range. Basal area of alder, expressed as a ...

Headwater Nutrient Concentration Patterns in Response to Storm Events Across Land Use Types using In Situ Sensors

NASA Astrophysics Data System (ADS)

Price, A.; Wollheim, W. M.; Mulukutla, G. K.; Carey, R. O.; McDowell, W. H.

2012-12-01

Understanding the aquatic biogeochemical impacts of land use change and climate variability will require improved understanding of nutrient variability over temporal scales ranging from storms to seasons. New in situ sensor technology offers the prospect of efficient nutrient measurements over multiple time scales. We quantified nutrient flux patterns in response to storm events across seasons using in situ nutrient sensors deployed in headwater streams draining three land use types (forest, suburban, and agriculture) within the Lamprey River watershed, New Hampshire, between April-December 2012. We utilized two sensor suites, each consisting of a Satlantic Submersible Ultraviolet Nitrate Analyzer (NO3-N), Turner Designs C6 Multi-Sensor Platform (CDOM, Turbidity, Chl), Hydrolab MS5 (Dissolved Oxygen, pH), WET Labs Cycle P (PO4-P), and Hobo Water Level & Conductivity meters. Preliminary spring/summer comparisons at the suburban site suggest increased baseflow nitrate concentrations and decreased diurnal nitrate variability (~0.05 vs. 0.035 mg/L daily fluctuation) following leaf emergence in spring. Nitrate concentrations were diluted during storms. Hysteresis was evident, suggesting groundwater nitrate sources attributable to septic systems were diluted by surface runoff during spring storms. The agricultural stream showed similar but more extreme patterns of increasing baseflow nitrate during the summer (~2.4 to 4.1 mg/L) and dilution during storms. The compilation of a high-frequency dataset for headwater streams across seasons and land-use types will provide valuable insight into complex land use/water quality relationships in urbanizing watersheds.

The response of stream periphyton to Pacific salmon: using a model to understand the role of environmental context

USGS Publications Warehouse

Bellmore, J. Ryan; Fremier, Alexander K.; Mejia, Francine; Newsom, Michael

2014-01-01

1. In stream ecosystems, Pacific salmon deliver subsidies of marine-derived nutrients and disturb the stream bed during spawning. The net effect of this nutrient subsidy and physical disturbance on biological communities can be hard to predict and is likely to be mediated by environmental conditions. For periphyton, empirical studies have revealed that the magnitude and direction of the response to salmon varies from one location to the next. Salmon appear to increase periphyton biomass and/or production in some contexts (a positive response), but decrease them in others (a negative response). 2. To reconcile these seemingly conflicting results, we constructed a system dynamics model that links periphyton biomass and production to salmon spawning. We used this model to explore how environmental conditions influence the periphyton response to salmon. 3. Our simulations suggest that the periphyton response to salmon is strongly mediated by both background nutrient concentrations and the proportion of the stream bed suitable for spawning. Positive periphyton responses occurred when both background nutrient concentrations were low (nutrient limiting conditions) and when little of the stream bed was suitable for spawning (because the substratum is too coarse). In contrast, negative responses occurred when nutrient concentrations were higher or a larger proportion of the bed was suitable for spawning. 4. Although periphyton biomass generally remained above or below background conditions for several months following spawning, periphyton production returned quickly to background values shortly afterwards. As a result, based upon our simulations, salmon did not greatly increase or decrease overall annual periphyton production. This suggests that any increase in production by fish or invertebrates in response to returning salmon is more likely to occur via direct consumption of salmon carcasses and/or eggs, rather than the indirect effects of greater periphyton production. 5. Overall, our simulations suggest that environmental factors need to be taken into account when considering the effects of spawning salmon on aquatic ecosystems. Our model offers researchers a framework for testing periphyton response to salmon across a range of conditions, which can be used to generate hypotheses, plan field experiments and guide data collection.

Biophysical Controls on Carbon Cycling in Restored and Unrestored Urban Streams

NASA Astrophysics Data System (ADS)

Larsen, L. G.; Harvey, J. W.; Singh, J. D.; Sinclair, G. A.; Langston, T.; Maglio, M. M.

2012-12-01

Stream restoration is a multibillion dollar industry, yet how restoration impacts the ecological functioning of streams remains poorly understood. Because stream restoration may alter numerous biophysical controls, including light availability (through tree removal during bank regrading), hydraulics, sediment characteristics, and/or nutrient concentrations, it can be challenging to achieve a general understanding of how different aspects of stream restoration design influence ecosystem function (e.g., carbon cycling). In this study we combined strategies of continuously monitoring hydrology, turbidity, and dissolved oxygen at a station with spatially distributed but temporally sparse synoptic sampling to understand how restoration and land-use impact carbon fixation and respiration in urban streams. The study was performed over three years in three adjacent 3rd-4th order stream reaches in the urban Chesapeake Bay watershed, one of which was restored in 2002 using the ubiquitous Natural Channel Design method. By parsing the dissolved oxygen time series into contributions from respiration and gross primary production, we found the unrestored urban reach to be the most heterotrophic. It removed two times more carbon from the stream to the atmosphere than an unrestored suburban stream that was nutrient impacted and five times more carbon than the restored urban stream. The synoptic sampling revealed that nutrients, light, and hydrodynamic disturbance were the primary controls on carbon fixation and respiration, with fine sediment also exhibiting importance, likely as a vehicle for nutrient transport. Low rates of net carbon removal in the restored stream arose from high light availability resulting in high primary production, combined with low fine sediment availability restricting respiration. Thus, while restoration may have been effective for stream stabilization, it has decreased the functionality of the stream for net carbon removal to the atmosphere. Surprisingly, streambed potential respiration rates were indistinguishable between different geomorphic zones within the streams, suggesting that large-scale factors (i.e., nutrient and fine sediment supply) were more dominant controls than geomorphically controlled local variability.

Breakpoint analysis and relations of nutrient and turbidity stressor variables to macroinvertebrate integrity in streams in the Crawford-Mammoth Cave Uplands Ecoregion, Kentucky, for the development of nutrient criteria

USGS Publications Warehouse

Crain, Angela S.; Caskey, Brian J.

2010-01-01

To assist Kentucky in refining numeric nutrient criteria in the Pennyroyal Bioregion, the U.S. Geological Survey and the Kentucky Division of Water collected and analyzed water chemistry, turbidity, and biological-community data from 22 streams throughout the Crawford-Mammoth Cave Upland ecoregion (U.S. Environmental Protection Agency Level IV Ecoregion, 71a) within the Pennyroyal Bioregion from September 2007 to May 2008. Statistically significant and ecologically relevant relations among the stressor (total phosphorus, total nitrogen, and turbidity) variables and response (macroinvertebrate-community attributes) variables and the breakpoint values of biological-community attributes and metrics in response to changes in stressor variables were determined. Thirteen of 18 macroinvertebrate attributes were significantly and ecologically correlated (p-value < 0.10) with at least one nutrient measure. Total number of individuals, Ephemeroptera-Plecoptera-Trichoptera richness, and average tolerance value were macroinvertebrate measures that most strongly correlated with the concentrations of nutrients. Comparison of the average macroinvertebrate-breakpoint value for the median concentration of total phosphorus (TP, 0.033 mg/L) and for median concentration of total nitrogen (TN, 1.1 mg/L) to Dodds' trophic classification for TP and TN indicates streams in the Crawford-Mammoth Cave Uplands ecoregion within the Pennyroyal Bioregion would be classified as mesotrophic-eutrophic. The biological breakpoint relations with median concentrations of TP in this study were similar to the U.S. Environmental Protection Agency proposed numeric TP criteria (0.037 mg/L), but were 1.5 times higher than the proposed numeric criteria for concentrations of TN (0.69 mg/L). No sites were impacted adversely using median turbidity values based on a 25 Formazin nephelometric turbidity unit biological threshold. The breakpoints determined in this study, in addition to Dodds' trophic classifications, were used as multiple lines of evidence to show changes in macroinvertebrate community and attributes based on exposure to nutrients.

Dissolved rainfall inputs and streamwater outputs in an undisturbed watershed on highly weathered soils in the Brazilian cerrado

NASA Astrophysics Data System (ADS)

Markewitz, Daniel; Resende, Julio C. F.; Parron, Lucilia; Bustamante, Mercedes; Klink, Carlos A.; Figueiredo, Ricardo De O.; Davidson, Eric A.

2006-08-01

The cerrados of Brazil cover 2 million km2. Despite the extent of these seasonally dry ecosystems, little watershed research has been focused in this region, particularly relative to the watersheds of the Amazon Basin. The cerrado shares pedogenic characteristics with the Amazon Basin in draining portions of the Brazilian shield and in possessing Oxisols over much of the landscape. The objective of this research was to quantify the stream water geochemical relationships of an undisturbed 1200 ha cerrado watershed for comparison to river geochemistry in the Amazon. Furthermore, this undisturbed watershed was used to evaluate stream discharge versus dissolved ion concentration relationships. This research was conducted in the Córrego Roncador watershed of the Reserva Ecológica do Roncador (RECOR) of the Instituto Brasileiro Geografia e Estatística (IBGE) near Brasilia, Brazil. Bulk precipitation and stream water chemistry were analysed between May 1998 and May 2000. The upland soils of this watershed are nutrient poor possessing total stocks of exchangeable elements in the upper 1 m of 81 +/- 13, 77 +/- 4, 25 +/- 3, and 1 +/- 1 kg ha-1 of K, Ca, Mg, and P, respectively. Bulk precipitation inputs of dissolved nutrients for this watershed are low and consistent with previous estimates. The nutrient-poor soils of this watershed, however, increase the relative importance of precipitation for nutrient replenishment to vegetation during episodes of ecosystem disturbance. Stream water dissolved loads were extremely dilute with conductivities ranging from 4 to 10 μS cm-1 during periods of high- and low-flow, respectively. Despite the low concentrations in this stream, geochemical relationships were similar to other Amazonian streams draining shield geologies. Discharge-concentration relationships for Ca and Mg in these highly weathered soils developed from igneous rocks of the Brazilian shield demonstrated a significant negative relationship indicating a continued predominance of groundwater baseflow contributions these cationic elements.

Nutrient Mass Balance for the Mobile River Basin in Alabama, Georgia, and Mississippi

NASA Astrophysics Data System (ADS)

Harned, D. A.; Harvill, J. S.; McMahon, G.

2001-12-01

The source and fate of nutrients in the Mobile River drainage basin are important water-quality concerns in Alabama, Georgia, and Mississippi. Land cover in the basin is 74 percent forested, 16 percent agricultural, 2.5 percent developed, and 4 percent wetland. A nutrient mass balance calculated for 18 watersheds in the Mobile River Basin indicates that agricultural non-point nitrogen and phosphorus sources and urban non-point nitrogen sources are the most important factors associated with nutrients in the streams. Nitrogen and phosphorus inputs from atmospheric deposition, crop fertilizer, biological nitrogen fixation, animal waste, and point sources were estimated for each of the 18 drainage basins. Total basin nitrogen inputs ranged from 27 to 93 percent from atmospheric deposition (56 percent mean), 4 to 45 percent from crop fertilizer (25 percent mean), <0.01 to 31 percent from biological nitrogen fixation (8 percent mean), 2 to 14 percent from animal waste (8 percent mean), and 0.2 to 11 percent from point sources (3 percent mean). Total basin phosphorus inputs ranged from 10 to 39 percent from atmospheric deposition (26 percent mean), 7 to 51 percent from crop fertilizer (28 percent mean), 20 to 64 percent from animal waste (41 percent mean), and 0.2 to 11 percent from point sources (3 percent mean). Nutrient outputs for the watersheds were estimated by calculating instream loads and estimating nutrient uptake, or withdrawal, by crops. The difference between the total basin inputs and outputs represents nutrients that are retained or processed within the basin while moving from the point of use to the stream, or in the stream. Nitrogen output, as a percentage of the total basin nitrogen inputs, ranged from 19 to 79 percent for instream loads (35 percent mean) and from 0.01 to 32 percent for crop harvest (10 percent mean). From 53 to 87 percent (75 percent mean) of nitrogen inputs were retained within the 18 basins. Phosphorus output ranged from 9 to 29 percent for instream loads (18 percent mean) and from 0.01 to 23 percent for crop harvest (7 percent mean). The basins retained from 60 to 87 percent (74 percent mean) of phosphorous inputs. Correlation of basin nutrient output loads and concentrations with the basin inputs and correlation of output loads and concentrations with basin land use were tested using the Spearman rank test. The correlation analysis indicated that higher nitrogen concentrations in the streams are associated with urban areas and higher loads are associated with agriculture; high phosphorus output loads and concentrations are associated with agriculture. Higher nutrient loads in agricultural basins are partly an effect of basin size-- larger basins generate larger nutrient loads. Nutrient loads and concentrations showed no significant correlation to point-source inputs. Nitrogen loads were significantly (p<0.05, correlation coefficient >0.5) higher in basins with greater cropland areas. Nitrogen concentrations also increased as residential, commercial, and total urban areas increased. Phosphorus loads were positively correlated with animal-waste inputs, pasture, and total agricultural land. Phosphorus concentrations were highest in basins with the greatest amounts of row-crop agriculture.

Invasive fishes generate biogeochemical hotspots in a nutrient-limited system.

PubMed

Capps, Krista A; Flecker, Alexander S

2013-01-01

Fishes can play important functional roles in the nutrient dynamics of freshwater systems. Aggregating fishes have the potential to generate areas of increased biogeochemical activity, or hotspots, in streams and rivers. Many of the studies documenting the functional role of fishes in nutrient dynamics have focused on native fish species; however, introduced fishes may restructure nutrient storage and cycling freshwater systems as they can attain high population densities in novel environments. The purpose of this study was to examine the impact of a non-native catfish (Loricariidae: Pterygoplichthys) on nitrogen and phosphorus remineralization and estimate whether large aggregations of these fish generate measurable biogeochemical hotspots within nutrient-limited ecosystems. Loricariids formed large aggregations during daylight hours and dispersed throughout the stream during evening hours to graze benthic habitats. Excretion rates of phosphorus were twice as great during nighttime hours when fishes were actively feeding; however, there was no diel pattern in nitrogen excretion rates. Our results indicate that spatially heterogeneous aggregations of loricariids can significantly elevate dissolved nutrient concentrations via excretion relative to ambient nitrogen and phosphorus concentrations during daylight hours, creating biogeochemical hotspots and potentially altering nutrient dynamics in invaded systems.

Invasive Fishes Generate Biogeochemical Hotspots in a Nutrient-Limited System

PubMed Central

Capps, Krista A.; Flecker, Alexander S.

2013-01-01

Fishes can play important functional roles in the nutrient dynamics of freshwater systems. Aggregating fishes have the potential to generate areas of increased biogeochemical activity, or hotspots, in streams and rivers. Many of the studies documenting the functional role of fishes in nutrient dynamics have focused on native fish species; however, introduced fishes may restructure nutrient storage and cycling freshwater systems as they can attain high population densities in novel environments. The purpose of this study was to examine the impact of a non-native catfish (Loricariidae: Pterygoplichthys) on nitrogen and phosphorus remineralization and estimate whether large aggregations of these fish generate measurable biogeochemical hotspots within nutrient-limited ecosystems. Loricariids formed large aggregations during daylight hours and dispersed throughout the stream during evening hours to graze benthic habitats. Excretion rates of phosphorus were twice as great during nighttime hours when fishes were actively feeding; however, there was no diel pattern in nitrogen excretion rates. Our results indicate that spatially heterogeneous aggregations of loricariids can significantly elevate dissolved nutrient concentrations via excretion relative to ambient nitrogen and phosphorus concentrations during daylight hours, creating biogeochemical hotspots and potentially altering nutrient dynamics in invaded systems. PMID:23342083

Nutrients in the Nation's Waters--Too Much of a Good Thing?

USGS Publications Warehouse

Mueller, David K.; Helsel, Dennis R.

1996-01-01

Historical data on nutrients (nitrogen and phosphorus) from about 12,000 ground-water and more than 22,000 stream samples have been compiled and related to possible sources. This existing information was collected by many agencies for a variety of purposes. Therefore, though it can be used to determine where concentrations differ, the exact percentages should not be taken as those for the Nation as a whole. Major findings include: (1) nutrient concentrations in water generally are related to land use in the area overlying ground-water aquifers or upstream from surface-water locations, (2) regional differences are related to differences in soil-drainage properties and agricultural practices, (3) nitrate concentrations in about 12 percent of domestic-supply wells in agricultural areas exceeded the U.S. Environmental Protection Agency's drinking-water standard (10 mg/L), and (4) nitrate concentrations in surface water rarely exceed the drinking-water standard. This information has helped identify locations across the Nation where ground water and streams are most likely to be vulnerable to nutrient contamination. Programs to manage and protect water resources can therefore be targeted to the most critical areas, providing the greatest protection for the least cost.

Analysis of selected water-quality data for surface water in St. Tammany Parish, Louisiana, April-August 1995

USGS Publications Warehouse

Demcheck, Dennis K.

1996-01-01

Physical and chemical-related properties, concentrations of chemical constituents, which included major ions and nutrients, and concentrations of fecal-coliform bacteria were determined for 17 sites on 11 streams in St. Tammany Parish, Louisiana, during the period April-August 1995. The streams were sampled to assess the effects of different streamflow conditions on the concentrations of water-quality constituents. The streams included in the study were Tchefuncte River, Bogue Falaya, Abita River, Bayou Chinchouba, Bayou Castine, Cane Bayou, Bayou Lacombe, Bayou Liberty, Bayou Bonfouca, Bogue Chitto, and West Pearl River. Water-quality samples were collected under several hydrologic conditions. These conditions included a period of wet weather and sustained high river stages; a period of local storms several days apart and river stages typical of that situation; and a period of dry weather and low river stages. The concentrations of inorganic chemical constituents in water from the upstream sites generally were low. Concentrations from the downstream sites varied and were higher. Nutrient and fecal-coliform bacteria concentrations varied and indicated that degraded water-quality conditions that typically occur during storms persisted less than 1-3 days. In general, the larger the drainage basin, the longer it takes for the stream to recover. Fecal-coliform concen- trations reflected the effects of small, isolated storms in the area. Bayou Castine, sampled immediately after a storm, had a fecal-coliform concentration of 26,000 colonies per 100 milliliters. The stream was resampled 24 hours later, and the fecal-coliform concentration had decreased to 1,700 colonies per 100 milliliters. This is an indication of the rapid water-quality changes that typically occur in small streams.

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America.

PubMed

Loiselle, Steven A; Gasparini Fernandes Cunha, Davi; Shupe, Scott; Valiente, Elsa; Rocha, Luciana; Heasley, Eleanore; Belmont, Patricia Pérez; Baruch, Avinoam

Global metrics of land cover and land use provide a fundamental basis to examine the spatial variability of human-induced impacts on freshwater ecosystems. However, microscale processes and site specific conditions related to bank vegetation, pollution sources, adjacent land use and water uses can have important influences on ecosystem conditions, in particular in smaller tributary rivers. Compared to larger order rivers, these low-order streams and rivers are more numerous, yet often under-monitored. The present study explored the relationship of nutrient concentrations in 150 streams in 57 hydrological basins in South, Central and North America (Buenos Aires, Curitiba, São Paulo, Rio de Janeiro, Mexico City and Vancouver) with macroscale information available from global datasets and microscale data acquired by trained citizen scientists. Average sub-basin phosphate (P-PO4) concentrations were found to be well correlated with sub-basin attributes on both macro and microscales, while the relationships between sub-basin attributes and nitrate (N-NO3) concentrations were limited. A phosphate threshold for eutrophic conditions (>0.1 mg L-1 P-PO4) was exceeded in basins where microscale point source discharge points (eg. residential, industrial, urban/road) were identified in more than 86% of stream reaches monitored by citizen scientists. The presence of bankside vegetation covaried (rho = -0.53) with lower phosphate concentrations in the ecosystems studied. Macroscale information on nutrient loading allowed for a strong separation between basins with and without eutrophic conditions. Most importantly, the combination of macroscale and microscale information acquired increased our ability to explain sub-basin variability of P-PO4 concentrations. The identification of microscale point sources and bank vegetation conditions by citizen scientists provided important information that local authorities could use to improve their management of lower order river ecosystems.

Micro and Macroscale Drivers of Nutrient Concentrations in Urban Streams in South, Central and North America

PubMed Central

Loiselle, Steven A.; Gasparini Fernandes Cunha, Davi; Shupe, Scott; Valiente, Elsa; Rocha, Luciana; Heasley, Eleanore; Belmont, Patricia Pérez; Baruch, Avinoam

2016-01-01

Global metrics of land cover and land use provide a fundamental basis to examine the spatial variability of human-induced impacts on freshwater ecosystems. However, microscale processes and site specific conditions related to bank vegetation, pollution sources, adjacent land use and water uses can have important influences on ecosystem conditions, in particular in smaller tributary rivers. Compared to larger order rivers, these low-order streams and rivers are more numerous, yet often under-monitored. The present study explored the relationship of nutrient concentrations in 150 streams in 57 hydrological basins in South, Central and North America (Buenos Aires, Curitiba, São Paulo, Rio de Janeiro, Mexico City and Vancouver) with macroscale information available from global datasets and microscale data acquired by trained citizen scientists. Average sub-basin phosphate (P-PO4) concentrations were found to be well correlated with sub-basin attributes on both macro and microscales, while the relationships between sub-basin attributes and nitrate (N-NO3) concentrations were limited. A phosphate threshold for eutrophic conditions (>0.1 mg L-1 P-PO4) was exceeded in basins where microscale point source discharge points (eg. residential, industrial, urban/road) were identified in more than 86% of stream reaches monitored by citizen scientists. The presence of bankside vegetation covaried (rho = –0.53) with lower phosphate concentrations in the ecosystems studied. Macroscale information on nutrient loading allowed for a strong separation between basins with and without eutrophic conditions. Most importantly, the combination of macroscale and microscale information acquired increased our ability to explain sub-basin variability of P-PO4 concentrations. The identification of microscale point sources and bank vegetation conditions by citizen scientists provided important information that local authorities could use to improve their management of lower order river ecosystems. PMID:27662192

Development of Denitrifying and Nitrifying Bacteria and Their Co-occurrence in Newly Created Biofilms in Urban Streams

NASA Astrophysics Data System (ADS)

Vaessen, T. N.; Martí Roca, E.; Pinay, G.; Merbt, S. N.

2015-12-01

Biofilms play a pivotal role on nutrient cycling in streams, which ultimately dictates the export of nutrients to downstream ecosystems. The extent to which biofilms influence the concentration of dissolved nutrients, oxygen and pH in the water column may be determined by the composition of the microbial assemblages and their activity. Evidence of biological interactions among bacteria and algae are well documented. However, the development, succession and co-occurence of nitrifying and denitrifying bacteria remain poorly understood. These bacteria play a relevant role on the biogeochemical process associated to N cycling, and their relative abundance can dictate the fate of dissolved inorganic nitrogen in streams. In particular, previous studies indicated that nitrifiers are enhanced in streams receiving inputs from wastewater treatment plant (WWTP) effluents due to both increases in ammonium concentration and inputs of nitrifiers. However, less is known about the development of denitrifiers in receiving streams, although environmental conditions seem to favor it. We conducted an in situ colonization experiment in a stream receiving effluent from a WWTP to examine how this input influences the development and co-occurrence of nitrifying and denitrifying bacteria. We placed artificial substrata at different locations relative to the effluent and sampled them over time to characterize the developed biofilm in terms of bulk measurements (organic matter content and algae) as well as in terms of abundance of nitrifiers and denitrifiers (using qPCR). The results of this study contribute to a better understanding of the temporal dynamics of denitrifiers and nitrifiers in relation to the developed organic matter, dissolved oxygen and pH and the biomass accrual in stream biofilms under the influence of nutrients inputs from WWTP effluent. Ultimately, the results provide insights on the potential role of nitrifiers and denitrifiers on N cycling in WWTP effluent receiving streams.

The Utility of Decomposition and Associated Microbial Parameters to Assess Changes in Stream Ecosystems due to Eutrophication

NASA Astrophysics Data System (ADS)

Gulis, V.; Ferreira, V. J.; Graca, M. A.

2005-05-01

Traditional approaches to assess stream ecosystem health rely on structural parameters, e.g. a variety of biotic indices. The goal of the Europe-wide RivFunction project is to develop methodology that uses functional parameters (e.g. plant litter decomposition) to this end. Here we report on decomposition experiments carried out in Portugal in five pairs of streams that differed in dissolved inorganic nutrients. On average, decomposition rates of alder and oak leaves were 2.8 and 1.4 times higher in high nutrient streams in coarse and fine mesh bags, respectively, than in corresponding reference streams. Breakdown rate correlated better with stream water SRP concentration rather than TIN. Fungal biomass and sporulation rates of aquatic hyphomycetes associated with decomposing leaves were stimulated by higher nutrient levels. Both fungal parameters measured at very early stages of decomposition (e.g. days 7-13) correlated well with overall decomposition rates. Eutrophication had no significant effect on shredder abundances in leaf bags but species richness was higher in disturbed streams. Decomposition is a key functional parameter in streams integrating many other variables and can be useful in assessing stream ecosystem health. We also argue that because decomposition is often controlled by fungal activity, microbial parameters can also be useful in bioassessment.

Effects of nutrient enrichment on the decomposition of wood and associated microbial activity in streams

USGS Publications Warehouse

Gulis, V.; Rosemond, A.D.; Suberkropp, K.; Weyers, H.S.; Benstead, J.P.

2004-01-01

1. We determined the effects of nutrient enrichment on wood decomposition rates and microbial activity during a 3-year study in two headwater streams at Coweeta Hydrologic Laboratory, NC, U.S.A. After a 1-year pretreatment period, one of the streams was continuously enriched with inorganic nutrients (nitrogen and phosphorus) for 2 years while the other stream served as a reference. We determined the effects of enrichment on both wood veneers and sticks, which have similar carbon quality but differ in physical characteristics (e.g. surface area to volume ratios, presence of bark) that potentially affect microbial colonisation and activity. 2. Oak wood veneers (0.5 mm thick) were placed in streams monthly and allowed to decompose for approximately 90 days. Nutrient addition stimulated ash-free dry mass loss and increased mean nitrogen content, fungal biomass and microbial respiration on veneers in the treatment stream compared with the reference. The magnitude of the response to enrichment was great, with mass loss 6.1 times, and per cent N, fungal biomass and microbial respiration approximately four times greater in the treatment versus reference stream. 3. Decomposition rate and nitrogen content of maple sticks (ca. 1-2 cm diameter) also increased; however, the effect was less pronounced than for veneers. Wood response overall was greater than that determined for leaves in a comparable study, supporting the hypothesis that response to enrichment may be greater for lower quality organic matter (high C:N) than for higher quality (low C:N) substrates. 4. Our results show that moderate nutrient enrichment can profoundly affect decomposition rate and microbial activity on wood in streams. Thus, the timing and availability of wood that provides retention, structure, attachment sites and food in stream ecosystems may be affected by nutrient concentrations raised by human activities.

Calculating discharge of phosphorus and nitrogen with groundwater base flow to a small urban stream reach

NASA Astrophysics Data System (ADS)

Fitzgerald, Alex; Roy, James W.; Smith, James E.

2015-09-01

Elevated levels of nutrients, especially phosphorus, in urban streams can lead to eutrophication and general degradation of stream water quality. Contributions of phosphorus from groundwater have typically been assumed minor, though elevated concentrations have been associated with riparian areas and urban settings. The objective of this study was to investigate the importance of groundwater as a pathway for phosphorus and nitrogen input to a gaining urban stream. The stream at the 28-m study reach was 3-5 m wide and straight, flowing generally eastward, with a relatively smooth bottom of predominantly sand, with some areas of finer sediments and a few boulders. Temperature-based methods were used to estimate the groundwater flux distribution. Detailed concentration distributions in discharging groundwater were mapped using in-stream piezometers and diffusion-based peepers, and showed elevated levels of soluble reactive phosphorus (SRP) and ammonium compared to the stream (while nitrate levels were lower), especially along the south bank, where groundwater fluxes were lower and geochemically reducing conditions dominated. Field evidence suggests the ammonium may originate from nearby landfills, but that local sediments likely contribute the SRP. Ammonium and SRP mass discharges with groundwater were then estimated as the product of the respective concentration distributions and the groundwater flux distribution. These were determined as approximately 9 and 200 g d-1 for SRP and ammonium, respectively, which compares to stream mass discharges over the observed range of base flows of 20-1100 and 270-7600 g d-1, respectively. This suggests that groundwater from this small reach, and any similar areas along Dyment's Creek, has the potential to contribute substantially to the stream nutrient concentrations.

Combined Effects of Dissolved Nutrients and Oxygen on Plant Litter Decomposition and Associated Fungal Communities.

PubMed

Gomes, Patrícia Pereira; Ferreira, Verónica; Tonin, Alan M; Medeiros, Adriana Oliveira; Júnior, José Francisco Gonçalves

2018-05-01

Aquatic ecosystems worldwide have been substantially altered by human activities, which often induce changes in multiple factors that can interact to produce complex effects. Here, we evaluated the combined effects of dissolved nutrients (nitrogen [N] and phosphorus [P]; three levels: concentration found in oligotrophic streams in the Cerrado biome, 10× and 100× enriched) and oxygen (O 2 ; three levels: hypoxic [4% O 2 ], depleted [55% O 2 ], and saturated [96% O 2 ]) on plant litter decomposition and associated fungal decomposers in laboratory microcosms simulating stream conditions under distinct scenarios of water quality deterioration. Senescent leaves of Maprounea guianensis were incubated for 10 days in an oligotrophic Cerrado stream to allow microbial colonization and subsequently incubated in microcosms for 21 days. Leaves lost 1.1-3.0% of their initial mass after 21 days, and this was not affected either by nutrients or oxygen levels. When considering simultaneous changes in nutrients and oxygen concentrations, simulating increased human pressure, fungal biomass accumulation, and sporulation rates were generally inhibited. Aquatic hyphomycete community structure was also affected by changes in nutrients and oxygen availability, with stronger effects found in hypoxic treatments than in depleted or saturated oxygen treatments. This study showed that the effects of simultaneous changes in the availability of dissolved nutrients and oxygen in aquatic environments can influence the activity and composition of fungal communities, although these effects were not translated into changes in litter decomposition rates.

Development and Application of Regression Models for Estimating Nutrient Concentrations in Streams of the Conterminous United States, 1992-2001

USGS Publications Warehouse

Spahr, Norman E.; Mueller, David K.; Wolock, David M.; Hitt, Kerie J.; Gronberg, JoAnn M.

2010-01-01

Data collected for the U.S. Geological Survey National Water-Quality Assessment program from 1992-2001 were used to investigate the relations between nutrient concentrations and nutrient sources, hydrology, and basin characteristics. Regression models were developed to estimate annual flow-weighted concentrations of total nitrogen and total phosphorus using explanatory variables derived from currently available national ancillary data. Different total-nitrogen regression models were used for agricultural (25 percent or more of basin area classified as agricultural land use) and nonagricultural basins. Atmospheric, fertilizer, and manure inputs of nitrogen, percent sand in soil, subsurface drainage, overland flow, mean annual precipitation, and percent undeveloped area were significant variables in the agricultural basin total nitrogen model. Significant explanatory variables in the nonagricultural total nitrogen model were total nonpoint-source nitrogen input (sum of nitrogen from manure, fertilizer, and atmospheric deposition), population density, mean annual runoff, and percent base flow. The concentrations of nutrients derived from regression (CONDOR) models were applied to drainage basins associated with the U.S. Environmental Protection Agency (USEPA) River Reach File (RF1) to predict flow-weighted mean annual total nitrogen concentrations for the conterminous United States. The majority of stream miles in the Nation have predicted concentrations less than 5 milligrams per liter. Concentrations greater than 5 milligrams per liter were predicted for a broad area extending from Ohio to eastern Nebraska, areas spatially associated with greater application of fertilizer and manure. Probabilities that mean annual total-nitrogen concentrations exceed the USEPA regional nutrient criteria were determined by incorporating model prediction uncertainty. In all nutrient regions where criteria have been established, there is at least a 50 percent probability of exceeding the criteria in more than half of the stream miles. Dividing calibration sites into agricultural and nonagricultural groups did not improve the explanatory capability for total phosphorus models. The group of explanatory variables that yielded the lowest model error for mean annual total phosphorus concentrations includes phosphorus input from manure, population density, amounts of range land and forest land, percent sand in soil, and percent base flow. However, the large unexplained variability and associated model error precluded the use of the total phosphorus model for nationwide extrapolations.

ORGANIC WASTE CONTAMINATION INDICATORS IN SMALL GEORGIA PIEDMONT STREAMS

EPA Science Inventory

We monitored concentrations of nitrous oxide, methane, carbon dioxide, nutrients and other parameters (T, conductivity, dissolved oxygen, alkalinity, pH, DOC, DON, flow rate) in 17 headwater streams (watershed sizes from 0.5 to 3.4 kilometers) of the South Fork Broad River waters...

Watershed-Scale Cover Crops Reduce Nutrient Export From Agricultural Landscapes.

NASA Astrophysics Data System (ADS)

Tank, J. L.; Hanrahan, B.; Christopher, S. F.; Trentman, M. T.; Royer, T. V.; Prior, K.

2016-12-01

The Midwestern US has undergone extensive land use change as forest, wetlands, and prairies have been converted to agroecosystems. Today, excess fertilizer nutrients from farm fields enter Midwestern agricultural streams, which degrades both local and downstream water quality, resulting in algal blooms and subsequent hypoxic "dead zones" far from the nutrient source. We are quantifying the benefits of watershed-scale conservation practices that may reduce nutrient runoff from adjacent farm fields. Specifically, research is lacking on whether the planting of winter cover crops in watersheds currently dominated by row-crop agriculture can significantly reduce nutrient inputs to adjacent streams. Since 2013, farmers have planted cover crops on 70% of croppable acres in the Shatto Ditch Watershed (IN), and "saturation level" implementation of this conservation practice has been sustained for 3 years. Every 14 days, we have quantified nutrient loss from fields by sampling nutrient fluxes from multiple subsurface tile drains and longitudinally along the stream channel throughout the watershed. Cover crops improved stream water quality by reducing dissolved inorganic nutrients exported downstream; nitrate-N and DRP concentrations and fluxes were significantly lower in tiles draining fields with cover crops compared to those without. Annual watershed nutrient export also decreased, and reductions in N and P loss ( 30-40%) exceeded what we expected based on only a 6-10% reduction in runoff due to increased watershed water holding capacity. We are also exploring the processes responsible for increased nutrient retention, where they are occurring (terrestrial vs. aquatic) and when (baseflow vs. storms). For example, whole-stream metabolism also responded to cover crop planting, showing reduced variation in primary production and respiration in years after watershed-scale planting of cover crops. In summary, widespread land cover change, through cover crop planting, can significantly reduce annual watershed-scale nutrient export. Moreover, successful outcomes highlighted through demonstration projects may facilitate widespread adoption, making them powerful agents of change for advancing conservation success.

Examining the role of dissolved organic nitrogen in stream ecosystems across biomes and Critical Zone gradients

NASA Astrophysics Data System (ADS)

Wymore, A.; Rodriguez-Cardona, B.; Coble, A. A.; Potter, J.; Lopez Lloreda, C.; Perez Rivera, K.; De Jesus Roman, A.; Bernal, S.; Martí Roca, E.; Kram, P.; Hruska, J.; Prokishkin, A. S.; McDowell, W. H.

2016-12-01

Watershed nitrogen exports are often dominated by dissolved organic nitrogen (DON); yet, little is known about the role ambient DON plays in ecosystems. As an organic nutrient, DON may serve as either an energy source or as a nutrient source. One hypothesized control on DON is nitrate (NO3-) availability. Here we examine the interaction of NO3- and DON in streams across temperate forests, tropical rainforests, and Mediterranean and taiga biomes. Experimental streams also drain contrasting Critical Zones which provide gradients of vegetation, soil type and lithology (e.g. volcaniclastic, granitic, ultramafic, Siberian Traps Flood Basalt) in which to explore how the architecture of the Critical Zone affects microbial biogeochemical reactions. Streams ranged in background dissolved organic carbon (DOC) concentration (1-50 mg C/L) and DOC: NO3- ratios (10-2000). We performed a series of ecosystem-scale NO3- additions in multiple streams within each environment and measured the change in DON concentration. Results demonstrate that there is considerable temporal and spatial variation across systems with DON both increasing and decreasing in response to NO3- addition. Ecologically this suggests that DON can serve as both a nutrient source and an energy source to aquatic microbial communities. In contrast, DOC concentrations rarely changed in response to NO3- additions suggesting that the N-rich fraction of the ambient dissolved organic matter pool is more bioreactive than the C-rich fraction. Contrasting responses of the DON and DOC pools indicate different mechanisms controlling their respective cycling. It is likely that DON plays a larger role in ecosystems than previously recognized.

Influence of environmental factors on biotic responses to nutrient enrichment in agricultural streams

USGS Publications Warehouse

Maret, Terry R.; Konrad, Christopher P.; Tranmer, Andrew W.

2010-01-01

The influence of environmental factors on biotic responses to nutrients was examined in three diverse agricultural regions of the United States. Seventy wadeable sites were selected along an agricultural land use gradient while minimizing natural variation within each region. Nutrients, habitat, algae, macroinvertebrates, and macrophyte cover were sampled during a single summer low-flow period in 2006 or 2007. Continuous stream stage and water temperature were collected at each site for 30 days prior to sampling. Wide ranges of concentrations were found for total nitrogen (TN) (0.07-9.61 mg/l) and total phosphorus (TP) (R2) for nutrients and biotic measures across all sites ranged from 0.08 to 0.32 and generally were not higher within each region. The biotic measures (RCHL, SCHL, and AQM) were combined in an index to evaluate eutrophic status across sites that could have different biotic responses to nutrient enrichment. Stepwise multiple regression identified TN, percent canopy, median riffle depth, and daily percent change in stage as significant factors for the eutrophic index (R2 = 0.50, p < 0.001). A TN threshold of 0.48 mg/l was identified where eutrophic index scores became less responsive to increasing TN concentrations, for all sites. Multiple plant growth indicators should be used when evaluating eutrophication, especially when streams contain an abundance of macrophytes.

Relation of watershed setting and stream nutrient yields at selected sites in central and eastern North Carolina, 1997-2008

USGS Publications Warehouse

Harden, Stephen L.; Cuffney, Thomas F.; Terziotti, Silvia; Kolb, Katharine R.

2013-01-01

Data collected between 1997 and 2008 at 48 stream sites were used to characterize relations between watershed settings and stream nutrient yields throughout central and eastern North Carolina. The focus of the investigation was to identify environmental variables in watersheds that influence nutrient export for supporting the development and prioritization of management strategies for restoring nutrient-impaired streams. Nutrient concentration data and streamflow data compiled for the 1997 to 2008 study period were used to compute stream yields of nitrate, total nitrogen (N), and total phosphorus (P) for each study site. Compiled environmental data (including variables for land cover, hydrologic soil groups, base-flow index, streams, wastewater treatment facilities, and concentrated animal feeding operations) were used to characterize the watershed settings for the study sites. Data for the environmental variables were analyzed in combination with the stream nutrient yields to explore relations based on watershed characteristics and to evaluate whether particular variables were useful indicators of watersheds having relatively higher or lower potential for exporting nutrients. Data evaluations included an examination of median annual nutrient yields based on a watershed land-use classification scheme developed as part of the study. An initial examination of the data indicated that the highest median annual nutrient yields occurred at both agricultural and urban sites, especially for urban sites having large percentages of point-source flow contributions to the streams. The results of statistical testing identified significant differences in annual nutrient yields when sites were analyzed on the basis of watershed land-use category. When statistical differences in median annual yields were noted, the results for nitrate, total N, and total P were similar in that highly urbanized watersheds (greater than 30 percent developed land use) and (or) watersheds with greater than 10 percent point-source flow contributions to streamflow had higher yields relative to undeveloped watersheds (having less than 10 and 15 percent developed and agricultural land uses, respectively) and watersheds with relatively low agricultural land use (between 15 and 30 percent). The statistical tests further indicated that the median annual yields for total P were statistically higher for watersheds with high agricultural land use (greater than 30 percent) compared to the undeveloped watersheds and watersheds with low agricultural land use. The total P yields also were higher for watersheds with low urban land use (between 10 and 30 percent developed land) compared to the undeveloped watersheds. The study data indicate that grouping and examining stream nutrient yields based on the land-use classifications used in this report can be useful for characterizing relations between watershed settings and nutrient yields in streams located throughout central and eastern North Carolina. Compiled study data also were analyzed with four regression tree models as a means of determining which watershed environmental variables or combination of variables result in basins that are likely to have high or low nutrient yields. The regression tree analyses indicated that some of the environmental variables examined in this study were useful for predicting yields of nitrate, total N, and total P. When the median annual nutrient yields for all 48 sites were evaluated as a group (Model 1), annual point-source flow yields had the greatest influence on nitrate and total N yields observed in streams, and annual streamflow yields had the greatest influence on yields of total P. The Model 1 results indicated that watersheds with higher annual point-source flow yields had higher annual yields of nitrate and total N, and watersheds with higher annual streamflow yields had higher annual yields of total P. When sites with high point-source flows (greater than 10 percent of total streamflow) were excluded from the regression tree analyses (Models 2–4), the percentage of forested land in the watersheds was identified as the primary environmental variable influencing stream yields for both total N and total P. Models 2, 3 and 4 did not identify any watershed environmental variables that could adequately explain the observed variability in the nitrate yields among the set of sites examined by each of these models. The results for Models 2, 3, and 4 indicated that watersheds with higher percentages of forested land had lower annual total N and total P yields compared to watersheds with lower percentages of forested land, which had higher median annual total N and total P yields. Additional environmental variables determined to further influence the stream nutrient yields included median annual percentage of point-source flow contributions to the streams, variables of land cover (percentage of forested land, agricultural land, and (or) forested land plus wetlands) in the watershed and (or) in the stream buffer, and drainage area. The regression tree models can serve as a tool for relating differences in select watershed attributes to differences in stream yields of nitrate, total N, and total P, which can provide beneficial information for improving nutrient management in streams throughout North Carolina and for reducing nutrient loads to coastal waters.

Water quality in Indiana: trends in concentrations of selected nutrients, metals, and ions in streams, 2000-10

USGS Publications Warehouse

Risch, Martin R.; Bunch, Aubrey R.; Vecchia, Aldo V.; Martin, Jeffrey D.; Baker, Nancy T.

2014-01-01

Statistically significant trends were identified that included 167 downward trends and 83 upward trends. The Kankakee River Basin had the most significant upward trends while the most significant downward trends were in the Whitewater River Basin, the Lake Michigan Basin, and the Patoka River Basin. For most constituents, a majority of sites had significant downward trends. Two streams in the Lake Michigan Basin have shown substantial decreases in most constituents. The West Fork White River near Indianapolis, Indiana, showed increases in nitrate and phosphorus and the Kankakee River Basin showed increases in copper, zinc, chloride, sulfate, and hardness. Upward trends in nutrients were identified at a few sites, but most nutrient trends were downward. Upward trends in metals corresponded with relatively small concentration increases while downward trends involved considerably larger concentration changes. Downward trends in chloride, sulfate, and suspended solids were observed statewide, but upward trends in hardness were observed in the northern half of Indiana.

Biogeochemistry of the Amazon River Basin: the role of aquatic ecosystems in the Amazon functioning

NASA Astrophysics Data System (ADS)

Victoria, R. L.; Ballester, V. R.; Krushe, A. V.; Richey, J. E.; Aufdenkampe, A. K.; Kavaguishi, N. L.; Gomes, B. M.; Victoria, D. D.; Montebello, A. A.; Niell, C.; Deegan, L.

2004-12-01

In this study we present the results of an integrated analysis of physical and anthropogenic controls of river biogeochemistry in Amazônia. At the meso-scale level, our results show that both soil properties and land use are the main drivers of river biogeochemistry and metabolism, with pasture cover and soil exchange cation capacity explaining 99% (p < 0.01) of the variability observed in surface water ions and nutrients concentrations. In small rivers, forest clearing can increase cations, P and C inputs. P and light are the main PPL limiting factors in forested streams, while in pasture streams N becomes limiting. P export to streams may increase or remain nearly undetectable after forest-to-pasture conversion, depending on soil type. Pasture streams on Oxisols have very low P export, while on Ultisols P export is increased. Conversions of forest to pasture leads to extensive growth of in channel Paspalum resulting in higher DOC concentrations and respiration rates. Pasture streams have higher DOC fluxes when compared to the forest ones. In pasture areas the soil are compacted, there is less infiltration and higher surface run off, leaching soil superficial layers and caring more DOC to the streams. In forest areas infiltration is deeper into the soils and canopy interaction is higher. Mineralogy and soil properties are key factors determining exports of nutrients to streams. Therefore, land use change effects on nutrient export from terrestrial to aquatic ecosystems and the atmosphere must be understood within the context of varying soil properties across the Amazon Basin.

Nutrient interleaving below the mixed layer of the Kuroshio Extension Front

NASA Astrophysics Data System (ADS)

Nagai, Takeyoshi; Clayton, Sophie

2017-08-01

Nitrate interleaving structures were observed below the mixed layer during a cruise to the Kuroshio Extension in October 2009. In this paper, we investigate the formation mechanisms for these vertical nitrate anomalies, which may be an important source of nitrate to the oligotrphoc surface waters south of the Kuroshio Extension Front. We found that nitrate concentrations below the main stream of the Kuroshio Extension were elevated compared to the ambient water of the same density ( σ 𝜃 = 23.5-25). This appears to be analogous to the "nutrient stream" below the mixed layer, associated with the Gulf Stream. Strong turbulence was observed above the vertical nitrate anomaly, and we found that this can drive a large vertical turbulent nitrate flux >O (1 mmol N m-2 day-1). A realistic, high-resolution (2 km) numerical simulation reproduces the observed Kuroshio nutrient stream and nitrate interleaving structures, with similar lateral and vertical scales. The model results suggest that the nitrate interleaving structures are first generated at the western side of the meander crest on the south side of the Kuroshio Extension, where the southern tip of the mixed layer front is under frontogenesis. Lagrangian analyses reveal that the vertical shear of geostrophic and subinertial ageostrophic flow below the mixed layer tilts the existing along-isopycnal nitrate gradient of the Kuroshio nutrient stream to form nitrate interleaving structures. This study suggests that the multi-scale combination of (i) the lateral stirring of the Kuroshio nutrient stream by developed mixed layer fronts during fall to winter, (ii) the associated tilting of along-isopycnal nitrate gradient of the nutrient stream by subinertial shear, which forms vertical interleaving structures, and (iii) the strong turbulent diffusion above them, may provide a route to supply nutrients to oligotrophic surface waters on the south side of the Kuroshio Extension.

Streamflow and nutrient dependence of temperature effects on dissolved oxygen in low-order forest streams

Treesearch

April Mason; Y. Jun Xu; Philip Saksa; Adrienne Viosca; Johnny M. Grace; John Beebe; Richard Stich

2007-01-01

Low dissolved oxygen (DO) concentrations in streams can be linked to both natural conditions and human activities. In Louisiana, natural stream conditions such as low flow, high temperature and high organic content, often result in DO levels already below current water quality criteria, making it difficult to develop standards for Best Management Practices (BMPs)....

Ecological health in the Nation's streams

USGS Publications Warehouse

Carlisle, Daren M.; Woodside, Michael D.

2013-01-01

Aquatic biological communities, which are collections of organisms, are a direct measure of stream health because they indicate the ability of a stream to support life. This fact sheet highlights selected findings of a national assessment of stream health by the National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey (USGS). The assessment was unique in that it integrated the condition of three biological communities—algae, macroinvertebrates, and fish—as well as measures of streamflow modification, pesticides, nutrients, and other factors. At least one biological community was altered at 83 percent of assessed streams, and the occurrence of altered communities was highest in urban streams. Streamflows were modified at 86 percent of assessed streams, and increasing severity of streamflow modification was associated with increased occurrence of altered biological communities. Agricultural and urban land use in watersheds may contribute pesticides and nutrients to stream waters, and increasing concentrations of these chemicals were associated with increased occurrence of altered biological communities.

Establishment of stream nutrient criteria by comparing reference conditions with ecological thresholds in a typical eutrophic lake basin.

PubMed

Cao, Xiaofeng; Wang, Jie; Jiang, Dalin; Sun, Jinhua; Huang, Yi; Luan, Shengji

2017-12-13

The establishment of numeric nutrient criteria is essential to aid the control of nutrient pollution and for protecting and restoring healthy ecological conditions. However, it's necessary to determine whether regional nutrient criteria can be defined in stream ecosystems with a poor ecological status. A database of periphytic diatom samples was collected in July and August 2011 and 2012. In total 172 samples were included in the database with matching environmental variables. Here, percentile estimates, nonparametric change-point analysis (nCPA) and Threshold Indicator Taxa ANalysis (TITAN) were conducted to detect the reference conditions and ecological thresholds along a total nitrogen (TN) and total phosphorus (TP) gradient and ammonia nitrogen (NH 3 -N) for the development of nutrient criteria in the streams of the Lake Dianchi basin. The results highlighted the possibility of establishing regional criteria for nutrient concentrations, which we recommended to be no more than 1.39 mg L -1 for TN, 0.04 mg L -1 for TP and 0.17 mg L -1 for NH 3 -N to prevent nuisance growths of tolerant taxa, and 0.38 mg L -1 for TN, 0.02 mg L -1 for TP and 0.02 mg L -1 for NH 3 -N to maintain high quality waters in streams. Additionally, the influence of excessive background nutrient enrichment on the threshold response, and the ecological interaction with other stressors (HQI, etc.) in the nutrient dynamic process need to be considered to establish the eventual nutrient criteria, regardless of which technique is applied.

The role of periphyton in mediating the effects of pollution in a stream ecosystem.

PubMed

Hill, Walter R; Ryon, Michael G; Smith, John G; Adams, S Marshall; Boston, Harry L; Stewart, Arthur J

2010-03-01

The effects of pollutants on primary producers ramify through ecosystems because primary producers provide food and structure for higher trophic levels and they mediate the biogeochemical cycling of nutrients and contaminants. Periphyton (attached algae) were studied as part of a long-term biological monitoring program designed to guide remediation efforts by the Department of Energy's Y-12 National Security Complex on East Fork Poplar Creek (EFPC) in Oak Ridge, Tennessee. High concentrations of nutrients entering EFPC were responsible for elevated periphyton production and placed the stream in a state of eutrophy. High rates of primary production at upstream locations in EFPC were associated with alterations in both invertebrate and fish communities. Grazers represented >50% of the biomass of invertebrates and fish near the Y-12 Complex but <10% at downstream and reference sites. An index of epilithic periphyton production accounted for 95% of the site-to-site variation in biomass of grazing fish. Analyses of heavy metals in EFPC periphyton showed that concentrations of zinc, cadmium, copper and nickel in periphyton decreased exponentially with distance downstream from Y-12. Zinc uptake by periphyton was estimated to reduce the concentration of this metal in stream water approximately 60% over a 5-km reach of EFPC. Management options for mitigating eutrophy in EFPC include additional reductions in nutrient inputs and/or allowing streamside trees to grow and shade the stream. However, reducing periphyton growth may lead to greater downstream transport of contaminants while simultaneously causing higher concentrations of mercury and PCBs in fish at upstream sites.

Decadal biogeochemical history of the south east Levantine basin: Simulations of the river Nile regimes

NASA Astrophysics Data System (ADS)

Suari, Yair; Brenner, Steve

2015-08-01

The south eastern Mediterranean is characterized by antiestuarine circulation which leads to extreme oligotrophic conditions. The Nile river that used to transport fresh water and nutrients into the basin was dammed in 1964 which led to a drastic reduction of fresh water fluxes, and later, changes in Egyptian agriculture and diet led to increased nutrient fluxes. In this paper we present the results of simulations with a biogeochemical model of the south eastern Mediterranean. Four experiments were conducted: (1) present day without riverine inputs; (2) Nile before damming (pre-1964); (3) post-damming 1995 Nile; and (4) fresh water and nutrient discharges of Israeli coastal streams. The present day input simulation (control run) successfully reproduced measured nutrient concentrations, with the exception of simulated chlorophyll concentrations which were slightly higher than observed. The pre-1964 Nile simulation showed a salinity reduction of 2 psu near the Egyptian coast and 0.5 psu along the Israeli coast, as well as elevated chlorophyll a concentrations mostly east of the Nile delta and north to Cyprus. The spring bloom extended from its present peak during February-March to a peak during February-May. The 1995 Nile simulation showed increased chlorophyll a concentrations close to the Egyptian coast. The Israeli coastal stream simulation showed that the effect of the Israeli coastal stream winter flow on chlorophyll converged to control concentrations within about one month, demonstrating the stability and sensitivity of the model to external forcing. The results of this study demonstrate the significance of fresh water fluxes in maintaining marine productivity, which may have large scale effects on the marine ecosystem.

Factors affecting low summer dissolved oxygen concentrations in Mississippi Delta bayous

USDA-ARS?s Scientific Manuscript database

Streams in watersheds supporting intensive row-crop agriculture are vulnerable to ecological degradation due to non-point source pollutants such as nutrients. Low gradient streams such as bayous are especially susceptible to pollutants due to increased water residence time, and they often exhibit po...

Suspended-sediment and nutrient loads for Waiakea and Alenaio Streams, Hilo, Hawaii, 2003-2006

USGS Publications Warehouse

Presley, Todd K.; Jamison, Marcael T.J.; Nishimoto, Dale C.

2008-01-01

Suspended sediment and nutrient samples were collected during wet-weather conditions at three sites on two ephemeral streams in the vicinity of Hilo, Hawaii during March 2004 to March 2006. Two sites were sampled on Waiakea Stream at 80- and 860-foot altitudes during March 2004 to August 2005. One site was sampled on Alenaio Stream at 10-foot altitude during November 2005 to March 2006. The sites were selected to represent different land uses and land covers in the area. Most of the drainage area above the upper Waiakea Stream site is conservation land. The drainage areas above the lower site on Waiakea Stream, and the site on Alenaio Stream, are a combination of conservation land, agriculture, rural, and urban land uses. In addition to the sampling, continuous-record streamflow sites were established at the three sampling sites, as well as an additional site on Alenaio Stream at altitude of 75 feet and 0.47 miles upstream from the sampling site. Stage was measured continuously at 15-minute intervals at these sites. Discharge, for any particular instant, or for selected periods of time, were computed based on a stage-discharge relation determined from individual discharge measurements. Continuous records of discharge were computed at the two sites on Waiakea Stream and the upper site on Aleniao Stream. Due to non-ideal hydraulic conditions within the channel of Alenaio Stream, a continuous record of discharge was not computed at the lower site on Alenaio Stream where samples were taken. Samples were analyzed for suspended sediment, and the nutrients total nitrogen, dissolved nitrite plus nitrate, and total phosphorus. Concentration data were converted to instantaneous load values: loads are the product of discharge and concentration, and are presented as tons per day for suspended sediment or pounds per day for nutrients. Daily-mean loads were computed by estimating concentrations relative to discharge using graphical constituent loading analysis techniques. Daily-mean loads were computed at the two Waiakea Stream sampling sites for the analyzed constituents, during the period October 1, 2003 to September 30, 2005. No record of daily-mean load was computed for the Alenaio Stream sampling site due to the problems with computing a discharge record. The maximum daily-mean loads for the upper site on Waiakea Stream for suspended sediment was 79 tons per day, and the maximum daily-mean loads for total nitrogen, dissolved nitrite plus nitrate, and total phosphorus were 1,350, 13, and 300 pounds per day, respectively. The maximum daily-mean loads for the lower site on Waiakea Stream for suspended sediment was 468 tons per day, and the maximum daily-mean loads for total nitrogen, nitrite plus nitrate, and total phosphorus were 913, 8.5, and 176 pounds per day, respectively. From the estimated continuous daily-mean load record, all of the maximum daily-mean loads occurred during October 2003 and September 2004, except for suspended sediment load for the lower site, which occurred on September 15, 2005. Maximum values were not all caused by a single storm event. Overall, the record of daily-mean loads showed lower loads during storm events for suspended sediments and nutrients at the downstream site of Waiakea Stream during 2004 than at the upstream site. During 2005, however, the suspended sediment loads were higher at the downstream site than the upstream site. Construction of a flood control channel between the two sites in 2005 may have contributed to the change in relative suspended-sediment loads.

Stream food web response to a salmon carcass analogue addition in two central Idaho, U.S.A. streams

PubMed Central

KOHLER, ANDRE E; RUGENSKI, AMANDA; TAKI, DOUG

2008-01-01

Pacific salmon and steelhead once contributed large amounts of marine-derived carbon, nitrogen and phosphorus to freshwater ecosystems in the Pacific Northwest of the United States of America (California, Oregon, Washington and Idaho). Declines in historically abundant anadromous salmonid populations represent a significant loss of returning nutrients across a large spatial scale. Recently, a manufactured salmon carcass analogue was developed and tested as a safe and effective method of delivering nutrients to freshwater and linked riparian ecosystems where marine-derived nutrients have been reduced or eliminated. We compared four streams: two reference and two treatment streams using salmon carcass analogue(s) (SCA) as a treatment. Response variables measured included: surface streamwater chemistry; nutrient limitation status; carbon and nitrogen stable isotopes; periphyton chlorophyll a and ash-free dry mass (AFDM); macroinvertebrate density and biomass; and leaf litter decomposition rates. Within each stream, upstream reference and downstream treatment reaches were sampled 1 year before, during, and 1 year after the addition of SCA. Periphyton chlorophyll a and AFDM and macroinvertebrate biomass were significantly higher in stream reaches treated with SCA. Enriched stable isotope (δ15N) signatures were observed in periphyton and macroinvertebrate samples collected from treatment reaches in both treatment streams, indicating trophic transfer from SCA to consumers. Densities of Ephemerellidae, Elmidae and Brachycentridae were significantly higher in treatment reaches. Macroinvertebrate community composition and structure, as measured by taxonomic richness and diversity, did not appear to respond significantly to SCA treatment. Leaf breakdown rates were variable among treatment streams: significantly higher in one stream treatment reach but not the other. Salmon carcass analogue treatments had no detectable effect on measured water chemistry variables. Our results suggest that SCA addition successfully increased periphyton and macroinvertebrate biomass with no detectable response in streamwater nutrient concentrations. Correspondingly, no change in nutrient limitation status was detected based on dissolved inorganic nitrogen to soluble reactive phosphorus ratios (DIN/SRP) and nutrient-diffusing substrata experiments. Salmon carcass analogues appear to increase freshwater productivity. Salmon carcass analogues represent a pathogen-free nutrient enhancement tool that mimics natural trophic transfer pathways, can be manufactured using recycled fish products, and is easily transported; however, salmon carcass analogues should not be viewed as a replacement for naturally spawning salmon and the important ecological processes they provide.

Beaver Ponds Increase Methylmercury and Nutrients Concentrations in Canadian Shield Streams

NASA Astrophysics Data System (ADS)

Roy, V.; Amyot, M.; Carignan, R.

2007-12-01

Beaver populations and the number of beaver dams are currently increasing in many Canadian regions. Since natural and anthropogenic impoundments have historically been identified as sources of the potent neurotoxin methylmercury (MeHg), beaver dams could also increase MeHg levels in streams. During summer 2006, we collected water samples upstream and downstream from twenty beaver dams of the Laurentians, located on the Canadian Shield. Samples were analysed for total Hg, MeHg and other chemical variables including DOC, TP, TDP, TN, and major ions. Significant increases of nutrients (DOC, TP, TDP, TN) and ammonium concentrations and depletions of oxygen, nitrate and sulphate concentrations between inlet and outlet show that beaver ponds provide environmental conditions that can favour methylation of inorganic mercury. Heterogeneity of the ratio MeHg/THg at the outlet among our sites was well explained by the estimated age of the impoundment, with methylation capacity of beaver ponds decreasing with age. Further, the geographic location of beaver ponds influenced water chemistry at the outlet, as we observed a dichotomy between northern and southern sites; these differences were based mainly on forest composition. On average, beaver impoundments increased MeHg concentrations by 5.7 fold, total Hg concentrations by 1.6 fold and nutrients concentrations by 2-3 fold. Overall, our results suggest that beaver dams may considerably increase MeHg and nutrients levels in downstream ecosystems. The impact of beavers on the cycling of contaminants and nutrients in boreal watersheds should therefore be considered in the management of their populations.

Poly-P storage by natural biofilms in streams with varying biogeochemistry

NASA Astrophysics Data System (ADS)

Carrick, H. J.

2015-12-01

Anthropogenic inputs of nitrogen (N) and phosphorus (P) have increased in many watersheds throughout the world; these inputs have been linked to the eutrophication of inland and coastal waters worldwide. We selected and surveyed 20, third-order streams that supported a range of water column biogeochemical conditions (conductivity, nutrient concentrations) located in the mid-Atlantic region, USA. Biofilm biomass, algal taxonomic composition, and nutrient stoichiometry (C, N, P, and poly-P) were measured at all stream sites. Pulse-amplitude modulation fluorometry (PAM) was used to estimate photosynthetic parameters for stream biofilms (e.g., alpha, Pmax), while microbiology techniques were used to verify poly-P storage by pro- and eukaryotic components of the biofilm (e.g., epi-fluorescent staining). As anticipated, chlorophyll ranged over 2 orders of magnitude among the streams (range 10-1,000 mg/m2). Biofilm chlorophyll and algal biovolume levels increased with water column nutrient contents, while the C:P ratio within the biofilm decreased. Both pro and eukaryotic organisms were present in resident biofilms and actively stored intracellular poly-P. Finally, the rate of photosynthetic within the biofilms appeared to be driven the nutritional condition of the biofilms; pmax and alpha values increased with significantly with stream biofilm poly-P content (r2 = 0.35 and 0.44, respectively). These results indicated that where nutrients are plentiful, biofilms P storage is favored, and this is likely a key regulator of stream biofilm biomass and productivity.

Relationships Among Watershed Condition, Nutrients, and Algae in New England Streams Affected by Urbanization

EPA Science Inventory

We examined algal metrics as indicators of altered watershed land cover and nutrients to inform their potential use in monitoring programs. Multiple regression models, in which impervious cover explained the most variation, indicated concentrations <0.202 mg/l NO3 and <0.015 mg/l...

Nutrient pressures and ecological responses to nutrient loading reductions in Danish streams, lakes and coastal waters

NASA Astrophysics Data System (ADS)

Kronvang, Brian; Jeppesen, Erik; Conley, Daniel J.; Søndergaard, Martin; Larsen, Søren E.; Ovesen, Niels B.; Carstensen, Jacob

2005-03-01

The Danish National Aquatic Monitoring and Assessment Programme (NOVA) was launched in 1988 following the adoption of the first Danish Action Plan on the Aquatic Environment in 1987 with the aim to reduce by 50% the nitrogen (N) loading and by 80% the phosphorus (P) loading to the aquatic environment. The 14 years of experience gathered from NOVA have shown that discharges of total N (TN) and P (TP) from point sources to the Danish Aquatic Environment have been reduced by 69% (N) and 82% (P) during the period 1989 2002. Consequently, the P concentration has decreased markedly in most Danish lakes and estuaries. Considerable changes in agricultural practice have resulted in a reduction of the net N-surplus from 136 to 88 kg N ha-1 yr-1 (41%) and the net P-surplus from 19 to 11 kg P ha-1 yr-1 (42%) during the period 1985 2002. Despite these efforts Danish agriculture is today the major source of both N (>80%) and P (>50%) in Danish streams, lakes and coastal waters. A non-parametric statistical trend analysis of TN concentrations in streams draining dominantly agricultural catchments has shown a significant (p<0.05) downward trend in 48 streams with the downward trend being stronger in loamy compared to sandy catchments, and more pronounced with increasing dominance of agricultural exploitation in the catchments. In contrast, a statistical trend analysis of TP concentrations in streams draining agricultural catchments did not reveal any significant trends. The large reduction in nutrient loading from point and non-point sources has in general improved the ecological conditions of Danish lakes in the form of increased summer Secchi depth, decreased chlorophyll a and reduced phytoplankton biomass. Major changes have also occurred in the fish communities in lakes, with positive cascading effects on water quality. In Danish estuaries and coastal waters only a few significant improvements in the ecological quality have been observed, although it is expected that the observed reduced nutrient concentrations are likely to improve the ecological quality of estuaries and coastal waters in Denmark in the long term.

Factors affecting low summer dissolved oxygen concentrations in Mississippi Delta bayous

USDA-ARS?s Scientific Manuscript database

Streams in watersheds supporting intensive row-crop agriculture are vulnerable to ecological degradation due to non-point source discharge of pollutants such as nutrients. Low gradient streams such as bayous are especially susceptible due to increased water residence time, and often result in poor w...

Continental-scale increase in stream and lake phosphorus: Are oligotrophic systems disappearing in the U.S.?

EPA Science Inventory

Phosphorus (P) is one of two nutrients that most commonly limit the productivity of freshwater ecosystems. Widespread increases in stream and lake total phosphorus (TP) concentrations over the period 2000-2014 were identified through periodic probability surveys of thousands of w...

BIOGEOCHEMICAL INDICATORS OF ORGANIC WASTE CONTAMINATION IN SMALL STREAMS OF THE GEORGIA PIEDMONT

EPA Science Inventory

We monitored concentrations of nitrous oxide, methane, carbon dioxide, nutrients and other parameters (T, conductivity, dissolved oxygen, alkalinity, pH, DOC, DON, flow rate) in 17 headwater streams (watershed sizes from 0.5 to 3.4 km2) of the South Fork Broad River, Georgia wate...

BIOGEOCHEMICAL INDICATORS OF ORGANIC WASTE CONTAMINATION IN GEORGIA PIEDMONT STREAMS

EPA Science Inventory

We monitored concentrations of nitrous oxide, methane, carbon dioxide, nutrients and other parameters (T, conductivity, dissolved oxygen, alkalinity, pH, DOC, DON, flow rate) in 17 headwater streams (watershed sizes from 0.5 to 3.4 km2) of the South Fork Broad River, Georgia wate...

Effects of wastewater effluent discharge and treatment facility upgrades on environmental and biological conditions of Indian Creek, Johnson County, Kansas, June 2004 through June 2013

USGS Publications Warehouse

Graham, Jennifer L.; Stone, Mandy L.; Rasmussen, Teresa J.; Foster, Guy M.; Poulton, Barry C.; Paxson, Chelsea R.; Harris, Theodore D.

2014-01-01

Indian Creek is one of the most urban drainage basins in Johnson County, Kansas, and environmental and biological conditions of the creek are affected by contaminants from point and other urban sources. The Johnson County Douglas L. Smith Middle Basin (hereafter referred to as the “Middle Basin”) and Tomahawk Creek Wastewater Treatment Facilities (WWTFs) discharge to Indian Creek. In summer 2010, upgrades were completed to increase capacity and include biological nutrient removal at the Middle Basin facility. There have been no recent infrastructure changes at the Tomahawk Creek facility; however, during 2009, chemically enhanced primary treatment was added to the treatment process for better process settling before disinfection and discharge with the added effect of enhanced phosphorus removal. The U.S. Geological Survey, in cooperation with Johnson County Wastewater, assessed the effects of wastewater effluent on environmental and biological conditions of Indian Creek by comparing two upstream sites to four sites located downstream from the WWTFs using data collected during June 2004 through June 2013. Environmental conditions were evaluated using previously and newly collected discrete and continuous data and were compared with an assessment of biological community composition and ecosystem function along the upstream-downstream gradient. This study improves the understanding of the effects of wastewater effluent on stream-water and streambed sediment quality, biological community composition, and ecosystem function in urban areas. After the addition of biological nutrient removal to the Middle Basin WWTF in 2010, annual mean total nitrogen concentrations in effluent decreased by 46 percent, but still exceeded the National Pollutant Discharge Elimination System (NPDES) wastewater effluent permit concentration goal of 8.0 milligrams per liter (mg/L); however, the NPDES wastewater effluent permit total phosphorus concentration goal of 1.5 mg/L or less was achieved at the Middle Basin WWTF. At the Tomahawk Creek WWTF, after the addition of chemically enhanced primary treatment in 2009, effluent discharges also had total phosphorus concentrations below 1.5 mg/L. After the addition of biological nutrient removal, annual total nitrogen and phosphorus loads from the Middle Basin WWTF decreased by 42 and 54 percent, respectively, even though effluent volume increased by 11 percent. Annual total phosphorus loads from the Tomahawk Creek WWTF after the addition of chemically enhanced primary treatment decreased by 54 percent despite a 33-percent increase in effluent volume. Total nitrogen and phosphorus from the WWTFs contributed between 30 and nearly 100 percent to annual nutrient loads in Indian Creek depending on streamflow conditions. In-stream total nitrogen primarily came from wastewater effluent except during years with the highest streamflows. Most of the in-stream total phosphorus typically came from effluent during dry years and from other urban sources during wet years. During 2010 through 2013, annual mean discharge from the Middle Basin WWTF was about 75 percent of permitted design capacity. Annual nutrient loads likely will increase when the facility is operated at permitted design capacity; however, estimated maximum annual nutrient loads from the Middle Basin WWTF were 27 to 38 percent lower than before capacity upgrades and the addition of biological nutrient removal to treatment processes. Thus, the addition of biological nutrient removal to the Middle Basin wastewater treatment process should reduce overall nutrient loads from the facility even when the facility is operated at permitted design capacity. The effects of wastewater effluent on the water quality of Indian Creek were most evident during below-normal and normal streamflows (about 75 percent of the time) when wastewater effluent represented about 24 percent or more of total streamflow. Wastewater effluent had the most substantial effect on nutrient concentrations in Indian Creek. Total and inorganic nutrient concentrations at the downstream sites during below-normal and normal streamflows were 10 to 100 times higher than at the upstream sites, even after changes in treatment practices at the WWTFs. Median total phosphorus concentrations during below-normal and normal streamflows at a downstream site were 43 percent lower following improvements in wastewater treatment processes. Similar decreases in total nitrogen were not observed, likely because total nitrogen concentrations only decreased in Middle Basin effluent and wastewater contributed a higher percentage to streamflows when nutrient samples were collected during the after-upgrade period. The wastewater effluent discharges to Indian Creek caused changes in stream-water quality that may affect biological community structure and ecosystem processes, including higher concentrations of bioavailable nutrients (nitrate and orthophosphorus) and warmer water temperatures during winter months. Other urban sources of contaminants also caused changes in stream-water quality that may affect biological community structure and ecosystem processes, including higher turbidities downstream from construction areas and higher specific conductance and chloride concentrations during winter months. Chloride concentrations exceeded acute and chronic exposure criteria at all Indian Creek study sites, regardless of wastewater influence, for weeks or months during winter. Streambed sediment chemistry was affected by wastewater (elevated nutrient and organic wastewater-indicator compound concentrations) and other contaminants from urban sources (elevated polyaromatic hydrocarbon concentrations). Overall habitat conditions were suboptimal or marginal at all sites; general decline in habitat conditions along the upstream-downstream gradient likely was caused by the cumulative effects of urbanization with increasing drainage basin size. Wastewater effluent likely affected algal periphyton biomass and community composition, primary production, and community respiration in Indian Creek. Functional stream health, evaluated using a preliminary framework based on primary production and community respiration, was mildly or severely impaired at most downstream sites relative to an urban upstream Indian Creek site. The mechanistic cause of the changes in these biological variables are unclear, though elevated nutrient concentrations were positively correlated with algal biomass, primary production, and community respiration. Macroinvertebrate communities indicated impairment at all sites, and Kansas Department of Health and Environment aquatic life support scores indicated conditions nonsupporting of aquatic life, regardless of wastewater influences. Urban influences, other than wastewater effluent discharge, likely control macroinvertebrate community structure in Indian Creek. Changes in treatment processes at the Middle Basin and Tomahawk Creek WWTFs improved wastewater effluent quality and decreased nutrient loads, but wastewater effluent discharges still had negative effects on the environmental and biological conditions at downstream Indian Creek sites. Wastewater effluent discharge into Indian Creek likely contributed to changes in measures of ecosystem structure (streamflow, water and streambed-sediment chemistry, algal biomass, and algal periphyton community composition) and function (primary production and community respiration) along the upstream-downstream gradient. Wastewater effluent discharges maintained streamflows and increased nutrient concentrations, algal biomass, primary production, and community respiration at the downstream sites. Functional stream health was severely impaired downstream from the Middle Basin WWTF and mildly impaired downstream from the Tomahawk WWTF relative to the urban upstream site. As distance from the Middle Basin WWTF increased, nutrient concentrations, algal biomass, primary production, and community respiration decreased, and functional stream health was no longer impaired 9.5 kilometers downstream from the discharge relative to the urban upstream site. Therefore, although wastewater effluent caused persistent changes in environmental and biological conditions and functional stream health at sites located immediately downstream from WWTF effluent discharges, some recovery to conditions more similar to the urban upstream site occurred within a relatively short distance.

Natural organic matter properties in Swedish agricultural streams

NASA Astrophysics Data System (ADS)

Bieroza, Magdalena; Kyllmar, Katarina; Bergström, Lars; Köhler, Stephan

2016-04-01

We have analysed natural organic matter (NOM) properties in 18 agricultural streams in Sweden covering a broad range of environmental (climate, soil type), land use and water quality (nutrient and concentrations, pH, alkalinity) characteristics. Stream water samples collected every two weeks within an ongoing Swedish Monitoring Programme for Agriculture have been analysed for total/dissolved organic carbon, absorbance and fluorescence spectroscopy. A number of quantitative and qualitative spectroscopic parameters was calculated to help to distinguish between terrestrially-derived, refractory organic material and autochthonous, labile material indicative of biogeochemical transformations of terrestrial NOM and recent biological production. The study provides insights into organic matter properties and carbon budgets in agricultural streams and improves understanding of how agricultural catchments transform natural and anthropogenic fluxes of organic matter and nutrients to signals observed in receiving waters.

Water quality and ecosystem management: Data-driven reality check of effects in streams and lakes

NASA Astrophysics Data System (ADS)

Destouni, Georgia; Fischer, Ida; Prieto, Carmen

2017-08-01

This study investigates nutrient-related water quality conditions and change trends in the first management periods of the EU Water Framework Directive (WFD; since 2009) and Baltic Sea Action Plan (BASP; since 2007). With mitigation of nutrients in inland waters and their discharges to the Baltic Sea being a common WFD and BSAP target, we use Sweden as a case study of observable effects, by compiling and analyzing all openly available water and nutrient monitoring data across Sweden since 2003. The data compilation reveals that nutrient monitoring covers only around 1% (down to 0.2% for nutrient loads) of the total number of WFD-classified stream and lake water bodies in Sweden. The data analysis further shows that the hydro-climatically driven water discharge dominates the determination of waterborne loads of both total phosphorus and total nitrogen across Sweden. Both water discharge and the related nutrient loads are in turn well correlated with the ecosystem status classification of Swedish water bodies. Nutrient concentrations do not exhibit such correlation and their changes over the study period are on average small, but concentration increases are found for moderate-to-bad status waters, for which both the WFD and the BSAP have instead targeted concentration decreases. In general, these results indicate insufficient distinction and mitigation of human-driven nutrient components in inland waters and their discharges to the sea by the internationally harmonized applications of the WFD and the BSAP. The results call for further comparative investigations of observable large-scale effects of such regulatory/management frameworks in different parts of the world.

Evidence for self-organization in determining spatial patterns of stream nutrients, despite primacy of the geomorphic template

PubMed Central

Dong, Xiaoli; Grimm, Nancy B.

2017-01-01

Nutrients in freshwater ecosystems are highly variable in space and time. Nevertheless, the variety of processes contributing to nutrient patchiness, and the wide range of spatial and temporal scales at which these processes operate, obfuscate how this spatial heterogeneity is generated. Here, we describe the spatial structure of stream nutrient concentration, quantify the relative importance of the physical template and biological processes, and detect and evaluate the role of self-organization in driving such patterns. We examined nutrient spatial patterns in Sycamore Creek, an intermittent desert stream in Arizona that experienced an ecosystem regime shift [from a gravel/algae-dominated to a vascular plant-dominated (hereafter, “wetland”) system] in 2000 when cattle grazing ceased. We conducted high-resolution nutrient surveys in surface water along a 10-km stream reach over four visits spanning 18 y (1995–2013) that represent different successional stages and prewetland stage vs. postwetland state. As expected, groundwater upwelling had a major influence on nutrient spatial patterns. However, self-organization realized by the mechanism of spatial feedbacks also was significant and intensified over ecosystem succession, as a resource (nitrogen) became increasingly limiting. By late succession, the effects of internal spatial feedbacks and groundwater upwelling were approximately equal in magnitude. Wetland establishment influenced nutrient spatial patterns only indirectly, by modifying the extent of surface water/groundwater exchange. This study illustrates that multiple mechanisms interact in a dynamic way to create spatial heterogeneity in riverine ecosystems, and provides a means to detect spatial self-organization against physical template heterogeneity as a dominant driver of spatial patterns. PMID:28559326

Evidence for self-organization in determining spatial patterns of stream nutrients, despite primacy of the geomorphic template.

PubMed

Dong, Xiaoli; Ruhí, Albert; Grimm, Nancy B

2017-06-13

Nutrients in freshwater ecosystems are highly variable in space and time. Nevertheless, the variety of processes contributing to nutrient patchiness, and the wide range of spatial and temporal scales at which these processes operate, obfuscate how this spatial heterogeneity is generated. Here, we describe the spatial structure of stream nutrient concentration, quantify the relative importance of the physical template and biological processes, and detect and evaluate the role of self-organization in driving such patterns. We examined nutrient spatial patterns in Sycamore Creek, an intermittent desert stream in Arizona that experienced an ecosystem regime shift [from a gravel/algae-dominated to a vascular plant-dominated (hereafter, "wetland") system] in 2000 when cattle grazing ceased. We conducted high-resolution nutrient surveys in surface water along a 10-km stream reach over four visits spanning 18 y (1995-2013) that represent different successional stages and prewetland stage vs. postwetland state. As expected, groundwater upwelling had a major influence on nutrient spatial patterns. However, self-organization realized by the mechanism of spatial feedbacks also was significant and intensified over ecosystem succession, as a resource (nitrogen) became increasingly limiting. By late succession, the effects of internal spatial feedbacks and groundwater upwelling were approximately equal in magnitude. Wetland establishment influenced nutrient spatial patterns only indirectly, by modifying the extent of surface water/groundwater exchange. This study illustrates that multiple mechanisms interact in a dynamic way to create spatial heterogeneity in riverine ecosystems, and provides a means to detect spatial self-organization against physical template heterogeneity as a dominant driver of spatial patterns.

Stream chemistry and groundwater-surface water interactions in Piedmont headwater streams (Charlotte, NC) prior to whole-watershed restoration

NASA Astrophysics Data System (ADS)

Vinson, D. S.; Allison, N.; Haydin, D.; Kiker, T.; Starnes, C.; Wickliff, E.; McMillan, S.; Clinton, S. M.

2017-12-01

While restoration is an established practice in urban streams, pre/post restoration hyporheic function and its potential role in nutrient processing is less well studied and understood. Here we report results from a pre-restoration sampling period in the 6.5 km2 headwaters of the Reedy Creek (RC) watershed, an urban forest stream in Charlotte, NC at the divide between the Catawba and Pee Dee river systems. Whole-watershed restoration of this deeply incised stream is scheduled to begin in fall 2017. To characterize the pre-restoration baseline condition, nutrients, DOC, temperature, and other biogeochemical parameters were analyzed quarterly from RC and 11 tributaries since 2014 and weekly since mid-2016. Riparian groundwater from 10 shallow wells has been analyzed quarterly since 2014. Nutrient concentrations vary among land uses. For example, median stream nitrate concentrations range from <0.1 mg/L as N in the undeveloped tributary to 2.5 mg/L as N in an agriculture-influenced tributary, and 0.2 mg/L as N at the RC outlet. As with nutrients, major ions, specific UV absorbance, and alkalinity vary among tributary watershed land uses. Riparian well and stream levels collected every 15 min since 2013 at 5 cross-sections indicate prevailing hydraulic gradients from the wells to the channel. At all 5 cross-sections, high stream flow events coincide with high groundwater levels, possibly indicating direct recharge to the aquifer by rain events, rather than large-scale recharge by the stream itself. Vertical hydraulic gradient measurements, slug tests, and radon-222 measurements were made at 25-75 cm deep sub-streambed piezometers. Radon-222 activities of piezometers (29-707 pCi/L; median=120 pCi/L, n=7) cover a larger range than either well water (170-647 pCi/L; median 268 pCi/L; n=7) or stream water (12-37 pCi/L, median 25 pCi/L; n=5), consistent with limited hyporheic mixing. Streambed hydraulic conductivity is requisite for significant exchange (e.g. low-K clay-rich saprolite to high-K sand and gravel are found in short stream reaches). Limited shallow downwelling may occur where the vertical hydraulic gradient and bed particle size are suitable. These results will be utilized to understand the pre- and post- restoration function of forested headwater systems in urban watersheds.

Assessment of selected inorganic constituents in streams in the Central Arizona Basins Study Area, Arizona and northern Mexico, through 1998

USGS Publications Warehouse

Anning, David W.

2003-01-01

Stream properties and water-chemistry constituent concentrations from data collected by the National Water-Quality Assessment and other U.S. Geological Survey water-quality programs were analyzed to (1) assess water quality, (2) determine natural and human factors affecting water quality, and (3) compute stream loads for the surface-water resources in the Central Arizona Basins study area. Stream temperature, pH, dissolved-oxygen concentration and percent saturation, and dissolved-solids, suspended-sediment, and nutrient concentration data collected at 41 stream-water quality monitoring stations through water year 1998 were used in this assessment. Water-quality standards applicable to the stream properties and water-chemistry constituent concentration data for the stations investigated in this study generally were met, although there were some exceedences. In a few samples from the White River, the Black River, and the Salt River below Stewart Mountain Dam, the pH in reaches designated as a domestic drinking water source was higher than the State of Arizona standard. More than half of the samples from the Salt River below Stewart Mountain Dam and almost all of the samples from the stations on the Central Arizona Project Canal?two of the three most important surface-water sources used for drinking water in the Central Arizona Basins study area?exceeded the U.S. Environmental Protection Agency drinking water Secondary Maximum Contaminant Level for dissolved solids. Two reach-specific standards for nutrients established by the State of Arizona were exceeded many times: (1) the annual mean concentration of total phosphorus was exceeded during several years at stations on the main stems of the Salt and Verde Rivers, and (2) the annual mean concentration of total nitrogen was exceeded during several years at the Salt River near Roosevelt and at the Salt River below Stewart Mountain Dam. Stream properties and water-chemistry constituent concentrations were related to streamflow, season, water management, stream permanence, and land and water use. Dissolved-oxygen percent saturation, pH, and nutrient concentrations were dependent on stream regulation, stream permanence, and upstream disposal of wastewater. Seasonality and correlation with streamflow were dependant on stream regulation, stream permanence, and upstream disposal of wastewater. Temporal trends in streamflow, stream properties, and water-chemistry constituent concentrations were common in streams in the Central Arizona Basins study area. Temporal trends in the streamflow of unregulated perennial reaches in the Central Highlands tended to be higher from 1900 through the 1930s, lower from the 1940s through the 1970s, and high again after the 1970s. This is similar to the pattern observed for the mean annual precipitation for the Southwestern United States and indicates long-term trends in flow of streams draining the Central Highlands were driven by long-term trends in climate. Streamflow increased over the period of record at stations on effluent-dependent reaches as a result of the increase in the urban population and associated wastewater returns to the Salt and Gila Rivers in the Phoenix metropolitan area and the Santa Cruz River in the Tucson metropolitan area. Concentrations of dissolved solids decreased in the Salt River below Stewart Mountain Dam and in the Verde River below Bartlett Dam. This decrease represents an improvement in the water quality and resulted from a concurrent increase in the amount of runoff entering the reservoirs. Stream loads of water-chemistry constituents were compared at different locations along the streams with one another, and stream loads were compared to upstream inputs of the constituent from natural and anthropogenic sources to determine the relative importance of different sources and to determine the fate of the water-chemistry constituent. Of the dissolved solids transported into the Basin and Range Lowlands each year

Interactions among irradiance, nutrients, and herbivores constrain a stream algal community.

PubMed

Rosemond, A D

1993-07-01

Using stream-side, flow-through channels, I tested for the effects of nutrients (NU) (nitrogen plus phosphorus), irradiance (L), and snail grazing (G) on a benthic algal community in a small, forested stream. Grazed communities were-dominated by a chlorophyte (basal cells ofStigeoclonium) and a cyanophyte (Chamaesiphon investiens), whereas ungrazed communities were comprised almost entirely of diatoms, regardless of nutrient and light levels. Snails maintained low algal biomass in all grazed treatments, presumably by consuming increased algal production in treatments to which L and NU were increased. When nutrients were increased, cellular nutrient content increased under ambient conditions (shaded, grazed) and biomass and productivity increased when snails were removed and light was increased. Together, nutrients and light had positive effects and grazing had negative effects on biomass (chlorophylla, AFDM, algal biovolume) and chlorophyll-and areal-specific productivity in ANOVAs. However, in most cases, only means from treatments in which all three factors were manipulated (ungrazed, +NU&L treatments) were significantly different from controls; effects of single factors were generally undetectable. These results indicate that all three factors simultaneously limited algal biomass and productivity in this stream during the summer months. Additionally, the effects of these factors in combination were in some cases different from the effects of single factors. For example, light had slight negative effects on some biomass parameters when added at ambient snail densities and nutrient concentrations, but had strong positive effects in conjunction with nutrient addition and snail removal. This study demonstrates that algal biomass and productivity can be under multiple constraints by irradiance, nutrients, and herbivores and indicates the need to employ multifactor experiments to test for such interactive effects.

Upland disturbance affects headwater stream nutrients and suspended sediments during baseflow and stormflow

USGS Publications Warehouse

Houser, J.N.; Mulholland, P.J.; Maloney, K.O.

2006-01-01

Because catchment characteristics determine sediment and nutrient inputs to streams, upland disturbance can affect stream chemistry. Catchments at the Fort Benning Military Installation (near Columbus, Georgia) experience a range of upland disturbance intensities due to spatial variability in the intensity of military training. We used this disturbance gradient to investigate the effects of upland soil and vegetation disturbance on stream chemistry. During baseflow, mean total suspended sediment (TSS) concentration and mean inorganic suspended sediment (ISS) concentration increased with catchment disturbance intensity (TSS: R2 = 0.7, p = 0.005, range = 4.0-10.1 mg L-1; ISS: R2 = 0.71, p = 0.004, range = 2.04-7.3 mg L-1); dissolved organic carbon (DOC) concentration (R2 = 0.79, p = 0.001, range = 1.5-4.1 mg L-1) and soluble reactive phosphorus (SRP) concentration (R2 = 0.75, p = 0.008, range = 1.9-6.2 ??g L-1) decreased with increasing disturbance intensity; and ammonia (NH 4+), nitrate (NO3-), and dissolved inorganic nitrogen (DIN) concentrations were unrelated to disturbance intensity. The increase in TSS and ISS during storms was positively correlated with disturbance (R2 = 0.78 and 0.78, p = 0.01 and 0.01, respectively); mean maximum change in SRP during storms increased with disturbance (r = 0.7, p = 0.04); and mean maximum change in NO3- during storms was marginally correlated with disturbance (r = 0.58, p = 0.06). Soil characteristics were significant predictors of baseflow DOC, SRP, and Ca 2+, but were not correlated with suspended sediment fractions, any nitrogen species, or pH. Despite the largely intact riparian zones of these headwater streams, upland soil and vegetation disturbances had clear effects on stream chemistry during baseflow and stormflow conditions. ?? ASA, CSSA, SSSA.

Upland disturbance affects headwater stream nutrients and suspended sediments during baseflow and stormflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Houser, Jeffrey N

2006-01-01

Because catchment characteristics determine sediment and nutrient inputs to streams, upland disturbance can affect stream chemistry. Catchments at the Fort Benning Military Installation (near Columbus, Georgia) experience a range of upland disturbance intensities due to spatial variability in the intensity of military training. We used this disturbance gradient to investigate the effects of upland soil and vegetation disturbance on stream chemistry. During baseflow, mean total suspended sediment (TSS) concentration and mean inorganic suspended sediment (ISS) concentration increased with catchment disturbance intensity (TSS: R 2 = 0.7, p = 0.005, range = 4.0-10.1 mg L-1; ISS: R 2 = 0.71, pmore » = 0.004, range = 2.04-7.3 mg L-1); dissolved organic carbon (DOC) concentration (R 2 = 0.79, p = 0.001, range = 1.5-4.1 mg L-1) and soluble reactive phosphorus (SRP) concentration (R 2 = 0.75, p = 0.008, range = 1.9-6.2 {micro}g L-1) decreased with increasing disturbance intensity; and ammonia (NH4 +), nitrate (NO3 -), and dissolved inorganic nitrogen (DIN) concentrations were unrelated to disturbance intensity. The increase in TSS and ISS during storms was positively correlated with disturbance (R 2 = 0.78 and 0.78, p = 0.01 and 0.01, respectively); mean maximum change in SRP during storms increased with disturbance (r = 0.7, p = 0.04); and mean maximum change in NO3 - during storms was marginally correlated with disturbance (r = 0.58, p = 0.06). Soil characteristics were significant predictors of baseflow DOC, SRP, and Ca2+, but were not correlated with suspended sediment fractions, any nitrogen species, or pH. Despite the largely intact riparian zones of these headwater streams, upland soil and vegetation disturbances had clear effects on stream chemistry during baseflow and stormflow conditions.« less

Nutrient and salt mass balance on the Lower Arkansas River and a contributing tributary in an irrigated agricultural setting

Treesearch

Alexander Hulzenga; Ryan T. Bailey; Timothy K. Gates

2016-01-01

The Lower Arkansas River Basin is an irrigated, agricultural valley suffering from high concentrations of nutrients and salts in the coupled groundwater-surface water system. The majority of water quality data collection and associated spatial analysis of concentrations and mass loadings from the aquifer to the stream network has been performed at the regional scale (...

Selected nutrients and pesticides in streams of the eastern Iowa basins, 1970-95

USGS Publications Warehouse

Schnoebelen, Douglas J.; Becher, Kent D.; Bobier, Matthew W.; Wilton, Thomas

1999-01-01

 The statistical analysis of the nutrient data typically indicated a strong positive correlation of nitrate with streamflow. Total phosphorus concentrations with streamflow showed greater variability than nitrate, perhaps reflecting the greater potential of transport of phosphorus on sediment rather than in the dissolved phase as with nitrate. Ammonia and ammonia plus organic nitrogen showed no correlation with streamflow or a weak positive correlation. Seasonal variations and the relations of nutrients and pesticides to streamflow generally corresponded with nonpoint‑source loadings, although possible point sources for nutrients were indicated by the data at selected monitoring sites. Statistical trend tests for concentrations and loads were computed for nitrate, ammonia, and total phosphorus. Trend analysis indicated decreases for ammonia and total phosphorus concentrations at several sites and increases for nitrate concentrations at other sites in the study unit.

Associations between iron concentration and productivity in montane streams of the Black Hills, South Dakota

USGS Publications Warehouse

Hayer, Cari Ann; Holcomb, Benjamin M.; Chipps, Steven R.

2013-01-01

Iron is an important micronutrient found in aquatic systems that can influence nutrient availability (e.g., phosphorus) and primary productivity. In streams, high iron concentrations often are associated with low pH as a result of acid mine drainage, which is known to affect fish and invertebrate communities. Streams in the Black Hills of South Dakota are generally circumneutral in pH, yet select streams exhibit high iron concentrations associated with natural iron deposits. In this study, we examined relationships among iron concentration, priphyton biomass, macroinvertebrate abundance, and fish assemblages in four Black Hills streams. The stream with the highest iron concentration (~5 mg Fe/L) had reduced periphyton biomass, invertebrate abundance, and fish biomass compared to the three streams with lower iron levels (0.1 to 0.6 mg Fe/L). Reduced stream productivity was attributed to indirect effects of ferric iron Fe+++), owing to iron-hydroxide precipitation that influenced habitat quality (i.e., substrate and turbidity) and food availability (periphyton and invertebrates) for higher trophic levels (e.g., fish). Additionally, reduced primary and secondary production was associated with reduced standing stocks of salmonid fishes. Our findings suggested that naturally occurring iron deposits may constrain macroinvertebrate and fish production.

Finding clean water habitats in urban landscapes: professional researcher vs citizen science approaches.

PubMed

McGoff, Elaine; Dunn, Francesca; Cachazo, Luis Moliner; Williams, Penny; Biggs, Jeremy; Nicolet, Pascale; Ewald, Naomi C

2017-03-01

This study investigated patterns of nutrient pollution in waterbody types across Greater London. Nitrate and phosphate data were collected by both citizen scientists and professional ecologists and their results were compared. The professional survey comprised 495 randomly selected pond, lake, river, stream and ditch sites. Citizen science survey sites were self-selected and comprised 76 ponds, lakes, rivers and streams. At each site, nutrient concentrations were assessed using field chemistry kits to measure nitrate-N and phosphate-P. The professional and the citizen science datasets both showed that standing waterbodies had significantly lower average nutrient concentrations than running waters. In the professional datasets 46% of ponds and lakes had nutrient levels below the threshold at which biological impairment is likely, whereas only 3% of running waters were unimpaired by nutrients. The citizen science dataset showed the same broad pattern, but there was a trend towards selection of higher quality waterbodies with 77% standing waters and 14% of rivers and streams unimpaired. Waterbody nutrient levels in the professional dataset were broadly correlated with landuse intensity. Rivers and streams had a significantly higher proportion of urban and suburban land cover than other waterbody types. Ponds had higher percentage of semi-natural vegetation within their much smaller catchments. Relationships with land cover and water quality were less apparent in the citizen-collected dataset probably because the areas visited by citizens were less representative of the landscape as whole. The results suggest that standing waterbodies, especially ponds, may represent an important clean water resource within urban areas. Small waterbodies, including ponds, small lakes<50ha and ditches, are rarely part of the statutory water quality monitoring programmes and are frequently overlooked. Citizen scientist data have the potential to partly fill this gap if they are co-ordinated to reduce bias in the type and location of the waterbodies selected. Copyright © 2016 Elsevier B.V. All rights reserved.

Bioassay of estrogenicity and chemical analyses of estrogens in streams across the United States associated with livestock operations

EPA Science Inventory

Animal manures, used as a nitrogen source for crop production, are often associated with negative impacts on nutrient levels in surface water. The concentration of estrogens in streams from these manures is of concern due to potential endocrine disruption in aquatic species. S...

USE OF OUTPUT FROM THE NEW ENGLAND SPARROW MODEL TO ESTIMATE CONCENTRATIONS OF TOTAL NITROGEN IN ESTUARIES

EPA Science Inventory

The USGS=s SPARROW Model is a statistical model with mechanistic features that has been used to calculate annual nutrient fluxes in nontidal streams nationally on the basis of nitrogen sources, landscape characteristics, and stream properties. This model has been useful for asses...

Model evaluation of potential impacts of on-site wastewater systems on phosphorus in Turkey creek watershed.

PubMed

Geza, Mengistu; McCray, John E; Murray, Kyle E

2010-01-01

Nutrient loading to surface water systems has traditionally been associated with agricultural sources. Sources such as on-site wastewater systems (OWS) may be of concern especially in rural, nonagricultural watersheds. The impact of various point and nonpoint sources including OWS in Turkey Creek Watershed was evaluated using the Watershed Analysis Risk Management Framework, which was calibrated using 10 yr of observed stream flow and total P concentrations. Doubling the population in the watershed or OWS septic tank effluent P concentration increased mean stream total P concentration by a factor of 1.05. Converting all the OWS to a conventional sewer system with a removal efficiency of 93% at the wastewater treatment plant increased the mean total P concentration at the watershed outlet by a factor of 1.26. Reducing the soil adsorption capacity by 50% increased the mean stream total P concentration by a factor of 3.2. Doubling the initial P concentration increased the mean stream total P concentration by a factor of 1.96. Stream flow and sediment transport also substantially affected stream P concentration. The results suggest that OWS contribution to stream P in this watershed is minimal compared with other factors within the simulated time frame of 10 yr.

Sediment and nutrient delivery from thermokarst features in the foothills of the North Slope, Alaska: Potential impacts on headwater stream ecosystems

USGS Publications Warehouse

Bowden, W.B.; Gooseff, M.N.; Balser, A.; Green, A.; Peterson, B.J.; Bradford, J.

2008-01-01

Permafrost is a defining characteristic of the Arctic environment. However, climate warming is thawing permafrost in many areas leading to failures in soil structure called thermokarst. An extensive survey of a 600 km2 area in and around the Toolik Lake Natural Research Area (TLNRA) revealed at least 34 thermokarst features, two thirds of which were new since ???1980 when a high resolution aerial survey of the area was done. Most of these thermokarst features were associated with headwater streams or lakes. We have measured significantly increased sediment and nutrient loading from thermokarst features to streams in two well-studied locations near the TLNRA. One small thermokarst gully that formed in 2003 on the Toolik River in a 0.9 km2 subcatchment delivered more sediment to the river than is normally delivered in 18 years from 132 km2 in the adjacent upper Kuparuk River basin (a long-term monitoring reference site). Ammonium, nitrate, and phosphate concentrations downstream from a thermokarst feature on Imnavait Creek increased significantly compared to upstream reference concentrations and the increased concentrations persisted over the period of sampling (1999-2005). The downstream concentrations were similar to those we have used in a long-term experimental manipulation of the Kuparuk River and that have significantly altered the structure and function of that river. A subsampling of other thermokarst features from the extensive regional survey showed that concentrations of ammonium, nitrate, and phosphate were always higher downstream of the thermokarst features. Our previous research has shown that even minor increases in nutrient loading stimulate primary and secondary production. However, increased sediment loading could interfere with benthic communities and change the responses to increased nutrient delivery. Although the terrestrial area impacted by thermokarsts is limited, the aquatic habitat altered by these failures can be extensive. If warming in the Arctic foothills accelerates thermokarst formation, there may be substantial and wide-spread impacts on arctic stream ecosystems that are currently poorly understood. Copyright 2008 by the American Geophysical Union.

Recovery of three arctic stream reaches from experimental nutrient enrichment

USGS Publications Warehouse

Benstead, J.P.; Green, A.C.; Deegan, Linda A.; Peterson, B.J.; Slavik, K.; Bowden, W.B.; Hershey, A.E.

2007-01-01

1. Nutrient enrichment and resulting eutrophication is a widespread anthropogenic influence on freshwater ecosystems, but recovery from nutrient enrichment is poorly understood, especially in stream environments. We examined multi-year patterns in community recovery from experimental low-concentration nutrient enrichment (N + P or P only) in three reaches of two Arctic tundra streams (Kuparuk River and Oksrukuyik Creek) on the North Slope of Alaska (U.S.A.). 2. Rates of recovery varied among community components and depended on duration of enrichment (2-13 consecutive growing seasons). Biomass of epilithic algae returned to reference levels rapidly (within 2 years), regardless of nutrients added or enrichment duration. Aquatic bryophyte cover, which increased greatly in the Kuparuk River only after long-term enrichment (8 years), took 8 years of recovery to approach reference levels, after storms had scoured most remnant moss in the recovering reach. 3. Multi-year persistence of bryophytes in the Kuparuk River appeared to prevent recovery of insect populations that had either been positively (e.g. the mayfly Ephemerella, most chironomid midge taxa) or negatively (e.g. the tube-building chironomid Orthocladius rivulorum) affected by this shift in dominant primary producer. These lags in recovery (of >3 years) were probably driven by the persistent effect of bryophytes on physical benthic habitat. 4. Summer growth rates of Arctic grayling (both adults and young-of-year) in Oksrukuyik Creek (fertilised for 6 years with no bryophyte colonisation), which were consistently increased by nutrient addition, returned to reference rates within 1-2 years. 5. Rates of recovery of these virtually pristine Arctic stream ecosystems from low-level nutrient enrichment appeared to be controlled largely by duration of enrichment, mediated through physical habitat shifts caused by eventual bryophyte colonisation, and subsequent physical disturbance that removed bryophytes. Nutrient enrichment of oligotrophic Arctic stream ecosystems caused by climate change or local anthropogenic activity may have dramatic and persistent consequences if it results in the colonisation of long-lived primary producers that alter physical habitat. ?? 2007 The Authors.

Hydrogeologic controls on groundwater discharge and nitrogen loads in a coastal watershed

USGS Publications Warehouse

Russoniello, Chrtopher J.; Konikow, Leonard F.; Kroeger, Kevin D.; Fernandez, Cristina; Andres, A. Scott; Michael, Holly A.

2016-01-01

Submarine groundwater discharge (SGD) is a small portion of the global water budget, but a potentially large contributor to coastal nutrient budgets due to high concentrations relative to stream discharge. A numerical groundwater flow model of the Inland Bays Watershed, Delaware, USA, was developed to identify the primary hydrogeologic factors that affect groundwater discharge rates and transit times to streams and bays. The distribution of groundwater discharge between streams and bays is sensitive to the depth of the water table below land surface. Higher recharge and reduced hydraulic conductivity raised the water table and increased discharge to streams relative to bays compared to the Reference case (in which 66% of recharge is discharged to streams). Increases to either factor decreased transit times for discharge to both streams and bays compared to the Reference case (in which mean transit times are 56.5 and 94.3 years, respectively), though sensitivity to recharge is greater. Groundwater-borne nitrogen loads were calculated from nitrogen concentrations measured in discharging fresh groundwater and modeled SGD rates. These loads combined with long SGD transit times suggest groundwater-borne nitrogen reductions and estuarine water quality improvements will lag decades behind implementation of efforts to manage nutrient sources. This work enhances understanding of the hydrogeologic controls on and uncertainties in absolute and relative rates and transit times of groundwater discharge to streams and bays in coastal watersheds.

Stream nitrate responses to hydrological forcing and climate change in northern forests of the USA (Invited)

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Campbell, J. L.; Shanley, J. B.; Pourmokhtarian, A.; Driscoll, C. T.; Boyer, E. W.

2009-12-01

There is a need to understand how climate variability and change affect nutrient delivery to surface waters. We analyzed long-term records of hydrochemical data to explore how the forms, concentrations, and loadings of nitrogen in forest streams throughout the northern USA vary with catchment wetness. We considered projected changes in growing season length and precipitation patterns to simulate future climate scenarios and to assess how stream nitrate loading responds to hydrological forcing under different climate change scenarios. At the Sleepers River Research Watershed in northeastern Vermont, model results suggest that stream nutrient loadings over the next century will respond to hydrological forcing during climate change that affects the amount of water that flows through the landscape. For example, growing season stream water yield (+20%) and nitrate loadings (+57%) increase in response to greater amounts of precipitation (+28%) during a warmer climate with a longer growing season (+43 days). We further explore these findings by presenting model results from a biogeochemical process model (PnET-BGC) to separate changes that are due to biogeochemical cycling and the effects of hydrological forcing. Our findings suggest that nitrogen cycling and transport will intensify during anthropogenic climate forcing, thereby affecting the timing and magnitude of annual stream nutrient loadings in northern forests of the USA.

Exploring factors controlling the variability of pesticide concentrations in the Willamette River Basin using tree-based models

USGS Publications Warehouse

Qian, S.S.; Anderson, Chauncey W.

1999-01-01

We analyzed available concentration data of five commonly used herbicides and three pesticides collected from small streams in the Willamette River Basin in Oregon to identify factors that affect the variation of their concentrations in the area. The emphasis of this paper is the innovative use of classification and regression tree models for exploratory data analysis as well as analyzing data with a substantial amount of left-censored values. Among variables included in this analysis, land-use pattern in the watershed is the most important for all but one (simazine) of the eight pesticides studied, followed by geographic location, intensity of agriculture activities in the watershed (represented by nutrient concentrations in the stream), and the size of the watershed. The significant difference between urban sites and agriculture sites is the variability of stream concentrations. While all 16 nonurban watersheds have significantly higher variation than urban sites, the same is not necessarily true for the mean concentrations. Seasonal variation accounts for only a small fraction of the total variance in all eight pesticides.We analyzed available concentration data of five commonly used herbicides and three pesticides collected from small streams in the Willamette River Basin in Oregon to identify factors that affect the variation of their concentrations in the area. The emphasis of this paper is the innovative use of classification and regression tree models for exploratory data analysis as well as analyzing data with a substantial amount of left-censored values. Among variables included in this analysis, land-use pattern in the watershed is the most important for all but one (simazine) of the eight pesticides studied, followed by geographic location, intensity of agriculture activities in the watershed (represented by nutrient concentrations in the stream), and the size of the watershed. The significant difference between urban sites and agriculture sites is the variability of stream concentrations. While all 16 nonurban watersheds have significantly higher variation than urban sites, the same is not necessarily true for the mean concentrations. Seasonal variation accounts for only a small fraction of the total variance in all eight pesticides.

Linkages Between Nutrients and Assemblages of Macroinvertebrates and Fish in Wadeable Streams: Implication to Nutrient Criteria Development

NASA Astrophysics Data System (ADS)

Wang, Lizhu; Robertson, Dale M.; Garrison, Paul J.

2007-02-01

We sampled 240 wadeable streams across Wisconsin for different forms of phosphorus and nitrogen, and assemblages of macroinvertebrates and fish to (1) examine how macroinvertebrate and fish measures correlated with the nutrients; (2) quantify relationships between key biological measures and nutrient forms to identify potential threshold levels of nutrients to support nutrient criteria development; and (3) evaluate the importance of nutrients in influencing biological assemblages relative to other physicochemical factors at different spatial scales. Twenty-three of the 35 fish and 18 of the 26 macroinvertebrate measures significantly correlated ( P < 0.05) with at least one nutrient measure. Percentages of carnivorous, intolerant, and omnivorous fishes, index of biotic integrity, and salmonid abundance were fish measures correlated with the most nutrient measures and had the highest correlation coefficients. Percentages of Ephemeroptera-Plecoptera-Trichoptera individuals and taxa, Hilsenhoff biotic index, and mean tolerance value were macroinvertebrate measures that most strongly correlated with the most nutrient measures. Selected biological measures showed clear trends toward degradation as concentrations of phosphorus and nitrogen increased, and some measures showed clear thresholds where biological measures changed drastically with small changes in nutrient concentrations. Our selected environmental factors explained 54% of the variation in the fish assemblages. Of this explained variance, 46% was attributed to catchment and instream habitat, 15% to nutrients, 3% to other water quality measures, and 36% to the interactions among all the environmental variables. Selected environmental factors explained 53% of the variation in macroinvertebrate assemblages. Of this explained variance, 42% was attributed to catchment and instream habitat, 22% to nutrients, 5% to other water quality measures, and 32% to the interactions among all the environmental variables.

Linkages between nutrients and assemblages of macroinvertebrates and fish in wadeable streams: Implication to nutrient criteria development

USGS Publications Warehouse

Wang, L.; Robertson, Dale M.; Garrison, P.J.

2007-01-01

We sampled 240 wadeable streams across Wisconsin for different forms of phosphorus and nitrogen, and assemblages of macroinvertebrates and fish to (1) examine how macroinvertebrate and fish measures correlated with the nutrients; (2) quantify relationships between key biological measures and nutrient forms to identify potential threshold levels of nutrients to support nutrient criteria development; and (3) evaluate the importance of nutrients in influencing biological assemblages relative to other physicochemical factors at different spatial scales. Twenty-three of the 35 fish and 18 of the 26 macroinvertebrate measures significantly correlated (P < 0.05) with at least one nutrient measure. Percentages of carnivorous, intolerant, and omnivorous fishes, index of biotic integrity, and salmonid abundance were fish measures correlated with the most nutrient measures and had the highest correlation coefficients. Percentages of Ephemeroptera-Plecoptera-Trichoptera individuals and taxa, Hilsenhoff biotic index, and mean tolerance value were macroinvertebrate measures that most strongly correlated with the most nutrient measures. Selected biological measures showed clear trends toward degradation as concentrations of phosphorus and nitrogen increased, and some measures showed clear thresholds where biological measures changed drastically with small changes in nutrient concentrations. Our selected environmental factors explained 54% of the variation in the fish assemblages. Of this explained variance, 46% was attributed to catchment and instream habitat, 15% to nutrients, 3% to other water quality measures, and 36% to the interactions among all the environmental variables. Selected environmental factors explained 53% of the variation in macroinvertebrate assemblages. Of this explained variance, 42% was attributed to catchment and instream habitat, 22% to nutrients, 5% to other water quality measures, and 32% to the interactions among all the environmental variables. ?? 2006 Springer Science+Business Media, Inc.

Water-quality and algal conditions in the Clackamas River basin, Oregon, and their relations to land and water management

USGS Publications Warehouse

Carpenter, Kurt D.

2003-01-01

In 1998, the U.S. Geological Survey sampled the Clackamas River, its major tributaries, and reservoirs to characterize basic water quality (nutrients, dissolved oxygen, pH, temperature, and conductance), water quantity (water sources within the basin), and algal conditions (biomass and species composition). Sampling locations reflected the dominant land uses in the basin (forest management, agriculture, and urban development) as well as the influence of hydroelectric projects, to examine how these human influences might be affecting water quality and algal conditions. Nuisance algal growths, with accompanying negative effects on water quality, were observed at several locations in the basin during this study. Algal biomass in the lower Clackamas River reached a maximum of 300 mg/m2 chlorophyll a, producing nuisance algal conditions, including fouled stream channels and daily fluctuations in pH and dissolved oxygen concentrations to levels that did not meet water-quality standards. Algal biomass was highest at sites immediately downstream from the hydroelectric project's reservoirs and/or powerhouses. Nuisance algal conditions also were observed in some of the tributaries, including the North Fork of the Clackamas River, Clear Creek, Rock Creek, and Sieben Creek. High amounts of drifting algae increased turbidity levels in the Clackamas River during June, which coincided with a general increase in the concentration of disinfection by-products found in treated Clackamas River water used for drinking, presumably due to the greater amounts of organic matter in the river. The highest nutrient concentrations were found in the four lowermost tributaries (Deep, Richardson, Rock, and Sieben Creeks), where most of the agriculture and urban development is concentrated. Of these, the greatest load of nutrients came from Deep Creek, which had both high nutrient concentrations and relatively high streamflow. Streams draining forestland in the upper basin (upper Clackamas River and Oak Grove Fork) had the highest concentrations of phosphorus (and lowest concentrations of nitrogen), and streams draining forestland in the middle basin (Clear Creek, Eagle Creek, and the North Fork of the Clackamas River) had relatively high concentrations of nitrogen (and low concentrations of phosphorus). In contrast, relatively low concentrations of both nitrogen and phosphorus were found at the two reference streams, reflecting their pristine condition. Relatively high phosphorus levels in the upper basin are probably due to the erosion of naturally occurring phosphorus deposits in this area. Likely sources of nitrogen (mostly nitrate) in the forested watersheds include nitrogen-fixing plants, atmospheric deposition, timber harvesting, and applications of urea fertilizers.

Temporal changes in nitrogen and phosphorus concentrations with comparisons to conservation practices and agricultural activities in the Lower Grand River, Missouri and Iowa, and selected watersheds, 1969–2015

USGS Publications Warehouse

Krempa, Heather M.; Flickinger, Allison K.

2017-08-01

This report presents the results of a cooperative study by the U.S. Geological Survey and Missouri Department of Natural Resources to estimate total nitrogen (TN) and total phosphorus (TP) concentrations at monitoring sites within and near the Lower Grand River hydrological unit. The primary objectives of the study were to quantify temporal changes in TN and TP concentrations and compare those concentrations to conservation practices and agricultural activities. Despite increases in funding during 2011–15 for conservation practices in the Lower Grand River from the Mississippi River Basin Healthy Watersheds Initiative, decreases in flow-normalized TN and TP concentrations during this time at the long-term Grand River site were less than at other long-term sites, which did not receive funding from the Mississippi River Basin Healthy Watersheds Initiative. The relative differences in the magnitude of flow-normalized TN and TP concentrations among long-term sites are directly related to the amount of agricultural land use within the watershed. Significant relations were determined between nitrogen from cattle manure and flow-normalized TN concentrations at selected long-term sites, indicating livestock manure may be a substantial source of nitrogen within the selected long-term site watersheds. Relations between flow-normalized TN and TP concentrations with Conservation Reserve Program acres and with nitrogen and phosphorus from commercial fertilizer indicate that changes in these factors alone did not have a substantial effect on stream TN and TP concentrations; other landscape activities, runoff, within-bank nutrients that are suspended during higher streamflows, or a combination of these have had a greater effect on stream TN and TP concentrations; or there is a lag time that is obscuring relations. Temporal changes in flow-adjusted TN and TP concentrations were not substantial at Lower Grand River Mississippi River Basin Healthy Watersheds Initiative sites, indicating factors besides stream variability did not have substantial effects on TN and TP concentrations. Flow-weighted TN and TP concentrations at Lower Grand River Mississippi River Basin Healthy Watershed Initiative sites increase with increasing streamflow, which indicates runoff, within-bank nutrients that are suspended during higher streamflows, or both, have more effect on stream TN and TP concentrations than consistent point sources or groundwater sources. Timing of TN and TP concentration increases compared to streamflow increases indicate that nitrogen and phosphorus loads are more strongly related to streamflow than to a particular period of the year, indicating that runoff, within-bank nutrients that are suspended during higher streamflows, or both are a substantial source of nutrients regardless of timing.

On the Complexity of Nutrient Transport in a Large Watershed in Ohio

NASA Astrophysics Data System (ADS)

Schwartz, F. W.; Allen, G.

2009-12-01

This paper examines key features of the hydrobiologic setting in controlling the cycling of nutrients through the major streams and rivers of a large agriculturally dominated watershed in central Ohio. The particular focus is on the roles of extreme rainfall events in generating nutrients, and role of reservoirs in attenuating nutrient concentrations. The study also highlights major gaps in process knowledge even in the face in the face of extensive regulatory and other monitoring. Although it has been recognized that reservoirs can significantly affect surface-water flows in watersheds, there is a growing recognition of the need for expanded and complementary studies to understand their role in nutrient transport. The study area is located in central Ohio and includes the entire Upper Scioto and the northern portion of the Lower Scioto River basins, an area encompassing approximately 9984 km2. Five of the sub-watersheds contain major surface-water storage reservoirs. Two watersheds are without reservoirs. There is intensive agriculture within the study area with corn and soybeans as the dominant crops. Tile drainage of fields provides an efficient and rapid connection of agricultural lands to surface waters, facilitating the loading of fertilizers and agrochemicals to surface streams. Storm flows in spring months that coincide with fertilizer applications often provide nitrate concentrations in excess of 10 mg/L as N. In spite of years of routine sampling for regulatory purposes, little is known about nutrient loading patterns during the few, brief, extreme events each year. Interpretations of a high resolution temporal chemical record of sampling on the Scioto River is frustrated by the complexity of loading and mixing as tributaries from sub-watersheds join the main stem of the Scioto River and nutrient utilization within the large reservoirs. Even with literally thousands of individual chemical measurements, extensive stream and precipitation data, the details of processes affecting nutrient transport remain uncertain.

High-frequency phosphorus and nitrate measurements for improved statutory water quality monitoring and management

NASA Astrophysics Data System (ADS)

Bieroza, Magdalena

2017-04-01

High-frequency nutrient (phosphorus and nitrogen) monitoring using wet-chemistry analysers and optical sensors has revolutionised the collection of biogeochemical data from streams, rivers and lakes. Matching the nutrient measurement time with timescales of hydrological responses has revealed biogeochemical patterns and nutrient hydrological responses not observed previously. Capturing a wider range of nutrient concentrations compared to traditional coarse resolution sampling enables more accurate estimation of mean concentrations and loads and thus improved water body classification. However, to date the scientific insights from the high-frequency nutrient monitoring studies have not been translated into policy and operational responses. The pertinent question is where and how often to measure nutrients to satisfy statutory monitoring requirements for the Water Framework Directive and the Nitrates Directive. Therefore this paper discusses how the reduced data uncertainty and improved process understanding obtained with the high-frequency measurements can improve statutory nutrient monitoring, using case studies from England and Sweden.

The effect of restored and native oxbows on hydraulic loads of nutrients and stream water quality

USGS Publications Warehouse

Kalkhoff, Stephen J.; Hubbard, Laura E.; Joseph P.Schubauer-Berigan,

2016-01-01

The use of oxbow wetlands has been identified as a potential strategy to reduce nutrient transport from agricultural drainage tiles to streams in Iowa. In 2013 and 2014, a study was conducted in north-central Iowa in a native oxbow in the Lyons Creek watershed and two restored oxbow wetlands in the Prairie Creek watershed (Smeltzer west and Smeltzer east) to assess their effectiveness at reducing nitrogen and phosphorus loads. The tile line inlets carrying agricultural runoff to the oxbows, the outfall from the oxbows, and the surface waters in the streams receiving the outfall water were monitored for discharge and nutrients from February 2013 to September 2015. Smeltzer west and east also had four monitoring wells each, two in the upland and two between the oxbow and Prairie Creek to monitor surface water-groundwater interaction. The Smeltzer west and east oxbow sites also were instrumented to continuously measure the nitrate concentration. Rainfall was measured at one Lyons Creek and one Smeltzer site. Daily mean nitrate-N concentrations in Lyons Creek in 2013 ranged from 11.8 mg/L to 40.9 mg/L, the median daily mean nitrate-N concentration was 33.0 mg/L. Daily mean nitrate-N concentrations in Prairie Creek in 2013 ranged from 0.07 mg/L in August to 32.2 mg/L in June. In 2014, daily mean nitrate-N concentrations in Prairie Creek ranged from 0.17 mg/L in April to 26.7 mg/L in July; the daily mean nitrate-N concentration for the sampled period was 9.78 mg/L. Nutrient load reduction occurred in oxbow wetlands in Lyons and Prairie Creek watersheds in north-central Iowa but efficiency of reduction was variable. Little nutrient reduction occurred in the native Lyons Creek oxbow during 2013. Concentrations of all nutrient constituents were not significantly (P>0.05, Wilcoxon rank sum) different in water discharging from the tile line than in water leaving the Lyons Creek oxbow. A combination of physical features and flow conditions suggest that the residence time of water in the oxbow may not have been sufficient to allow for removal of substantial amounts of nutrients. Approximately 54 percent less nitrate-N was measured leaving the Smeltzer west oxbow than was measured entering from a small 6-inch field tile. The efficiency of nitrate-N removal in the oxbow was not able to be definitively quantified as other hydrologic factors such as overland and groundwater flow into and through the oxbow were not addressed and may provide alternative routes for nutrient transport. Damage to the Smeltzer east oxbow outfall weir prevented analysis of its nutrient load reduction capability. The study provides important information to managers and land owners looking for strategies to reduce nutrient transport from fields. Additional research is needed to understand how increased discharge from larger field tiles and drainage district mains may influence the efficiency of nutrient reduction in relation to the size, type, and landscape setting of a wetland.

Scaling of physical constraints at the root-soil interface to macroscopic patterns of nutrient retention in ecosystems.

PubMed

Gerber, Stefan; Brookshire, E N Jack

2014-03-01

Nutrient limitation in terrestrial ecosystems is often accompanied with maintaining a nearly closed vegetation-soil nutrient cycle. The ability to retain nutrients in an ecosystem requires the capacity of the plant-soil system to draw down nutrient levels in soils effectually such that export concentrations in soil solutions remain low. Here we address the physical constraints of plant nutrient uptake that may be limited by the diffusive movement of nutrients in soils, by the uptake at the root/mycorrhizal surface, and from interactions with soil water flow. We derive an analytical framework of soil nutrient transport and uptake and predict levels of plant available nutrient concentration and residence time. Our results, which we evaluate for nitrogen, show that the physical environment permits plants to lower soil solute concentration substantially. Our analysis confirms that plant uptake capacities in soils are considerable, such that water movement in soils is generally too small to significantly erode dissolved plant-available nitrogen. Inorganic nitrogen concentrations in headwater streams are congruent with the prediction of our theoretical framework. Our framework offers a physical-based parameterization of nutrient uptake in ecosystem models and has the potential to serve as an important tool toward scaling biogeochemical cycles from individual roots to landscapes.

Fate of acetone in an outdoor model stream in southern Mississippi, U.S.A.

USGS Publications Warehouse

Rathbun, R.E.; Stephens, D.W.; Shultz, D.J.; Tai, D.Y.

1988-01-01

The fate of acetone in water was investigated in an outdoor model stream located in southern Mississippi, U.S.A. Acetone was injected continuously for 32 days resulting in small milligram-perliter concentrations in the stream. Rhodamine-WT dye was injected at the beginning and at the end of the study to determine the time-of-travel and dispersion characteristics of the stream. A 12-h injection of t-butyl alcohol (TBA) was used to determine the volatilization characteristics of the stream. Volatilization controlled the acetone concentration in the stream. Significant bacterial degradation of acetone did not occur, contrary to expectations based on previous laboratory studies. Attempts to induce degradation of the acetone by injecting glucose and a nutrient solution containing bacteria acclimated to acetone were unsuccessful. Possible explanations for the lack of bacterial degradation included a nitrate limitation and a limited residence time in the stream system. ?? 1988.

Instream Attenuation of Nitrogen and Phosphorus in Non-Point Source Dominated Streams: Hydrologic and Biogeochemical Controls

NASA Astrophysics Data System (ADS)

Bray, E. N.; Chen, X.; Keller, A. A.

2010-12-01

Non-point source inputs of total nitrogen (TN) and total phosphorus (TP) in rivers are the leading causes of water quality degradation in the United States (Turner and Rabalais, 2003; Broussard and Turner, 2009). Yet it remains a challenge to adequately quantify the relative role and influence of physical hydrological processes versus biogeochemical processes on the attenuation of TN and TP for individual river reaches. A watershed-scale study of instream dynamics and attenuation of TN and TP in northeastern U.S. headwater streams demonstrates that physical and hydrological processes exert greater control over nutrient removal than biogeochemical processes. To explore these interactions under various attenuation scenarios, we developed the watershed-scale model (WARMF) for 97 catchments to simulate watershed processes, hydrology, and diffuse source loads of nutrients. We simulated a hypothetical nutrient release at a rate of 1 kg/d of TN (50% as ammonium and 50% as nitrate) and TP (100% as phosphate) to predict response lengths of downstream catchments. Resulting attenuation factors are presented as the change in mean load at a given location, normalized to the change in the catchment in which the load is applied. Results indicate that for most catchments, the TN and TP load increase is attenuated from the stream within a few tens of kilometers. Fifty percent attenuation occurs across length scales ranging from a few hundreds of meters to kilometers if the load is introduced in the headwaters, indicating the most rapid nutrient removal occurs in the smallest headwater streams but generally decreases with distance downstream. There are some differences in the attenuation factors for TN and TP, although the pattern of attenuation is the same. Sensitivity analyses highlight five hydrological parameters of paramount importance to concentrations of N and P, namely precipitation, evaporation coefficients (magnitude and skewness), soil layer thickness, soil saturated moisture and soil hydraulic conductivity. These model parameters have a significant effect on the concentrations of nutrients, with TN exhibiting greater sensitivity. Further, attenuation results suggest that stream depth, flow regime, and density of agriculture in small headwater streams are potentially important controls to nutrient uptake and removal; i.e. during periods of low flow, dilution is reduced, attenuation length increases, and removal processes may be dominated by settling as opposed to biogeochemistry. Instream attenuation and model results can be used to assess 1) the scale and nature of best management practices which must be adopted to result in nutrient reductions, 2) the downstream distance at which load reductions will be effective, and 3) the hydrological characteristics of the river network which exert considerable influence on attenuation lengths and nutrient removal.

Shifts in leaf litter breakdown along a forest-pasture-urban gradient in Andean streams.

PubMed

Iñiguez-Armijos, Carlos; Rausche, Sirkka; Cueva, Augusta; Sánchez-Rodríguez, Aminael; Espinosa, Carlos; Breuer, Lutz

2016-07-01

Tropical montane ecosystems of the Andes are critically threatened by a rapid land-use change which can potentially affect stream variables, aquatic communities, and ecosystem processes such as leaf litter breakdown. However, these effects have not been sufficiently investigated in the Andean region and at high altitude locations in general. Here, we studied the influence of land use (forest-pasture-urban) on stream physico-chemical variables (e.g., water temperature, nutrient concentration, and pH), aquatic communities (macroinvertebrates and aquatic fungi) and leaf litter breakdown rates in Andean streams (southern Ecuador), and how variation in those stream physico-chemical variables affect macroinvertebrates and fungi related to leaf litter breakdown. We found that pH, water temperature, and nutrient concentration increased along the land-use gradient. Macroinvertebrate communities were significantly different between land uses. Shredder richness and abundance were lower in pasture than forest sites and totally absent in urban sites, and fungal richness and biomass were higher in forest sites than in pasture and urban sites. Leaf litter breakdown rates became slower as riparian land use changed from natural to anthropogenically disturbed conditions and were largely determined by pH, water temperature, phosphate concentration, fungal activity, and single species of leaf-shredding invertebrates. Our findings provide evidence that leaf litter breakdown in Andean streams is sensitive to riparian land-use change, with urban streams being the most affected. In addition, this study highlights the role of fungal biomass and shredder species (Phylloicus; Trichoptera and Anchytarsus; Coleoptera) on leaf litter breakdown in Andean streams and the contribution of aquatic fungi in supporting this ecosystem process when shredders are absent or present low abundance in streams affected by urbanization. Finally, we summarize important implications in terms of managing of native vegetation and riparian buffers to promote ecological integrity and functioning of tropical Andean stream ecosystems.

Land cover impacts on stream nutrients and fecal coliform in the lower Piedmont of West Georgia

NASA Astrophysics Data System (ADS)

Schoonover, Jon E.; Lockaby, B. Graeme

2006-12-01

SummaryAs urbanization infiltrates into rural areas, stream water quality is expected to decline as a result from increased impervious surface and greater sources for pollutants. Consequently, West Georgia's water quality is threatened by extensive development as well as other land uses such as livestock grazing and silvicultural activity. Maintenance of stream water quality, as land development occurs, is critical for the protection of drinking water and biotic integrity. A 2-phase, watershed-scale study was established to develop relationships among land cover and water quality within western Georgia. During phase 1, nutrient and fecal coliform data were collected within 18 mixed land use watersheds, ranging in size from 500 to 2500 ha. Regression models were developed that related land cover to stream water nutrient and fecal coliform concentrations. Nutrient and fecal coliform concentrations within watersheds having >24% impervious surface (IS) were often higher than those in nonurban watersheds (i.e., <5% IS) during both base flow (N: 1.64 mg/L versus 0.61 mg/L, and FC: 430 versus 120 MPN/100 ml) and storm flow (N: 1.93 mg/L versus 0.36 mg/L, and FC: 1600 versus 167 MPN/100 ml). Fecal coliform bacteria in urbanized areas consistently exceeded the US EPA's review criterion for recreational waters during both base flow and to a greater extent storm flow. During phase 2, regression models were tested based on data from six newly chosen watersheds with similar land use/cover patterns. Lastly, theoretical watersheds, based on land use percentages, were created to illustrate trends in water quality impairment as land development occurs. The models developed from this research could be used to forecast water quality changes under various land use scenarios in the developing Piedmont region of the US.

Natural organic matter properties in Swedish agricultural streams

NASA Astrophysics Data System (ADS)

Bieroza, Magdalena; Kyllmar, Katarina; Bergström, Lars; Köhler, Stephan

2017-04-01

The following paper shows natural organic matter (NOM) properties of stream water samples collected from 8 agricultural streams and 12 agricultural observational fields in Sweden. The catchments and observational fields cover a broad range of environmental (climate, soil type), land use and water quality (nutrient and concentrations, pH, alkalinity) characteristics. Stream water samples collected every two weeks within an ongoing Swedish Monitoring Programme for Agriculture have been analysed for total/dissolved organic carbon, absorbance and fluorescence spectroscopy. A number of quantitative and qualitative spectroscopic parameters was calculated to help to distinguish between terrestrially-derived, refractory organic material and autochthonous, labile material indicative of biogeochemical transformations of terrestrial NOM and recent biological production. The study provides insights into organic matter properties and carbon budgets in agricultural streams and improves understanding of how agricultural catchments transform natural and anthropogenic fluxes of organic matter and nutrients. The insights from the grab sampling are supported by high-frequency turbidity, fulvic-like and tryptophan-like fluorescence measurements with in situ optical sensor.

Limnology of Blue Mesa, Morrow Point, and Crystal Reservoirs, Curecanti National Recreation area, during 1999, and a 25-year retrospective of nutrient conditions in Blue Mesa Reservoir, Colorado

USGS Publications Warehouse

Bauch, Nancy J.; Malick, Matt

2003-01-01

The U.S. Geological Survey and the National Park Service conducted a water-quality investigation in Curecanti National Recreation Area in Colorado from April through December 1999. Current (as of 1999) limnological characteristics, including nutrients, phytoplankton, chlorophyll-a, trophic status, and the water quality of stream inflows and reservoir outflows, of Blue Mesa, Morrow Point, and Crystal Reservoirs were assessed, and a 25-year retrospective of nutrient conditions in Blue Mesa Reservoir was conducted. The three reservoirs are in a series on the Gunnison River, with an upstream to downstream order of Blue Mesa, Morrow Point, and Crystal Reservoirs. Physical properties and water-quality samples were collected four times during 1999 from reservoir, inflow, and outflow sites in and around the recreation area. Samples were analyzed for nutrients, phytoplankton and chlorophyll-a (reservoir sites only), and suspended sediment (stream inflows only). Nutrient concentrations in the reservoirs were low; median total nitrogen and phosphorus concentrations were less than 0.4 and 0.06 milligram per liter, respectively. During water-column stratification, samples collected at depth had higher nutrient concentrations than photic-zone samples. Phytoplankton community and density were affected by water temperature, nutrients, and water residence time. Diatoms were the dominant phytoplankton throughout the year in Morrow Point and Crystal Reservoirs and during spring and early winter in Blue Mesa Reservoir. Blue-green algae were dominant in Blue Mesa Reservoir during summer and fall. Phytoplankton density was highest in Blue Mesa Reservoir and lowest in Crystal Reservoir. Longer residence times and warmer temperatures in Blue Mesa Reservoir were favorable for phytoplankton growth and development. Shorter residence times and cooler temperatures in the downstream reservoirs probably limited phytoplankton growth and development. Median chlorophyll-a concentrations were higher in Blue Mesa Reservoir than Morrow Point or Crystal Reservoirs. Blue Mesa Reservoir was mesotrophic in upstream areas and oligotrophic downstream. Both Morrow Point and Crystal Reservoirs were oligotrophic. Trophic-state index values were determined for total phosphorus, chlorophyll-a, and Secchi depth for each reservoir by the Carlson method; all values ranged between 29 and 55. Only the upstream areas in Blue Mesa Reservoir had total phosphorus and chlorophyll-a indices above 50, reflecting mesotrophic conditions. Nutrient inflows to Blue Mesa Reservoir, which were derived primarily from the Gunnison River, varied on a seasonal basis, whereas nutrient inflows to Morrow Point and Crystal Reservoirs, which were derived primarily from deep water releases from the respective upstream reservoir, were steady throughout the sampling period. Total phosphorus concentrations were elevated in many stream inflows. A comparison of current (as of 1999) and historical nutrient, chlorophyll-a, and trophic conditions in Blue Mesa Reservoir and its tributaries indicated that the trophic status in Blue Mesa Reservoir has not changed over the last 25 years, and more recent nutrient enrichment has not occurred.

Continental-scale increase in stream and lake phosphorus ...

EPA Pesticide Factsheets

Phosphorus (P) is one of two nutrients that most commonly limit the productivity of freshwater ecosystems. Widespread increases in stream and lake total phosphorus (TP) concentrations over the period 2000-2014 were identified through periodic probability surveys of thousands of water bodies in the conterminous U.S. The increases were most notable in sites where TP was initially low (e.g., less than 10 µg L-1); an analysis of sites with relatively undisturbed watersheds suggests median annual TP increases of +2.0 µg L-1 yr-1 for streams (2000 to 2014) and +1.7 µg L-1 yr-1 for lakes (2007 to 2012). Because increasing TP is observed in relatively undeveloped catchments, expected mechanisms of accelerated TP delivery to aquatic habitats, such as runoff from agriculture, stormwater and wastewater, are unlikely explanations for the observed increase over time. We examine other possible drivers, such as changes in hydrology and atmospheric deposition, and conclude that increased atmospheric delivery of P to these minimally-disturbed lakes and streams, especially through dust—an increasingly important but poorly studied source of P—is the mechanism best supported by the data and worthy of further study. Phosphorus has long been regarded as the most important nutrient controlling the eutrophication of freshwater lakes and streams. This paper describes widespread increases in stream and lake total phosphorus (TP) concentrations over the period 2000-2014 that were

TRACE GAS CONCENTRATIONS IN SMALL STREAMS OF THE GEORGIA PIEDMONT

EPA Science Inventory

Seventeen headwater watersheds within the SFBR watershed ranging from 0.5 to 3.4 km2 were selected. We have been monitoring concentrations of the trace gases nitrous oxide, methane, and carbon dioxide, and other parameters (T, conductivity, dissolved oxygen, pH, nutrients, flow r...

Effects of Streambank Fencing of Near-Stream Pasture Land on a Small Watershed in Lancaster County, Pennsylvania

USGS Publications Warehouse

Galeone, Daniel G.; Low, Dennis J.; Brightbill, Robin A.

2006-01-01

This study indicated that a small buffer width along a stream in pasture land can have a positive influence on surface-water quality, benthic macroinvertebrates, and near-stream shallow ground-water quality. Overland runoff processes that move suspended sediment to the stream were controlled (or reduced) to some extent by the vegetative buffer established. Results indicated streambank fencing resulted in decreases in N-species, total-P, and suspended-sediment concentrations and yields at the outlet of the treatment basin relative to untreated sites; however, dissolved-P concentrations and yields increased. These results indicate that nutrient management, in conjunction with streambank fencing, is important in helping to control nutrient loadings to streams in this agricultural setting. An upstream site (T-2) in the treatment basin showed post-treatment reductions in suspended-sediment yields and increases in N and P yields. The different results for these treated sites indicates the effects of streambank fencing should be studied at as large a scale as possible because field-scale influences on water quality as drainage area decreases can mute the effects of fencing. Benthic-macroinvertebrate data indicated streambank fencing had a positive influence on benthic macroinvertebrates and their habitat. More improvement was detected at the outlet of the treatment basin than the upstream sites. Probably the most important biological metric, taxa richness, indicated a greater number of benthic-macroinvertebrate taxa at treated relative to control sites after fencing. Results indicated fencing improved shallow ground-water quality (for the well nest in a stream-gaining area), as noted by decreased concentrations of N species and fecal-streptococcus counts. This improvement only occurred at the well nest where the stream was gaining water from the shallow ground-water system.

Interpolation of Water Quality Along Stream Networks from Synoptic Data

NASA Astrophysics Data System (ADS)

Lyon, S. W.; Seibert, J.; Lembo, A. J.; Walter, M. T.; Gburek, W. J.; Thongs, D.; Schneiderman, E.; Steenhuis, T. S.

2005-12-01

Effective catchment management requires water quality monitoring that identifies major pollutant sources and transport and transformation processes. While traditional monitoring schemes involve regular sampling at fixed locations in the stream, there is an interest synoptic or `snapshot' sampling to quantify water quality throughout a catchment. This type of sampling enables insights to biogeochemical behavior throughout a stream network at low flow conditions. Since baseflow concentrations are temporally persistence, they are indicative of the health of the ecosystems. A major problem with snapshot sampling is the lack of analytical techniques to represent the spatially distributed data in a manner that is 1) easily understood, 2) representative of the stream network, and 3) capable of being used to develop land management scenarios. This study presents a kriging application using the landscape composition of the contributing area along a stream network to define a new distance metric. This allows for locations that are more `similar' to stay spatially close together while less similar locations `move' further apart. We analyze a snapshot sampling campaign consisting of 125 manually collected grab samples during a summer recession flow period in the Townbrook Research Watershed. The watershed is located in the Catskill region of New York State and represents the mixed forest-agriculture land uses of the region. Our initial analysis indicated that stream nutrients (nitrogen and phosphorus) and chemical (major cations and anions) concentrations are controlled by the composition of landscape characteristics (landuse classes and soil types) surrounding the stream. Based on these relationships, an intuitively defined distance metric is developed by combining the traditional distance between observations and the relative difference in composition of contributing area. This metric is used to interpolate between the sampling locations with traditional geostatistic techniques (semivariograms and ordinary kriging). The resulting interpolations provide continuous stream nutrient and chemical concentrations with reduced kriging RMSE (i.e., the interpolation fits the actual data better) performed without path restriction to the stream channel (i.e., the current default for most geostatistical packages) or performed with an in-channel, Euclidean distance metric (i.e., `as the fish swims' distance). In addition to being quantifiably better, the new metric also produces maps of stream concentrations that match expected continuous stream concentrations based on expert knowledge of the watershed. This analysis and its resulting stream concentration maps provide a representation of spatially distributed synoptic data that can be used to quantify water quality for more effective catchment management that focuses on pollutant sources and transport and transformation processes.

Effects of Gravel Bars on Nutrient Spiraling in Bedrock-Alluvium Streams

NASA Astrophysics Data System (ADS)

Iobst, B. R.; Carroll, E. P.; Furbish, D. J.

2007-05-01

The importance of the connection between nutrient transport and local stream geomorphology is becoming increasingly important. Studies have shown that the interconnectivity of nutrient cycles in the downstream direction is in part controlled by the distribution and size of gravel bars in low order streams, as hyporheic flow occurs dominantly through alternate and mid-channel gravel bars. For this investigation multiple gravel bars in a 3rd order bedrock-alluvium stream were studied to determine general relationships between nutrient spiraling and hyporheic flow. The first goal was to understand (1) the extent to which water moves through hyporheic zones and (2) the basic chemistry of the hyporheic water. The second part of the study was to understand how nutrients, notably nitrogen, are affected in their cycling by the relatively long residence times encountered in gravel bars during hyporheic flow. Wells were installed along a 600 m reach of Panther Creek, KY in selected bars, as well as in a secondary location involving a grid installation pattern in one large bar. Results have shown that hyporheic flow through gravel bars is an important factor in influencing stream chemistry. Background water chemistry surveys have shown that certain parameters, specifically ammonium and nitrogen concentrations vary downstream, and that the dominant control over these changes is gravel bar location. Rhodamine WT was used in field tracer tests to track the travel times of water through bars as well as partitioning of water between the open channel and hyporheic flows. Further tests will be conducted utilizing a stable isotope study to determine how nitrogen is affected by hyporheic flow, and what implications this has for nutrient transport. We expect results to show that the spacing and size of gravel bars is a dominant control in key nutrient spiraling parameters, namely uptake lengths and overall nitrogen cycling rates. This has implications for how natural systems will respond to human impacts, both through the modification of the physical template of stream systems as well as increased anthropogenic loading of nitrogen.

Concentrations and loads of suspended sediment and nutrients in surface water of the Yakima River basin, Washington, 1999-2000 [electronic resource] : with an analysis of trends in concentrations

USGS Publications Warehouse

Ebbert, James C.; Embrey, Sandra S.; Kelley, Janet A.

2003-01-01

Spatial and temporal variations in concentrations and loads of suspended sediment and nutrients in surface water of the Yakima River Basin were assessed using data collected during 1999?2000 as part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Program. Samples were collected at 34 sites located throughout the Basin in August 1999 using a Lagrangian sampling design, and also were collected weekly and monthly from May 1999 through January 2000 at three of the sites. Nutrient and sediment data collected at various time intervals from 1973 through 2001 by the USGS, Bureau of Reclamation, Washington State Department of Ecology, and Roza-Sunnyside Board of Joint Control were used to assess trends in concentrations. During irrigation season (mid-March to mid-October), concentrations of suspended sediment and nutrients in the Yakima River increase as relatively pristine water from the forested headwaters moves downstream and mixes with discharges from streams, agricultural drains, and wastewater treatment plants. Concentrations of nutrients also depend partly on the proportions of mixing between river water and discharges: in years of ample water supply in headwater reservoirs, more water is released during irrigation season and there is more dilution of nutrients discharged to the river downstream. For example, streamflow from river mile (RM) 103.7 to RM 72 in August 1999 exceeded streamflow in July 1988 by a factor of almost 2.5, but loads of total nitrogen and phosphorus discharged to the reach from streams, drains, and wastewater treatment plants were only 1.2 and 1.1 times larger. In years of ample water supply, canal water, which is diverted from either the Yakima or Naches River, makes up more of the flow in drains and streams carrying agricultural return flows. The canal water dilutes nutrients (especially nitrate) transported to the drains and streams in runoff from fields and in discharges from subsurface field drains and the shallow ground-water system. The average concentration of total nitrogen in drains and streams discharging to the Yakima River from RM 103.7 to RM 72 in August 1999 was 2.63 mg/L, and in July 1988 was 3.16 mg/L; average concentrations of total phosphorus were 0.20 and 0.26 mg/L. After irrigation season, streamflow in agricultural drains decreases because irrigation water is no longer diverted from the Yakima and Naches Rivers. As a result, concentrations of total nitrogen in drains increase because nitrate, which constitutes much of total nitrogen, continues to enter the drains from subsurface drains and shallow ground water. Concentrations of total phosphorus and suspended sediment often decrease, because they are transported to the drains in runoff of irrigation water from fields. In Granger Drain, concentrations of total nitrogen ranged from 2-4 mg/L during irrigation season and increased to about 6 mg/L after irrigation season, and concentrations of total phosphorus, as high as 1 mg/L, decreased to about 0.2 mg/L. In calendar year 1999, Moxee Drain transported an average of 28,000 lb/d (pounds per day) of suspended sediment, 380 lb/d of total nitrogen, and 46 lb/d of total phosphorus to the Yakima River. These loads were about half the average loads transported by Granger Drain during the same period. Average streamflows were similar for the two drains, so the difference in loads was due to differences in constituent concentrations: those in Moxee Drain were about 40-60 percent less than those in Granger Drain. Loads of suspended sediment and total phosphorus in Moxee and Granger Drains were nearly four times higher during irrigation season than during the non-irrigation season because with increased flow during irrigation season, concentrations of suspended sediment and total phosphorus are usually higher. Loads of nitrate in the drains were about the same in both seasons because nitrate concentrations are higher during the non-irrigation season.

Salmon influences on dissolved organic matter in a coastal temperate brown-water stream: an application of fluorescence spectroscopy.

Treesearch

E. Hood; J. Fellman; R.T. Edwards

2007-01-01

The annual return of spawning Pacific salmon (genus Oncorhynchus) can have a dramatic effect on the nutrient budgets of recipient freshwater ecosystems. We examined how spawning salmon affect streamwater concentrations of inorganic nitrogen and phosphorus and dissolved organic carbon (DOC) in Peterson Creek, a salmon stream in southeast Alaska. In...

Cultural Treatments Influence Hardwood Growth and Foliar Nutrient Concentration on a Minor Stream Bottom Site

Treesearch

Harvey E. Kennedy

1985-01-01

Seedlings or cuttings of nine species of hardwoods were planted on a minor stream bottom (Aeric Fluvaquents) in southeast Arkansas and mowed or disked several times annually for 4 years. Disking to eliminate competition significantly increased heights and diameters of all, and survival of some, species. Soil nitrogen, organic matter, and pH were significantly lowered...

Stoichiometry of hydrological C, N, and P losses across climate and geology: An environmental matrix approach across New Zealand primary forests

NASA Astrophysics Data System (ADS)

McGroddy, M. E.; Baisden, W. T.; Hedin, L. O.

2008-03-01

Hydrologic losses can play a key role in regulating ecosystem nutrient balances, particularly in regions where baseline nutrient cycles are not augmented by industrial deposition. We used first-order streams to integrate hydrologic losses at the watershed scale across unpolluted old-growth forests in New Zealand. We employed a matrix approach to resolve how stream water concentrations of dissolved organic carbon (DOC), organic and inorganic nitrogen (DON and DIN), and organic and inorganic phosphorus (DOP and DIP) varied as a function of landscape differences in climate and geology. We found stream water total dissolved nitrogen (TDN) to be dominated by organic forms (medians for DON, 81.3%, nitrate-N, 12.6%, and ammonium-N, 3.9%). The median stream water DOC:TDN:TDP molar ratio of 1050:21:1 favored C slightly over N and P when compared to typical temperate forest foliage ratios. Using the full set of variables in a multiple regression approach explained approximately half of the variability in DON, DOC, and TDP concentrations. Building on this approach we combined a simplified set of variables with a simple water balance model in a regression designed to predict DON export at larger spatial scales. Incorporating the effects of climate and geologic variables on nutrient exports will greatly aid the development of integrated Earth-climate biogeochemical models which are able to take into account multiple element dynamics and complex natural landscapes.

Regional patterns of total nitrogen concentrations in the National Rivers and Streams Assessment

USGS Publications Warehouse

Omernik, James M.; Paulsen, Steven G.; Griffith, Glenn E.; Weber, Marc H.

2016-01-01

Patterns of nitrogen (N) concentrations in streams sampled by the National Rivers and Streams Assessment (NRSA) were examined semiquantitatively to identify regional differences in stream N levels. The data were categorized and analyzed by watershed size classes to reveal patterns of the concentrations that are consistent with the spatial homogeneity in natural and anthropogenic characteristics associated with regional differences in N levels. Ecoregions and mapped information on human activities including agricultural practices were used to determine the resultant regions. Marked differences in N levels were found among the nine aggregations of ecoregions used to report the results of the NRSA. We identified distinct regional patterns of stream N concentrations within the reporting regions that are associated with the characteristics of specific Level III ecoregions, groups of Level III ecoregions, groups of Level IV ecoregions, certain geographic characteristics within ecoregions, and/or particular watershed size classes. We described each of these regions and illustrated their areal extent and median and range in N concentrations. Understanding the spatial variability of nutrient concentrations in flowing waters and the apparent contributions that human and nonhuman factors have on different sizes of streams and rivers is critical to the development of effective water quality assessment and management plans. This semi-quantitative analysis is also intended to identify areas within which more detailed quantitative work can be conducted to determine specific regional factors associated with variations in stream N concentrations.

Implementation of sediment dynamics in a global integrated assessment model for an improved simulation of nutrient retention and transfers in surface freshwaters

NASA Astrophysics Data System (ADS)

Vilmin, L.; Beusen, A.; Mogollón, J.; Bouwman, L.

2017-12-01

Sediment dynamics play a significant role in river biogeochemical functioning. They notably control the transfer of particle-bound nutrients, have a direct influence on light availability for primary production, and particle accumulation can affect oxic conditions of river beds. In the perspective of improving our current understanding of large scale nutrient fluxes in rivers, it is hence necessary to include these dynamics in global models. In this scope, we implement particle accumulation and remobilization in a coupled global hydrology-nutrient model (IMAGE-GNM), at a spatial resolution of 0.5°. The transfer of soil loss from natural and agricultural lands is simulated mechanistically, from headwater streams to estuaries. First tests of the model are performed in the Mississippi river basin. At a yearly time step for the period 1978-2000, the average difference between simulated and measured suspended sediment concentrations at the most downstream monitoring station is 25%. Sediment retention is estimated in the different Strahler stream orders, in lakes and reservoirs. We discuss: 1) the distribution of sediment loads to small streams, which has a significant effect on transfers through watersheds and larger scale river fluxes and 2) the potential effect of damming on the fate of particle-bound nutrients. These new developments are crucial for future assessments of large scale nutrient and carbon fluxes in river systems.

Characterization of nutrients and fecal indicator bacteria at a concentrated swine feeding operation in Wake County, North Carolina, 2009-2011

USGS Publications Warehouse

Harden, Stephen L.; Rogers, Shane W.; Jahne, Michael A.; Shaffer, Carrie E.; Smith, Douglas G.

2012-01-01

Study sites were sampled for laboratory analysis of nutrients, total suspended solids (TSS), and (or) fecal indicator bacteria (FIB). Nutrient analyses included measurement of dissolved ammonia, total and dissolved ammonia + organic nitrogen, dissolved nitrate + nitrite, dissolved orthophosphate, and total phosphorus. The FIB analyses included measurement of Escherichia coli and enterococci. Samples of wastewater at the swine facility were collected from a pipe outfall from the swine housing units, two storage lagoons, and the spray fields for analysis of nutrients, TSS, and FIB. Soil samples collected from a spray field were analyzed for FIB. Monitoring locations were established for collecting discharge and water-quality data during storm events at three in-field runoff sites and two sites on the headwater stream (one upstream and one downstream) next to the swine facility. Stormflow samples at the five monitoring locations were collected for four storm events during 2009 to 2010 and analyzed for nutrients, TSS, and FIB. Monthly water samples also were collected during base-flow conditions at all four stream sites for laboratory analysis of nutrients, TSS, and (or) FIB.

Identifying nutrient reference sites in nutrient-enriched regions-Using algal, invertebrate, and fish-community measures to identify stressor-breakpoint thresholds in Indiana rivers and streams, 2005-9

USGS Publications Warehouse

Caskey, Brian J.; Bunch, Aubrey R.; Shoda, Megan E.; Frey, Jeffrey W.; Selvaratnam, Shivi; Miltner, Robert J.

2013-01-01

Excess nutrients in aquatic ecosystems can lead to shifts in species composition, reduced dissolved oxygen concentrations, fish kills, and toxic algal blooms. In this study, nutrients, periphyton chlorophyll a (CHLa), and invertebrate- and fishcommunity data collected during 2005-9 were analyzed from 318 sites on Indiana rivers and streams. The objective of this study was to determine which invertebrate and fish-taxa attributes best reflect the conditions of streams in Indiana along a gradient of nutrient concentrations by (1) determining statistically and ecologically significant relations among the stressor (total nitrogen, total phosphorus, and periphyton CHLa) and response (invertebrate and fish community) variables; and (2) determining the levels at which invertebrate- and fish-community measures change in response to nutrients or periphyton CHLa. For water samples at the headwater sites, total nitrogen (TN) concentrations ranged from 0.343 to 21.6 milligrams per liter (mg/L) (median 2.12 mg/L), total phosphorus (TP) concentrations ranged from 0.050 to 1.44 mg/L (median 0.093 mg/L), and periphyton CHLa ranged from 0.947 to 629 mg/L (median 69.7 mg/L). At the wadable sites, TN concentrations ranged from 0.340 to 10.0 mg/L (median 2.31 mg/L), TP concentrations ranged from 0.050 to 1.24 mg/L (median 0.110 mg/L), and periphyton CHLa ranged from 0.383 to 719 mg/L (median 44.7 mg/L). Recursive partitioning identified statistically significant low and high breakpoint thresholds on invertebrate and fish measures, which demonstrated the ecological response in enriched conditions. The combined community (invertebrate and fish) mean low and high TN breakpoint thresholds were 1.03 and 2.61 mg/L, respectively. The mean low and high breakpoint thresholds for TP were 0.083 and 0.144 mg/L, respectively. The mean low and high breakpoint thresholds for periphyton CHLa were 20.9 and 98.6 milligrams per square meter (mg/m2), respectively. Additive quantile regression analysis found similar thresholds (TN of 0.656 mg/L, mean TP of 0.118 mg/L, and periphyton CHLa of 27.2 mg/m2) for some stressor variables as determined by the breakpoint analysis. The TN and TP concentrations in this study showed a nutrient gradient that spanned three orders of magnitude. Sites were divided into Low, Medium, and High nutrient groups based on the 10th and 75th percentiles. The invertebrate and fish communities were similar along the nutrient gradient, using an analysis of similarity, demonstrating there was not a species trophic gradient. Within all nutrient groups, invertebrate and fish communities were dominated by nutrient tolerant taxa (algivores, herbivores, and omnivores) that included invertebrates, such as Cheumatopsyche sp., Physella sp., and fish such as Stonerollers (Campostoma spp.) and Bluntnose Minnow (Pimephales notatus). To determine if low nutrient concentrations at some sites were caused by algal uptake and not oligotrophic conditions, sites with low nutrient concentrations (less than 10th percentile for TN or TP) were examined based on the Low (less than or equal to the 10th percentile) and High (greater than the 75th percentile) periphyton CHLa concentrations. Within low nutrient sites, the invertebrate and fish communities were statistically different between Low and High periphyton CHLa categories. The majority of variance between the Low and High periphyton CHLa categories was caused by Cheumatopsyche sp. (caddisfly), Physella sp. (pulmonate snail), and Caenis latipennis (a mayfly) in the invertebrate community; and caused by Stonerollers, Western Blacknose Dace (Rhinichthys atratulus meleagris), and Creek Chub (Semotilus atromaculatus) in the fish community. The dominance of tolerant herbivore and omnivore taxa in the High periphyton CHLa group indicates that low nutrient concentrations are a result of nutrient uptake and increased algal growth. This study highlights the importance of assessing multiple lines of evidence when attempting to identify the trophic condition of a site.

Water-quality characteristics, trends, and nutrient and sediment loads of streams in the Treyburn development area, North Carolina, 1988–2009

USGS Publications Warehouse

Fine, Jason M.; Harned, Douglas A.; Oblinger, Carolyn J.

2013-01-01

Streamflow and water-quality data, including concentrations of nutrients, metals, and pesticides, were collected from October 1988 through September 2009 at six sites in the Treyburn development study area. A review of water-quality data for streams in and near a 5,400-acre planned, mixed-use development in the Falls Lake watershed in the upper Neuse River Basin of North Carolina indicated only small-scale changes in water quality since the previous assessment of data collected from 1988 to 1998. Loads and yields were estimated for sediment and nutrients, and temporal trends were assessed for specific conductance, pH, and concentrations of dissolved oxygen, suspended sediment, and nutrients. Water-quality conditions for the Little River tributary and Mountain Creek may reflect development within these basins. The nitrogen and phosphorus concentrations at the Treyburn sites are low compared to sites nationally. The herbicides atrazine, metolachlor, prometon, and simazine were detected frequently at Mountain Creek and Little River tributary but concentrations are low compared to sites nationally. Little River tributary had the lowest median suspended-sediment yield over the 1988–2009 study period, whereas Flat River tributary had the largest median yield. The yields estimated for suspended sediment and nutrients were low compared to yields estimated for other basins in the Southeastern United States. Recent increasing trends were detected in total nitrogen concentration and suspended-sediment concentrations for Mountain Creek, and an increasing trend was detected in specific conductance for Little River tributary. Decreasing trends were detected in dissolved nitrite plus nitrate nitrogen, total ammonia plus organic nitrogen, sediment, and specific conductance for Flat River tributary. Water chemical concentrations, loads, yields, and trends for the Treyburn study sites reflect some effects of upstream development. These measures of water quality are generally low, however, compared to regional and national averages.

Assessing possible visitor-use impacts on water quality in Yosemite National Park, California

USGS Publications Warehouse

Clow, David W.; Peavler, Rachael S.; Roche, Jim; Panorska, Anna K.; Thomas, James M.; Smith, Steve

2011-01-01

There is concern that visitor-use associated activities, such as bathing, dish washing, wastewater production, and stock animal use near lakes and streams, could cause degradation of water quality in Yosemite National Park. A study was conducted during 2004–2007 to assess patterns in nutrient and Escherichia coli (E. coli) concentrations in the Merced and Tuolumne Rivers and characterize natural background concentrations of nutrients in the park. Results indicated that nutrient and E. coli concentrations were low, even compared to other undeveloped sites in the United States. A multiple linear regression approach was used to model natural background concentrations of nutrients, with basin characteristics as explanatory variables. Modeled nitrogen concentrations increased with elevation, and modeled phosphorus concentrations increased with basin size. Observed concentrations (±uncertainty) were compared to modeled concentrations (±uncertainty) to identify sites that might be impacted by point sources of nutrients, as indicated by large model residuals. Statistically significant differences in observed and modeled concentrations were observed at only a few locations, indicating that most sites were representative of natural background conditions. The empirical modeling approach used in this study can be used to estimate natural background conditions at any point along a study reach in areas minimally impacted by development, and may be useful for setting water-quality standards in many national parks.

Scaling Dissolved Nutrient Removal in River Networks: A Comparative Modeling Investigation

NASA Astrophysics Data System (ADS)

Ye, Sheng; Reisinger, Alexander J.; Tank, Jennifer L.; Baker, Michelle A.; Hall, Robert O.; Rosi, Emma J.; Sivapalan, Murugesu

2017-11-01

Along the river network, water, sediment, and nutrients are transported, cycled, and altered by coupled hydrological and biogeochemical processes. Our current understanding of the rates and processes controlling the cycling and removal of dissolved inorganic nutrients in river networks is limited due to a lack of empirical measurements in large, (nonwadeable), rivers. The goal of this paper was to develop a coupled hydrological and biogeochemical process model to simulate nutrient uptake at the network scale during summer base flow conditions. The model was parameterized with literature values from headwater streams, and empirical measurements made in 15 rivers with varying hydrological, biological, and topographic characteristics, to simulate nutrient uptake at the network scale. We applied the coupled model to 15 catchments describing patterns in uptake for three different solutes to determine the role of rivers in network-scale nutrient cycling. Model simulation results, constrained by empirical data, suggested that rivers contributed proportionally more to nutrient removal than headwater streams given the fraction of their length represented in a network. In addition, variability of nutrient removal patterns among catchments was varied among solutes, and as expected, was influenced by nutrient concentration and discharge. Net ammonium uptake was not significantly correlated with any environmental descriptor. In contrast, net daily nitrate removal was linked to suspended chlorophyll a (an indicator of primary producers) and land use characteristics. Finally, suspended sediment characteristics and agricultural land use were correlated with net daily removal of soluble reactive phosphorus, likely reflecting abiotic sorption dynamics. Rivers are understudied relative to streams, and our model suggests that rivers can contribute more to network-scale nutrient removal than would be expected based upon their representative fraction of network channel length.

Sensitivity analysis of a pulse nutrient addition technique for estimating nutrient uptake in large streams

Treesearch

Laurence Lin; J.R. Webster

2012-01-01

The constant nutrient addition technique has been used extensively to measure nutrient uptake in streams. However, this technique is impractical for large streams, and the pulse nutrient addition (PNA) has been suggested as an alternative. We developed a computer model to simulate Monod kinetics nutrient uptake in large rivers and used this model to evaluate the...

Summary of Surface-Water Quality Data from the Illinois River Basin in Northeast Oklahoma, 1970-2007

USGS Publications Warehouse

Andrews, William J.; Becker, Mark F.; Smith, S. Jerrod; Tortorelli, Robert L.

2009-01-01

The quality of streams in the Illinois River Basin of northeastern Oklahoma is potentially threatened by increased quantities of wastes discharged from increasing human populations, grazing of about 160,000 cattle, and confined animal feeding operations raising about 20 million chickens. Increasing numbers of humans and livestock in the basin contribute nutrients and bacteria to surface water and groundwater, causing greater than the typical concentrations of those constituents for this region. Consequences of increasing contributions of these substances can include increased algal growth (eutrophication) in streams and lakes; impairment of habitat for native aquatic animals, including desirable game fish species; impairment of drinking-water quality by sediments, turbidity, taste-and-odor causing chemicals, toxic algal compounds, and bacteria; and reduction in the aesthetic quality of the streams. The U.S. Geological Survey, in cooperation with the Oklahoma Scenic Rivers Commission, prepared this report to summarize the surface-water-quality data collected by the U.S. Geological Survey at five long-term surface-water-quality monitoring sites. The data summarized include major ions, nutrients, sediment, and fecal-indicator bacteria from the Illinois River Basin in Oklahoma for 1970 through 2007. General water chemistry, concentrations of nitrogen and phosphorus compounds, chlorophyll-a (an indicator of algal biomass), fecal-indicator bacteria counts, and sediment concentrations were similar among the five long-term monitoring sites in the Illinois River Basin in northeast Oklahoma. Most water samples were phosphorus-limited, meaning that they contained a smaller proportion of phosphorus, relative to nitrogen, than typically occurs in algal tissues. Greater degrees of nitrogen limitation occurred at three of the five sites which were sampled back to the 1970s, probably due to use of detergents containing greater concentrations of phosphorus than in subsequent periods. Concentrations of nitrogen, phosphorus, and sediment, and counts of bacteria generally increased with streamflow at the five sites, probably due to runoff from the land surface and re-suspension of streambed sediments. Phosphorus concentrations typically exceeded the Oklahoma standard of 0.037 milligrams per liter for Scenic Rivers. Concentrations of chlorophyll-a in phytoplankton in water samples collected at the five sites were not well correlated with streamflow, nor to concentrations of the nutrients nitrogen and phosphorus, probably because much of the algae growing in these streams are periphyton attached to streambed cobbles and other debris, rather than phytoplankton in the water column. Sediment concentrations correlated with phosphorus concentrations in water samples collected at the sites, probably due to sorption of phosphorus to soil particles and streambed sediments and runoff of soils and animal wastes at the land surface and resuspension of streambed sediments and phosphorus during wet, high-flow periods. Fecal coliform bacteria counts at the five sites sometimes exceeded the Oklahoma Primary Body Contact Standard of 400 colonies per 100 milliliters when streamflows were greater than 1000 cubic feet per second. Ultimately, Lake Tenkiller, an important ecological and economic resource for the region, receives the compounds that runoff the land surface or seep to local streams from groundwater in the basin. Because of eutrophication from increased nutrient loading, Lake Tenkiller is listed for impairment by diminished dissolved oxygen concentrations, phosphorus, and chlorophyll-a by the State of Oklahoma in evaluation of surface-water quality required by section 303d of the Clean Water Act. Stored phosphorus in soils and streambed and lakebed sediments may continue to provide phosphorus to local streams and lakes for decades to come. Steps are being made to reduce local sources of phosphorus, including upgrades in capacity and effective

Nutrient enrichment and fish nutrient tolerance: Assessing biologically relevant nutrient criteria

USGS Publications Warehouse

Meador, Michael R.

2013-01-01

Relationships between nutrient concentrations and fish nutrient tolerance were assessed relative to established nutrient criteria. Fish community, nitrate plus nitrite (nitrate), and total phosphorus (TP) data were collected during summer low-flow periods in 2003 and 2004 at stream sites along a nutrient-enrichment gradient in an agricultural basin in Indiana and Ohio and an urban basin in the Atlanta, Georgia, area. Tolerance indicator values for nitrate and TP were assigned for each species and averaged separately for fish communities at each site (TIVo). Models were used to predict fish species expected to occur at a site under minimally disturbed conditions and average tolerance indicator values were determined for nitrate and TP separately for expected communities (TIVe). In both areas, tolerance scores (TIVo/TIVe) for nitrate increased significantly with increased nitrate concentrations whereas no significant relationships were detected between TP tolerance scores and TP concentrations. A 0% increase in the tolerance score (TIVo/TIVe = 1) for nitrate corresponded to a nitrate concentration of 0.19 mg/l (compared with a USEPA summer nitrate criterion of 0.17 mg/l) in the urban area and 0.31 mg/l (compared with a USEPA summer nitrate criterion of 0.86 mg/l) in the agricultural area. Fish nutrient tolerance values offer the ability to evaluate nutrient enrichment based on a quantitative approach that can provide insights into biologically relevant nutrient criteria.

Exploring the impact of agriculture on nitrogen and phosphorus biogeochemistry in global rivers during the twentieth century (Invited)

NASA Astrophysics Data System (ADS)

Bouwman, L.; Beusen, A.; Van Beek, L. P.

2013-12-01

Nutrients are transported from land to sea through the continuum formed by soils, groundwater, riparian zones, floodplains, streams, rivers, lakes, and reservoirs. The hydrology, ecology and biogeochemical processing in each of these components are strongly coupled and result in retention of a significant fraction of the nutrients transported. This paper analyzes the global changes in nutrient biogeochemical processes and retention in rivers during the past century (1900-2000); this period encompasses dramatic increases in human population and economic human activities including agriculture that have resulted in major changes in land use, nutrient use in agriculture, wastewater flows and human interventions in the hydrology (1). We use the hydrological PCR-GLOBWB model (2) for the period 1900-2000, including climate variability and the history of dam construction and land use conversion. Global agricultural and natural N and P soil budgets for the period 1900-2000 are the starting point to simulate nutrient flows from the soil via surface runoff and leaching through the groundwater system and riparian zones. In-stream processes are described with the nutrient spiraling concept. In the period 1900-2000, the global soil N budget surplus (inputs minus withdrawal in harvested crops) for agricultural and natural ecosystems increased from 118 to 202 Tg yr-1, and the global P budget increased from < 0.5 to 11 Tg P yr-1. As a result of this massive increase, nutrient delivery to streams and river nutrient export has increased rapidly in the 20th century. Model results are sensitive to factors determining the N and P delivery, as well as in-stream processes. The most uncertain factors are N delivery to streams by groundwater (denitrification as a function of thickness and reactivity of aquifers), and in-stream N and P retention parameters (net uptake velocity, retention as function of concentration). References 1. Bouwman AF, Beusen AHW, Griffioen J, Van Groenigen JW, Hefting MM, Oenema O, et al. Global trends and uncertainties in terrestrial denitrification and N2O emissions. Philosophical Transactions of the Royal Society B: Biological Sciences. 2013;368(20130112). 2. Van Beek LPH, Wada Y, Bierkens MFP. Global monthly water stress: 1. Water balance and water availability. Water Resour Res. 2011;47(7):W07517.

Occurrence and distribution of nutrients, suspended sediment, and pesticides in the Mobile River Basin, Alabama, Georgia, Mississippi, and Tennessee, 1999-2001

USGS Publications Warehouse

McPherson, Ann K.; Moreland, Richard S.; Atkins, J. Brian

2003-01-01

The Mobile River Basin is one of more than 50 river basins and aquifer systems being investigated as part of the U.S. Geological Survey's National Water- Quality Assessment (NAWQA) Program. This basin is the sixth largest river basin in the United States and the fourth largest in terms of streamflow. The Mobile River Basin encompasses parts of Alabama, Georgia, Mississippi, and Tennessee, and almost two-thirds of the 44,0000-square-mile basin is located in Alabama. The extensive water resources of the Mobile River Basin are influenced by an array of natural and cultural factors, which impart unique and variable qualities to the streams, rivers, and aquifers and provide abundant habitat to sustain the diverse aquatic life in the basin. From January 1999 to December 2001, a study was conducted of the occurrence and distribution of nutrients, suspended sediment, and pesticides in surface water of the Mobile River Basin. Nine sampling sites were selected on the basis of land use. The nine sites included two streams draining agricultural areas, two urban streams, and five large rivers with mixed land use. Surface-water samples were collected from one to four times each month to characterize the spatial and temporal variation in nutrient and pesticide concentrations. Nutrient and suspended-sediment concentrations were highest in watersheds dominated by urban or agricultural land uses. Forty-two percent of the total phosphorus concentrations at all nine sites exceeded the U.S. Environmental Protection Agency's recommended maximum concentration of 0.1 milligram per liter. Flow-weighted mean concentrations at the Mobile River Basin sites generally were in the lower to middle percentile ranges compared with data from other NAWQA studies across the Nation. However, flow-weighted mean concentrations of ammonia, total nitrogen, orthophosphate, and total phosphorus at Bogue Chitto Creek, an agricultural watershed, ranked in the upper 20th percentile of agricultural sites sampled across the Nation as part of the NAWQA Program. Nutrient loads in the Tombigbee River were nearly twice as high compared with nutrient loads in the Alabama River. Nutrient yields were highest in Bogue Chitto Creek, Cahaba Valley Creek, and Threemile Branch because of agricultural and urban land uses in these watersheds. Of the 104 pesticides and degradation products analyzed in the stream samples, 69 were detected in one or more samples. Of the 69 detected pesticides, 51 were herbicides, 15 were insecticides, and 3 were fungicides. A relatively small number of heavily used herbicides accounted for most of the detections, including atrazine and its metabolites (deethylatrazine, 2-hydroxyatrazine, deisopropylatrazine, and deethyldeisopropylatrazine), simazine, metolachlor, tebuthiuron, prometon, diuron, and 2,4-D. Diazinon, chlorpyrifos, and carbaryl were the most frequently detected insecticides; metalaxyl was the most frequently detected fungicide in the Mobile River Basin. Concentrations of pesticides detected in surface water of the Mobile River Basin were among the highest concentrations recorded nationally by the NAWQA Program during 1991 to 2001. The three highest concentrations of atrazine detected at sites across the country were recorded at Bogue Chitto Creek; the highest concentrations of 2,4-D, imazaquin, and malathion recorded nationally were detected at Threemile Branch. Aquatic-life criteria were exceeded by concentrations of five herbicides (2,4-D, atrazine, cyanazine, diuron, and metolachlor), six insecticides (carbaryl, chlorpyrifos, diazinon, dieldrin, malathion, and p,p'-DDE), and one fungicide (chlorothalonil). Drinking-water standards were exceeded by concentrations of four herbicides (2,4-D, atrazine, cyanazine, and simazine), three insecticides (alpha- HCH, diazinon, and dieldrin), and one fungicide (chlorothalonil). The types and concentrations of pesticides found in surface water are linked to land use and to the types of pesti

Water-quality trend analysis and sampling design for streams in North Dakota, 1971-2000

USGS Publications Warehouse

Vecchia, Aldo V.

2003-01-01

This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the North Dakota Department of Health, to analyze historical water-quality trends in selected dissolved major ions, nutrients, and dissolved trace metals for 10 streams in southwestern and eastern North Dakota and to develop an efficient sampling design to monitor future water-quality trends. A time-series model for daily streamflow and constituent concentration was used to identify significant concentration trends, separate natural hydroclimatic variability in concentration from variability that could have resulted from anthropogenic causes, and evaluate various sampling designs to monitor future water-quality trends. The interannual variability in concentration as a result of variability in streamflow, referred to as the annual concentration anomaly, generally was high for all constituents and streams used in the trend analysis and was particularly sensitive to the severe drought that occurred in the late 1980's and the very wet period that began in 1993 and has persisted to the present (2002). Although climatic conditions were similar across North Dakota during the trend-analysis period (1971-2000), significant differences occurred in the annual concentration anomalies from constituent to constituent and location to location, especially during the drought and the wet period. Numerous trends were detected in the historical constituent concentrations after the annual concentration anomalies were removed. The trends within each of the constituent groups (major ions, nutrients, and trace metals) showed general agreement among the streams. For most locations, the largest dissolved major-ion concentrations occurred during the late 1970's and concentrations in the mid- to late 1990's were smaller than concentrations during the late 1970's. However, the largest concentrations for three of the Missouri River tributaries and one of the Red River of the North tributaries occurred during the mid- to late 1990's. Concentration trends for total ammonia plus organic nitrogen showed close agreement among the streams for which that constituent was evaluated. The largest concentrations occurred during the early 1980's, and the smallest concentrations occurred during the early 1990's. Nutrient data were not available for the early 1970's or late 1990's. Although a detailed analysis of the causes of the trends was beyond the scope of this report, a preliminary analysis of cropland, livestock-inventory, and oil-production data for 1971-2000 indicated the concentration trends may be related to the livestock-inventory and oil-production activities in the basins. Dissolved iron and manganese concentrations for the southwestern North Dakota streams generally remained stable during 1971-2000. However, many of the recorded concentrations for those streams were less than the detection limit, and trends that were masked by censoring may have occurred. Several significant trends were detected in dissolved iron and manganese concentrations for the eastern North Dakota streams. Concentrations for those streams either remained stable or increased during most of the 1970's and then decreased rapidly for about 2 years beginning in the late 1970's. The concentrations were relatively stable from the early 1980's to 2000 except at two locations where dissolved iron concentrations increased during the early 1990's. The most efficient overall sampling designs for the detection of annual trends (that is, trends that occur uniformly during the entire year) consisted of balanced designs in which the sampling dates and the number of samples collected remained fixed from year to year and in which the samples were collected throughout the year rather than in a short timespan. The best overall design for the detection of annual trends consisted of three samples per year, with samples collected near the beginning of December, April, and August. That design had acceptable sensitivity for the detection of trends in most constituents at all locations. Little improvement in sensitivity was achieved by collecting more than three samples per year.The sampling designs that were first evaluated for annual trends also were evaluated with regard to their sensitivity to detect seasonal trends that occurred during three seasons--April through August, August through December, and December through April. Design results indicated that an average of one extra sample per station per year resulted in an efficient design for detecting seasonal trends. However, allocation of the extra samples varied depending on the station, month, and constituent group (major ions, nutrients, and trace metals).

Seasonal and spatial variability of nutrients and pesticides in streams of the Willamette Basin, Oregon, 1993-95

USGS Publications Warehouse

Rinella, F.A.; Janet, M.L.

1998-01-01

From April 1993 to September 1995, the U.S. Geological Survey conducted a study of the occurrence and distribution of nutrients and pesticides in surface water of the Willamette and Sandy River Basins, Oregon, as part of the U.S. Geological Survey National Water-Quality Assessment (NAWQA) Program. About 260 samples were collected at 51 sites during the study; of these, more than 60 percent of the pesticide samples and more than 70 percent of the nutrient samples were collected at 7 sites in a fixed-station network (primary sites) to characterize seasonal water-quality variability related to a variety of land-use activities. Samples collected at the remain ing 44 sites were used primarily to characterize spatial water- quality variability in agricultural river subbasins located throughout the study area.This report describes concentrations of 4 nutrient species (total nitrogen, filtered nitrite plus nitrate, total phosphorus, and soluble reactive phosphorus) and 86 pesticides and pesticide degradation products in streams, during high- and low-flow conditions, receiving runoff from urban, agricultural, forested, and mixed-use lands. Although most nutrient and pesticide concentrations were relatively low, some concentrations exceeded maximum contaminant levels for drinking water and water-quality criteria for chronic toxicity established for the protection of freshwater aquatic life. The largest number of exceedances generally occurred at sites receiving predominantly agricultural inputs. Total nitrogen, filtered nitrite plus nitrate, total phosphorus, and soluble reactive phosphorus concentrations were detected in 89 to 98 percent of the samples; atrazine, simazine, metolachlor, and desethylatrazine were detected in 72 to 94 percent of the samples. Fifty different pesticides and degradation products was detected during the 2-1/2 year study.Seasonally, peak nutrient and pesticide concentrations at the seven primary sites were observed during winter and spring rains. With the exception of soluble reactive phosphorus, peak nutrient concentrations were recorded at agricultural sites during winter rains, whereas peak pesticide concentrations occurred at agricultural sites during spring rains.Spatially, although nutrients were detected slightly more often in samples from the northern Willamette Basin relative to the southern Willamette Basin, concentration distributions in the two areas were similar. About 75 percent more pesticides were detected in the northern basin; however, two-thirds of the pesticide detections in the southern basin were larger in concentration than for the same pesticides detected in the northern basin.Nutrient and pesticide concentrations were associated with percent of upstream drainage area in forest, urbanization, and agriculture. Nutrient concentrations at forested sites were among the smallest observed at any of the sites sampled. In addition, only one pesticide and one pesticide degradation product were detected at forested sites, at concentrations near the method detection limits. The highest nutrient concentrations were observed at agricultural sites. Further, the largest numbers of different pesticides detected were at agricultural sites, at concentrations generally larger than at most other land-use sites. Three pesticides--dichlobenil, prometon, and tebuthiuron--were detected more frequently at a site receiving predominantly urban inputs.

Geomorphic stream restoration as an approach for reducing nutrients in degraded urban watersheds

EPA Science Inventory

Elevated nitrate levels in streams and groundwater pose human and ecological threats. Stream restoration may improve the nutrient removal capacity of streams, yet few studies have investigated the effectiveness of restoration as a nutrient BMP despite significant national effort...

DEVELOPMENT OF A METHOD FOR DETERMINING PHOSPHORUS NUTRIENT CRITERIA IN STREAMS AND RIVERS OF THE MID-ATLANTIC REGION

EPA Science Inventory

Nutrient enrichment of phosphorus and nitrogen is the second most cited cause for impairment of streams and rivers in the U.S. There is a need to develop stream nutrient criteria to control nutrient loadings. Since biotic metrics can assess the overall impact of nutrient enrichm...

Root uptake and translocation of perfluorinated alkyl acids by three hydroponically grown crops.

PubMed

Felizeter, Sebastian; McLachlan, Michael S; De Voogt, Pim

2014-04-16

Tomato, cabbage, and zucchini plants were grown hydroponically in a greenhouse. They were exposed to 14 perfluorinated alkyl acids (PFAAs) at four different concentrations via the nutrient solution. At maturity the plants were harvested, and the roots, stems, leaves, twigs (where applicable), and edible parts (tomatoes, cabbage head, zucchinis) were analyzed separately. Uptake and transfer factors were calculated for all plant parts to assess PFAA translocation and distribution within the plants. Root concentration factors were highest for long-chain PFAAs (>C11) in all three plant species, but these chemicals were not found in the edible parts. All other PFAAs were present in all above-ground plant parts, with transpiration stream concentration factors (TSCFs) of 0.05-0.25. These PFAAs are taken up with the transpiration stream and accumulate primarily in the leaves. Although some systematic differences were observed, overall their uptake from nutrient solution to roots and their further distribution within the plants were similar between plant species and among PFAAs.

Nutrient and sediment concentrations, yields, and loads in impaired streams and rivers in the Taunton River Basin, Massachusetts, 1997-2008

USGS Publications Warehouse

Barbaro, Jeffrey R.; Sorenson, Jason R.

2013-01-01

Rapid development, population growth, and the changes in land and water use accompanying development are placing increasing stress on water resources in the Taunton River Basin. An assessment by the Massachusetts Department of Environmental Protection determined that a number of tributary streams to the Taunton River are impaired for a variety of beneficial uses because of nutrient enrichment. Most of the impaired reaches are in the Matfield River drainage area in the vicinity of the City of Brockton. In addition to impairments of stream reaches in the basin, discharge of nutrient-rich water from the Taunton River contributes to eutrophication of Mount Hope and Narragansett Bays. To assess water quality and loading in the impaired tributary stream reaches in the basin, the U.S. Geological Survey, in cooperation with the Massachusetts Department of Environmental Protection compiled existing water-quality data from previous studies for the period 1997-2006, developed and calibrated a Hydrological Simulation Program-FORTRAN (HSPF) precipitation-runoff model to simulate streamflow in areas of the basin that contain the impaired reaches for the same time period, and collected additional streamflow and water-quality data from sites on the Matfield and Taunton Rivers in 2008. A majority of the waterquality samples used in the study were collected between 1999 and 2006. Overall, the concentration, yield, and load data presented in this report represent water-quality conditions in the basin for the period 1997-2008. Water-quality data from 52 unique sites were used in the study. Most of the samples from previous studies were collected between June and September under dry weather conditions. Simulated or measured daily mean streamflow and water-quality data were used to estimate constituent yields and loads in the impaired tributary stream reaches and the main stem of the Taunton River and to develop yield-duration plots for reaches with sufficient water-quality data. Total phosphorus concentrations in the impaired-reach areas ranged from 0.0046 to 0.91 milligrams per liter (mg/L) in individual samples (number of samples (n)=331), with a median of 0.090 mg/L; total nitrogen concentrations ranged from 0.34 to 14 mg/L in individual samples (n=139), with a median of 1.35 mg/L; and total suspended solids concentrations ranged from 2/d) for total phosphorus and 100 lb/mi2/d for total nitrogen in these reaches. In most of the impaired reaches not affected by the Brockton Advanced Water Reclamation Facility outfall, yields were lower than in reaches downstream from the outfall, and the difference between measured and threshold yields was fairly uniform over a wide range of flows, suggesting that multiple processes contribute to nonpoint loading in these reaches. The Northeast and Mid-Atlantic SPAtially-Referenced Regression On Watershed (SPARROW) models for total phosphorus and total nitrogen also were used to estimate annual nutrient loads in the impaired tributary stream reaches and main stem of the Taunton River and predict the distribution of these loads among point and diffuse sources in reach drainage areas. SPARROW is a regional, statistical model that relates nutrient loads in streams to upstream sources and land-use characteristics and can be used to make predictions for streams that do not have nutrient-load data. The model predicts mean annual loads based on longterm streamflow and water-quality data and nutrient source conditions for the year 2002. Predicted mean annual nutrient loads from the SPARROW models were consistent with the measured yield and load data from sampling sites in the basin. For conditions in 2002, the Brockton Advanced Water Reclamation Facility outfall accounted for over 75 percent of the total nitrogen load and over 93 percent of the total phosphorus load in the Salisbury Plain and Matfield Rivers downstream from the outfall. Municipal point sources also accounted for most of the load in the main stem of the Taunton River. Multiple municipal wastewater discharges in the basin accounted for about 76 and 46 percent of the delivered loads of total phosphorus and total nitrogen, respectively, to Mount Hope Bay. For similarly sized watersheds, total delivered loads were lower in watersheds without point sources compared to those with point sources, and sources associated with developed land accounted for most of the delivered phosphorus and nitrogen loads to the impaired reaches. The concentration, yield, and load data evaluated in this study may not be representative of current (2012) point-source loading in the basin; in particular, most of the water-quality data used in the study (1999-2006) were collected prior to completion of upgrades to the Brockton Advanced Water Reclamation Facility that reduced total phosphorus and nitrogen concentrations in treated effluent. Effluent concentration data indicate that, for a given flow rate, effluent loads of total phosphorus and total nitrogen declined by about 80 and 30 percent, respectively, between the late 1990s and 2008 in response to plant upgrades. Consequently, current (2012) water-quality conditions in the impaired reaches downstream from the facility likely have improved compared to conditions described in the report.

Fuzzy rule based estimation of agricultural diffuse pollution concentration in streams.

PubMed

Singh, Raj Mohan

2008-04-01

Outflow from the agricultural fields carries diffuse pollutants like nutrients, pesticides, herbicides etc. and transports the pollutants into the nearby streams. It is a matter of serious concern for water managers and environmental researchers. The application of chemicals in the agricultural fields, and transport of these chemicals into streams are uncertain that cause complexity in reliable stream quality predictions. The chemical characteristics of applied chemical, percentage of area under the chemical application etc. are some of the main inputs that cause pollution concentration as output in streams. Each of these inputs and outputs may contain measurement errors. Fuzzy rule based model based on fuzzy sets suits to address uncertainties in inputs by incorporating overlapping membership functions for each of inputs even for limited data availability situations. In this study, the property of fuzzy sets to address the uncertainty in input-output relationship is utilized to obtain the estimate of concentrations of a herbicide, atrazine, in a stream. The data of White river basin, a part of the Mississippi river system, is used for developing the fuzzy rule based models. The performance of the developed methodology is found encouraging.

Disentangling nutrient concentrations trends in transfer pathways of agricultural watersheds

NASA Astrophysics Data System (ADS)

Mellander, P. E.; Jordan, P.

2017-12-01

Targeted schemes designed to attenuate agricultural pollution to water are needed to reach goals of sustainable food production. Such approaches require insight into temporal and spatial variability in the most representative flows and active pollution transfer pathways. Interpreting changes in total stream flow can be misleading since some changes may only be apparent in specific pathways. The aim of this study was to investigate changing land use pressures on water quality. The objectives were to assess intra-annual and inter-annual changes in phosphorus (P) and nitrogen (N) concentrations and loads in apportioned pathways. Pathways were separated using hydrograph and loadograph separation techniques on a seven-year dataset of sub-hourly river discharge and concentrations of NO3-N, reactive P and total P in two intensively managed agricultural watersheds of contrasting hydrology in Ireland. Active transfer pathways were dictated by soil drainage. There were intra-annual variability in both P and N concentrations in different pathways and loads, and these had the largest influence of all-year baseflow (BF) concentrations and summer quickflow (QF) concentrations. Nutrient loss responded to seasonality in the river discharge in all pathways in both watersheds and was mostly transport limited. In both watersheds there were inter-annual trends in P concentration in some pathways and seasons that did not correspond to the trend of total river P concentration. The response in stream water quality to management, mitigation measures and changes in weather may be hidden by counteracting responses in different pathways. The hydrology had a major impact on seasonal changes in N and P loss. By apportioning different transfer pathways more information on the temporal and site-specific nature of nutrient transfer was provided. BF and QF pathways largely contributed to the river P concentrations in summer while all pathways contributed to the P and N loads in wintertime. The data indicated that increasing trends in river P concentrations were mostly linked to trends in BF concentration in both catchment types. This may be explained by increased point source influence, increased vertical transfer through increased soil P loading, or decreased stream bed attenuation. Each will require different policy considerations.

Filling Gaps in Biogeochemical Understanding of Wildfire Effects on Watersheds and Water Quality

NASA Astrophysics Data System (ADS)

Rhoades, Charles; Covino, Timothy; Chow, Alex

2017-04-01

Large, high-severity wildfires alter the biogeochemical conditions that determine how watersheds retain and release nutrients and influence stream water quality. These effects are commonly expected to abate within a few years, but recent studies show that post-fire watershed changes can have persistent, but poorly-understood biogeochemical consequences. Owing to the increased frequency and extent of high-severity wildfires predicted for western North America, and the growing awareness of the links between wildfire and clean water supply, there is a need to address these knowledge gaps. For the past 15 years we have tracked stream nutrients, chemistry, temperature, and sediment after the 2002 Hayman Fire, the largest wildfire in Colorado history. Our earlier work showed that headwater catchments that experienced extensive, high-severity forest fires had elevated stream nitrate, temperature, and turbidity for five post-fire years. Recent sampling, conducted 13 and 14 years after the fire, found that turbidity had largely returned to pretreatment levels, but that stream nitrate remained an order of magnitude above pre-fire levels in catchments with extensive high-severity wildfire. Stream temperature and total dissolved nitrogen concentration also remained higher in those catchments compared to unburned streams. Decreased plant demand is the mechanism commonly credited for post-fire nutrient losses, though our current work is evaluating the implications of soil and stream nutrient uptake and supply on persistent nitrogen (N) export from severely-burned catchments. For example, we have measured higher total soil N and higher net N mineralization in severely-burned portions of the Hayman Fire compared to moderately or unburned areas, indicating that higher soil N supply may contribute to N losses from upland soils. Conversely, using a nutrient tracer approach we found reduced N uptake in burned streams, which suggests a switch from the N-limited conditions typical of pristine catchments. Low stream dissolved organic carbon (DOC) in severely-burned catchments suggests greater carbon limitation on in-stream biological activity. This is the likely result of organic matter losses during the wildfire compounded by low allochthonous inputs from uplands or riparian zones. We also find that catchments with severely-burned headwater reaches and sparse riparian vegetation have high stream nitrate. Our findings regarding soil N supply and in-stream N retention coupled with the persistent N losses from burned headwaters and exposed riparian zones help prioritize restoration efforts aimed at mitigating long-term water quality effects of severe wildfires.

Performance of UASB septic tank for treatment of concentrated black water within DESAR concept.

PubMed

Kujawa-Roeleveld, K; Fernandes, T; Wiryawan, Y; Tawfik, A; Visser, M; Zeeman, G

2005-01-01

Separation of wastewater streams produced in households according to their origin, degree of pollution and affinity to a specific treatment constitutes a starting point in the DESAR concept (decentralised sanitation and reuse). Concentrated black water and kitchen waste carry the highest load of organic matter and nutrients from all waste(water)streams generated from different human activities. Anaerobic digestion of concentrated black water is a core technology in the DESAR concept. The applicability of the UASB septic tank for treatment of concentrated black water was investigated under two different temperatures, 15 and 25 degrees C. The removal of total COD was dependent on the operational temperature and attained 61 and 74% respectively. A high removal of the suspended COD of 88 and 94% respectively was measured. Effluent nutrients were mainly in the soluble form. Precipitation of phosphate was observed. Effective sludge/water separation, long HRT and higher operational temperature contributed to a reduction of E. coli. Based on standards there is little risk of contamination with heavy metals when treated effluent is to be applied in agriculture as fertiliser.

Water quality of the Flint River basin, Alabama and Tennessee, 1999-2000

USGS Publications Warehouse

Hoos, Anne B.; Garrett, Jerry W.; Knight, Rodney R.

2002-01-01

The U.S. Geological Survey monitored eight stream sites in the Flint River Basin during the period January 1999 through May 2000, to characterize patterns in the occurrence of pesticides, fecal-indicator bacteria, and nutrients in relation to season and streamflow conditions and to land-use patterns. This study is part of the National Water-Quality Assessment Program, which was designed to assess water quality as it relates to various land uses. Every water sample collected from the Flint River Basin had detectable levels of at least two pesticides; 64 percent of the samples contained mixtures of at least five pesticides. In general, pesticides detected most frequently and at highest concentrations in streams corresponded to the pesticides with the highest rates of use in the watersheds. Detections of fluometuron, norflurazon, and atrazine were more frequent (by a margin of 15 percent or more) in samples from the Flint River when compared with the frequencies of pesticide detections at 62 agricultural stream sites across the Nation. Detections of fluometuron in the Flint River were more frequent even when compared with a cotton-cultivation subset of the 62 sites. For most pesticides, maximum concentrations did not exceed criteria to protect aquatic life; however, maximum concentrations of atrazine, cyanazine, and malathion exceeded aquaticlife criteria in at least one sample. Concentrations near or exceeding the aquatic-life criteria occurred only during the spring and summer (April-July), and generally occurred during storm flows. Less than 5 percent of the estimated mass of pesticides applied annually to agricultural areas in the Flint River Basin was transported to the stream at the monitoring points on the Flint River near Brownsboro, Alabama, and on Hester Creek near Plevna, Alabama. The pesticides with the highest ratios (greater than 3 percent) of the amount transported instream to the amount applied?atrazine, metolachlor, fluometuron, and norflurazon?are preemergent herbicides applied to the soil before the crops have emerged, which increases the probability of transport in surface runoff. Concentrations of the fecal-bacteria indicator Escherichia coli (E. coli) in the Flint River and Hester Creek exceeded the U.S. Environmental Protection Agency criterion for recreation in almost all storm samples, and in many samples collected up to 6 days following a storm. Concentrations in the Flint River were strongly correlated with sample turbidity, suggesting that turbidity might be useful as a surrogate for estimating E. coli concentrations. Concentrations of the nutrients nitrogen and phosphorus in samples from the Flint River generally exceeded thresholds indicating eutrophic potential, whereas concentrations in samples from Hester Creek were generally below the thresholds. When compared with nutrient data from a set of 24 agricultural basins across the southeastern region of the United States, concentrations in the Flint River and Hester Creek were slightly above the regional median. Base-flow concentrations of certain pesticides, nutrients, and E. coli were compared to land-use information for eight sites in the Flint River Basin. The highest base-flow concentrations of aldicarb sulfoxide, fluometuron, and phosphorus were found in the tributaries with the greatest density of cotton acreage in the watershed. Similarly, high base-flow concentrations of total nitrogen were correlated with a high percentage of cultivated land in the watershed. Lack of information about distribution of stream access by livestock weakened the analysis of correlation between livestock and base-flow concentrations of E. coli and nutrients. Input of dissolved and suspended chemicals from the Flint River during storms influences water quality in the reach of the Tennessee River from which the City of Huntsville, Alabama, withdraws about 40 percent of its drinking water. During the storm of April 2-5, 2000, concentrations of several pesticides were

Quality of streams in Johnson County, Kansas, 2002--10

USGS Publications Warehouse

Rasmussen, Teresa J.; Stone, Mandy S.; Poulton, Barry C.; Graham, Jennifer L.

2012-01-01

Stream quality in Johnson County, northeastern Kansas, was assessed on the basis of land use, hydrology, stream-water and streambed-sediment chemistry, riparian and in-stream habitat, and periphyton and macroinvertebrate community data collected from 22 sites during 2002 through 2010. Stream conditions at the end of the study period are evaluated and compared to previous years, stream biological communities and physical and chemical conditions are characterized, streams are described relative to Kansas Department of Health and Environment impairment categories and water-quality standards, and environmental factors that most strongly correlate with biological stream quality are evaluated. The information is useful for improving water-quality management programs, documenting changing conditions with time, and evaluating compliance with water-quality standards, total maximum daily loads (TMDLs), National Pollutant Discharge Elimination System (NPDES) permit conditions, and other established guidelines and goals. Constituent concentrations in water during base flow varied across the study area and 2010 conditions were not markedly different from those measured in 2003, 2004, and 2007. Generally the highest specific conductance and concentrations of dissolved solids and major ions in water occurred at urban sites except the upstream Cedar Creek site, which is rural and has a large area of commercial and industrial land less than 1 mile upstream on both sides of the creek. The highest base-flow nutrient concentrations in water occurred downstream from wastewater treatment facilities. Water chemistry data represent base-flow conditions only, and do not show the variability in concentrations that occurs during stormwater runoff. Constituent concentrations in streambed sediment also varied across the study area and some notable changes occurred from previously collected data. High organic carbon and nutrient concentrations at the rural Big Bull Creek site in 2003 decreased to at least one-fourth of those concentrations in 2007 and 2010 likely because of the reduction in upstream wastewater discharge contributions. The highest concentrations of trace metals in 2010 occurred at urban sites on Mill and Indian Creeks. Zinc was the only metal to exceed the probable effects concentration in 2010, which occurred at a site on Indian Creek. In 2007, chromium and nickel at the upstream urban Cedar Creek site exceeded the probable effects concentrations, and in 2003, no metals exceeded the probable effects concentrations. Of 72 organic compounds analyzed in streambed sediment, 26 were detected including pesticides, polycyclic aromatic hydrocarbons (PAHs), fuel products, fragrances, preservatives, plasticizers, manufacturing byproducts, flame retardants, and disinfectants. All 6 PAH compounds analyzed were detected, and the probable effects concentrations for 4 of the 6 PAH compounds analyzed were exceeded in 2010. Only five pesticide compounds were detected in streambed sediment, including carbazole and four pyrethroid compounds. Chronic toxicity guidelines for pyrethroid compounds were exceeded at five sites. Biological conditions reflected a gradient in urban land use, with the less disturbed streams located in rural areas of Johnson County. About 19 percent of sites in 2010 (four sites) were fully supporting of aquatic life on the basis of the four metrics used by Kansas Department of Health and Environment to categorize sites. This is a notable difference compared to previous years when no sites (in 2003 and 2004) or just one site (in 2007) was fully supporting of aquatic life. Multimetric macroinvertebrate scores improved at the Big Bull Creek site where wastewater discharges were reduced in 2007. Environmental variables that consistently were highly negatively correlated with biological conditions were percent impervious surface and percent urban land use. In addition, density of stormwater outfall points adjacent to streams was significantly negatively correlated with biological conditions. Specific conductance of water and sum of PAH concentrations in streambed sediment also were significantly negatively correlated with biological conditions. Total nitrogen in water and total phosphorus in streambed sediment were correlated with most of the invertebrate variables, which is a notable difference from previous analyses using smaller datasets, in which nutrient relations were weak or not detected. The most important habitat variables were sinuosity, length and continuity of natural buffers, riffle substrate embeddedness, and substrate cover diversity, each of which was correlated with all invertebrate metrics including a 10-metric combined score. Correlation analysis indicated that if riparian and in-stream habitat conditions improve then so might invertebrate communities and stream biological quality. Sixty-two percent of the variance in macroinvertebrate community metrics was explained by the single environmental factor, percent impervious surface. Invertebrate responses to urbanization in Johnson County indicated linearity rather than identifiable thresholds. Multiple linear regression models developed for each of the four macroinvertebrate metrics used to determine aquatic-life-support status indicated that percent impervious surface, as a measure of urban land use, explained 34 to 67 percent of the variability in biological communities. Results indicate that although multiple factors are correlated with stream quality degradation, general urbanization, as indicated by impervious surface area or urban land use, consistently is determined to be the fundamental factor causing change in stream quality. Effects of urbanization on Johnson County streams are similar to effects described in national studies that assess effects of urbanization on stream health. Individually important environmental factors such as specific conductance of water, PAHs in streambed sediment, and stream buffer conditions, are affected by urbanization and, collectively, all contribute to stream impairments. Policies and management practices that may be most important in protecting the health of streams in Johnson County are those minimizing the effects of impervious surface, protecting stream corridors, and decreasing the loads of sediment, nutrients, and toxic chemicals that directly enter streams through stormwater runoff and discharges.

"Land-Cover Conversion in Amazonia, The Role of ENV" Ironment and Substrate composition in Modifying SOI

NASA Technical Reports Server (NTRS)

Roberts, Dar A.; Chadwick, Oliver A.; Batista, Getulio T.

2003-01-01

LBA research from the first phase of LBA focused on three broad categories: 1) mapping land cover and quantifying rates of change, persistence of pasture, and area of recovering forest; 2) evaluating the role of environmental factors and land-use history on soil biogeochemistry; and 3) quantifying the natural and human controls on stream nutrient concentrations. The focus of the research was regional, concentrating primarily in the state of RondBnia, but also included land-cover mapping in the vicinity of Maraba, Para, and Manaus, Amazonas. Remote sensing analysis utilized Landsat Thematic Mapper (TM) and Multispectral Scanner (MS S) data to map historical patterns of land-cover change. Specific questions addressed by the remote sensing component of the research included: 1) what is the areal extent of dominant land-cover classes? 2) what are the rates of change of dominant land cover through processes of deforestation, disturbance and regeneration? and 3) what are the dynamic properties of each class that characterize temporal variability, duration, and frequency of repeat disturbance? Biogeochemical analysis focused on natural variability and impacts of land-use/land-cover changes on soil and stream biogeochemical properties at the regional scale. An emphasis was given to specific soil properties considered to be primary limiting factors regionally, including phosphorus, nitrogen, base cations and cation-exchange properties. Stream sampling emphasized the relative effects of the rates and timing of land-cover change on stream nutrients, demonstrating that vegetation conversion alone does not impact nutrients as much as subsequent land use and urbanization.

Carbon and nitrogen stoichiometry across stream ecosystems

NASA Astrophysics Data System (ADS)

Wymore, A.; Kaushal, S.; McDowell, W. H.; Kortelainen, P.; Bernhardt, E. S.; Johnes, P.; Dodds, W. K.; Johnson, S.; Brookshire, J.; Spencer, R.; Rodriguez-Cardona, B.; Helton, A. M.; Barnes, R.; Argerich, A.; Haq, S.; Sullivan, P. L.; López-Lloreda, C.; Coble, A. A.; Daley, M.

2017-12-01

Anthropogenic activities are altering carbon and nitrogen concentrations in surface waters globally. The stoichiometry of carbon and nitrogen regulates important watershed biogeochemical cycles; however, controls on carbon and nitrogen ratios in aquatic environments are poorly understood. Here we use a multi-biome and global dataset (tropics to Arctic) of stream water chemistry to assess relationships between dissolved organic carbon (DOC) and nitrate, ammonium and dissolved organic nitrogen (DON), providing a new conceptual framework to consider interactions between DOC and the multiple forms of dissolved nitrogen. We found that across streams the total dissolved nitrogen (TDN) pool is comprised of very little ammonium and as DOC concentrations increase the TDN pool shifts from nitrate to DON dominated. This suggests that in high DOC systems, DON serves as the primary source of nitrogen. At the global scale, DOC and DON are positively correlated (r2 = 0.67) and the average C: N ratio of dissolved organic matter (molar ratio of DOC: DON) across our data set is approximately 31. At the biome and smaller regional scale the relationship between DOC and DON is highly variable (r2 = 0.07 - 0.56) with the strongest relationships found in streams draining the mixed temperate forests of the northeastern United States. DOC: DON relationships also display spatial and temporal variability including latitudinal and seasonal trends, and interactions with land-use. DOC: DON ratios correlated positively with gradients of energy versus nutrient limitation pointing to the ecological role (energy source versus nutrient source) that DON plays with stream ecosystems. Contrary to previous findings we found consistently weak relationships between DON and nitrate which may reflect DON's duality as an energy or nutrient source. Collectively these analyses demonstrate how gradients of DOC drive compositional changes in the TDN pool and reveal a high degree of variability in the C: N ratio (3-100) of stream water dissolved organic matter.

Water-quality assessment of the largely urban blue river basin, Metropolitan Kansas City, USA, 1998 to 2007

USGS Publications Warehouse

Wilkison, D.H.; Armstrong, D.J.; Hampton, S.A.

2009-01-01

From 1998 through 2007, over 750 surface-water or bed-sediment samples in the Blue River Basin - a largely urban basin in metropolitan Kansas City - were analyzed for more than 100 anthropogenic compounds. Compounds analyzed included nutrients, fecal-indicator bacteria, suspended sediment, pharmaceuticals and personal care products. Non-point source runoff, hydrologic alterations, and numerous waste-water discharge points resulted in the routine detection of complex mixtures of anthropogenic compounds in samples from basin stream sites. Temporal and spatial variations in concentrations and loads of nutrients, pharmaceuticals, and organic wastewater compounds were observed, primarily related to a site's proximity to point-source discharges and stream-flow dynamics. ?? 2009 ASCE.

Spectral Quantitation Of Hydroponic Nutrients

NASA Technical Reports Server (NTRS)

Schlager, Kenneth J.; Kahle, Scott J.; Wilson, Monica A.; Boehlen, Michelle

1996-01-01

Instrument continuously monitors hydroponic solution by use of absorption and emission spectrometry to determine concentrations of principal nutrients, including nitrate, iron, potassium, calcium, magnesium, phosphorus, sodium, and others. Does not depend on extraction and processing of samples, use of such surrograte parameters as pH or electrical conductivity for control, or addition of analytical reagents to solution. Solution not chemically altered by analysis and can be returned to hydroponic process stream after analysis.

Water-quality assessment of the Ozark Plateaus study unit, Arkansas, Kansas, Missouri, and Oklahoma; nutrients, bacteria, organic carbon, and suspended sediment in surface water, 1993-95

USGS Publications Warehouse

Davis, Jerri V.; Bell, Richard W.

1998-01-01

Nutrient, bacteria, organic carbon, and suspended- sediment samples were collected from 1993-95 at 43 surface-water-quality sampling sites within the Ozark Plateaus National Water- Quality Assessment Program study unit. Most surface-water-quality sites have small or medium drainage basins, near-homogenous land uses (primarily agricultural or forest), and are located predominantly in the Springfield and Salem Plateaus. The water-quality data were analyzed using selected descriptive and statistical methods to determine factors affecting occurrence in streams in the study unit. Nitrogen and phosphorus fertilizer use increased in the Ozark Plateaus study unit for the period 1965-85, but the application rates are well below the national median. Fertilizer use differed substantially among the major river basins and physiographic areas in the study unit. Livestock and poultry waste is a major source of nutrient loading in parts of the study unit. The quantity of nitrogen and phosphorus from livestock and poultry wastes differed substantially among the river basins of the study unit's sampling network. Eighty six municipal sewage-treatment plants in the study unit have effluents of 0.5 million gallons per day or more (for the years 1985-91). Statistically significant differences existed in surface-water quality that can be attributed to land use, physiography, and drainage basin size. Dissolved nitrite plus nitrate, total phosphorus, fecal coliform bacteria, and dissolved organic carbon concentrations generally were larger at sites associated with agricultural basins than at sites associated with forested basins. A large difference in dissolved nitrite plus nitrate concentrations occurred between streams draining basins with agricultural land use in the Springfield and Salem Plateaus. Streams draining both small and medium agricultural basins in the Springfield Plateau had much larger concentrations than their counterparts in the Salem Plateau. Drainage basin size was not a significant factor in affecting total phosphorus, fecal coliform bacteria, or dissolved organic carbon concentrations. Suspended-sediment concentrations generally were small and indicative of the clear water in streams in the Ozark Plateaus. A comparison of the dissolved nitrite plus nitrate, total phosphorus, and fecal coliform data collected at the fixed and synoptic sites indicates that generally the data for streams draining basins of similar physiography, land-use setting, and drainage basin size group together. Many of the variations are most likely the result of differences in percent agricultural land use between the sites being compared or are discharge related. The relation of dissolved nitrite plus nitrate, total phosphorus, and fecal coliform concentration to percent agricultural land use has a strong positive 2 Water-Quality Assessment-Nutrients, Bacteria, Organic Carbon, and Suspended Sediment in Surface Water, 1993-95 correlation, with percent agricultural land use accounting for between 42 and 60 percent of the variation in the observed concentrations.

Denitrification associated with stream periphyton: Chamber estimates from undisrupted communities

USGS Publications Warehouse

Duff, J.H.; Triska, F.J.; Oremland, R.S.

1984-01-01

Undisrupted periphyton communities from a N-rich (NO3- = 63 ??mol L-1) and pristine (NO3- = 2.9 ??mol L-1) stream were assayed for denitrifying activity (acetylene-blockage technique) in 40-L chambers incubated at in situ temperature and nutrient concentrations. Nitrous oxide formation associated with periphyton from the N-rich stream was immediate and linear (52.1 ??mol N2O m-2 h-1) in the dark, anaerobic chamber (50 kPa C2H2). In the corresponding light, aerobic chamber (50 kPa C2H2), N2O production was inhibited by 82% (9.3 ??mol N2O m-2 h-1). Nitrous oxide formation was not associated with periphyton from the pristine stream incubated in situ, either with or without NO3- amendment. Denitrification estimates made with undisrupted periphyton communities at in situ temperature and nutrient concentrations (40-L chambers) were less variable than estimates made with periphyton 'scrapings' in small flasks (room temperature). The calculated diel periphyton-associated denitrification rate based on a 14-h light-10-h dark day was 651 ??mol N2O m-2 d-1. The data suggest denitrification within periphyton mats may contribute toward removal of NO3- from N-rich fluvial environments.

Quality of nutrient data from streams and ground water sampled during water years 1992-2001

USGS Publications Warehouse

Mueller, David K.; Titus, Cindy J.

2005-01-01

Proper interpretation of water-quality data requires consideration of the effects that bias and variability might have on measured constituent concentrations. In this report, methods are described to estimate the bias due to contamination of samples in the field or laboratory and the variability due to sample collection, processing, shipment, and analysis. Contamination can adversely affect interpretation of measured concentrations in comparison to standards or criteria. Variability can affect interpretation of small differences between individual measurements or mean concentrations. Contamination and variability are determined for nutrient data from quality-control samples (field blanks and replicates) collected as part of the National Water-Quality Assessment (NAWQA) Program during water years 1992-2001. Statistical methods are used to estimate the likelihood of contamination and variability in all samples. Results are presented for five nutrient analytes from stream samples and four nutrient analytes from ground-water samples. Ammonia contamination can add at least 0.04 milligram per liter in up to 5 percent of all samples. This could account for more than 22 percent of measured concentrations at the low range of aquatic-life criteria (0.18 milligram per liter). Orthophosphate contamination, at least 0.019 milligram per liter in up to 5 percent of all samples, could account for more than 38 percent of measured concentrations at the limit to avoid eutrophication (0.05 milligram per liter). Nitrite-plus-nitrate and Kjeldahl nitrogen contamination is less than 0.4 milligram per liter in 99 percent of all samples; thus there is no significant effect on measured concentrations of environmental significance. Sampling variability has little or no effect on reported concentrations of ammonia, nitrite-plus-nitrate, orthophosphate, or total phosphorus sampled after 1998. The potential errors due to sampling variability are greater for the Kjeldahl nitrogen analytes and for total phosphorus sampled before 1999. The uncertainty in a mean of 10 concentrations caused by sampling variability is within a small range (1 to 7 percent) for all nutrients. These results can be applied to interpretation of environmental data collected during water years 1992-2001 in 52 NAWQA study units.

Leaf breakdown in streams differing in catchment land use

USGS Publications Warehouse

Paul, M.J.; Meyer, J.L.; Couch, C.A.

2006-01-01

1. The impact of changes in land use on stream ecosystem function is poorly understood. We studied leaf breakdown, a fundamental process of stream ecosystems, in streams that represent a range of catchment land use in the Piedmont physiographic province of the south-eastern United States. 2. We placed bags of chalk maple (Acer barbatum) leaves in similar-sized streams in 12 catchments of differing dominant land use: four forested, three agricultural, two suburban and three urban catchments. We measured leaf mass, invertebrate abundance and fungal biomass in leaf bags over time. 3. Leaves decayed significantly faster in agricultural (0.0465 day-1) and urban (0.0474 day-1) streams than in suburban (0.0173 day-1) and forested (0.0100 day-1) streams. Additionally, breakdown rates in the agricultural and urban streams were among the fastest reported for deciduous leaves in any stream. Nutrient concentrations in agricultural streams were significantly higher than in any other land-use type. Fungal biomass associated with leaves was significantly lower in urban streams; while shredder abundance in leaf bags was significantly higher in forested and agricultural streams than in suburban and urban streams. Storm runoff was significantly higher in urban and suburban catchments that had higher impervious surface cover than forested or agricultural catchments. 4. We propose that processes accelerating leaf breakdown in agricultural and urban streams were not the same: faster breakdown in agricultural streams was due to increased biological activity as a result of nutrient enrichment, whereas faster breakdown in urban streams was a result of physical fragmentation resulting from higher storm runoff. ?? 2006 The Authors.

Spatial and seasonal variations in mercury methylation and microbial community structure in a historic mercury mining area, Yolo County, California

USGS Publications Warehouse

Holloway, J.M.; Goldhaber, M.B.; Scow, K.M.; Drenovsky, R.E.

2009-01-01

The relationships between soil parent lithology, nutrient concentrations, microbial biomass and community structure were evaluated in soils from a small watershed impacted by historic Hg mining. Upland and wetland soils, stream sediments and tailings were collected and analyzed for nutrients (DOC, SO4=, NO3-), Hg, MeHg, and phospholipid fatty acids (PLFA). Stream sediment was derived from serpentinite, siltstone, volcanic rocks and mineralized serpentine with cinnabar, metacinnabar and other Hg phases. Soils from different parent materials had distinct PLFA biomass and community structures that are related to nutrient concentrations and toxicity effects of trace metals including Hg. The formation of MeHg appears to be most strongly linked to soil moisture, which in turn has a correlative relationship with PLFA biomass in wetland soils. The greatest concentrations of MeHg (> 0.5??ng g- 1 MeHg) were measured in wetland soils and soil with a volcanic parent (9.5-37????g g- 1 Hg). Mercury methylation was associated with sulfate-reducing bacteria, including Desulfobacter sp. and Desulfovibrio sp., although these organisms are not exclusively responsible for Hg methylation. Statistical models of the data demonstrated that soil microbial communities varied more with soil type than with season.

Nutrient concentrations in surface water and groundwater, and nitrate source identification using stable isotope analysis, in the Barnegat Bay-Little Egg Harbor watershed, New Jersey, 2010–11

USGS Publications Warehouse

Wieben, Christine M.; Baker, Ronald J.; Nicholson, Robert S.

2013-01-01

Five streams in the Barnegat Bay-Little Egg Harbor (BB-LEH) watershed in southern New Jersey were sampled for nutrient concentrations and stable isotope composition under base-flow and stormflow conditions, and during the growing and nongrowing seasons, to help quantify and identify sources of nutrient loading. Samples were analyzed for concentrations of total nitrogen, ammonia, nitrate plus nitrite, organic nitrogen, total phosphorus, and orthophosphate, and for nitrogen and oxygen stable isotope ratios. Concentrations of total nitrogen in the five streams appear to be related to land use, such that streams in subbasins characterized by extensive urban development (and historical agricultural land use)—North Branch Metedeconk and Toms Rivers—exhibited the highest total nitrogen concentrations (0.84–1.36 milligrams per liter (mg/L) in base flow). Base-flow total nitrogen concentrations in these two streams were dominated by nitrate; nitrate concentrations decreased during storm events as a result of dilution by storm runoff. The two streams in subbasins with the least development—Cedar Creek and Westecunk Creek—exhibited the lowest total nitrogen concentrations (0.16–0.26 mg/L in base flow), with organic nitrogen as the dominant species in both base flow and stormflow. A large proportion of these subbasins lies within forested parts of the Pinelands Area, indicating the likelihood of natural inputs of organic nitrogen to the streams that increase during periods of storm runoff. Base-flow total nitrogen concentrations in Mill Creek, in a moderately developed basin, were 0.43 to 0.62 mg/L and were dominated by ammonia, likely associated with leachate from a landfill located upstream. Total phosphorus and orthophosphate were not found at detectable concentrations in most of the surface-water samples, with the exception of samples collected from the North Branch Metedeconk River, where concentrations ranged from 0.02 to 0.09 mg/L for total phosphorus and 0.008 to 0.011 mg/L for orthophosphate. Measurements of nitrogen and oxygen stable isotope ratios of nitrate in surface-water samples revealed that a mixture of multiple subsurface sources, which may include some combination of animal and septic waste, soil nitrogen, and commercial fertilizers, likely contribute to the base-flow nitrogen load. The results also indicate that atmospheric deposition is not a predominant source of nitrogen transported to the BB-LEH estuary from the watershed, although the contribution of nitrate from the atmosphere increases during stormflow. Atmospheric deposition of nitrate has a greater influence in the less developed subbasins within the BB-LEH watershed, likely because few other major sources of nitrogen (animal and septic waste, fertilizers) are present in the less developed subbasins. Atmospheric sources appear to contribute proportionally less of the overall nitrate as development increases within the BB-LEH watershed. Groundwater samples collected from five wells located within the BB-LEH watershed and screened in the unconfined Kirkwood-Cohansey aquifer system were analyzed for nutrient and stable isotope composition. Concentrations of nitrate ranged from not detected to 3.63 mg/L, with the higher concentrations occurring in the highly developed northern portion of the watershed, indicating the likelihood of anthropogenic sources of nitrogen. Isotope data for the two wells with the highest nitrate concentrations are more consistent with fertilizer sources than with animal or septic waste. Total phosphorus was not detected in any of the wells sampled, and orthophosphate was either not detected or measured at very low concentrations (0.005–0.009 mg/L) in each of the wells sampled.

Simulation of nutrient and sediment concentrations and loads in the Delaware inland bays watershed: Extension of the hydrologic and water-quality model to ungaged segments

USGS Publications Warehouse

Gutierrez-Magness, Angelica L.

2006-01-01

Rapid population increases, agriculture, and industrial practices have been identified as important sources of excessive nutrients and sediments in the Delaware Inland Bays watershed. The amount and effect of excessive nutrients and sediments in the Inland Bays watershed have been well documented by the Delaware Geological Survey, the Delaware Department of Natural Resources and Environmental Control, the U.S. Environmental Protection Agency's National Estuary Program, the Delaware Center for Inland Bays, the University of Delaware, and other agencies. This documentation and data previously were used to develop a hydrologic and water-quality model of the Delaware Inland Bays watershed to simulate nutrients and sediment concentrations and loads, and to calibrate the model by comparing concentrations and streamflow data at six stations in the watershed over a limited period of time (October 1998 through April 2000). Although the model predictions of nutrient and sediment concentrations for the calibrated segments were fairly accurate, the predictions for the 28 ungaged segments located near tidal areas, where stream data were not available, were above the range of values measured in the area. The cooperative study established in 2000 by the Delaware Department of Natural Resources and Environmental Control, the Delaware Geological Survey, and the U.S. Geological Survey was extended to evaluate the model predictions in ungaged segments and to ensure that the model, developed as a planning and management tool, could accurately predict nutrient and sediment concentrations within the measured range of values in the area. The evaluation of the predictions was limited to the period of calibration (1999) of the 2003 model. To develop estimates on ungaged watersheds, parameter values from calibrated segments are transferred to the ungaged segments; however, accurate predictions are unlikely where parameter transference is subject to error. The unexpected nutrient and sediment concentrations simulated with the 2003 model were likely the result of inappropriate criteria for the transference of parameter values. From a model-simulation perspective, it is a common practice to transfer parameter values based on the similarity of soils or the similarity of land-use proportions between segments. For the Inland Bays model, the similarity of soils between segments was used as the basis to transfer parameter values. An alternative approach, which is documented in this report, is based on the similarity of the spatial distribution of the land use between segments and the similarity of land-use proportions, as these can be important factors for the transference of parameter values in lumped models. Previous work determined that the difference in the variation of runoff due to various spatial distributions of land use within a watershed can cause substantialloss of accuracy in the model predictions. The incorporation of the spatial distribution of land use to transfer parameter values from calibrated to uncalibrated segments provided more consistent and rational predictions of flow, especially during the summer, and consequently, predictions of lower nutrient concentrations during the same period. For the segments where the similarity of spatial distribution of land use was not clearly established with a calibrated segment, the similarity of the location of the most impervious areas was also used as a criterion for the transference of parameter values. The model predictions from the 28 ungaged segments were verified through comparison with measured in-stream concentrations from local and nearby streams provided by the Delaware Department of Natural Resources and Environmental Control. Model results indicated that the predicted edge-of-stream total suspended solids loads in the Inland Bays watershed were low in comparison to loads reported for the Eastern Shore of Maryland from the Chesapeake Bay watershed model. The flatness of the ter

Nutrient and Suspended-Sediment Transport and Trends in the Columbia River and Puget Sound Basins, 1993-2003

USGS Publications Warehouse

Wise, Daniel R.; Rinella, Frank A.; Rinella, Joseph F.; Fuhrer, Greg J.; Embrey, Sandra S.; Clark, Gregory M.; Schwarz, Gregory E.; Sobieszczyk, Steven

2007-01-01

This study focused on three areas that might be of interest to water-quality managers in the Pacific Northwest: (1) annual loads of total nitrogen (TN), total phosphorus (TP) and suspended sediment (SS) transported through the Columbia River and Puget Sound Basins, (2) annual yields of TN, TP, and SS relative to differences in landscape and climatic conditions between subbasin catchments (drainage basins), and (3) trends in TN, TP, and SS concentrations and loads in comparison to changes in landscape and climatic conditions in the catchments. During water year 2000, an average streamflow year in the Pacific Northwest, the Columbia River discharged about 570,000 pounds per day of TN, about 55,000 pounds per day of TP, and about 14,000 tons per day of SS to the Pacific Ocean. The Snake, Yakima, Deschutes, and Willamette Rivers contributed most of the load discharged to the Columbia River. Point-source nutrient loads to the catchments (almost exclusively from municipal wastewater treatment plants) generally were a small percentage of the total in-stream nutrient loads; however, in some reaches of the Spokane, Boise, Walla Walla, and Willamette River Basins, point sources were responsible for much of the annual in-stream nutrient load. Point-source nutrient loads generally were a small percentage of the total catchment nutrient loads compared to nonpoint sources, except for a few catchments where point-source loads comprised as much as 30 percent of the TN load and as much as 80 percent of the TP load. The annual TN and TP loads from point sources discharging directly to the Puget Sound were about equal to the annual loads from eight major tributaries. Yields of TN, TP, and SS generally were greater in catchments west of the Cascade Range. A multiple linear regression analysis showed that TN yields were significantly (p < 0.05) and positively related to precipitation, atmospheric nitrogen load, fertilizer and manure load, and point-source load, and were negatively related to average slope. TP yields were significantly related positively to precipitation, and point-source load and SS yields were significantly related positively to precipitation. Forty-eight percent of the available monitoring sites for TN had significant trends in concentration (2 increasing, 19 decreasing), 32 percent of the available sites for TP had significant trends in concentration (7 increasing, 9 decreasing), and 40 percent of the available sites for SS had significant trends in concentration (4 increasing, 15 decreasing). The trends in load followed a similar pattern, but with fewer sites showing significant trends. The results from this study indicate that inputs from nonpoint sources of nutrients probably have decreased over time in many of the catchments. Despite the generally small contribution of point-source nutrient loads, they still may have been partially responsible for the significant decreasing trends for nutrients at sites where the total point-source nutrient loads to the catchments equaled a substantial proportion of the in-stream load.

Water-Quality Data for Selected Stream Sites in Bridgeport Valley, Mono County, California, April 2000 to June 2003

USGS Publications Warehouse

Rockwell, Gerald L.; Honeywell, Paul D.

2004-01-01

The U.S. Geological Survey, in cooperation with the California Regional Water Quality Control Board, Lahonton Region, carried out a water-quality data collection program of selected streams in and near Bridgeport Valley, California, during April 2000 to June 2003. These data were collected to provide information used by the California Regional Water Quality Control Board to develop total maximum daily load standards. Field measurements of streamflow, barometric pressure, dissolved oxygen, pH, specific conductance, and water temperature were made at 15 sites located on 6 streams. Water samples were analyzed for nutrients, major ions, turbidity, fecal coliform, fecal streptococci, and suspended sediment. Field data, turbidity, nutrient, major ion, and sediment concentrations and fecal coliform and fecal streptococci densities are given in tables for each site. Field blank data are also presented in a table.

Ecological effects on streams from forest fertilization; literature review and conceptual framework for future study in the western Cascades

USGS Publications Warehouse

Anderson, Chauncey W.

2002-03-19

Studies of the responses of stream biota to fertilization have been rare and have targeted either immediate, toxicity-based responses or used methods insensitive to ongoing ecological processes. This report reviews water-quality studies following forest fertilizations, emphasizing Cascade streams in the Pacific Northwest and documented biological responses in those streams. A conceptual model predicting potential ecological response to fertilization, which includes effects on algal growth and primary production, is presented. In this model, applied fertilizer nitrogen reaching streams is mostly exported during winter. However, some nitrogen retained in soils or stream and riparian areas may become available to aquatic biota during spring and summer. Biological responses may be minimal in small streams nearest to application because of light limitation, but may be elevated downstream where light is sufficient to allow algal growth. Ultimately, algal response could be greatest in downstream reaches, although ambient nutrient concentrations remain low due to uptake and benthic nutrient recycling. Ground-water flow paths and hyporheic processing could be critical in determining the fate of applied nitrogen. A framework is provided for testing this response in the Little River watershed, a tributary to the North Umpqua River, Oregon, at basic and intensive levels of investigation.

Fate of acetone in an outdoor model stream with a nitrate supplement, southern Mississippi, U.S.A.

USGS Publications Warehouse

Rathbun, R.E.; Stephens, D.W.; Tai, D.Y.

1991-01-01

The fate of acetone in an outdoor model stream to which nitrate was added as a nutrient supplement was determined. The stream, in southern Mississippi, U.S.A. was 234 m long. Water was supplied to the stream by an artesian well at about 1.21 s-1, resulting in a mean water velocity of about 0.5 m min-1. Acetone was injected continuously for 26 days resulting in concentrations of 20-40 mg l-1. A nitrate solution was injected for 21 days resulting in an instream concentration of about 1.7 mg l-1 at the upstream end of the stream. Rhodamine-WT dye was used to determine the travel time and dispersion characteristics of the stream, and t-butyl alcohol was used to determine the volatilization characteristics. Volatilization controlled the fate of acetone in the model stream. The lack of substantial bacterial degradation of acetone was contrary to expectations based on the results of laboratory degradation studies using model stream water enriched with nitrate. A possible explanation for the lack of significant degradation in the model stream may be the limited 6-h residence time of the acetone in the stream. ?? 1991.

Bioremediation of reject water from anaerobically digested waste water sludge with macroalgae (Ulva lactuca, Chlorophyta).

PubMed

Sode, Sidsel; Bruhn, Annette; Balsby, Thorsten J S; Larsen, Martin Mørk; Gotfredsen, Annemarie; Rasmussen, Michael Bo

2013-10-01

Phosphorus and biologically active nitrogen are valuable nutrient resources. Bioremediation with macroalgae is a potential means for recovering nutrients from waste streams. In this study, reject water from anaerobically digested sewage sludge was successfully tested as nutrient source for cultivation of the green macroalgae Ulva lactuca. Maximal growth rates of 54.57±2.16% FW d(-1) were achieved at reject water concentrations equivalent to 50 μM NH4(+). Based on the results, the growth and nutrient removal was parameterised as function of NH4(+) concentration a tool for optimisation of any similar phycoremediation system. Maximal nutrient removal rates of 22.7 mg N g DW(-1) d(-1) and 2.7 mg P g DW(-1) d(-1) were achieved at reject water concentrations equivalent to 80 and 89 μM NH4(+), respectively. A combined and integrated use of the produced biomass in a biorefinery is thought to improve the feasibility of using Ulva for bioremediation of reject water. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

N : P stoichiometry in a forested runoff during storm events: comparisons with regions and vegetation types.

PubMed

Guo, Lanlan; Chen, Yi; Zhang, Zhao; Fukushima, Takehiko

2012-01-01

Nitrogen and phosphorus are considered the most important limiting elements in terrestrial and aquatic ecosystems. however, very few studies have focused on which is from forested streams, a bridge between these two systems. To fill this gap, we examined the concentrations of dissolved N and P in storm waters from forested watersheds of five regions in Japan, to characterize nutrient limitation and its potential controlling factors. First, dissolved N and P concentrations and the N : P ratio on forested streams were higher during storm events relative to baseflow conditions. Second, significantly higher dissolved inorganic N concentrations were found in storm waters from evergreen coniferous forest streams than those from deciduous broadleaf forest streams in Aichi, Kochi, Mie, Nagano, and with the exception of Tokyo. Finally, almost all the N : P ratios in the storm water were generally higher than 34, implying that the storm water should be P-limited, especially for Tokyo.

N : P Stoichiometry in a Forested Runoff during Storm Events: Comparisons with Regions and Vegetation Types

PubMed Central

Guo, Lanlan; Chen, Yi; Zhang, Zhao; Fukushima, Takehiko

2012-01-01

Nitrogen and phosphorus are considered the most important limiting elements in terrestrial and aquatic ecosystems. however, very few studies have focused on which is from forested streams, a bridge between these two systems. To fill this gap, we examined the concentrations of dissolved N and P in storm waters from forested watersheds of five regions in Japan, to characterize nutrient limitation and its potential controlling factors. First, dissolved N and P concentrations and the N : P ratio on forested streams were higher during storm events relative to baseflow conditions. Second, significantly higher dissolved inorganic N concentrations were found in storm waters from evergreen coniferous forest streams than those from deciduous broadleaf forest streams in Aichi, Kochi, Mie, Nagano, and with the exception of Tokyo. Finally, almost all the N : P ratios in the storm water were generally higher than 34, implying that the storm water should be P-limited, especially for Tokyo. PMID:22547978

Spatial and seasonal variation in the ecological significance of nutrient recycling by larval salamanders in Appalachian headwater streams

Treesearch

S. Conor Keitzer; Reuben R. Goforth

2013-01-01

Salamanders are abundant consumers in many temperate streams and may be important recyclers of biologically essential nutrients, but their ecological role is poorly understood. The ecological significance of nutrient recycling by salamanders may vary spatially and seasonally because of their potentially patchy distribution in streams and the dynamic nature of stream...

Algal community characteristics and response to nitrogen and phosphorus concentrations in streams in the Ozark Plateaus, Southern Missouri, 1993-95 and 2006-07

USGS Publications Warehouse

Femmer, Suzanne R.

2012-01-01

Nutrient and algae data were collected in the 1990s and 2000s by the U.S. Geological Survey for the National Water- Quality Assessment program in the Ozark Highlands, southern Missouri. These data were collected at sites of differing drainage area, land use, nutrient concentrations, and physiography. All samples were collected at sites with a riffle/pool structure and cobble/gravel bed material. A total of 60 samples from 45 sites were available for analyses to determine relations between nutrient concentrations and algal community structure in this region. This information can be used by the Missouri Department of Natural Resources to develop the State's nutrient criteria plan. Water samples collected for this study had total nitrogen concentrations ranging from 0.07 to 4.41 milligram per liter (mg/L) with a median of 0.26 mg/L, and total phosphorus concentrations ranging from 0.003 to 0.78 mg/L with a median of 0.007 mg/L. These nutrient concentrations were transformed into nutrient categories consisting of varying percentiles of data. Algal community data were entered into the U.S. Geological Survey's Algae Data Analysis System for the computation of more than 250 metrics. These metrics were correlated with nutrient categories, and four metrics with the strongest relation with the nutrient data were selected. These metrics were Organic Nitrogen Tolerance, Oxygen Tolerance, Bahls Pollution Class, and the Saprobien index with the 25th and 80th percentile nutrient categories. These data indicate that near the 80th percentile (Total Nitrogen = 0.84 mg/L, Total Phosphorus = 0.035 mg/L) the algae communities significantly changed from nitrogen-fixing species dominance to those species more tolerant of eutrophic conditions.

Nutrient dynamics in five off-stream reservoirs in the lower South Platte River basin, March-September 1995

USGS Publications Warehouse

Sprague, Lori A.

2002-01-01

In 1995, the U.S. Geological Survey conducted a study to characterize nutrient concentrations in five off-stream reservoirs in the lower South Platte River Basin?Riverside, Jackson, Prewitt, North Sterling, and Julesburg. These reservoirs are critical sources of irrigation water for agricultural areas, and several also are used for fishing, boating, swimming, hunting, and camping. Data collected for this study include depth profiles of water temperature, dissolved oxygen, pH, and specific conductance; nutrient species concentrations in the water column, bottom sediment, and inflow and outflow canals; and chlorophyll-a concentrations in the water column. Data were collected during the irrigation season from March through September 1995 at five sites each in Riverside, Jackson, Prewitt, and Julesburg Reservoirs and at six sites in North Sterling Reservoir. The five reservoirs studied are located in similar geographic, climatic, and land-use areas and, as a result, have a number of similarities in their internal nutrient dynamics. Nitrogen concentrations in the reservoirs were highest in March and decreased through September as a result of dilution from river inflows and biological activity. From March through June, decreases in nitrogen concentrations in the river and biological activity contributed to decreases in reservoir concentrations. From July through September, inflows from the river were cut off, and biological activity in the reservoirs led to further decreases in nitrate concentrations, which fell to near or below detectable levels. Phosphorus concentrations in the reservoirs did not show the same consistent decrease from March through September. Phosphorus likely was recycled continuously back to algae during the study period through processes such as excretion from fish, decay of aquatic plants and animals, and release of orthophosphate from bottom sediment during periods of low oxygen. With the exception of phosphorus in Jackson Reservoir, the reservoirs acted as a sink for both nitrogen and phosphorus; the percentage of the total mass (initial storage plus inflows) trapped in the reservoirs during the study period ranged from 49 to 88 percent for nitrogen and from 20 to 86 percent for phosphorus. The nutrient loading, morphology, and operation of the five reservoirs differed, however, leading to several important differences in nutrient dynamics among the reservoirs. Mean nutrient concentrations during the study period decreased in a downstream direction from Riverside Reservoir to Julesburg Reservoir because concentrations in the source water?the South Platte River?decreased downstream as a result of increased distance from wastewater loading upstream from Kersey, Colorado, and the replacement of diverted river water with more dilute ground-water return flow. North Sterling was an exception to this decrease; the strong stratification and resulting anoxia that developed in the reservoir led to nutrient release from the bottom sediments that offset the decrease in external nutrient loading. Variations in nutrient loading also contributed to differences in the nutrient limiting algal growth in the reservoirs, as indicated by mass nitrogen:phosphorus ratios. In Riverside and Jackson Reservoirs, nitrogen became the potential limiting nutrient by midsummer as biological activity depleted the available supply of nitrogen while the high initial phosphorus load was recycled. Prewitt, North Sterling, and Julesburg Reservoirs, with lower initial loadings of phosphorus, were phosphorus-limited throughout the study period, with additional colimitation of nitrogen as biological uptake reduced nitrogen concentrations to near or below laboratory detection limits. The percentage of the total nitrogen and phosphorus mass lost through outflow and trapped in the reservoir due to processes such as biological uptake and sedimentation varied between reservoirs.Generally, reservoirs with short residence times such as North Ste

Diminished Stream Nitrate Concentrations Linked to Dissolved Organic Carbon Dynamics After Leaf Fall

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Doctor, D. H.; Kendall, C.

2004-05-01

Thermodynamic coupling of the nitrogen and carbon cycles has broad implications for controls on catchment nutrient fluxes. In the northeast US, leaf fall occurs in early October and the availability of organic carbon increases as the leaves decompose. At the Sleepers River Research Watershed in northeastern Vermont (USA), we sampled stream chemistry from seven nested catchments to determine how stream dissolved organic carbon (DOC) and nitrate vary as a function of flow conditions, land-use, and basin size in response to leaf fall. Following leaf fall, nitrate concentration patterns were quantitatively different from other times of the year. Under baseflow conditions, stream and soil water DOC concentrations were higher than normal, whereas nitrate concentrations declined sharply at the five smallest catchments and more modestly at the two largest catchments. Under high flow conditions, flushing of nitrate was observed, as is typical for stormflow response at Sleepers River. Our field data suggest that in-stream processing of nitrate is likely thermodynamically and kinetically favorable under baseflow but not at higher flow conditions when expanding variable source areas make hydrological connections between nitrate source areas and streams. We are working to evaluate this hypothesis with isotopic and other monitoring data, and to model the coupled interactions of water, DOC, and nitrate fluxes in these nested catchments.

Concentrations of dissolved solids and nutrients in water sources and selected streams of the Santa Ana Basin, California, Octoger 1998 - September 2001

USGS Publications Warehouse

Kent, Robert; Belitz, Kenneth

2004-01-01

Concentrations of total dissolved solids (TDS) and nutrients in selected Santa Ana Basin streams were examined as a function of water source. The principal water sources are mountain runoff, wastewater, urban runoff, and stormflow. Rising ground water also enters basin streams in some reaches. Data were collected from October 1998 to September 2001 from 6 fixed sites (including a mountain site), 6 additional mountain sites (including an alpine indicator site), and more than 20 synoptic sites. The fixed mountain site on the Santa Ana River near Mentone appears to be a good representative of reference conditions for water entering the basin. TDS can be related to water source. The median TDS concentration in base-flow samples from mountain sites was 200 mg/L (milligrams per liter). Base-flow TDS concentrations from sites on the valley floor typically ranged from 400 to 600 mg/L; base flow to most of these sites is predominantly treated wastewater, with minor contributions of rising ground water and urban runoff. Sparse data suggest that TDS concentrations in urban runoff are about 300 mg/L. TDS concentrations appear to increase on a downstream gradient along the main stem of the Santa Ana River, regardless of source inputs. The major-ion compositions observed in samples from the different sites can be related to water source, as well as to in-stream processes in the basin. Water compositions from mountain sites are categorized into two groups: one group had a composition close to that of the alpine indicator site high in the watershed, and another group had ionic characteristics closer to those in tributaries on the valley floor. The water composition at Warm Creek, a tributary urban indicator site, was highly variable but approximately intermediate to the compositions of the upgradient mountain sites. Water compositions at the Prado Dam and Imperial Highway sites, located 11 miles apart on the Santa Ana River, were similar to one another and appeared to be a mixture of the waters of the upstream sites, Santa Ana River at MWD Crossing, Cucamonga Creek, and Warm Creek. Rainfall usually dilutes stream TDS concentrations. The median TDS concentration in all storm-event discrete samples was 260 mg/L. The median flow-weighted average TDS concentration for stormflow, based on continuous measurement of specific conductance and hydrograph separation of the continuous discharge record, was 190 mg/L. However, stormflow TDS concentrations were variable, and depended on whether the storm was associated with a relatively small or large rainfall event. TDS concentrations in stormflow associated with relatively small events ranged from about 50 to 600 mg/L with a median of 220 mg/L, whereas concentrations in stormflow associated with relatively large events ranged from about 40 to 300 mg/L with a median of 100 mg/L. From the perspective of water managers, the nutrient species of highest concern in Santa Ana Basin streams is nitrate. Most mountain streams had median base-flow concentrations of nitrate below 0.3 mg/L as nitrogen. Nitrate concentrations in both urban runoff and stormflow were near 1 mg/L, which is close to the level found in rainfall for the region. In fact, results from this study suggest that much of the nitrate load in urban storm runoff comes from rainwater. Nitrate concentrations in the Santa Ana River and its major tributaries are highest downstream from wastewater inputs, where median base-flow concentrations of nitrite+nitrate ranged from about 5 to 7 mg/L. About 4 percent of samples collected from sites receiving treated wastewater had nitrate concentrations greater than 10 mg/L. Rising ground water also appears to have high nitrate concentrations (greater than 10 mg/L) in some reaches of the river. Concentrations of other nitrogen species were much lower than nitrate concentrations in base-flow samples. However, storm events increased concentrations and the proportion of organic nitro

Monitoring the effects of climate and agriculture intensity on nutrient fluxes in lowland streams: a comparison between temperate Denmark and subtropical Uruguay

NASA Astrophysics Data System (ADS)

Goyenola, Guillermo; Meerhof, Mariane; Teixeira de Mello, Franco; González-Bergonzoni, Ivan; Graeber, Daniel; Vidal, Nicolas; Mazzeo, Nestor; Ovesen, Niels; Jeppesen, Erik; Thodsen, Hans; Kronvang, Brian

2014-05-01

Climate is changing towards more extreme conditions all over the world. At the same time, land use is becoming more intensive worldwide and particularly in many developing countries, whereas several developed countries are trying to reduce the impacts of intensive agricultural production and lower the excessive nutrient loading and eutrophication symptoms in water bodies. In 2009, we initiated a comparative research project between the subtropical region (Uruguay) and the temperate region (Denmark) to compare the hydrology and nutrient fluxes in paired micro-catchments with extensive production or intensive agriculture. The four selected streams drained catchments of similar size (7 to 19 km2). We have established similarly equipped monitoring stations in the four micro-catchments in spring (November 2009, Uruguay; March 2010, Denmark) to monitor the effects of land use and agriculture intensity on stream hydrology and nutrient concentrations and fluxes under different climate conditions. We have conducted high frequency measurements in the four lowland streams with underwater probes (turbidity, pH, conductivity and oxygen measured every 15 minutes), fortnight grab sampling of water and automatic sampling of composite water samples for nutrient analysis (total and dissolved nitrogen and phosphorus; sampled every four hours and accumulated fortnightly). Moreover, water level and meteorological information (precipitation, air temperature, global radiation, humidity) has been recorded every 10 minutes and instantaneous flow measurements have been conducted at regular intervals, to facilitate the calculation of instantaneous discharge from continuous records of water level (stage-discharge relationships). We will show results of ca. 2 years from this comparative study between Uruguay and Denmark, and the importance of differences in climate and land use will be discussed.

Local and Long-Distance Effects of Land Use Change on Nutrient Levels in Streams and Rivers of the Conterminous United States

NASA Astrophysics Data System (ADS)

Smith, R. A.; Alexander, R. B.; Schwarz, G. E.

2003-12-01

Determining the effects of land use change (e.g. urbanization, deforestation) on water quality at large spatial scales has been difficult because water quality measurements in large rivers with heterogeneous basins show the integrated effects of multiple factors. Moreover, the observed effects of land use changes on water quality in small homogeneous stream basins may not be indicative of downstream effects (including effects on such ecologically relevant characteristics as nutrient levels and elemental ratios) because of loss processes occurring during downstream transport in river channels. In this study we used the USGS SPARROW (Spatially-Referenced Regression on Watersheds) models of total nitrogen (TN) and total phosphorus (TP) in streams and rivers of the conterminous US to examine the effects of various aspects of land use change on nutrient concentrations and flux from the pre-development era to the present. The models were calibrated with data from 370 long-term monitoring stations representing a wide range of basin sizes, land use/cover classes, climates, and physiographies. The non-linear formulation for each model includes 20+ statistically estimated parameters relating to land use/cover characteristics and other environmental variables such as temperature, soil conditions, hill slope, and the hydraulic characteristics of 2200 large lakes and reservoirs. Model predictions are available for 62,000 river/stream channel nodes. Model predictions of pre-development water quality compare favorably with nutrient data from 63 undeveloped (reference) sites. Error statistics are available for predictions at all nodes. Model simulations were chosen to compare the effects of selected aspects of land use change on nutrient levels at large and small basin scales, lacustrine and coastal receiving waters, and among the major US geographic regions.

Assessing the Effects of Water Rights Purchases on Dissolved Oxygen, Stream Temperatures, and Fish Habitat

NASA Astrophysics Data System (ADS)

Mouzon, N. R.; Null, S. E.

2014-12-01

Human impacts from land and water development have degraded water quality and altered the physical, chemical, and biological integrity of Nevada's Walker River. Reduced instream flows and increased nutrient concentrations affect native fish populations through warm daily stream temperatures and low nightly dissolved oxygen concentrations. Water rights purchases are being considered to maintain instream flows, improve water quality, and enhance habitat for native fish species, such as Lahontan cutthroat trout. This study uses the River Modeling System (RMSv4), an hourly, physically-based hydrodynamic and water quality model, to estimate streamflows, temperatures, and dissolved oxygen concentrations in the Walker River. We simulate thermal and dissolved oxygen changes from increased streamflow to prioritize the time periods and locations that water purchases most enhance native trout habitat. Stream temperatures and dissolved oxygen concentrations are proxies for trout habitat. Monitoring results indicate stream temperature and dissolved oxygen limitations generally exist in the 115 kilometers upstream of Walker Lake (about 37% of the study area) from approximately May through September, and this reach currently acts as a water quality barrier for fish passage.

Agricultural disturbance response models for invertebrate and algal metrics from streams at two spatial scales within the U.S.

USGS Publications Warehouse

Waite, Ian R.

2014-01-01

As part of the USGS study of nutrient enrichment of streams in agricultural regions throughout the United States, about 30 sites within each of eight study areas were selected to capture a gradient of nutrient conditions. The objective was to develop watershed disturbance predictive models for macroinvertebrate and algal metrics at national and three regional landscape scales to obtain a better understanding of important explanatory variables. Explanatory variables in models were generated from landscape data, habitat, and chemistry. Instream nutrient concentration and variables assessing the amount of disturbance to the riparian zone (e.g., percent row crops or percent agriculture) were selected as most important explanatory variable in almost all boosted regression tree models regardless of landscape scale or assemblage. Frequently, TN and TP concentration and riparian agricultural land use variables showed a threshold type response at relatively low values to biotic metrics modeled. Some measure of habitat condition was also commonly selected in the final invertebrate models, though the variable(s) varied across regions. Results suggest national models tended to account for more general landscape/climate differences, while regional models incorporated both broad landscape scale and more specific local-scale variables.

Analysis of postfire hydrology, water quality, and sediment transport for selected streams in areas of the 2002 Hayman and Hinman fires, Colorado

USGS Publications Warehouse

Stevens, Michael R.

2013-01-01

The U.S. Geological Survey (USGS) began a 5-year study in 2003 that focused on postfire stream-water quality and postfire sediment load in streams within the Hayman and Hinman fire study areas. This report compares water quality of selected streams receiving runoff from unburned areas and burned areas using concentrations and loads, and trend analysis, from seasonal data (approximately April–November) collected 2003–2007 at the Hayman fire study area, and data collected from 1999–2000 (prefire) and 2003 (postfire) at the Hinman fire study area. The water-quality data collected during this study include onsite measurements of streamflow, specific conductance, and turbidity, laboratory-determined pH, and concentrations of major ions, nutrients, organic carbon, trace elements, and suspended sediment. Postfire floods and effects on water quality of streams, lakes and reservoirs, drinking-water treatment, and the comparison of measured concentrations to applicable water quality standards also are discussed. Exceedances of Colorado water-quality standards in streams of both the Hayman and Hinman fire study areas only occurred for concentrations of five trace elements (not all trace-element exceedances occurred in every stream). Selected samples analyzed for total recoverable arsenic (fixed), dissolved copper (acute and chronic), total recoverable iron (chronic), dissolved manganese (acute, chronic, and fixed) and total recoverable mercury (chronic) exceeded Colorado aquatic-life standards.

Changes in biogeochemical cycling following forest defoliation by pine wilt disease in Kiryu experimental catchment in Japan

NASA Astrophysics Data System (ADS)

Tokuchi, Naoko; Ohte, Nobuhito; Hobara, Satoru; Kim, Su-Jin; Masanori, Katsuyama

2004-10-01

Changes in nutrient budgets and hydrological processes due to the natural disturbance of pine wilt disease (PWD) were monitored in a small, forested watershed in Japan. The disturbance caused changes in soil nitrogen transformations. Pre-disturbance, mineralized nitrogen remained in the form of NH4+, whereas in disturbed areas most mineralized nitrogen was nitrified. Stream NO3- concentrations increased following PWD. There was a delay between time of disturbance and the increase of NO3- in ground and stream waters. Stream concentrations of NO3- and cations (Ca2+ + Mg2+) were significantly correlated from 1994 to 1996, whereas the correlation among NO3-, H+, and SO42- was significant only in 1995. Although both cation exchange and SO42- adsorption buffered protons, cation exchange was the dominant and continuous mechanism for acid buffering. SO42- adsorption was variable and highly pH dependent. The disturbance also resulted in slight delayed changes of input-output nutrient balances. The nitrogen contribution to PWD litter inputs was 7.39 kmol ha-1, and nitrogen loss from streamwater was less than 0.5 kmol ha-1 year-1 throughout the observation period. This large discrepancy suggested substantial nitrogen immobilization.

The role of hydrodynamics in shaping the composition and architecture of epilithic biofilms in fluvial ecosystems.

PubMed

Risse-Buhl, Ute; Anlanger, Christine; Kalla, Katalin; Neu, Thomas R; Noss, Christian; Lorke, Andreas; Weitere, Markus

2017-12-15

Previous laboratory and on-site experiments have highlighted the importance of hydrodynamics in shaping biofilm composition and architecture. In how far responses to hydrodynamics can be found in natural flows under the complex interplay of environmental factors is still unknown. In this study we investigated the effect of near streambed turbulence in terms of turbulent kinetic energy (TKE) on the composition and architecture of biofilms matured in two mountainous streams differing in dissolved nutrient concentrations. Over both streams, TKE significantly explained 7% and 8% of the variability in biofilm composition and architecture, respectively. However, effects were more pronounced in the nutrient richer stream, where TKE significantly explained 12% and 3% of the variability in biofilm composition and architecture, respectively. While at lower nutrient concentrations seasonally varying factors such as stoichiometry of dissolved nutrients (N/P ratio) and light were more important and explained 41% and 6% of the variability in biofilm composition and architecture, respectively. Specific biofilm features such as elongated ripples and streamers, which were observed in response to the uniform and unidirectional flow in experimental settings, were not observed. Microbial biovolume and surface area covered by the biofilm canopy increased with TKE, while biofilm thickness and porosity where not affected or decreased. These findings indicate that under natural flows where near bed flow velocities and turbulence intensities fluctuate with time and space, biofilms became more compact. They spread uniformly on the mineral surface as a film of densely packed coccoid cells appearing like cobblestone pavement. The compact growth of biofilms seemed to be advantageous for resisting hydrodynamic shear forces in order to avoid displacement. Thus, near streambed turbulence can be considered as important factor shaping the composition and architecture of biofilms grown under natural flows. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pesticide and nitrate transport in an agriculturally influenced stream in Indiana.

PubMed

Elias, Daniel; Bernot, Melody J

2017-04-01

Agrochemicals can be transported from agricultural fields into streams where they might have adverse effects on water quality and ecosystems. Three enrichment experiments were conducted in a central Indiana stream to quantify pesticide and nitrogen transport dynamics. In an enrichment experiment, a compound solution is added at a constant rate into a stream to increase compound background concentration. A conservative tracer (e.g., bromide) is added to determine discharge. Water and sediment samples are taken at several locations downstream to measure uptake metrics. We assessed transport of nitrate, atrazine, metolachlor, and carbaryl through direct measurement of uptake length (S w ), uptake velocity (V f ), and areal uptake (U). S w measures the distance traveled by a nutrient along the stream reach. V f measures the velocity a nutrient moves from the water column to immobilization sites. U represents the amount of nutrient immobilized in an area of streambed per unit of time. S w varied less than one order of magnitude across pesticides. The highest S w for atrazine suggests greater transport to downstream ecosystems. Across compounds, pesticide S w was longest in August relative to October and July. V f varied less than one order of magnitude across pesticides with the highest V f for metolachlor. U varied three orders of magnitude across pesticides with the highest U associate with sediment-bound carbaryl. Increasing nitrate S w suggests a lower nitrate demand of biota in this stream. Overall, pesticide transport was best predicted by compound solubility which can complement and improve models of pesticide abundance used by water quality programs and risk assessments.

Seasonal persistence of marine-derived nutrients in south-central Alaskan salmon streams

USGS Publications Warehouse

Rinella, Daniel J.; Wipfi, Mark S.; Walker, Coowe M.; Stricker, Craig A.; Heintz, Ron A.

2013-01-01

Spawning salmon deliver annual pulses of marine-derived nutrients (MDN) to riverine ecosystems around the Pacific Rim, leading to increased growth and condition in aquatic and riparian biota. The influence of pulsed resources may last for extended periods of time when recipient food webs have effective storage mechanisms, yet few studies have tracked the seasonal persistence of MDN. With this as our goal, we sampled stream water chemistry and selected stream and riparian biota spring through fall at 18 stations (in six watersheds) that vary widely in spawner abundance and at nine stations (in three watersheds) where salmon runs were blocked by waterfalls. We then developed regression models that related dissolved nutrient concentrations and biochemical measures of MDN assimilation to localized spawner density across these 27 stations. Stream water ammonium-N and orthophosphate-P concentrations increased with spawner density during the summer salmon runs, but responses did not persist into the following fall. The effect of spawner density on δ15N in generalist macroinvertebrates and three independent MDN metrics (δ15N, δ34S, and ω3:ω6 fatty acids) in juvenile Dolly Varden (Salvelinus malma) was positive and similar during each season, indicating that MDN levels in biota increased with spawner abundance and were maintained for at least nine months after inputs. Delta 15N in a riparian plant, horsetail (Equisetum fluviatile), and scraper macroinvertebrates did not vary with spawner density in any season, suggesting a lack of MDN assimilation by these lower trophic levels. Our results demonstrate the ready assimilation of MDN by generalist consumers and the persistence of this pulsed subsidy in these organisms through the winter and into the next growing season.

Effects of nutrient enrichment on the decomposition of wood and associated microbial activity in streams

Treesearch

Vladislav Gulis; Amy D. Rosemond; Keller Suberkropp; Holly S. Weyers; Jonathan P. Benstead

2004-01-01

We determined the effects of nutrient enrichment on wood decomposition rates and microbial activity during a 3-year study in two headwater streams at Coweeta Hydrologic Laboratory, NC, U.S.A. After a 1-year pretreatment period, one of the streams was continuously enriched with inorganic nutrients (nitrogen and phosphorus) for 2 years while the other stream served as a...

Selected water-quality and biological characteristics of streams in some forested basins of North Carolina, 1985-88

USGS Publications Warehouse

Caldwell, W.S.

1992-01-01

Selected physical, chemical and biological components of streams draining undeveloped, forested basins in North Carolina were characterized on the basis of samples collected at nine sites on streams in basins that ranged in size from 0.67 to 11.2 sq mi. Water analysis included specific conductance, dissolved oxygen, water temperature, suspended sediment, pH, major dissolved constituents, nutrients, minor constituents, organochlorine insecticides, and biochemical oxygen demand. Biological characteristics included fish tissue analysis for minor constituents and synthetic organic compounds, fish community structure, and benthic macroinvertebrates. Precipitation is the source of 10 to 40% of the chloride concentration and 20 to 30% of the sulfate concentration in stormflow. Mean total nitrogen concentrations ranged from 0.16 mg/L during low-flow conditions to 1.2 mg/L during stormflow. Organic nitrogen was 60 to 85% of the total nitrogen concentration. Stream water was free of organochlorine insecticides. DDD, DDE, DDT, Lindane, and Mirex were detected in 18 of 60 samples of streambed material. About 35% of fish tissue analyses showed detectable concentrations of copper, lead, mercury and nickel. Synthetic organic chemicals were not detected in fish tissue. Fish community structure data were rated using Karr's Index of Biotic Integrity. Streams rated poor to good because of natural stresses on fish communities. Five streams in the Piedmont and mountains received excellent bioclassification ratings based on benthic macroinvertebrtate data. Two streams in the Coastal Plain rated good to fair because of natural stresses.

GEOGRAPHIC TARGETING OF INCREASES IN NUTRIENT EXPORT DUE TO FUTURE URBANIZATION

EPA Science Inventory

Urbanization replaces the extant natural resource base (e.g., forests, wet- lands) with an infrastructure that is capable of supporting humans. One ecological consequence of urbanization is higher concentrations of nitrogen (N) and phosphorous (P) in streams, lakes, and estuaries...

MODIFICATIONS OF WASP FOR SIMULATING PERIPHYTON DYNAMICS

EPA Science Inventory

Conventional water quality models that are in current use today for the development of TMDLs and waste load allocations usually use dissolved oxygen, nutrient concentrations and algal growth as indicators to water health. In shallow streams and rivers, water health can be contro...

Rating curve estimation of nutrient loads in Iowa rivers

USGS Publications Warehouse

Stenback, G.A.; Crumpton, W.G.; Schilling, K.E.; Helmers, M.J.

2011-01-01

Accurate estimation of nutrient loads in rivers and streams is critical for many applications including determination of sources of nutrient loads in watersheds, evaluating long-term trends in loads, and estimating loading to downstream waterbodies. Since in many cases nutrient concentrations are measured on a weekly or monthly frequency, there is a need to estimate concentration and loads during periods when no data is available. The objectives of this study were to: (i) document the performance of a multiple regression model to predict loads of nitrate and total phosphorus (TP) in Iowa rivers and streams; (ii) determine whether there is any systematic bias in the load prediction estimates for nitrate and TP; and (iii) evaluate streamflow and concentration factors that could affect the load prediction efficiency. A commonly cited rating curve regression is utilized to estimate riverine nitrate and TP loads for rivers in Iowa with watershed areas ranging from 17.4 to over 34,600km2. Forty-nine nitrate and 44 TP datasets each comprising 5-22years of approximately weekly to monthly concentrations were examined. Three nitrate data sets had sample collection frequencies averaging about three samples per week. The accuracy and precision of annual and long term riverine load prediction was assessed by direct comparison of rating curve load predictions with observed daily loads. Significant positive bias of annual and long term nitrate loads was detected. Long term rating curve nitrate load predictions exceeded observed loads by 25% or more at 33% of the 49 measurement sites. No bias was found for TP load prediction although 15% of the 44 cases either underestimated or overestimate observed long-term loads by more than 25%. The rating curve was found to poorly characterize nitrate and phosphorus variation in some rivers. ?? 2010 .

Water-quality data from lakes and streams in the Grand Portage Reservation, Minnesota, 1997-98

USGS Publications Warehouse

Winterstein, Thomas A.

1999-01-01

The purpose of this report is to present the data collected by the USGS from the study during 1997-98. Water-quality data include temperature, pH, specific conductance, dissolved oxygen, alkalinity, and concentrations of major ions, nutrients, and trace metals. Lake sediment data include concentrations of trace metals and selected organic compounds.

Effects of Atmospheric Nitrate on an Upland Stream of the Northeastern USA

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Kendall, C.

2009-05-01

Excess nitrogen cascades through terrestrial biogeochemical cycles and affects stream nitrate concentrations in upland forests where atmospheric deposition is an important source of anthropogenic nitrogen. We will discuss approaches including high-frequency sampling, isotopic tracers, and end-member mixing analysis that can be used to decipher the sources, transformations, and hydrological processes that affect nitrate transport through forested upland catchments to streams. We present results of studies at the Sleepers River Research Watershed in Vermont, USA, a site where we have intensively measured stream nitrate concentrations during baseflow and stormflow. Stream nitrate concentrations are typically low and nearly 75% of annual inorganic N inputs from atmospheric deposition are retained within the catchment. However, high concentrations and stream loadings of nitrate occur during storm events due to source variation and hydrological flushing of nitrate from catchment soils. Using isotopic tracers and end-member mixing analysis, we have quantified source inputs of unprocessed atmospheric nitrate and show that this stream is directly affected by nitrogen pollution. Using a long-term record of stream hydrochemistry and our findings on event- scale nitrate flushing dynamics, we then explore how stream nitrate loading may respond to anthropogenic climate forcing during the next century. Results suggest that stream runoff and nitrate loadings will change during future emission scenarios (i.e. longer growing seasons and higher winter precipitation rates). Understanding the timing and magnitude of hydrological and hydrochemical responses is important because climate change effects on catchment hydrology may alter how nitrate is retained, produced, and hydrologically flushed in headwater ecosystems with implications for aquatic metabolism, nutrient export from catchments, and downstream eutrophication.

Controls of event-based nutrient transport within nested headwater agricultural watersheds of the western Lake Erie basin

NASA Astrophysics Data System (ADS)

Williams, Mark R.; Livingston, Stanley J.; Penn, Chad J.; Smith, Douglas R.; King, Kevin W.; Huang, Chi-hua

2018-04-01

Understanding the processes controlling nutrient delivery in headwater agricultural watersheds is essential for predicting and mitigating eutrophication and harmful algal blooms in receiving surface waters. The objective of this study was to elucidate nutrient transport pathways and examine key components driving nutrient delivery processes during storm events in four nested agricultural watersheds (298-19,341 ha) in the western Lake Erie basin with poorly drained soils and an extensive artificial drainage network typical of the Midwestern U.S. Concentration-discharge hysteresis patterns of nitrate-nitrogen (NO3-N), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP) occurring during 47 storm events over a 6 year period (2004-2009) were evaluated. An assessment of the factors producing nutrient hysteresis was completed following a factor analysis on a suite of measured environmental variables representing the fluvial and wider watershed conditions prior to, and during the monitored storm events. Results showed the artificial drainage network (i.e., surface tile inlets and subsurface tile drains) in these watersheds was the primary flow pathway for nutrient delivery to streams, but nutrient behavior and export during storm events was regulated by the flow paths to and the intensity of the drainage network, the availability of nutrients, and the relative contributions of upland and in-stream nutrient sources. Potential sources and flow pathways for transport varied among NO3-N, PP, and DRP with results underscoring the challenge of mitigating nutrient loss in these watersheds. Conservation practices addressing both nutrient management and hydrologic connectivity will likely be required to decrease nutrient loss in artificially drained landscapes.

Effects of Forest Harvesting on Ecosystem Health in the Headwaters of the New York City Water Supply, Catskill Mountains, New York

USGS Publications Warehouse

McHale, Michael R.; Murdoch, Peter S.; Burns, Douglas A.; Baldigo, Barry P.

2008-01-01

The effects of forest clearcutting and selective harvesting on forest soils, soil and stream water chemistry, forest regrowth, and aquatic communities were studied in four small headwater catchments. This research was conducted to identify the sensitivity of forested ecosystems to forest disturbance in the northeastern United States. The study area was in the headwaters of the Neversink Reservoir watershed, part of the New York City water supply system, in the Catskill Mountains of southeastern New York. Two sub-catchments of the Shelter Creek watershed were selectively harvested, one in its northern half and one more heavily in its southern half in 1995?96, the Dry Creek watershed was clearcut in the winter of 1996?97, and the Clear Creek watershed was left undisturbed and monitored as a control site. Monitoring was conducted from 4 years before the harvests until 4 years after the harvests. Clearcutting caused a large release of nitrate (NO3-) from watershed soils and a concurrent release of inorganic monomeric aluminum (Alim), which is toxic to some aquatic biota. The increased soil NO3- concentrations measured after the harvest could be completely accounted for by the decrease in nitrogen (N) uptake by watershed trees, rather than an increase in N mineralization and nitrification. The large increase in stream water NO3- and Alim concentrations caused 100-percent mortality of caged brook trout (Salvelinus fontinalis) during the first year after the clearcut and adversely affected macroinvertebrate communities for 2 years after the harvest. Nutrient uptake and biomass accumulation increased in uncut mature trees after the two selective harvests. There was no increase in stream-water NO3- or Alim concentrations, and so there were no adverse affects on macroinvertebrate or trout communities. The amount of tree biomass that can be removed without causing a sharp increase in stream-water NO3- and Alim stream-water concentrations is unknown, but probably depends on the history of forest-disturbance and acid deposition and the level of soil acidification. Results of this study indicate that macroinvertebrate and brook trout communities were sensitive to clearcutting and that deer browsing may affect water quality by suppressing forest regeneration and nutrient uptake. Further studies of selective harvests could identify the harvesting threshold below which changes in water quality and soil chemistry are minimized, and nutrient retention is maximized, thus reducing the damage that logging can inflict on stream and aquatic communities.

Stream reconnaissance for nutrients and other water-quality parameters, Greater Pittsburgh Region, Pennsylvania

USGS Publications Warehouse

Beall, Robert M.

1975-01-01

Eighty-five stream sites in and near the six-county Greater Pittsburgh Region were sampled in mid-June 1971 in mid-October 1972. Data are reported for 89 sites because 4 substitute sites were sampled in the second period. Drainage areas of the basins sampled ranged from 4.1 to 19,5000 square miles (10.6 to 50,500 square kilometres). The chemical analyses included constituents of three general classes: (1) nutrients, (2) activity indicators, and (3) dominant anions. Modification of the natural chemical and physical characteristics of the surface waters by man's activities is evident in some of the data. However, the activities are so diverse in type and in areal extent that their influence in terms of cause and effect is often obscure. Nutrient concentrations were high enough to indicate potential problems at about a quarter of the sampling sites. Temperature, dissolved oxygen, and pH values indicated a generally favorable capacity for regeneration or recovery from degradation, although a number a streams east of the Allegheny and Monongahela Rivers are marginal or lacking in the capacity. Regionally, sulfate is the dominant ion and was observed in concentrations of 40 milligrams per litre or more at 90 percent of the sites. Bicarbonate exceeded 100 milligrams per litre at 22 sites. A moderate to high degree of mineralization, as indicated by conductance readings of more than 500 micromhos per cetrimetre at half of the sampling sites, is a characteristic of the region's surface waters.

Phosphate dynamics in an acidic mountain stream: Interactions involving algal uptake, sorption by iron oxide, and photoreduction

USGS Publications Warehouse

Tate, Cathy M.; Broshears, Robert E.; McKnight, Diane M.

1995-01-01

Acid mine drainage streams in the Rocky Mountains typically have few algal species and abundant iron oxide deposits which can sorb phosphate. An instream injection of radiolabeled phosphate (32P0,) into St. Kevin Gulch, an acid mine drainage stream, was used to test the ability of a dominant algal species, Ulothrix sp., to rapidly assimilate phosphate. Approximately 90% of the injected phosphate was removed from the water column in the 175-m stream reach. When shaded stream reaches were exposed to full sunlight after the injection ended, photoreductive dissolution of iron oxide released sorbed 32P, which was then also removed downstream. The removal from the stream was modeled as a first-order process by using a reactive solute transport transient storage model. Concentrations of 32P mass-’ of algae were typically lo-fold greater than concentrations in hydrous iron oxides. During the injection, concentrations of 32P increased in the cellular P pool containing soluble, low-molecular-weight compounds and confirmed direct algal uptake of 32P0, from water. Mass balance calculations indicated that algal uptake and sorption on iron oxides were significant in removing phosphate. We conclude that in stream ecosystems, PO, sorbed by iron oxides can act as a dynamic nutrient reservoir regulated by photoreduction.

Changes in stream chemistry and nutrient export following a partial harvest in the Catskill Mountains, New York, USA

USGS Publications Warehouse

Wang, X.; Burns, Douglas A.; Yanai, R.D.; Briggs, R.D.; Germain, R.H.

2006-01-01

Clearcut forest harvesting typically results in large changes in stream water chemistry in northeastern North America. The effects of partial forest harvests on stream chemistry have not received as much attention, even though partial cutting is a more common forestry practice than clearcutting in this region. Changes in stream water chemistry following a partial cut are reported here from a 10 ha study catchment in a northern hardwood forest in the Catskill Mountains of southern New York, and are compared to those of a nearby 48 ha reference catchment. The lower two thirds of the treatment catchment was harvested in February-April 2002 by a shelterwood method, such that 33% of the basal area of the catchment was removed. Stream NO3-, NH4+, Ca2+, K+, and total dissolved aluminum (Alto) concentrations increased significantly after the harvest. Stream Ca2+, Mg2+ and NH4+ concentrations peaked 5 months after the initiation of the harvest, NO 3- and K+ concentrations peaked 6 months after cutting, and Alto concentrations peaked 1 year after cutting. Streamflow was not significantly affected by the harvest when compared to the flow of three nearby streams. Export of NO3- in stream water increased five-fold the year after the cut, and briefly exceeded atmospheric inputs of inorganic nitrogen during 4 months in the fall of 2002. Changes in stream NO3- and K+ concentrations were less than predicted by the relative basal area removed compared with those of a recent nearby clearcut. In contrast, changes in Ca2+, Mg 2+ and Alto concentrations were approximately proportional to basal area removal in these two cuts. Stream chemistry returned to values close to those of the pre-cut period and to reference values by early spring of 2003, just over a year after the initiation of the harvest, except for NO 3- concentrations, which remained elevated above background 18-20 months after completion of the cut.

Sediment and solute transport in a mountainous watershed in Valle del Cauca, Colombia

NASA Astrophysics Data System (ADS)

Guzman, Christian; Hoyos Villada, Fanny; Morales Vargas, Amalia; Rivera, Baudelino; Da Silva, Mayesse; Moreno Padilla, Pedro; Steenhuis, Tammo

2015-04-01

Sediment samples and solute concentrations were measured from the La Vega micro watershed in the southwestern region of the Colombian Andes. A main goal of this study was to improve prediction of soil surface and soil nutrient changes, based on field measurements, within small basin of the Aguaclara watershed network receiving different types of conservation measures. Two modeling approaches for stream discharge and sediment transport predictions were used with one of these based on infiltration-excess and the other on saturation-excess runoff. These streams are a part of a recent initiative from a water fund established by Asobolo, Asocaña, and Cenicaña in collaboration with the Natural Capital Project to improve conservation efforts and monitor their effects. On-site soil depth changes, groundwater depth measurements, and soil nutrient concentrations were also monitored to provide more information about changes within this mountainous watershed during one part of the yearly rainy season. This information is being coupled closely with the outlet sediment concentration and solute concentration patterns to discern correlations between scales. Lateral transects in the upper, middle, and lower part of the hillsides in the La Vega micro watershed showed differences in soil nutrient status and soil surface depth changes. The model based on saturation-excess, semi-distributed hydrology was able to reproduce discharge and sediment transport rates as well as the initially used infiltration excess model indicating available options for comparison of conservation changes in the future.

Estimated Nutrient Concentrations and Continuous Water-Quality Monitoring in the Eucha-Spavinaw Basin, Northwestern Arkansas and Northeastern Oklahoma, 2004-2007

USGS Publications Warehouse

Christensen, Victoria G.; Esralew, Rachel A.; Allen, Monica L.

2008-01-01

The Eucha-Spavinaw basin is the source of water for Lake Eucha and Spavinaw Lake, which are part of the water supply for the City of Tulsa. The City of Tulsa has received complaints of taste and odor in the finished drinking water because of deteriorating water quality. The deterioration is largely because of algal growth from the input of nutrients from the Eucha-Spavinaw basin. The U.S. Geological Survey, in cooperation with the City of Tulsa, implemented a continuous, real-time water-quality monitoring program in the Eucha-Spavinaw basin to better understand the source of the nutrient loading. This program included the manual collection of samples analyzed for nutrients and the collection of continuous, in-stream data from water-quality monitors. Continuous water-quality monitors were installed at two existing continuous streamflow-gaging stations - Spavinaw Creek near Colcord, Oklahoma, and Beaty Creek near Jay, Oklahoma, from October 2004 through September 2007. Total nitrogen concentrations for manually collected water samples ranged from 2.08 to 9.66 milligrams per liter for the water samples collected from Spavinaw Creek near Colcord, Oklahoma, and from 0.67 to 5.12 milligrams per liter for manually collected water samples from Beaty Creek near Jay, Oklahoma. Total phosphorus concentrations ranged from 0.04 to 1.5 milligrams per liter for the water samples collected from Spavinaw Creek near Colcord and from 0.028 to 1.0 milligram per liter for the water samples collected from Beaty Creek near Jay. Data from water samples and in-stream monitors at Spavinaw and Beaty Creeks (specific conductance and turbidity) were used to develop linear regression equations relating in-stream water properties to total nitrogen and total phosphorus concentrations. The equations developed for the Spavinaw and Beaty sites are site specific and only valid for the concentration ranges of the explanatory variables used in the analysis. The range in estimated and measured phosphorus is not representative for the range of historic streamflow at the Beaty site and that regression equation would benefit from more high flow and high turbidity samples. In addition, all three study years had below average annual precipitation for the area, and streamflow was especially low in Water Year 2006. Average nutrient concentrations from October 2004 through September 2007, which were drier than others, may not be a good indication of conditions in future wetter years. The equations for the Spavinaw and Beaty sites may be used to estimate instantaneous nutrient concentrations, which can be used to compute loads and yields in real time in order to better characterize the effect of land-management practices in these watersheds on the transport of nutrients to Lake Eucha and Spavinaw Lake. The methods used in this study show promise for monitoring future effectiveness of implemented best management practices, development and monitoring of total maximum daily loads, early detection of taste-and-odor occurrences, and to anticipate treatment needs for water suppliers.

Monitoring Stream Nutrient Concentration Trends in a Mixed-Land-Use Watershed

NASA Astrophysics Data System (ADS)

Zeiger, S. J.; Hubbart, J. A.

2014-12-01

Mixed-land use watersheds are often a complex patchwork of forested, agricultural, and urban land-uses where differential land-use mediated non-point source pollution can significantly impact water quality. Stream nitrogen and phosphorus concentrations serve as important variables for quantifying land use effects on non-point source pollution in receiving waters and relative impacts on aquatic biota. The Hinkson Creek Watershed (HCW) is a representative mixed land use urbanizing catchment (231 km2) located in central Missouri, USA. A nested-scale experimental watershed study including five permanent hydroclimate stations was established in 2009 to provide quantitative understanding of multiple land use impacts on nutrient loading. Spectrophotometric analysis was used to quantify total inorganic nitrogen (TIN) and total phosphorus (TP as PO4) regimes. Results (2010 - 2013) indicate average nitrate (NO3-) concentration (mg/l) range of 0.28 to 0.46 mg/l, nitrite (NO2-) range of 0.02 to 0.03 mg/l, ammonia (NH3) ranged from 0.04 to 0.08 mg/l, and TP range of 0.26 to 0.39 mg/l. With n=858, NO3-, NO2-, NH3, and TP concentrations were significantly (CI=95%, p=0.00) higher in the subbasin with the greatest percent cumulative agricultural land use (57%). NH3 and TP concentrations were significantly (CI=95%, p=0.00) higher (with the exception of the agricultural subbasin) in the subbasin with the greatest percent cumulative urban land use (26%). Results from multiple regression analyses showed percent cumulative agricultural and urban land uses accounted for 85% and 96% of the explained variance in TIN loading (CI=95%, p=0.08) and TP loading (CI=95%, p=0.02), respectively, between gauging sites. These results improve understanding of agricultural and urban land use impacts on nutrient concentrations in mixed use watersheds of the Midwest and have implications for nutrient reduction programs in the Mississippi River Basin and hypoxia reductions in the Gulf of Mexico, USA.

Nutrient loadings to streams of the continental United States from municipal and industrial effluent?

USGS Publications Warehouse

Maupin, Molly A.; Ivahnenko, Tamara

2011-01-01

Data from the United States Environmental Protection Agency Permit Compliance System national database were used to calculate annual total nitrogen (TN) and total phosphorus (TP) loads to surface waters from municipal and industrial facilities in six major regions of the United States for 1992, 1997, and 2002. Concentration and effluent flow data were examined for approximately 118,250 facilities in 45 states and the District of Columbia. Inconsistent and incomplete discharge locations, effluent flows, and effluent nutrient concentrations limited the use of these data for calculating nutrient loads. More concentrations were reported for major facilities, those discharging more than 1 million gallons per day, than for minor facilities, and more concentrations were reported for TP than for TN. Analytical methods to check and improve the quality of the Permit Compliance System data were used. Annual loads were calculated using "typical pollutant concentrations" to supplement missing concentrations based on the type and size of facilities. Annual nutrient loads for over 26,600 facilities were calculated for at least one of the three years. Sewage systems represented 74% of all TN loads and 58% of all TP loads. This work represents an initial set of data to develop a comprehensive and consistent national database of point-source nutrient loads. These loads can be used to inform a wide range of water-quality management, watershed modeling, and research efforts at multiple scales.

User-inspired Research Quantifies How Floodplain Restoration Paired With Cover Crops Reduces Nutrient Export From an Agricultural Catchment Translating to Conservation Success in the Midwestern Cornbelt.

NASA Astrophysics Data System (ADS)

Tank, J. L.; Hanrahan, B.; Christopher, S. F.; Mahl, U. H.; Royer, T. V.

2017-12-01

The Midwestern US has undergone extensive land use change as forest, wetlands, and prairies have been converted to agroecosystems. Today, excess fertilizer nutrients from farm fields enter agricultural streams, which degrades both local and downstream water quality. We are quantifying the nutrient reduction benefits of two conservation practices implemented at the catchment scale. In partnership with The Nature Conservancy, in a small Indiana catchment, we have quantified how 600m of floodplain restoration (i.e., a two-stage ditch) increased nitrate-N removal via denitrification and reduced sediment export, but impacts on stream nutrient concentrations were negligible due to very high catchment loading relative to the short implementation reach. Requests from state and federal partners led to development and parameterization of a new two-stage ditch module in the SWAT model to determine the potential catchment-scale benefits when implementation lengths were extended. More recently, in partnership with state SWCD managers, we have added a landscape practice to quantify how winter cover crops reduce nutrient loss from fields, sampling year-round nutrient fluxes from multiple subsurface tile drains and longitudinally along the stream channel. Nitrate-N and dissolved P fluxes were significantly lower in tiles draining fields with cover crops compared to those without. At the urging of farmers and federal NRCS partners, we also linked tile drain nutrient reductions to changes in soil chemistry. Both soil nitrate-N and dissolved P were lower in cover cropped fields, and we found significant correlations between soil and tile drain nutrients, which may encourage future adoption of the conservation practice as soil health benefits appeal to farmers. As biogeochemists, this research has provided valuable insights on how floodplains and land cover change can alter patterns of catchment-scale nutrient export. The translation of successful soil and water quality outcomes through this significant regional demonstration project make it a potentially powerful agent of change for advancing conservation success.

Effects of Atrazine, Metolachlor, Carbaryl and Chlorothalonil on Benthic Microbes and Their Nutrient Dynamics

PubMed Central

Elias, Daniel; Bernot, Melody J.

2014-01-01

Atrazine, metolachlor, carbaryl, and chlorothalonil are detected in streams throughout the U.S. at concentrations that may have adverse effects on benthic microbes. Sediment samples were exposed to these pesticides to quantify responses of ammonium, nitrate, and phosphate uptake by the benthic microbial community. Control uptake rates of sediments had net remineralization of nitrate (−1.58 NO3 µg gdm−1 h−1), and net assimilation of phosphate (1.34 PO4 µg gdm−1 h−1) and ammonium (0.03 NH4 µg gdm−1 h−1). Metolachlor decreased ammonium and phosphate uptake. Chlorothalonil decreased nitrate remineralization and phosphate uptake. Nitrate, ammonium, and phosphate uptake rates are more pronounced in the presence of these pesticides due to microbial adaptations to toxicants. Our interpretation of pesticide availability based on their water/solid affinities supports no effects for atrazine and carbaryl, decreasing nitrate remineralization, and phosphate assimilation in response to chlorothalonil. Further, decreased ammonium and phosphate uptake in response to metolachlor is likely due to affinity. Because atrazine target autotrophs, and carbaryl synaptic activity, effects on benthic microbes were not hypothesized, consistent with results. Metolachlor and chlorothalonil (non-specific modes of action) had significant effects on sediment microbial nutrient dynamics. Thus, pesticides with a higher affinity to sediments and/or broad modes of action are likely to affect sediment microbes' nutrient dynamics than pesticides dissolved in water or specific modes of action. Predicted nutrient uptake rates were calculated at mean and peak concentrations of metolachlor and chlorothalonil in freshwaters using polynomial equations generated in this experiment. We concluded that in natural ecosystems, peak chlorothalonil and metolachlor concentrations could affect phosphate and ammonium by decreasing net assimilation, and nitrate uptake rates by decreasing remineralization, relative to mean concentrations of metolachlor and chlorothalonil. Our regression equations can complement models of nitrogen and phosphorus availability in streams to predict potential changes in nutrient dynamics in response to pesticides in freshwaters. PMID:25275369

Response of an algal assemblage to nutrient enrichment and shading in a Hawaiian stream

USGS Publications Warehouse

Stephens, S.H.; Brasher, A.M.D.; Smith, C.M.

2012-01-01

To investigate the effects of nitrate enrichment, phosphate enrichment, and light availability on benthic algae, nutrient-diffusing clay flowerpots were colonized with algae at two sites in a Hawaiian stream during spring and autumn 2002 using a randomized factorial design. The algal assemblage that developed under the experimental conditions was investigated by determining biomass (ash-free dry mass and chlorophyll a concentrations) and composition of the diatom assemblage. In situ pulse amplitude-modulated fluorometry was also used to model photosynthetic rate of the algal assemblage. Algal biomass and maximum photosynthetic rate were significantly higher at the unshaded site than at the shaded site. These parameters were higher at the unshaded site with either nitrate, or to a lesser degree, nitrate plus phosphate enrichment. Analysis of similarity of diatom assemblages showed significant differences between shaded and unshaded sites, as well as between spring and autumn experiments, but not between nutrient treatments. However, several individual species of diatoms responded significantly to nitrate enrichment. These results demonstrate that light availability (shaded vs. unshaded) is the primary limiting factor to algal growth in this stream, with nitrogen as a secondary limiting factor. ?? 2011 Springer Science+Business Media B.V.

Recovery of Three Arctic Stream Reaches From Experimental Nutrient Enrichment.

NASA Astrophysics Data System (ADS)

Green, A. C.; Benstead, J. P.; Deegan, L. A.; Peterson, B. J.; Bowden, W. B.; Huryn, A. D.; Slavik, K.; Hershey, A. E.

2005-05-01

We examined multi-year patterns in community recovery from experimental low-concentration nutrient (N+P and P only) enrichment in three reaches of two Arctic tundra streams (Kuparuk River and Oksrukuyik Creek) on the North Slope of Alaska (USA). Rates of recovery varied among community components and depended on duration of enrichment (2 to 13 consecutive growing seasons). Biomass and C:P ratio of epilithic algae returned to reference levels rapidly (within 2 years), regardless of enrichment duration. Bryophyte cover, which increased greatly after long-term enrichment (>8 years), recovered to reference levels only after 7 years, when a storm scoured most remnant moss in the recovering reach. Persistence of bryophytes slowed recovery rates of insect taxa that had either been positively (e.g., Ephemerella, most chironomid taxa) or negatively (e.g., Orthocladius rivulorum) affected by this shift in dominant primary producer and its consequence for benthic habitat. Growth of Arctic grayling (adults and young-of-year), the top predator, returned to reference rates within two years. Recovery of these Arctic stream ecosystems from nutrient enrichment was consequently controlled largely by interactions between duration of enrichment and physical disturbance, mediated through physical habitat shifts caused by bryophytes.

Salmon-mediated nutrient flux in selected streams of the Columbia River basin, USA

USGS Publications Warehouse

Kohler, Andre E.; Kusnierz, Paul C.; Copeland, Timothy; Venditti, David A.; Denny, Lytle; Gable, Josh; Lewis, Bert; Kinzer, Ryan; Barnett, Bruce; Wipfli, Mark S.

2013-01-01

Salmon provide an important resource subsidy and linkage between marine and land-based ecosystems. This flow of energy and nutrients is not uni-directional (i.e., upstream only); in addition to passive nutrient export via stream flow, juvenile emigrants actively export nutrients from freshwater environments. In some cases, nutrient export can exceed import. We evaluated nutrient fluxes in streams across central Idaho, USA using Chinook salmon (Oncorhynchus tshawytscha) adult escapement and juvenile production data from 1998 to 2008. We found in the majority of stream-years evaluated, adults imported more nutrients than progeny exported; however, in 3% of the years, juveniles exported more nutrients than their parents imported. On average, juvenile emigrants exported 22 ± 3% of the nitrogen and 30 ± 4% of the phosphorus their parents imported. This relationship was density dependent and nonlinear; during periods of low adult abundance juveniles were larger and exported up to 194% and 268% of parental nitrogen and phosphorus inputs, respectively. We highlight minimum escapement thresholds that appear to 1) maintain consistently positive net nutrient flux and 2) reduce the average proportional rate of export across study streams. Our results suggest a state-shift occurs when adult spawner abundance falls below a threshold to a point where the probability of juvenile nutrient exports exceeding adult imports becomes increasingly likely.

Foliar litter decomposition in an alpine forest meta-ecosystem on the eastern Tibetan Plateau.

PubMed

Yue, Kai; Yang, Wanqin; Peng, Changhui; Peng, Yan; Zhang, Chuan; Huang, Chunping; Tan, Yu; Wu, Fuzhong

2016-10-01

Litter decomposition is a biological process fundamental to element cycling and a main nutrient source within forest meta-ecosystems, but few studies have looked into this process simultaneously in individual ecosystems, where environmental factors can vary substantially. A two-year field study conducted in an alpine forest meta-ecosystem with four litter species (i.e., willow: Salix paraplesia, azalea: Rhododendron lapponicum, cypress: Sabina saltuaria, and larch: Larix mastersiana) that varied widely in chemical traits showed that both litter species and ecosystem type (i.e., forest floor, stream and riparian zone) are important factors affecting litter decomposition, and their effects can be moderated by local-scale environmental factors such as temperature and nutrient availability. Litter decomposed fastest in the streams followed by the riparian zone and forest floor regardless of species. For a given litter species, both the k value and limit value varied significantly among ecosystems, indicating that the litter decomposition rate and extent (i.e., reaching a limit value) can be substantially affected by ecosystem type and the local-scale environmental factors. Apart from litter initial acid unhydrolyzable residue (AUR) concentration and its ratio to nitrogen concentration (i.e., AUR/N ratio), the initial nutrient concentrations of phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were also important litter traits that affected decomposition depending on the ecosystem type. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental and Biological Data of the Nutrient Enrichment Effects on Stream Ecosystems Project of the National Water Quality Assessment Program, 2003-04

USGS Publications Warehouse

Brightbill, Robin A.; Munn, Mark D.

2008-01-01

In 2000, the U.S. Environmental Protection Agency began the process of developing regional nutrient criteria for streams and rivers. In response to concerns about nutrients by the U.S. Environmental Protection Agency and others, the U.S. Geological Survey National Water Quality Assessment Program began studying the effects of nutrient enrichment on agricultural stream ecosystems to aid in the understanding of how nutrients affect the biota in agricultural streams. Streams within five study areas were sampled either in 2003 or 2004. These five study areas were located within six NAWQA study units: the combined Apalachicola-Chattahoochee-Flint River Basin (ACFB) and Georgia-Florida Coastal Plain Drainages (GAFL), Central Columbia Plateau?Yakima River Basin (CCYK), Central Nebraska Basins (CNBR), Potomac River?Delmarva Peninsula (PODL), and the White-Miami River Basin (WHMI). Data collected included nutrients (nitrogen and phosphorous) and other chemical parameters, biological samples (chlorophyll, algal assemblages, invertebrate assemblages, and some fish assemblages), stream habitat, and riparian and basin information. This report describes and presents the data collected from these study areas.

GREAT II Upper Mississippi River (Guttenberg, Iowa to Saverton, Missouri) Water Quality Work Group Appendix.

DTIC Science & Technology

1980-12-01

DO trends in area. this segment of the river. Statistical tests, however, showed the differences in average A concentration of at least 5 mg/i DO is...as ponds and streams immediately below milling mercury concentration against body length * sites had accumulations of lead up to 178 and is shown in...65 1 Relative Proportions of Major Ions in Mississippi (1976) 83 2 Mean Nutrient Concentrations - Mississippi River

Riverine C, N, Si and P transport to the coastal ocean: An overview

USGS Publications Warehouse

Peterson, David H.; Hager, Stephen W.; Schemel, Laurence E.; Cayan, Daniel R.

1988-01-01

Terrestrial ecosystems cycle and recyle inorganic nutrients including a feedback to atmospheric dry deposition and precipitation (cf. Lewis et al., 1985). Each year, however, a small fraction per unit area of the atmosphere/plant/soil flux leaks from these land-based cycles via precipitation/runoff (Meybeck, 1982). These losses are, in general, unpreventable. Moreover, such nutrient “losses” have increased with increasing human population (Wollast, 1983); although to some extent this anthropogenic component can be controlled. Most rivers eventually flow into estuaries and the coastal ocean where their natural and anthropogenic nutrient loads continue to recycle, are lost to the atmosphere, or are buried in sediment. In one extreme, when riverine nutrient concentrations are exceedingly low, as in southwestern Canadian streams (Naiman and Sibert, 1978; Stockner and Shortreed, 1978, 1985), downstream plant biomass can be nutrient limited. In the other extreme, when these nutrient concentrations are very high such as in highly populated European river basins, downstream plant biomass can increase, perhaps intensifying natural anoxia cycles within the receiving estuarine/coastal ocean waters if these waters are stratified (Rosenberg, 1985).

Microbial enzyme activity, nutrient uptake and nutrient limitation in forested streams

Treesearch

Brian H. Hill; Frank H. McCormick; Bret C. Harvey; Sherri L. Johnson; Melvin L. Warren; Colleen M. Elonen

2010-01-01

The flow of organic matter and nutrients from catchments into the streams draining them and the biogeochemical transformations of organic matter and nutrients along flow paths are fundamental processes instreams (Hynes,1975; Fisher, Sponseller & Heffernan, 2004). Microbial biofilms are often the primary interface for organic matter and nutrient uptake and...

An alternative regionalization scheme for defining nutrient criteria for rivers and streams

USGS Publications Warehouse

Robertson, Dale M.; Saad, David A.; Wieben, Ann M.

2001-01-01

The environmental nutrient zone approach can be applied to specific states or nutrient ecoregions and used to develop criteria as a function of stream type. This approach can also be applied on the basis of environmental characteristics of the watershed alone rather than the general environmental characteristics from the region in which the site is located. The environmental nutrient zone approach will enable states to refine the basic nutrient criteria established by the USEPA by developing attainable criteria given the environmental characteristics where the streams are located.

Data Used in Analyses of Trends, and Nutrient and Suspended-Sediment Loads for Streams in the Southeastern United States, 1973-2005

USGS Publications Warehouse

Staub, Erik L.; Peak, Kelly L.; Tighe, Kirsten C.; Sadorf, Eric M.; Harned, Douglas A.

2010-01-01

Water-quality data from selected surface-water monitoring sites in the Southeastern United States were assessed for trends in concentrations of nutrients, suspended sediment, and major constituents and for in-stream nutrient and suspended-sediment loads for the period 1973-2005. The area of interest includes river basins draining into the southern Atlantic Ocean, the Gulf of Mexico, and the Tennessee River-drainage basins in Hydrologic Regions 03 (South Atlantic - Gulf) and 06 (Tennessee). This data assessment is related to studies of several major river basins as part of the U.S. Geological Survey National Water-Quality Assessment Program, which was designed to assess national water-quality trends during a common time period (1993-2004). Included in this report are data on which trend tests could be performed from 44 U.S. Geological Survey National Water Information System (NWIS) sampling sites. The constituents examined include major ions, nutrients, and suspended sediment; the physical properties examined include pH, specific conductance, dissolved oxygen, and streamflow. Also included are data that were tested for trends from an additional 290 sites from the U.S. Environmental Protection Agency Storage and Retrieval (STORET) database. The trend analyses of the STORET data were limited to total nitrogen and total phosphorus concentrations. Data from 48 U.S. Geological Survey NWIS sampling sites with sufficient water-quality and continuous streamflow data for estimating nutrient and sediment loads are included. The methods of data compilation and modification used prior to performing trend tests and load estimation are described. Results of the seasonal Kendall trend test and the Tobit trend test are given for the 334 monitoring sites, and in-stream load estimates are given for the 48 monitoring sites. Basin characteristics are provided, including regional landscape variables and agricultural nutrient sources (annual variations in cropping and fertilizer use). The data and results presented in this report are in tabular format and can be downloaded and used by environmental researchers and water managers, particularly in the Southeast.

Concentration-discharge relationships for variably sized streams in Florida: Patterns and drivers in long-term catchment studies

NASA Astrophysics Data System (ADS)

Diamond, J.; Cohen, M.

2012-12-01

Catchment-scale analyses can provide important insight into the processes governing solute sources, transport and storage. Understanding solute dynamics is vital for water management both for accurate predictions of chemical fluxes as well as ecosystem responses to them. This project synthesized long-term (>15 years) hydrochemical data from 80 variably sized (101-105 m2) watersheds in Florida. Our goal was to evaluate scaling effects on flow-solute relationships, and determine the factors that control observed inter-catchment variation. We obtained long term records of a variety of chemical parameters include color, nutrients (N and P), and geogenic solutes (Ca, Si, Mg, Na, Cl) from stations where chemistry and flow data were matched. Catchment attributes (land use, terrain, surface geology) were obtained for each stream as potential covariates. Concentration-discharge relationships were modeled as power functions, the exponents (b) of which were categorized into three end-member scenarios: (1) b>0, or chemodynamic conditions, where increased discharge increases concentration, (2) b=0, or chemostatic conditions, where concentration is independent of discharge, and (3) b<0, or dilution conditions, where increased discharge decreases concentrations. Color was strongly chemodynamic, while geogenic solutes tended to be chemostatic;nutrient-flow relationships varied substantially (from dilution to chemodynamic) suggesting important ancillary controls. To assess between-site variability, power function exponents were compared against land use and catchment area. These results indicate that watersheds dominated by urban land use exhibit stronger dilution effects for most solutes while watersheds dominated by agricultural land use were generally chemostatic particularly for nutrients. This synthesis approach to understanding controls on observed concentration-discharge relationships is crucial to understanding the dynamics and early-warning indicators of anthropogenically-induced transition from dilution to chemostatic behavior.

Water Quality in the Blue River Basin, Kansas City Metropolitan Area, Missouri and Kansas, July 1998 to October 2004

USGS Publications Warehouse

Wilkison, Donald H.; Armstrong, Daniel J.; Norman, Richard D.; Polton, Barry C.; Furlong, Edward T.; Zaugg, Steven D.

2006-01-01

Water-quality data were collected from sites in the Blue River Basin from July 1998 to October. Sites upstream from wastewater-treatment plants or the combined sewer system area had lower concentrations of total nitrogen, phosphorus, organic wastewater compounds, and pharmaceuticals, and more diverse aquatic communities. Sites downstream from wastewater-treatment plants had the largest concentrations and loads of nutrients, organic wastewater compounds, and pharmaceuticals. Approximately 60 percent of the total nitrogen and phosphorus in Blue River originated from the Indian Creek, smaller amounts from the upper Blue River (from 28 to 16 percent), and less than 5 percent from Brush Creek. Nutrient yields from the Indian Creek and the middle Blue River were significantly greater than yields from the upper Blue River, lower Brush Creek, the outside control site, and other U.S. urban sites. Large concentrations of nutrients led to eutrophication of impounded Brush Creek reaches. Bottom sediment samples collected from impoundments generally had concentrations of organic wastewater and pharmaceutical compounds equivalent to or greater than, concentrations observed in streambed sediments downstream from wastewater-treatment plants. Bacteria in streams largely was the result of nonpoint-source contributions during storms. Based on genetic source-tracking, average contributions of in-stream Esherichia coli bacteria in the basin from dogs ranged from 26-32 percent of the total concentration, and human sources ranged from 28-42 percent. Macro invertebrate diversity was highest at sites with the largest percentage of upstream land use devoted to forests and grasslands. Declines in macro invertebrate community metrics were correlated strongly with increases in several, inter-related urbanization factors.

Water quality in the Blue River basin, Kansas City metropolitan area, Missouri and Kansas, July 1998 to October 2004

USGS Publications Warehouse

Wilkison, Donald H.; Armstrong, Daniel J.; Norman, Richard D.; Poulton, Barry C.; Furlong, Edward T.; Zaugg, Steven D.

2006-01-01

Water-quality data were collected from sites in the Blue River Basin from July 1998 to October. Sites upstream from wastewater-treatment plants or the combined sewer system area had lower concentrations of total nitrogen, phosphorus, organic wastewater compounds, and pharmaceuticals, and more diverse aquatic communities. Sites downstream from wastewater-treatment plants had the largest concentrations and loads of nutrients, organic wastewater compounds, and pharmaceuticals. Approximately 60 percent of the total nitrogen and phosphorus in Blue River originated from the Indian Creek, smaller amounts from the upper Blue River (from 28 to 16 percent), and less than 5 percent from Brush Creek. Nutrient yields from the Indian Creek and the middle Blue River were significantly greater than yields from the upper Blue River, lower Brush Creek, the outside control site, and other U.S. urban sites. Large concentrations of nutrients led to eutrophication of impounded Brush Creek reaches. Bottom sediment samples collected from impoundments generally had concentrations of organic wastewater and pharmaceutical compounds equivalent to or greater than, concentrations observed in streambed sediments downstream from wastewater-treatment plants. Bacteria in streams largely was the result of nonpoint-source contributions during storms. Based on genetic source-tracking, average contributions of in-stream Esherichia coli bacteria in the basin from dogs ranged from 26-32 percent of the total concentration, and human sources ranged from 28-42 percent. Macro invertebrate diversity was highest at sites with the largest percentage of upstream land use devoted to forests and grasslands. Declines in macro invertebrate community metrics were correlated strongly with increases in several, inter-related urbanization factors.

Effects of urbanization on stream water quality in the city of Atlanta, Georgia, USA

USGS Publications Warehouse

Peters, N.E.

2009-01-01

A long-term stream water quality monitoring network was established in the city of Atlanta, Georgia during 2003 to assess baseline water quality conditions and the effects of urbanization on stream water quality. Routine hydrologically based manual stream sampling, including several concurrent manual point and equal width increment sampling, was conducted ???12 times annually at 21 stations, with drainage areas ranging from 3.7 to 232 km2. Eleven of the stations are real-time (RT) stations having continuous measures of stream stage/ discharge, pH, dissolved oxygen, specific conductance, water temperature and turbidity, and automatic samplers for stormwater collection. Samples were analyzed for field parameters, and a broad suite of water quality and sediment-related constituents. Field parameters and concentrations of major ions, metals, nutrient species and coliform bacteria among stations were evaluated and with respect to watershed characteristics and plausible sources from 2003 through September 2007. Most constituent concentrations are much higher than nearby reference streams. Concentrations are statistically different among stations for several constituents, despite high variability both within and among stations. Routine manual sampling, automatic sampling during stormflows and RT water quality monitoring provided sufficient information about urban stream water quality variability to evaluate causes of water quality differences among streams. Fecal coliform bacteria concentrations of most samples exceeded Georgia's water quality standard for any water-usage class. High chloride concentrations occur at three stations and are hypothesized to be associated with discharges of chlorinated combined sewer overflows, drainage of swimming pool(s) and dissolution and transport during rainstorms of CaCl2, a deicing salt applied to roads during winter storms. One stream was affected by dissolution and transport of ammonium alum [NH4Al(SO4)2] from an alum-manufacturing plant; streamwater has low pH (<5), low alkalinity and high metals concentrations. Several trace metals exceed acute and chronic water quality standards and high concentrations are attributed to washoff from impervious surfaces.

Connecting Seasonal Riparian Buffer Metrics and Nitrogen Concentrations in a Pulse-Driven Agricultural System

EPA Science Inventory

Riparian buffers have been well studied as best management practices for nutrient reduction at field scales yet their effectiveness for bettering water quality at watershed scales has been difficult to determine. Seasonal dynamics of the stream network are often overlooked when ...

A suite of microplate reader-based colorimetric methods to quantify ammonium, nitrate, orthophosphate and silicate concentrations for aquatic nutrient monitoring.

PubMed

Ringuet, Stephanie; Sassano, Lara; Johnson, Zackary I

2011-02-01

A sensitive, accurate and rapid analysis of major nutrients in aquatic systems is essential for monitoring and maintaining healthy aquatic environments. In particular, monitoring ammonium (NH(4)(+)) concentrations is necessary for maintenance of many fish stocks, while accurate monitoring and regulation of ammonium, orthophosphate (PO(4)(3-)), silicate (Si(OH)(4)) and nitrate (NO(3)(-)) concentrations are required for regulating algae production. Monitoring of wastewater streams is also required for many aquaculture, municipal and industrial wastewater facilities to comply with local, state or federal water quality effluent regulations. Traditional methods for quantifying these nutrient concentrations often require laborious techniques or expensive specialized equipment making these analyses difficult. Here we present four alternative microcolorimetric assays that are based on a standard 96-well microplate format and microplate reader that simplify the quantification of each of these nutrients. Each method uses small sample volumes (200 µL), has a detection limit ≤ 1 µM in freshwater and ≤ 2 µM in saltwater, precision of at least 8% and compares favorably with standard analytical procedures. Routine use of these techniques in the laboratory and at an aquaculture facility to monitor nutrient concentrations associated with microalgae growth demonstrates that they are rapid, accurate and highly reproducible among different users. These techniques offer an alternative to standard nutrient analyses and because they are based on the standard 96-well format, they significantly decrease the cost and time of processing while maintaining high precision and sensitivity.

Repeat synoptic sampling reveals drivers of change in carbon and nutrient chemistry of Arctic catchments

NASA Astrophysics Data System (ADS)

Zarnetske, J. P.; Abbott, B. W.; Bowden, W. B.; Iannucci, F.; Griffin, N.; Parker, S.; Pinay, G.; Aanderud, Z.

2017-12-01

Dissolved organic carbon (DOC), nutrients, and other solute concentrations are increasing in rivers across the Arctic. Two hypotheses have been proposed to explain these trends: 1. distributed, top-down permafrost degradation, and 2. discrete, point-source delivery of DOC and nutrients from permafrost collapse features (thermokarst). While long-term monitoring at a single station cannot discriminate between these mechanisms, synoptic sampling of multiple points in the stream network could reveal the spatial structure of solute sources. In this context, we sampled carbon and nutrient chemistry three times over two years in 119 subcatchments of three distinct Arctic catchments (North Slope, Alaska). Subcatchments ranged from 0.1 to 80 km2, and included three distinct types of Arctic landscapes - mountainous, tundra, and glacial-lake catchments. We quantified the stability of spatial patterns in synoptic water chemistry and analyzed high-frequency time series from the catchment outlets across the thaw season to identify source areas for DOC, nutrients, and major ions. We found that variance in solute concentrations between subcatchments collapsed at spatial scales between 1 to 20 km2, indicating a continuum of diffuse- and point-source dynamics, depending on solute and catchment characteristics (e.g. reactivity, topography, vegetation, surficial geology). Spatially-distributed mass balance revealed conservative transport of DOC and nitrogen, and indicates there may be strong in-stream retention of phosphorus, providing a network-scale confirmation of previous reach-scale studies in these Arctic catchments. Overall, we present new approaches to analyzing synoptic data for change detection and quantification of ecohydrological mechanisms in ecosystems in the Arctic and beyond.

Direct and indirect effects of multiple stressors on stream invertebrates across watershed, reach and site scales: A structural equation modelling better informing on hydromorphological impacts.

PubMed

Villeneuve, B; Piffady, J; Valette, L; Souchon, Y; Usseglio-Polatera, P

2018-01-15

The purpose of our approach was to take into account the nested spatial scales driving stream functioning in the description of pressures/ecological status links by analysing the results of a hierarchical model. The development of this model has allowed us to answer the following questions: Does the consideration of the indirect links between anthropogenic pressures and stream ecological status modify the hierarchy of pressure types impacting benthic invertebrates? Do the different nested scales play different roles in the anthropogenic pressures/ecological status relationship? Does this model lead to better understanding of the specific role of hydromorphology in the evaluation of stream ecological status? To achieve that goal, we used the Partial Least Square (PLS) path modelling method to develop a structural model linking variables describing (i) land use and hydromorphological alterations at the watershed scale, (ii) hydromorphological alterations at the reach scale, (iii) nutrients-organic matter contamination levels at the site scale, and (iv) substrate characteristics at the sampling site scale, to explain variation in values of a macroinvertebrate-based multimetric index: the French I 2 M 2 . We have highlighted the importance of land use effects exerted on both hydromorphological and chemical characteristics of streams observed at finer scales and their subsequent indirect impact on stream ecological status. Hydromorphological alterations have an effect on the substrate mosaic structure and on the concentrations of nutrients and organic matter at site scale. This result implies that stream hydromorphology can have a major indirect effect on macroinvertebrate assemblages and that the hierarchy of impacts of anthropogenic pressures on stream ecological status generally described in the literature - often determining strategic restoration priorities - has to be re-examined. Finally, the effects of nutrients and organic matter on macroinvertebrate assemblages are lower than expected when all the indirect effects of land use and hydromorphological alterations are taken into account. Copyright © 2017 Elsevier B.V. All rights reserved.

Using high-frequency nitrogen and carbon measurements to decouple temporal dynamics of catchment and in-stream transport and reaction processes in a headwater stream

NASA Astrophysics Data System (ADS)

Blaen, P.; Riml, J.; Khamis, K.; Krause, S.

2017-12-01

Within river catchments across the world, headwater streams represent important sites of nutrient transformation and uptake due to their high rates of microbial community processing and relative abundance in the landscape. However, separating the combined influence of in-stream transport and reaction processes from the overall catchment response can be difficult due to spatio-temporal variability in nutrient and organic matter inputs, flow regimes, and reaction rates. Recent developments in optical sensor technologies enable high-frequency, in situ nutrient measurements, and thus provide opportunities for greater insights into in-stream processes. Here, we use in-stream observations of hourly nitrate (NO3-N), dissolved organic carbon (DOC) and dissolved oxygen (DO) measurements from paired in situ sensors that bound a 1 km headwater stream reach in a mixed-use catchment in central England. We employ a spectral approach to decompose (1) variances in solute loading from the surrounding landscape, and (2) variances in reach-scale in-stream nutrient transport and reaction processes. In addition, we estimate continuous rates of reach-scale NO3-N and DOC assimilation/dissimilation, ecosystem respiration and primary production. Comparison of these results over a range of hydrological conditions (baseflow, variable storm events) and timescales (event-based, diel, seasonal) facilitates new insights into the physical and biogeochemical processes that drive in-stream nutrient dynamics in headwater streams.

Changing climate and nutrient transfers: Evidence from high temporal resolution concentration-flow dynamics in headwater catchments.

PubMed

Ockenden, M C; Deasy, C E; Benskin, C McW H; Beven, K J; Burke, S; Collins, A L; Evans, R; Falloon, P D; Forber, K J; Hiscock, K M; Hollaway, M J; Kahana, R; Macleod, C J A; Reaney, S M; Snell, M A; Villamizar, M L; Wearing, C; Withers, P J A; Zhou, J G; Haygarth, P M

2016-04-01

We hypothesise that climate change, together with intensive agricultural systems, will increase the transfer of pollutants from land to water and impact on stream health. This study builds, for the first time, an integrated assessment of nutrient transfers, bringing together a) high-frequency data from the outlets of two surface water-dominated, headwater (~10km(2)) agricultural catchments, b) event-by-event analysis of nutrient transfers, c) concentration duration curves for comparison with EU Water Framework Directive water quality targets, d) event analysis of location-specific, sub-daily rainfall projections (UKCP, 2009), and e) a linear model relating storm rainfall to phosphorus load. These components, in combination, bring innovation and new insight into the estimation of future phosphorus transfers, which was not available from individual components. The data demonstrated two features of particular concern for climate change impacts. Firstly, the bulk of the suspended sediment and total phosphorus (TP) load (greater than 90% and 80% respectively) was transferred during the highest discharge events. The linear model of rainfall-driven TP transfers estimated that, with the projected increase in winter rainfall (+8% to +17% in the catchments by 2050s), annual event loads might increase by around 9% on average, if agricultural practices remain unchanged. Secondly, events following dry periods of several weeks, particularly in summer, were responsible for high concentrations of phosphorus, but relatively low loads. The high concentrations, associated with low flow, could become more frequent or last longer in the future, with a corresponding increase in the length of time that threshold concentrations (e.g. for water quality status) are exceeded. The results suggest that in order to build resilience in stream health and help mitigate potential increases in diffuse agricultural water pollution due to climate change, land management practices should target controllable risk factors, such as soil nutrient status, soil condition and crop cover. Copyright © 2015 Elsevier B.V. All rights reserved.

Preliminary effects of streambank fencing of pasture land on the quality of surface water in a small watershed in Lancaster County, Pennsylvania

USGS Publications Warehouse

Galeone, Daniel G.

2000-01-01

The use of fencing to exclude pastured animals from streams has been recognized as an agricultural best-management practice. Streambank fencing was installed in a small basin within the Mill Creek Watershed of Lancaster County, Pa., during summer 1997 to evaluate the effectiveness of fencing on surface-water quality. A preliminary review of data collected during a pre-treatment, or calibration period (October 1993 through June 1997), and part of the post-treatment period (July 1997 through November 1998) has identified a varied instream nutrient response to streambank fencing.Concentrations of total nitrogen (N) during low-flow periods were significantly reduced by 20 to 31 percent at treated relative to untreated sites, but the yield of total N during low-flow conditions did not change significantly. Low-flow concentrations and yields of total phosphorus (P) did not change significantly at the outlet of the treatment basin, but data from a tributary site (T-2) in the treatment basin showed a 19- to 79-percent increase in the concentration and yield of total P relative to those at untreated sites. The total-P increase was due to increased concentrations of dissolved P. The processes causing the decrease in the concentration of total N and an increase in the concentration of total P were related to stream discharge, which declined after fencing to about one-third lower than the period-of-record mean. Declines in stream discharge after fence installation were caused by lower than normal precipitation. As concentrations of dissolved oxygen decreased in the stream channel as flows decreased, there was increased potential for instream denitrification and solubilization of P from sediments in the stream channel. Vegetative uptake of nitrate could also have contributed to decreased N concentrations. There were few significant changes in concentrations and yields of nutrients during stormflow except for significant reductions of 16 percent for total-N concentrations and 26 percent for total-P concentrations at site T-2 relative to the site at the outlet of the control basin.Suspended-sediment concentrations in the stream were significantly reduced by fencing. These reductions were partially caused by reduced cow access to the stream and hence reduced potential for the cows to destabilize streambanks through trampling. Development of a vegetative buffer along the stream channel after fence installation also helped to retain soil eroding from upgradient land. Reductions in suspended sediment during low flow ranged from 17 to 26 percent; stormflow reductions in suspended sediment ranged from 21 to 54 percent at treated relative to untreated sites. Suspended-sediment yields, however, were significantly reduced only at site T-2, where low-flow and stormflow yields were reduced by about 25 and 10 percent, respectively, relative to untreated sites.Benthic-macroinvertebrate sampling has identified increased number of taxa in the treatment basin after fence installation. Relative to the control basin, there was about a 30-percent increase in the total number of taxa. This increase was most likely related to improved instream habitat as a result of channel revegetation.

Estimation of Total Nitrogen and Phosphorus in New England Streams Using Spatially Referenced Regression Models

USGS Publications Warehouse

Moore, Richard Bridge; Johnston, Craig M.; Robinson, Keith W.; Deacon, Jeffrey R.

2004-01-01

The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA) and the New England Interstate Water Pollution Control Commission (NEIWPCC), has developed a water-quality model, called SPARROW (Spatially Referenced Regressions on Watershed Attributes), to assist in regional total maximum daily load (TMDL) and nutrient-criteria activities in New England. SPARROW is a spatially detailed, statistical model that uses regression equations to relate total nitrogen and phosphorus (nutrient) stream loads to nutrient sources and watershed characteristics. The statistical relations in these equations are then used to predict nutrient loads in unmonitored streams. The New England SPARROW models are built using a hydrologic network of 42,000 stream reaches and associated watersheds. Watershed boundaries are defined for each stream reach in the network through the use of a digital elevation model and existing digitized watershed divides. Nutrient source data is from permitted wastewater discharge data from USEPA's Permit Compliance System (PCS), various land-use sources, and atmospheric deposition. Physical watershed characteristics include drainage area, land use, streamflow, time-of-travel, stream density, percent wetlands, slope of the land surface, and soil permeability. The New England SPARROW models for total nitrogen and total phosphorus have R-squared values of 0.95 and 0.94, with mean square errors of 0.16 and 0.23, respectively. Variables that were statistically significant in the total nitrogen model include permitted municipal-wastewater discharges, atmospheric deposition, agricultural area, and developed land area. Total nitrogen stream-loss rates were significant only in streams with average annual flows less than or equal to 2.83 cubic meters per second. In streams larger than this, there is nondetectable in-stream loss of annual total nitrogen in New England. Variables that were statistically significant in the total phosphorus model include discharges for municipal wastewater-treatment facilities and pulp and paper facilities, developed land area, agricultural area, and forested area. For total phosphorus, loss rates were significant for reservoirs with surface areas of 10 square kilometers or less, and in streams with flows less than or equal to 2.83 cubic meters per second. Applications of SPARROW for evaluating nutrient loading in New England waters include estimates of the spatial distributions of total nitrogen and phosphorus yields, sources of the nutrients, and the potential for delivery of those yields to receiving waters. This information can be used to (1) predict ranges in nutrient levels in surface waters, (2) identify the environmental variables that are statistically significant predictors of nutrient levels in streams, (3) evaluate monitoring efforts for better determination of nutrient loads, and (4) evaluate management options for reducing nutrient loads to achieve water-quality goals.

Biogeochemical patterns of intermittent streams over space and time as surface flows decrease

NASA Astrophysics Data System (ADS)

MacNeille, R. B.; Lohse, K. A.; Godsey, S.; McCorkle, E. P.; Parsons, S.; Baxter, C.

2016-12-01

Climate change in the western United States is projected to lead to earlier snowmelt, increasing fire risk and potentially transitioning perennial streams to intermittent ones. Differences between perennial and intermittent streams, especially the temporal and spatial patterns of carbon and nutrient dynamics during periods of drying, are understudied. We examined spatial and temporal patterns in surface water biogeochemistry in southwest Idaho and hypothesized that as streams dry, carbon concentrations would increase due to evapoconcentration and/or increased in-stream production. Furthermore, we expected that biogeochemical patterns of streams would become increasingly spatially heterogeneous with drying. Finally, we expected that these patterns would vary in response to fire. To test these hypotheses, we collected water samples every 50 meters from two intermittent streams, one burned and one unburned, in April, May and June, 2016 to determine surface water biogeochemistry. Results showed average concentrations of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) increased 3-fold from April to June in the burned site compared to the unburned site where concentrations remained relatively constant. Interestingly, average concentrations of total nitrogen (TN) dropped substantially for the burned site over these three months, but only decreased slightly for the unburned site over the same time period. We also assessed changes in spatial correlation between the burned and unburned site: carbon concentrations were less spatially correlated at the unburned site than at the burned site. Scatterplot matrices of DIC values indicated that at a lag distance of 300 m in April and June, the unburned site had r-values of 0.7416 and 0.5975, respectively, while the burned site had r-values of 0.9468 and 0.8783, respectively. These initial findings support our hypotheses that carbon concentrations and spatial heterogeneity increased over time.

Nitrate Loads and Concentrations in Surface-Water Base Flow and Shallow Groundwater for Selected Basins in the United States, Water Years 1990-2006

USGS Publications Warehouse

Spahr, Norman E.; Dubrovsky, Neil M.; Gronberg, JoAnn M.; Franke, O. Lehn; Wolock, David M.

2010-01-01

Hydrograph separation was used to determine the base-flow component of streamflow for 148 sites sampled as part of the National Water-Quality Assessment program. Sites in the Southwest and the Northwest tend to have base-flow index values greater than 0.5. Sites in the Midwest and the eastern portion of the Southern Plains generally have values less than 0.5. Base-flow index values for sites in the Southeast and Northeast are mixed with values less than and greater than 0.5. Hypothesized flow paths based on relative scaling of soil and bedrock permeability explain some of the differences found in base-flow index. Sites in areas with impermeable soils and bedrock (areas where overland flow may be the primary hydrologic flow path) tend to have lower base-flow index values than sites in areas with either permeable bedrock or permeable soils (areas where deep groundwater flow paths or shallow groundwater flow paths may occur). The percentage of nitrate load contributed by base flow was determined using total flow and base flow nitrate load models. These regression-based models were calibrated using available nitrate samples and total streamflow or base-flow nitrate samples and the base-flow component of total streamflow. Many streams in the country have a large proportion of nitrate load contributed by base flow: 40 percent of sites have more than 50 percent of the total nitrate load contributed by base flow. Sites in the Midwest and eastern portion of the Southern Plains generally have less than 50 percent of the total nitrate load contributed by base flow. Sites in the Northern Plains and Northwest have nitrate load ratios that generally are greater than 50 percent. Nitrate load ratios for sites in the Southeast and Northeast are mixed with values less than and greater than 50 percent. Significantly lower contributions of nitrate from base flow were found at sites in areas with impermeable soils and impermeable bedrock. These areas could be most responsive to nutrient management practices designed to reduce nutrient transport to streams by runoff. Conversely, sites with potential for shallow or deep groundwater contribution (some combination of permeable soils or permeable bedrock) had significantly greater contributions of nitrate from base flow. Effective nutrient management strategies would consider groundwater nitrate contributions in these areas. Mean annual base-flow nitrate concentrations were compared to shallow-groundwater nitrate concentrations for 27 sites. Concentrations in groundwater tended to be greater than base-flow concentrations for this group of sites. Sites where groundwater concentrations were much greater than base-flow concentrations were found in areas of high infiltration and oxic groundwater conditions. The lack of correspondingly high concentrations in the base flow of the paired surface-water sites may have multiple causes. In some settings, there has not been sufficient time for enough high-nitrate shallow groundwater to migrate to the nearby stream. In these cases, the stream nitrate concentrations lag behind those in the shallow groundwater, and concentrations may increase in the future as more high-nitrate groundwater reaches the stream. Alternatively, some of these sites may have processes that rapidly remove nitrate as water moves from the aquifer into the stream channel. Partitioning streamflow and nitrate load between the quick-flow and base-flow portions of the hydrograph coupled with relative scales of soil permeability can infer the importance of surface water compared to groundwater nitrate sources. Study of the relation of nitrate concentrations to base-flow index and the comparison of groundwater nitrate concentrations to stream nitrate concentrations during times when base-flow index is high can provide evidence of potential nitrate transport mechanisms. Accounting for the surface-water and groundwater contributions of nitrate is crucial to effective management and remediat

Influences of spatial scale and soil permeability on relationships between land cover and baseflow stream nutrient concentrations

EPA Science Inventory

The Little Miami River (LMR) basin, dominated by agriculture, contains two geologically-distinct regions; a glaciated northern till plain with soils three times more permeable than a southern, pre-Wisconsinan drift plain. The influences of two landscape measures, percent row crop...

Nitrogen processing by grazers in a headwater stream: riparian connections

DOE PAGES

Hill, Walter R.; Griffiths, Natalie A.

2016-10-19

Primary consumers play important roles in the cycling of nutrients in headwater streams, storing assimilated nutrients in growing tissue and recycling them through excretion. Though environmental conditions in most headwater streams and their surrounding terrestrial ecosystems vary considerably over the course of a year, relatively little is known about the effects of seasonality on consumer nutrient recycling these streams. Here, we measured nitrogen accumulated through growth and excreted by the grazing snail Elimia clavaeformis (Pleuroceridae) over the course of 12 months in Walker Branch, identifying close connections between in-stream nitrogen processing and seasonal changes in the surrounding forest.

A method to quantify and value floodplain sediment and nutrient retention ecosystem services

USGS Publications Warehouse

Hopkins, Kristina G.; Noe, Gregory; Franco, Fabiano; Pindilli, Emily J.; Gordon, Stephanie; Metes, Marina J.; Claggett, Peter; Gellis, Allen; Hupp, Cliff R.; Hogan, Dianna

2018-01-01

Floodplains provide critical ecosystem services to local and downstream communities by retaining floodwaters, sediments, and nutrients. The dynamic nature of floodplains is such that these areas can both accumulate sediment and nutrients through deposition, and export material downstream through erosion. Therefore, estimating floodplain sediment and nutrient retention should consider the net flux of both depositional and erosive processes. An ecosystem services framework was used to quantify and value the sediment and nutrient ecosystem service provided by floodplains in the Difficult Run watershed, a small (151 km2) suburban watershed located in the Piedmont of Virginia (USA). A sediment balance was developed for Difficult Run and two nested watersheds. The balance included upland sediment delivery to streams, stream bank flux, floodplain flux, and stream load. Upland sediment delivery was estimated using geospatial datasets and a modified Revised Universal Soil Loss Equation. Predictive models were developed to extrapolate field measurements of the flux of sediment, sediment-bound nitrogen (N), and sediment-bound phosphorus (P) from stream banks and floodplains to 3232 delineated stream segments in the study area. A replacement cost approach was used to estimate the economic value of the sediment and nutrient retention ecosystem service based on estimated net stream bank and floodplain flux of sediment-bound N for all streams in the study area. Results indicated the net fluvial fluxes of sediment, sediment-bound N, and sediment-bound P were −10,439 Mg yr−1 (net export), 57,300 kg-N yr−1(net trapping), and 98 kg-P yr−1(net trapping), respectively. For sediment, floodplain retention was offset by substantial losses from stream bank erosion, particularly in headwater catchments, resulting in a net export of sediment. Nutrient retention in the floodplain exceeded that lost through stream bank erosion resulting in net retention of nutrients (TN and TP). Using a conservative cost estimate of $12.69 (USD) per kilogram of nitrogen, derived from wastewater treatment costs, the estimated annual value for sediment and nutrient retention on Difficult Run floodplains was $727,226 ± 194,220 USD/yr. Values and differences in floodplain nitrogen retention among stream reaches can be used to target areas for floodplain conservation and stream restoration. The methods presented are scalable and transferable to other areas if appropriate datasets are available for validation.

Freeze-thaw processes and intense winter rainfall: The one-two punch for high streambank legacy sediment and nutrient loads from Mid-Atlantic watersheds

NASA Astrophysics Data System (ADS)

Inamdar, S. P.; Johnson, E. R.; Rowland, R. D.; Walter, R. C.; Merritts, D.

2017-12-01

Historic and contemporary anthropogenic soil erosion combined with early-American milldams resulted in large deposits of legacy sediments in the valley bottoms of Piedmont watersheds of the eastern US. Breaching of milldams subsequently yielded highly incised streams with exposed vertical streambanks that are vulnerable to erosion. Streambank erosion is attributed to fluvial scouring, freeze-thaw processes and mass wasting. While streambanks represent a large reservoir of fine sediments and nutrients, there is considerable uncertainty about the contribution of these sources to watershed nonpoint source pollution. Using high-frequency hydrologic, sediment, and turbidity data we show that freeze-thaw events followed by intense winter rainstorms can export unusually high concentrations of suspended sediment and particulate nutrients from watersheds. Data from a 12 ha forested, Piedmont, stream following an intense rain event (54 mm) on February 2016 yielded suspended sediment and particulate nutrient (organic carbon and nitrogen) concentrations and exports that exceeded those from tropical storms Irene, Lee, and Sandy that had much greater rainfall and discharge amounts, but which occurred later in the year. A similar response was also observed with regards to turbidity data for USGS stream monitoring locations at Brandywine Creek (813 km2) and White Clay Creek (153 km2). We hypothesize that much of the sediment export associated with winter storms is likely due to erosion of streambank sediments and was driven by the coupled occurrence of freeze-thaw conditions and intense rainfall events. We propose that freeze-thaw erosion represents an important and underappreciated mechanism in streams that "recharges" the sediment supply, which then is available for flushing by moderate to large storms. Future climate projections indicate increased intensification of storm events and increased variability of winter temperatures. Freeze-thaw cycles coupled with winter rain events could increase erosion and transport of streambank sediments with detrimental consequences for water quality and health of downstream aquatic ecosystems. This study underscores the need to better understand the mechanisms of legacy sediment erosion and transport along with appropriate restoration strategies.

Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams

USGS Publications Warehouse

Black, R.W.; Moran, P.W.; Frankforter, J.D.

2011-01-01

Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria. ?? 2010 The Author(s).

Response of algal metrics to nutrients and physical factors and identification of nutrient thresholds in agricultural streams.

PubMed

Black, Robert W; Moran, Patrick W; Frankforter, Jill D

2011-04-01

Many streams within the United States are impaired due to nutrient enrichment, particularly in agricultural settings. The present study examines the response of benthic algal communities in agricultural and minimally disturbed sites from across the western United States to a suite of environmental factors, including nutrients, collected at multiple scales. The first objective was to identify the relative importance of nutrients, habitat and watershed features, and macroinvertebrate trophic structure to explain algal metrics derived from deposition and erosion habitats. The second objective was to determine if thresholds in total nitrogen (TN) and total phosphorus (TP) related to algal metrics could be identified and how these thresholds varied across metrics and habitats. Nutrient concentrations within the agricultural areas were elevated and greater than published threshold values. All algal metrics examined responded to nutrients as hypothesized. Although nutrients typically were the most important variables in explaining the variation in each of the algal metrics, environmental factors operating at multiple scales also were important. Calculated thresholds for TN or TP based on the algal metrics generated from samples collected from erosion and deposition habitats were not significantly different. Little variability in threshold values for each metric for TN and TP was observed. The consistency of the threshold values measured across multiple metrics and habitats suggest that the thresholds identified in this study are ecologically relevant. Additional work to characterize the relationship between algal metrics, physical and chemical features, and nuisance algal growth would be of benefit to the development of nutrient thresholds and criteria.

Water-quality assessment of the Cook Inlet basin, Alaska : summary of data through 1997

USGS Publications Warehouse

Glass, Roy L.

1999-01-01

Among the first activities undertaken in each National Water-Quality Assessment (NAWQA) investigation are the compilation, screening, and statistical summary of available data concerning water-quality conditions in the study unit. The water-quality conditions of interest are those that are representative of the general ambient water quality of a given stream reach or area of an aquifer. This report identifies which existing water-quality data are suitable for characterizing general conditions in a nationally consistent manner and describes, to the extent possible, general water-quality conditions in the Cook Inlet Basin in southcentral Alaska. The study unit consists of all lands that drain into Cook Inlet, but not the marine environment itself. Surface-water-quality data are summarized for 31 sites on streams. Ground-water quality data are summarized for four regions using analyses from about 550 wells that yield water from unconsolidated glacial and alluvial deposits and analyses from 17 wells in western Cook Inlet, some of which may yield water from coal or weakly consolidated sandstone or conglomerate. The summaries focus on the central tendencies and typical variations in the data and use nonparametric statistics such as frequencies and percentile values. Few surface- and ground-water sites have long-term water-quality records and very few data are available for dissolved oxygen, nutrients, metals, trace elements, organic compounds, and radionuclides. In general, most waters in streams and wells have small concentrations of major inorganic constituents, nutrients, trace elements, and organic compounds. Most streams have water that is generally suitable for drinking-water supply, the growth and propagation of cold-water anadromous fish, and water-contact recreation. However, suspended-sediment concentrations in glacier-fed streams are naturally high and can make water from glacier-fed streams unsuitable for many uses unless the water is treated to remove the suspended sediment. Several streams and lakes in Anchorage have fecal coliform bacteria concentrations higher than allowed for drinking or water-contact recreation. Ground water in the major withdrawal regions is generally suitable for drinking and most other purposes, but some wells yield water having nitrate, iron, or arsenic concentrations higher than drinking-water criteria. Ground-water quality has been degraded in several areas as the result of leaks or spills of petroleum products.

Benthic invertebrate assemblages and their relation to physical and chemical characteristics of streams in the Eastern Iowa Basins, 1996-98

USGS Publications Warehouse

Brigham, Allison R.; Sadorf, Eric M.

2001-01-01

Stream size, a reflection of basin area, was a principal influence in categorizing the benthic invertebrate assemblages, with sites that have the largest basin areas forming a separate group. Although it is difficult to distinguish among the contributions of large basin area, increased concentrations of nutrients and pesticides, and decreasing instream habitat diversity, the resulting invertebrate assemblage described was distinct. The remaining sites were headwater or tributary streams that reflected conditions more common to smaller streams, such as higher gradients and the potential for more diverse or extensive riparian habitat, but were distinguished by landform. Following basin area in importance, landform contributed to the differences observed among the benthic invertebrate communities at the remaining sites.

Nutrient dynamics in streams and the role of J-NABS

Treesearch

Patrick J. Mulholland; Jackson R. Webster

2010-01-01

Nutrient dynamics in streams has been an important topic of research since the 1960s. Here we review this topic and the significant role played by J-NABS in its development. We limit this review almost exclusively to studies of N and P because these elements have been shown to limit productivity in streams. We use the expression nutrient dynamics for studies that...

Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams

USGS Publications Warehouse

Roberts, B.J.; Mulholland, P.J.; Houser, J.N.

2007-01-01

Delivery of water, sediments, nutrients, and organic matter to stream ecosystems is strongly influenced by the catchment of the stream and can be altered greatly by upland soil and vegetation disturbance. At the Fort Benning Military Installation (near Columbus, Georgia), spatial variability in intensity of military training results in a wide range of intensities of upland disturbance in stream catchments. A set of 8 streams in catchments spanning this upland disturbance gradient was selected for investigation of the impact of disturbance intensity on hydrodynamics and nutrient uptake. The size of transient storage zones and rates of NH4+ uptake in all study streams were among the lowest reported in the literature. Upland disturbance did not appear to influence stream hydrodynamics strongly, but it caused significant decreases in instream nutrient uptake. In October 2003, coarse woody debris (CWD) was added to 1/2 of the study streams (spanning the disturbance gradient) in an attempt to increase hydrodynamic and structural complexity, with the goals of enhancing biotic habitat and increasing nutrient uptake rates. CWD additions had positive short-term (within 1 mo) effects on hydrodynamic complexity (water velocity decreased and transient storage zone cross-sectional area, relative size of the transient storage zone, fraction of the median travel time attributable to transient storage over a standardized length of 200 m, and the hydraulic retention factor increased) and nutrient uptake (NH4+ uptake rates increased). Our results suggest that water quality in streams with intense upland disturbances can be improved by enhancing instream biotic nutrient uptake capacity through measures such as restoring stream CWD. ?? 2007 by The North American Benthological Society.

Response of nutrients, biofilm, and benthic insects to salmon carcass addition.

Treesearch

Shannon M. Claeson; Judith L. Li; Jana E. Compton; Peter A. Bisson

2006-01-01

Salmon carcass addition to streams is expected to increase stream productivity at multiple trophic levels. This study examined stream nutrient (nitrogen, phosphorus, and carbon), epilithic biofilm (ash-free dry mass and chlorophyll a), leaf-litter decomposition, and macroinvertebrate (density and biomass) responses to carcass addition in three headwater streams of...

Evaluating hillslope and riparian contributions to dissolved nitrogen (N) export from a boreal forest catchment

NASA Astrophysics Data System (ADS)

Blackburn, M.; Ledesma, José L. J.; Näsholm, Torgny; Laudon, Hjalmar; Sponseller, Ryan A.

2017-02-01

Catchment science has long held that the chemistry of small streams reflects the landscapes they drain. However, understanding the contribution of different landscape units to stream chemistry remains a challenge which frequently limits our understanding of export dynamics. For limiting nutrients such as nitrogen (N), an implicit assumption is that the most spatially extensive landscape units (e.g., uplands) act as the primary sources to surface waters, while near-stream zones function more often as sinks. These assumptions, based largely on studies in high-gradient systems or in regions with elevated inputs of anthropogenic N, may not apply to low-gradient, nutrient-poor, and peat-rich catchments characteristic of many northern ecosystems. We quantified patterns of N mobilization along a hillslope transect in a northern boreal catchment to assess the extent to which organic matter-rich riparian soils regulate the flux of N to streams. Contrary to the prevailing view of riparian functioning, we found that near-stream, organic soils supported concentrations and fluxes of ammonium (NH4+) and dissolved organic nitrogen that were much higher than the contributing upslope forest soils. These results suggest that stream N chemistry is connected to N mobilization and mineralization within the riparian zone rather than the wider landscape. Results further suggest that water table fluctuation in near-surface riparian soils may promote elevated rates of net N mineralization in these landscapes.

Metolachlor metabolite (MESA) reveals agricultural nitrate-N fate and transport in Choptank River watershed

USGS Publications Warehouse

McCarty, Gregory W.; Hapeman, Cathleen J.; Rice, Clifford P.; Hively, W. Dean; McConnell, Laura L.; Sadeghi, Ali M.; Lang, Megan W.; Whitall, David R.; Bialek, Krystyna; Downey, Peter

2014-01-01

Over 50% of streams in the Chesapeake Bay watershed have been rated as poor or very poor based on the index of biological integrity. The Choptank River estuary, a Bay tributary on the eastern shore, is one such waterway, where corn and soybean production in upland areas of the watershed contribute significant loads of nutrients and sediment to streams. We adopted a novel approach utilizing the relationship between the concentration of nitrate-N and the stable, water-soluble herbicide degradation product MESA {2-[2-ethyl-N-(1-methoxypropan-2-yl)-6-methylanilino]-2-oxoethanesulfonic acid} to distinguish between dilution and denitrification effects on the stream concentration of nitrate-N in agricultural subwatersheds. The ratio of mean nitrate-N concentration/(mean MESA concentration * 1000) for 15 subwatersheds was examined as a function of percent cropland on hydric soil. This inverse relationship (R2 = 0.65, p 2 ≤ 0.99) for all eight sampling dates except one where R2 = 0.90. This very strong correlation indicates that nitrate-N was conserved in much of the Choptank River estuary, that dilution alone is responsible for the changes in nitrate-N and MESA concentrations, and more importantly nitrate-N loads are not reduced in the estuary prior to entering the Chesapeake Bay. Thus, a critical need exists to minimize nutrient export from agricultural production fields and to identify specific conservation practices to address the hydrologic conditions within each subwatershed. In well drained areas, removal of residual N within the cropland is most critical, and practices such as cover crops which sequester the residual N should be strongly encouraged. In poorly drained areas where denitrification can occur, wetland restoration and controlled drained structures that minimize ditch flow should be used to maximize denitrification.

Regional assessments of the Nation's water quality—Improved understanding of stream nutrient sources through enhanced modeling capabilities

USGS Publications Warehouse

Preston, Stephen D.; Alexander, Richard B.; Woodside, Michael D.

2011-01-01

The U.S. Geological Survey (USGS) recently completed assessments of stream nutrients in six major regions extending over much of the conterminous United States. SPARROW (SPAtially Referenced Regressions On Watershed attributes) models were developed for each region to explain spatial patterns in monitored stream nutrient loads in relation to human activities and natural resources and processes. The model information, reported by stream reach and catchment, provides contrasting views of the spatial patterns of nutrient source contributions, including those from urban (wastewater effluent and diffuse runoff from developed land), agricultural (farm fertilizers and animal manure), and specific background sources (atmospheric nitrogen deposition, soil phosphorus, forest nitrogen fixation, and channel erosion).

In-stream biogeochemical processes of a temporary river.

PubMed

Tzoraki, Ourania; Nikolaidis, Nikolaos P; Amaxidis, Yorgos; Skoulikidis, Nikolaos Th

2007-02-15

A reach at the estuary of Krathis River in Greece was used to assess how in-stream processes alter its hydrologic and biogeochemical regime. Krathis River exhibited high annual flow variability and its transmission losses become significant, especially during the dry months. These transmission losses are enhanced in chemistry due to release of nutrients from river sediments. These fluxes are significant because they correspond to 11% of the dissolved inorganic nitrogen flux of the river. Release of nitrogen species was influenced by temperature, while release of phosphate was not because phosphate levels were below the equilibrium concentration. There is a significant amount of sediments with fine composition that create "hot spot" areas in the river reach. These sediments are mobilized during the first flush events in the fall carrying with them a significant load of nutrient and suspended matter to the coastal zone. The nutrient organic content of sediments was also significant and it was studied in terms of its mineralization capacity. The capacity for mineralization was influenced by soil moisture, exhibiting significant capacity even at moisture levels of 40%. Temporary rivers are sensitive ecosystems, vulnerable to climate changes. In-stream processes play a significant role in altering the hydrology and biogeochemistry of the water and its impacts to the coastal zone.

Coupled hydrological and biogeochemical processes controlling variability of nitrogen species in streamflow during autumn in an upland forest

USGS Publications Warehouse

Sebestyen, Stephen D.; Shanley, James B.; Boyer, Elizabeth W.; Kendall, Carol; Doctor, Daniel H.

2014-01-01

Autumn is a season of dynamic change in forest streams of the northeastern United States due to effects of leaf fall on both hydrology and biogeochemistry. Few studies have explored how interactions of biogeochemical transformations, various nitrogen sources, and catchment flow paths affect stream nitrogen variation during autumn. To provide more information on this critical period, we studied (1) the timing, duration, and magnitude of changes to stream nitrate, dissolved organic nitrogen (DON), and ammonium concentrations; (2) changes in nitrate sources and cycling; and (3) source areas of the landscape that most influence stream nitrogen. We collected samples at higher temporal resolution for a longer duration than typical studies of stream nitrogen during autumn. This sampling scheme encompassed the patterns and extremes that occurred during base flow and stormflow events of autumn. Base flow nitrate concentrations decreased by an order of magnitude from 5.4 to 0.7 µmol L−1 during the week when most leaves fell from deciduous trees. Changes to rates of biogeochemical transformations during autumn base flow explained the low nitrate concentrations; in-stream transformations retained up to 72% of the nitrate that entered a stream reach. A decrease of in-stream nitrification coupled with heterotrophic nitrate cycling were primary factors in the seasonal nitrate decline. The period of low nitrate concentrations ended with a storm event in which stream nitrate concentrations increased by 25-fold. In the ensuing weeks, peak stormflow nitrate concentrations progressively decreased over closely spaced, yet similarly sized events. Most stormflow nitrate originated from nitrification in near-stream areas with occasional, large inputs of unprocessed atmospheric nitrate, which has rarely been reported for nonsnowmelt events. A maximum input of 33% unprocessed atmospheric nitrate to the stream occurred during one event. Large inputs of unprocessed atmospheric nitrate show direct and rapid effects on forest streams that may be widespread, although undocumented, throughout nitrogen-polluted temperate forests. In contrast to a week-long nitrate decline during peak autumn litterfall, base flow DON concentrations increased after leaf fall and remained high for 2 months. Dissolved organic nitrogen was hydrologically flushed to the stream from riparian soils during stormflow. In contrast to distinct seasonal changes in base flow nitrate and DON concentrations, ammonium concentrations were typically at or below the detection limit, similar to the rest of the year. Our findings reveal couplings among catchment flow paths, nutrient sources, and transformations that control seasonal extremes of stream nitrogen in forested landscapes.

Simulation of stream discharge and transport of nitrate and selected herbicides in the Mississippi River Basin

USGS Publications Warehouse

Broshears, R.E.; Clark, G.M.; Jobson, H.E.

2001-01-01

Stream discharge and the transport of nitrate, atrazine, and metolachlor in the Mississippi River Basin were simulated using the DAFLOW/BLTM hydrologic model. The simulated domain for stream discharge included river reaches downstream from the following stations in the National Stream Quality Accounting Network: Mississippi River at Clinton, IA; Missouri River at Hermann, MO: Ohio River at Grand Chain, IL: And Arkansas River at Little Rock, AR. Coefficients of hydraulic geometry were calibrated using data from water year 1996; the model was validated by favourable simulation of observed discharges in water years 1992-1994. The transport of nitrate, atrazine, and metolachlor was simulated downstream from the Mississippi River at Thebes, IL, and the Ohio River at Grand Chain. Simulated concentrations compared favourably with observed concentrations at Baton Rouge, LA. Development of this model is a preliminary step in gaining a more quantitative understanding of the sources and fate of nutrients and pesticides delivered from the Mississippi River Basin to the Gulf of Mexico.

Physical, chemical, and biological data for two sites on the upper Kenai River, Alaska, 1998

USGS Publications Warehouse

Dorava, Joseph M.; Ness, Lee

1999-01-01

Water-quality data were collected and stream characteristics were documented from two sites along the upper Kenai River in the Kenai National Wildlife Refuge, Alaska. These data were collected to describe the current status of the sites and to provide baseline information from which changes in the future could be evaluated. Physical characteristics included channel geometry surveys, and measurements of channel widths and water discharge at each site. Chemical data included stream water temperature, dissolved-oxygen concentration, pH, specific conductance, E. coli and fecal coliform counts, and nutrient concentration. Data on concentrations of trace elements and various organic compounds in bed sediments and the tissue of slimy sculpin were also collected. Biological characteristics were evaluated using measurements of the bacteria, benthic macroinvertebrate, and fish communities.

Factors Affecting Nitrate Delivery to Streams from Shallow Ground Water in the North Carolina Coastal Plain

USGS Publications Warehouse

Harden, Stephen L.; Spruill, Timothy B.

2008-01-01

An analysis of data collected at five flow-path study sites between 1997 and 2006 was performed to identify the factors needed to formulate a comprehensive program, with a focus on nitrogen, for protecting ground water and surface water in the North Carolina Coastal Plain. Water-quality protection in the Coastal Plain requires the identification of factors that affect the transport of nutrients from recharge areas to streams through the shallow ground-water system. Some basins process or retain nitrogen more readily than others, and the factors that affect nitrogen processing and retention were the focus of this investigation to improve nutrient management in Coastal Plain streams and to reduce nutrient loads to coastal waters. Nitrate reduction in ground water was observed at all five flow-path study sites in the North Carolina Coastal Plain, although the extent of reduction at each site was influenced by various environmental, hydrogeologic, and geochemical factors. Denitrification was the most common factor responsible for decreases in nitrate along the ground-water flow paths. Specific factors, some of which affect denitrification rates, that appeared to influence ground-water nitrate concentrations along the flow paths or in the streams include soil drainage, presence or absence of riparian buffers, evapotranspiration, fertilizer use, ground-water recharge rates and residence times, aquifer properties, subsurface tile drainage, sources and amounts of organic matter, and hyporheic processes. The study data indicate that the nitrate-reducing capacity of the buffer zone combined with that of the hyporheic zone can substantially lower the amount of ground-water nitrate discharged to streams in agricultural settings of the North Carolina Coastal Plain. At the watershed scale, the effects of ground-water discharge on surface-water quality appear to be greatly influenced by streamflow conditions and the presence of extensive riparian vegetation. Streamflow statistics that reflect base flow and the general hydrologic dynamics of a stream are important in understanding nutrient transport from a watershed and may be useful indicators of watersheds that are likely to have higher yields of nutrients and water. Combining streamflow statistics with information on such factors as land use, soil drainage, extent of riparian vegetation, geochemical conditions, and subsurface tile drainage in the Coastal Plain can be useful in identifying watersheds that are most likely to export excessive nitrogen due to nonpoint-source loadings and watersheds that are effective in processing nitrogen.

Stream Restoration to Manage Nutrients in Degraded Watersheds

EPA Science Inventory

Historic land-use change can reduce water quality by impairing the ability of stream ecosystems to efficiently process nutrients such as nitrogen. Study results of two streams (Minebank Run and Big Spring Run) affected by urbanization, quarrying, agriculture, and impoundments in...

RESPONSE OF NUTRIENTS, BIOFILM, AND BENTHIC INSECTS TO SALMON CARCASS ADDITION

EPA Science Inventory

Salmon carcass addition to streams is expected to increase stream productivity at multiple trophic levels. This study examined stream nutrient (nitrogen, phosphorus, and carbon), epilithic biofilm (ash-free dry mass and chlorophyll a), leaf-litter decomposition, and macroinverte...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Walter R.; Griffiths, Natalie A.

Primary consumers play important roles in the cycling of nutrients in headwater streams, storing assimilated nutrients in growing tissue and recycling them through excretion. Though environmental conditions in most headwater streams and their surrounding terrestrial ecosystems vary considerably over the course of a year, relatively little is known about the effects of seasonality on consumer nutrient recycling these streams. Here, we measured nitrogen accumulated through growth and excreted by the grazing snail Elimia clavaeformis (Pleuroceridae) over the course of 12 months in Walker Branch, identifying close connections between in-stream nitrogen processing and seasonal changes in the surrounding forest.

Importance of terrestrial arthropods as subsidies in lowland Neotropical rain forest stream ecosystems

USGS Publications Warehouse

Small, Gaston E.; Torres, Pedro J.; Schwizer, Lauren M.; Duff, John H.; Pringle, Catherine M.

2013-01-01

The importance of terrestrial arthropods has been documented in temperate stream ecosystems, but little is known about the magnitude of these inputs in tropical streams. Terrestrial arthropods falling from the canopy of tropical forests may be an important subsidy to tropical stream food webs and could also represent an important flux of nitrogen (N) and phosphorus (P) in nutrient-poor headwater streams. We quantified input rates of terrestrial insects in eight streams draining lowland tropical wet forest in Costa Rica. In two focal headwater streams, we also measured capture efficiency by the fish assemblage and quantified terrestrially derived N- and P-excretion relative to stream nutrient uptake rates. Average input rates of terrestrial insects ranged from 5 to 41 mg dry mass/m2/d, exceeding previous measurements of aquatic invertebrate secondary production in these study streams, and were relatively consistent year-round, in contrast to values reported in temperate streams. Terrestrial insects accounted for half of the diet of the dominant fish species, Priapicthys annectens. Although terrestrially derived fish excretion was found to be a small flux relative to measured nutrient uptake rates in the focal streams, the efficient capture and processing of terrestrial arthropods by fish made these nutrients available to the local stream ecosystem. This aquatic-terrestrial linkage is likely being decoupled by deforestation in many tropical regions, with largely unknown but potentially important ecological consequences.

Effects of nonpoint and selected point contaminant sources on stream-water quality and relation to land use in Johnson County, northeastern Kansas, October 2002 through June 2004

USGS Publications Warehouse

Lee, Casey J.; Mau, D.P.; Rasmussen, T.J.

2005-01-01

Water and sediment samples were collected by the U.S. Geological Survey in 12 watersheds in Johnson County, northeastern Kansas, to determine the effects of nonpoint and selected point contaminant sources on stream-water quality and their relation to varying land use. The streams studied were located in urban areas of the county (Brush, Dykes Branch, Indian, Tomahawk, and Turkey Creeks), developing areas of the county (Blue River and Mill Creek), and in more rural areas of the county (Big Bull, Captain, Cedar, Kill, and Little Bull Creeks). Two base-flow synoptic surveys (73 total samples) were conducted in 11 watersheds, a minimum of three stormflow samples were collected in each of six watersheds, and 15 streambed-sediment sites were sampled in nine watersheds from October 2002 through June 2004. Discharge from seven wastewater treatment facilities (WWTFs) were sampled during base-flow synoptic surveys. Discharge from these facilities comprised greater than 50 percent of streamflow at the farthest downstream sampling site in six of the seven watersheds during base-flow conditions. Nutrients, organic wastewater-indicator compounds, and prescription and nonprescription pharmaceutical compounds generally were found in the largest concentrations during base-flow conditions at sites at, or immediately downstream from, point-source discharges from WWTFs. Downstream from WWTF discharges streamflow conditions were generally stable, whereas nutrient and wastewater-indicator compound concentrations decreased in samples from sites farther downstream. During base-flow conditions, sites upstream from WWTF discharges had significantly larger fecal coliform and Escherichia coli densities than downstream sites. Stormflow samples had the largest suspended-sediment concentrations and indicator bacteria densities. Other than in samples from sites in proximity to WWTF discharges, stormflow samples generally had the largest nutrient concentrations in Johnson County streams. Discharge from WWTFs with trickling-filter secondary treatment processes had the largest concentrations of many potential contaminants during base-flow conditions. Samples from two of three trickling-filter WWTFs exceeded Kansas Department of Health and Environment pH- and temperature-dependent chronic aquatic-life criteria for ammonia when early-life stages of fish are present. Discharge from trickling-filter facilities generally had the most detections and largest concentrations of many organic wastewater-indicator compounds in Johnson County stream-water samples. Caffeine (stimulant), nonylphenol-diethoxylate (detergent surfactant), and tris(2-butoxyethyl) phosphate (floor polish, flame retardant, and plasticizer) were found at concentrations larger than maximum concentrations in comparable studies. Land use and seasonality affected the occurrence and magnitude of many potential water-quality contaminants originating from nonpoint sources. Base-flow samples from urban sites located upstream from WWTF discharges had larger indicator bacteria densities and wastewater-indicator compound concentrations than did base-flow samples from sites in nonurban areas. Dissolved-solids concentrations were the largest in winter stormflow samples from urban sites and likely were due to runoff from road-salt application. One sample from an urban watershed had a chloride concentration of 1,000 milligrams per liter, which exceeded the Kansas Department of Health and Environment's acute aquatic-life use criterion (860 milligrams per liter) likely due to effects from road-salt application. Pesticide concentrations were the largest in spring stormflow samples collected in nonurban watersheds. Although most wastewater-indicator compounds were found at the largest concentrations in samples from WWTF discharges, the compounds 9-10, anthraquinone (bird repellent), caffeine (stimulant), carbazole (component of coal tar, petroleum products), nonylphenol-diethoxylate (detergent surfactant),

Spatiotemporal variability of inorganic nutrients during wastewater effluent dominated streamflow conditions in Indian Creek, Johnson County, Kansas, 2012–15

USGS Publications Warehouse

Foster, Guy M.; Graham, Jennifer L.; Williams, Thomas J.; King, Lindsey R.

2016-10-31

Nutrients, particularly nitrogen and phosphorus, are a leading cause of water-quality impairment in Kansas and the Nation. Indian Creek is one of the most urban drainage basins in Johnson County, Kansas, and environmental and biological conditions are affected by contaminants from point and other urban sources. The Johnson County Douglas L. Smith Middle Basin (hereinafter Middle Basin) wastewater treatment facility (WWTF) is the largest point-source discharge on Indian Creek. A second facility, the Tomahawk Creek WWTF, discharges into Indian Creek approximately 11.6 kilometers downstream from the Middle Basin WWTF. To better characterize the spatiotemporal variability of nutrients in Indian Creek, the U.S. Geological Survey, in cooperation with the Kansas Department of Health and Environment and Johnson County Wastewater, collected high-resolution spatial and temporal (a large number of samples collected over the entire reach or at single locations over a long period of time) inorganic nutrient (nitrate plus nitrite and orthophosphorus) data using a combination of discrete samples and sensor-measured data during 2012 through 2015.Nutrient patterns observed in Indian Creek along the upstream-downstream gradient during wastewater effluent dominated streamflow conditions were largely affected by the WWTFs and by travel time of the parcels of water. Nitrate plus nitrite concentrations in the Middle Basin WWTF effluent and at downstream sites varied by as much as 6 milligrams per liter over a 24-hour period. The cyclical variability in the Middle Basin WWTF effluent generated a nitrate plus nitrite pulse that could be tracked for approximately 11.5 kilometers downstream in Indian Creek, until the effect was masked by the Tomahawk Creek WWTF effluent discharge. All longitudinal surveys showed the same general patterns along the upstream-downstream gradient, though streamflows, wastewater effluent contributions to streamflow, and nutrient concentrations spanned a wide range. Differences in orthophosphorus and nitrate plus nitrite patterns were clear along the upstream-downstream gradient in Indian Creek, and orthophosphorus concentrations were not as variable as nitrate plus nitrite concentrations. In general, nitrate plus nitrite concentrations decreased downstream from the Middle Basin WWTF to minima near the confluence with Tomahawk Creek, increased downstream from the Tomahawk Creek WWTF, and then varied little within the study reach. Orthophosphorus concentrations generally decreased downstream from the Middle Basin WWTF.Despite the marked variability in nitrate plus nitrite concentrations caused by the Middle Basin WWTF effluent discharges, decreases in nitrate plus nitrite concentrations were discernable along the study reach between the two WWTFs. Decreases in nitrate plus nitrite concentrations along study reach were less variable than the cyclical variability typically measured, reiterating the effect of the Middle Basin WWTF effluent discharges on the spatiotemporal variability of nitrate plus nitrite in Indian Creek. Although decreases and rates of change in nitrate plus nitrite concentration were similar between the upper and lower reaches of Indian Creek, relations with initial nitrate plus nitrite concentrations and seasonal patterns were different between the upper (from College to the Marty study sites) and lower reaches (from Marty to the Mission Farms study sites) and did not reflect patterns observed for the overall reach. Quantifying the decreases in nitrate plus nitrite concentration caused by dilution and other in-stream processes were beyond the scope of this study, and were limited by available data. The data that are available suggest that dilution and other in-stream processes play a role in decreasing nitrate plus nitrite concentrations downstream from the Middle Basin WWTF in Indian Creek.Analysis of the spatiotemporal variability of nutrients focused on below-normal and normal streamflow conditions, when streamflow and nutrient conditions in Indian Creek were largely controlled by WWTF effluent flows and nutrient removal processes. Spatial and temporal data indicate there are decreases in nutrient concentrations along the upstream-downstream gradient in Indian Creek, but quantifying decreases is complicated by the variability in nutrient concentrations caused by the WWTFs. During below-normal and normal streamflow conditions, Indian Creek nutrient concentrations downstream from the Middle Basin WWTF primarily reflect effluent concentrations in the hours or days before depending on relative distance downstream.

Bayesian Modeling of the Assimilative Capacity Component of Stream Nutrient Export

EPA Science Inventory

Implementing stream restoration techniques and best management practices to reduce nonpoint source nutrients implies enhancement of the assimilative capacity for the stream system. In this paper, a Bayesian method for evaluating this component of a TMDL load capacity is developed...

Developing Ecological Indicators for Nutrients and Urban Impacts to Streams in Coastal Watersheds

EPA Science Inventory

Increased nutrient loads associated with human activities are among leading causes of impairment to streams and receiving waterbodies. For streams draining to the environmentally and economically important Narragansett Bay estuary, we developed indicators based on (1) nitrogen an...

Nutrient enrichment, phytoplankton algal growth, and estimated rates of instream metabolic processes in the Quinebaug River Basin, Connecticut, 2000-2001

USGS Publications Warehouse

Colombo, Michael J.; Grady, Stephen J.; Todd Trench, Elaine C.

2004-01-01

A consistent and pervasive pattern of nutrient enrichment was substantiated by water-quality sampling in the Quinebaug River and its tributaries in eastern Connecticut during water years 2000 and 2001. Median total nitrogen and total phosphorus concentrations exceeded the U.S. Environmental Protection Agency?s recently recommended regional ambient water-qual-ity criteria for streams (0.71 and 0.031 milligrams per liter, respectively). Maximum total phosphorus concentrations exceeded 0.1 milligrams per liter at nearly half the sampled locations in the Quinebaug River Basin. Elevated total nitrogen and total phosphorus concentrations were measured at all stations on the mainstem of the Quinebaug River, the French River, and the Little River. Nutrient enrichment was related to municipal wastewater point sources at the sites on the mainstem of the Quinebaug River and French River, and to agricultural nonpoint nutrient sources in the Little River Basin. Nutrient enrichment and favorable physical factors have resulted in excessive, nuisance algal blooms during summer months, particularly in the numerous impoundments in the Quinebaug River system. Phytoplankton algal density as high as 85,000 cells per milliliter was measured during such nuisance blooms in water years 2000 and 2001. Different hydrologic conditions during the summers of 2000 and 2001 produced very different seston algal populations. Larger amounts of precipitation sustained higher streamflows in the summer of 2000 (than in 2001), which resulted in lower total algal abundance and inhibited the typical algal succession from diatoms to cyanobacteria. Despite this, nearly half of all seston chlorophyll-a concentrations measured during this study exceeded the recommended regional ambient stream-water-quality criterion (3.75 micrograms per liter), and seston chlorophyll-a concentrations as large as 42 micrograms per liter were observed in wastewa-ter-receiving reaches of the Quinebaug River. Estimates of primary productivity and respiration obtained from diel dissolved oxygen monitoring and from light- and dark-bottle dissolved oxygen measurements demonstrated that instream metabolic processes are consistent with a seston-algae dominant system. The highest estimated maximum primary productivity rate was 1.72 grams of oxygen per cubic meter per hour at the Quinebaug River at Jewett City during September 2001. The observed extremes in diel dissolved oxygen concentrations (less than 5 milligrams per liter) and pH (greater than 9) may periodically stress aquatic organisms in the Quinebaug River Basin.

Effects of land use on the water quality and biota of three streams in the Piedmont province of North Carolina

USGS Publications Warehouse

Crawford, J.K.; Lenat, D.R.

1989-01-01

Three small streams in North Carolina 's northern Piedmont were studied to compare the effects of land use in their watersheds on water quality characteristics and aquatic biota. Devil 's Cradle Creek (agricultural watershed) had more than two times the sediment yield of Smith Creek (forested watershed) (0.34 tons/acre compared to 0.13 tons/acre), and Marsh Creek (urban watershed) had more than four times the yield of Smith Creek (0.59 tons/acre). Concentrations of nutrients were consistently highest in Devil 's Craddle Creek. Concentrations of total copper, iron, and lead in samples from each of the three streams at times exceeded State water quality standards as did concentrations of total zinc in samples from both Smith and Marsh Creeks. Successively lower aquatic invertebrate taxa richness was found in the forested, the agricultural, and the urban watershed streams. Invertebrate biota in Smith Creek was dominated by insects, such as Ephemeroptera, that are intolerant to stress from pollution, whereas Devil 's Cradle Creek was dominated by the more tolerant Diptera, and Marsh Creek was dominated by the most pollution-tolerant group, the Oligochaeta. Fish communities in the forested and agricultural watershed streams were characterized by more species and more individuals of each species, relative to a limited community in urban Marsh Creek. Three independent variables closely linked to land use--suspended-sediment yield, suspended-sediment load, and total lead concentrations in stream water--are inversely associated with the biological communities of the streams.

Use of continuous monitoring to assess stream nitrate flux and transformation patterns.

PubMed

Jones, Christopher; Kim, Sea-Won; Schilling, Keith

2017-01-01

Delivery of nitrogen from farmed fields to the stream network is an ongoing water quality issue in central North America and other parts of the world. Although fertilization and other farming practices have been refined to produce environmental improvements, stemming loss of nitrogen, especially in the soluble nitrate form, is a problem that has seemingly defied solution. The Iowa Nutrient Reduction Strategy is a policy initiative designed to implement conservation and other farm management practices to produce reductions in nitrate loading. The strategy does not focus on how the streams themselves may or may not be processing nitrogen and reducing downstream loading. We used continuous high-frequency nitrate and discharge monitoring over 3 years at two sites separated by 18 km in a low-order, agricultural stream in eastern Iowa to estimate how nitrogen is processed, and whether or not these processes are reducing downstream loading. We conclude that the upstream to downstream nitrate concentration decline between the two sites was not driven by denitrification. These data also show that nitrate concentrations are closely coupled to discharge during periods of adequate moisture, but decoupling of concentration from discharge occurs during dry periods. This decoupling is a possible indicator of in-stream nitrate processing. Finally, nitrate concentrations are likely diluted by water sourced from non-row crop land covers in the lower reaches of the watershed.

New England SPARROW Water-Quality Modeling to Assist with the Development of Total Maximum Daily Loads in the Connecticut River Basin

NASA Astrophysics Data System (ADS)

Moore, R. B.; Robinson, K. W.; Simcox, A. C.; Johnston, C. M.

2002-05-01

The U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (USEPA) and the New England Interstate Water Pollution Control Commission (NEWIPCC), is currently preparing a water-quality model, called SPARROW, to assist in the regional total maximum daily load (TMDL) studies in New England. A model is required to provide estimates of nutrient loads and confidence intervals at unmonitored stream reaches. SPARROW (Spatially Referenced Regressions on Watershed Attributes) is a spatially detailed, statistical model that uses regression equations to relate total phosphorus and nitrogen (nutrient) stream loads to pollution sources and watershed characteristics. These statistical relations are then used to predict nutrient loads in unmonitored streams. The New England SPARROW model is based on a hydrologic network of 42,000 stream reaches and associated watersheds. Point source data are derived from USEPA's Permit Compliance System (PCS). Information about nonpoint sources is derived from data such as fertilizer use, livestock wastes, and atmospheric deposition. Watershed characteristics include land use, streamflow, time-of-travel, stream density, percent wetlands, slope of the land surface, and soil permeability. Preliminary SPARROW results are expected in Spring 2002. The New England SPARROW model is proposed for use in the TMDL determination for nutrients in the Connecticut River Basin, upstream of Connecticut. The model will be used to estimate nitrogen loads from each of the upstream states to Long Island Sound. It will provide estimates and confidence intervals of phosphorus and nitrogen loads, area-weighted yields of nutrients by watershed, sources of nutrients, and the downstream movement of nutrients. This information will be used to (1) understand ranges in nutrient levels in surface waters, (2) identify the environmental factors that affect nutrient levels in streams, (3) evaluate monitoring efforts for better determination of nutrient loads, and (4) evaluate management options for reducing nutrient loads to achieve water-quality goals.

Temporal variability in domestic point source discharges and their associated impact on receiving waters.

PubMed

Richards, Samia; Withers, Paul J A; Paterson, Eric; McRoberts, Colin W; Stutter, Marc

2016-11-15

Discharges from the widely distributed small point sources of pollutants such as septic tanks contribute to microbial and nutrient loading of streams and can pose risks to human health and stream ecology, especially during periods of ecological sensitivity. Here we present the first comprehensive data on the compositional variability of septic tank effluents (STE) as a potential source of water pollution during different seasons and the associated links to their influence on stream waters. To determine STE parameters and nutrient variations, the biological and physicochemical properties of effluents sampled quarterly from 12 septic tank systems were investigated with concurrent analyses of upstream and downstream receiving waters. The study revealed that during the warmer dryer months of spring and summer, effluents were similar in composition, as were the colder wetter months of autumn and winter. However, spring/summer effluents differed significantly (P<0.05) from autumn/winter for concentrations of biological oxygen demand (BOD), arsenic, barium (Ba), cobalt, chromium, manganese, strontium (Sr), titanium, tungsten (W) and zinc (Zn). With the exception of BOD, Ba and Sr which were greater in summer and spring, the concentrations of these parameters were greater in winter. Receiving stream waters also showed significant seasonal variation (P≤0.05) in alkalinity, BOD, dissolved organic carbon, sulphate, sulphur, lithium, W, Zn and Escherichiacoli abundance. There was a clear significant influence of STE on downstream waters relative to upstream from the source (P<0.05) for total suspended solids, total particulate P and N, ammonium-N, coliforms and E. coli. The findings of this study found seasonal variation in STE and place effluent discharges as a factor affecting adjacent stream quality and call for appropriate measures to reduce or redirect STE discharges away from water courses. Copyright © 2016 Elsevier B.V. All rights reserved.

River-groundwater connectivity and nutrient dynamics in a mesoscale catchment

NASA Astrophysics Data System (ADS)

Fleckenstein, Jan H.; Musolff, Andreas; Gilfedder, Benjamin; Frei, Sven; Wankmüller, Fabian; Trauth, Nico

2017-04-01

Diffuse solute exports from catchments are governed by many interrelated factors such as land use, climate, geological-/ hydrogeological setup and morphology. Those factors create spatial variations in solute concentrations and turnover rates in the subsurface as well as in the stream network. River-groundwater connectivity is a crucial control in this context: On the one hand groundwater is a main pathway for nitrate inputs to the stream. On the other hand, groundwater connectivity with the stream affects the magnitude of hyporheic exchange of stream water with the stream bed. We present results of a longitudinal sampling campaign along the Selke river, a 67 km long third-order stream in the Harz mountains in central Germany. Water quality at the catchment outlet is strongly impacted by agriculture with high concentrations of nitrate and a chemostatic nitrate export regime. However, the specific nitrate pathways to the stream are not fully understood as there is arable land distributed throughout the catchment. While the sparsely distributed arable land in the mountainous upper catchment receives much higher amounts of precipitation, the downstream alluvial plains are drier, but more intensively used. The three-day campaign was conducted in June 2016 under constant low flow conditions. Stream water samples were taken every 2 km along the main stem of the river and at its major tributaries. Samples were analyzed for field parameters, major cations and anions, N-O isotopes, nutrients and Radon-222 (Rn) concentrations. Additionally, at each sampling location, river discharge was manually measured using current meters. Groundwater influxes to each sampled river section were quantified from the Rn measurements using the code FINIFLUX, (Frei and Gilfedder 2015). Rn and ion concentrations showed an increase from the spring to the mouth, indicating a growing impact of groundwater flux to the river. However, increases in groundwater gains were not gradual. The strongest gains were observed downstream of where the Selke River leaves the Harz Mountains and enters the alluvial plains. At this location, land use, hydrogeological setup and river slope as well as average slope of the contributing catchment area change significantly. Downstream of this point 15N isotope values were also significantly higher, suggesting higher denitrification activity in the deeper aquifers of lower catchment. While specific discharge (discharge per catchment area) was 3 times higher in the upper catchment, nitrate mass flux per area was more than 3 times higher in lower catchment compared to the respective other part of the catchment. We conclude that catchment morphology, (hydro)geology and hydrology control river-groundwater connectivity while the interplay with land use controls in stream nitrate concentrations. Repeated sampling campaigns will allow assessing seasonal changes in solute inputs and turnover. References Frei, S. & Gilfedder, B.S. (2015): FINIFLUX: An implicit finite element model for quantification of groundwater fluxes and hyporheic exchange in streams and rivers using radon. Water Resources Research, DOI: 10.1002/2015WR017212.

Water quality, physical habitat, and fish community composition in streams in the Twin Cities metropolitan area, Minnesota, 1997-98

USGS Publications Warehouse

Talmage, Philip J.; Lee, Kathy E.; Goldstein, Robert M.; Anderson, Jesse P.; Fallon, James D.

1999-01-01

Water quality, physical habitat, and fish-community composition were characterized at 13 Twin Cities metropolitan area streams during low-flow conditions, September 1997. Fish communities were resampled during September 1998. Sites were selected based on a range of human population density. Nutrient concentrations were generally low, rarely exceeding concentrations found in agricultural streams or water-quality criteria. Seventeen pesticides and five pesticide metabolites were detected, with atrazine being the only pesticide detected at all 13 streams. Colony counts of fecal coliform bacteria ranged from 54 to greater than 11,000 colonies per 100 mL. Instream fish habitat was sparse with little woody debris and few boulders, cobble, or other suitable fish habitat. Thirty-eight species and one hybrid from 10 families were collected. Fish communities were characterized by high percentages of omnivores and tolerant species with few intolerant species. Index of Biotic Integrity scores were low, with most streams rating fair to very poor. Percent impervious surface was positively correlated with sodium and chloride concentrations and human population density, but was negatively correlated with fish species richness and diversity. Urban land use and human population density influence fish communities and water quality in Twin Cities metropolitan area streams. Other factors that may influence fish community composition include percent impervious cover, water chemistry, water temperature, geomorphology, substrate, instream habitat, and migration barriers.

C-13 dynamics in benthic algae: Effects of light, phosphorus, and biomass development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hill, Walter; Fanta, S.E.; Roberts, Brian J

2008-07-01

We performed three experiments in indoor streams and one experiment in a natural stream to investigate the effects of growth factors on {delta}{sup 13}C levels in benthic microalgae. In the indoor streams, algae grown under conditions of high light and high phosphorus had {delta}{sup 13}C values that were 16% higher than those in algae grown under conditions of low light and low phosphorus. Light effects were much stronger than phosphorus effects. The effects of both factors increased in strength as algal biomass accrued, and by the end of the experiments, algal {delta}{sup 13}C and biomass were highly correlated. In themore » natural stream, algae exposed to direct sunlight were enriched 15% over shaded algae, corroborating the strong effect of light in the indoor streams. Growth factors such as light and nutrients probably reduce discrimination against {delta}{sup 13}C (raising {delta}{sup 13}C values) in benthic microalgae by causing CO{sub 2} depletion both within individual cells and within the assemblage matrix. However, because the most marked fractionation occurred in older and thicker assemblages, CO{sub 2} depletion within the assemblage matrix appeared to be more important than depletion within individual cells. In the absence of carbon-concentrating mechanisms, elevated {delta}{sup 13}C suggests that inorganic carbon may limit the growth of benthic algae. The extensive range of d13C values (-14{per_thousand} to -36{per_thousand}) created by light and nutrient manipulations in this study easily encompassed the mean {delta}{sup 13}C values of both C{sub 3} and C{sub 4} terrestrial plants, indicating the challenge aquatic ecologists face in identifying carbon sources for higher trophic levels when light and nutrient conditions vary.« less

Effects of sea lamprey substrate modification and carcass nutrients on macroinvertebrate assemblages in a small Atlantic coastal stream

USGS Publications Warehouse

Weaver, Daniel M.; Coghlan, Stephen M.; Zydlewski, Joseph D.

2018-01-01

Aquatic macroinvertebrates respond to patch dynamics arising from interactions of physical and chemical disturbances across space and time. Anadromous fish, such as sea lamprey, Petromyzon marinus, migrate from the ocean and alter physical and chemical properties of recipient spawning streams. Sea lamprey disturb stream benthos physically through nest construction and spawning, and enrich food webs through nutrient deposition from decomposing carcasses. Sea lamprey spawning nests support greater macroinvertebrate abundance than adjacent reference areas, but concurrent effects of stream bed modification and nutrient supplementation have not been examined sequentially. We added carcasses and cleared substrate experimentally to mimic the physical disturbance and nutrient enrichment associated with lamprey spawning, and characterized effects on macroinvertebrate assemblage structure. We found that areas receiving cleared substrate and carcass nutrients were colonized largely by Simuliidae compared to upstream and downstream control areas that were colonized largely by Hydropsychidae, Philopotamidae, and Chironomidae. Environmental factors such as stream flow likely shape assemblages by physically constraining macroinvertebrate establishment and feeding. Our results indicate potential changes in macroinvertebrate assemblages from the physical and chemical changes to streams brought by spawning populations of sea lamprey.

An exploratory analysis of Indiana and Illinois biotic ...

EPA Pesticide Factsheets

EPA recognizes the importance of nutrient criteria in protecting designated uses from eutrophication effects associated with elevated phosphorus and nitrogen in streams and has worked with states over the past 12 years to assist them in developing nutrient criteria. Towards that end, EPA has provided states and tribes with technical guidance to assess nutrient impacts and to develop criteria. EPA published recommendations in 2000 on scientifically defensible empirical approaches for setting numeric criteria. EPA also published eco-regional criteria recommendations in 2000-2001 based on a frequency distribution approach meant to approximate reference condition concentrations. In 2010, EPA elaborated on one of these empirical approaches (i.e., stressor-response relationships) for developing nutrient criteria. The purpose of this report was to conduct exploratory analyses of state datasets from Illinois and Indiana to determine threshold values for nutrients and chlorophyll a that could guide Indiana and Illinois criteria development. Box and whisker plots were used to compare nutrient and chlorophyll a concentrations between Illinois and Indiana. Stressor response analyses, using piece-wise linear regression and change-point analysis (Illinois only) were conducted to determine thresholds of change in relationships between nutrients and biotic assemblages. Impact stmt: The purpose of this report was to conduct exploratory analyses of state datasets from Illinois

NUTRIENTS, CANOPY COVER, AND GRAZERS: THEIR EFFECTS ON SUMMER PERIPHYTON IN SMALL MIDWESTERN STREAMS

EPA Science Inventory

Numerous studies in artificial streams suggest the relationship between nurients and periphyton biomass (AFDM) and chlorophyll a in streams is affected by ambient light, which is influenced by canopy cover, and by grazer densities. To assess the relationships between nutrients a...

The influence of stormwater management practices on denitrification rates of receiving streams in an urban watershed

NASA Astrophysics Data System (ADS)

Cronenberger, M. S.; McMillan, S. K.

2011-12-01

Increasing urbanization and the subsequent disruption of floodplains has led to the need for implementing stormwater management strategies to mitigate the effects of urbanization, including soil and streambank erosion, increased export of nutrients and contaminants and decreased biotic richness. Excessive stormwater runoff due to the abundance of impervious surfaces associated with an urban landscape has led to the ubiquitous use of best management practices (BMPs) to attenuate runoff events and prevent the destructive delivery of large volumes of water to stream channels. As a result, effluent from BMPs (i.e. wetlands and wet ponds) has the potential to alter the character of the receiving stream channel and thus, key ecosystem processes such as denitrification. The purpose of this study was to determine the extent to which BMPs, in the form of constructed wetlands and wet ponds, influence in-stream denitrification rates in the urban landscape of Charlotte, NC. Four sites, two of each BMP type, were evaluated. Sediment samples were collected upstream and downstream of the BMP outflow from May-July 2011 to determine the effect of wetland discharge on in-stream nitrogen removal via denitrification. Denitrification rates were determined using the acetylene block method; water column nutrient and carbon concentrations and sediment organic matter content were also measured. Generally, wetland sites exhibited higher denitrification rates, nitrate concentrations and sediment organic matter content. Our work and others has demonstrated a significant positive correlation between nitrate concentration and denitrification rates, which is the likely driver of the higher observed rates at the wetland sites. Geomorphology was also found to be a key factor in elevated denitrification rates at sites with riffles and boulder jams. Sediment organic matter was found to be higher downstream of BMP outflows at all four sites, but demonstrated no significant relationship with denitrification rates. We are continuing to investigate these spatial (e.g. BMPs, streams) and temporal (e.g. storm pulse, delayed wetland release) patterns, particularly in the context of factors that influence the specific drivers of denitrification. Understanding these patterns is critical to managing stormwater in urban landscapes as we aim to improve water quality while enhancing ecosystem functions.

Nutrient Loadings to Streams of the Continental United States from Municipal and Industrial Effluent

USGS Publications Warehouse

Maupin, M.A.; Ivahnenko, T.

2011-01-01

Data from the United States Environmental Protection Agency Permit Compliance System national database were used to calculate annual total nitrogen (TN) and total phosphorus (TP) loads to surface waters from municipal and industrial facilities in six major regions of the United States for 1992, 1997, and 2002. Concentration and effluent flow data were examined for approximately 118,250 facilities in 45 states and the District of Columbia. Inconsistent and incomplete discharge locations, effluent flows, and effluent nutrient concentrations limited the use of these data for calculating nutrient loads. More concentrations were reported for major facilities, those discharging more than 1million gallons per day, than for minor facilities, and more concentrations were reported for TP than for TN. Analytical methods to check and improve the quality of the Permit Compliance System data were used. Annual loads were calculated using "typical pollutant concentrations" to supplement missing concentrations based on the type and size of facilities. Annual nutrient loads for over 26,600 facilities were calculated for at least one of the three years. Sewage systems represented 74% of all TN loads and 58% of all TP loads. This work represents an initial set of data to develop a comprehensive and consistent national database of point-source nutrient loads. These loads can be used to inform a wide range of water-quality management, watershed modeling, and research efforts at multiple scales. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

Attempting to link hydro-morphology, transient storage and metabolism in streams: Insights from reactive tracer experiments

NASA Astrophysics Data System (ADS)

Kurz, Marie J.; Schmidt, Christian; Blaen, Phillip; Knapp, Julia L. A.; Drummond, Jennifer D.; Martí, Eugenia; Zarnetske, Jay P.; Ward, Adam S.; Krause, Stefan

2016-04-01

In-stream transient storage zones, including the hyporheic zone and vegetation beds, can be hotspots of biogeochemical processing in streams, enhancing ecosystem functions such as metabolism and nutrient uptake. The spatio-temporal dynamics and reactivity of these storage zones are influenced by multiple factors, including channel geomorphology, substrate composition and hydrology, and by anthropogenic modifications to flow regimes and nutrient loads. Tracer injections are a commonly employed method to evaluate solute transport and transient storage in streams; however, reactive tracers are needed to differentiate between metabolically active and inactive transient storage zones. The reactive stream tracer resazurin (Raz), a weakly fluorescent dye which irreversibly transforms to resorufin (Rru) under mildly reducing conditions, provides a proxy for aerobic respiration and an estimate of the metabolic activity associated with transient storage zones. Across a range of lotic ecosystems, we try to assess the influence of stream channel hydro-morphology, morphologic heterogeneity, and substrate type on reach (103 m) and sub-reach (102 m) scale transient storage, respiration, and nutrient uptake. To do so, we coupled injections of Raz and conservative tracers (uranine and/or salt) at each study site. The study sites included: vegetated mesocosms controlled for water depth; vegetated and un-vegetated sediment-filled mesocosms fed by waste-water effluent; a contrasting sand- vs. gravel-bedded lowland stream (Q = 0.08 m3/s); and a series of upland streams with varying size (Q = 0.1 - 1.5 m3/s) and prevalence of morphologic features. Continuous time-series of tracer concentrations were recorded using in-situ fluorometers and EC loggers. At the stream sites, time-series were recorded at multiple downstream locations in order to resolve sub-reach dynamics. Analyses yielded highly variable transport metrics and Raz-Rru transformation between study sites and between sub-reaches within stream sites. Higher Raz-Rru transformation rates were typically observed in smaller streams, in sub-reaches with higher prevalence of morphologic features known to promote hyporheic exchange, and in mesocosms with higher water depth, vegetation density and retention time. However, relationships between transformation rates and common metrics of transient storage were not consistent among study cases, indicating the existence of yet unrealized complexities in the relationships between water and solute transport and metabolism. Further insights were also gained related to the utility of Raz and improved tracer test practices.

Increasing floodplain connectivity through urban stream restoration increases nutrient and sediment retention

USGS Publications Warehouse

McMillan, Sara K.; Noe, Gregory

2017-01-01

Stream restoration practices frequently aim to increase connectivity between the stream channel and its floodplain to improve channel stability and enhance water quality through sediment trapping and nutrient retention. To measure the effectiveness of restoration and to understand the drivers of these functional responses, we monitored five restored urban streams that represent a range of channel morphology and restoration ages. High and low elevation floodplain plots were established in triplicate in each stream to capture variation in floodplain connectivity. We measured ecosystem geomorphic and soil attributes, sediment and nutrient loading, and rates of soil nutrient biogeochemistry processes (denitrification; N and P mineralization) then used boosted regression trees (BRT) to identify controls on sedimentation and nutrient processing. Local channel and floodplain morphology and position within the river network controlled connectivity with increased sedimentation at sites downstream of impaired reaches and at floodplain plots near the stream channel and at low elevations. We observed that nitrogen loading (both dissolved and particulate) was positively correlated with denitrification and N mineralization and dissolved phosphate loading positively influenced P mineralization; however, none of these input rates or transformations differed between floodplain elevation categories. Instead, continuous gradients of connectivity were observed rather than categorical shifts between inset and high floodplains. Organic matter and nutrient content in floodplain soils increased with the time since restoration, which highlights the importance of recovery time after construction that is needed for restored systems to increase ecosystem functions. Our results highlight the importance of restoring floodplains downstream of sources of impairment and building them at lower elevations so they flood frequently, not just during bankfull events. This integrated approach has the greatest potential for increasing trapping of sediment, nutrients, and associated pollutants in restored streams and thereby improving water quality in urban watersheds.

Spiraling in Urban Streams: A Novel Approach to Link Geomorphic Structure with Ecosystem Function

NASA Astrophysics Data System (ADS)

Bean, R. A.; Lafrenz, M. D.

2011-12-01

The goal of this study is to quantify the relationship between channel complexity and nutrient spiraling along several reaches of an urbanized watershed in Portland, Oregon. Much research points to the effect urbanization has on watershed hydrology and nutrient loading at the watershed scale for various sized catchments. However the flux of nutrients over short reaches within a stream channel has been less studied because of the effort and costs associated with fieldwork and subsequent laboratory analysis of both surface and hyporheic water samples. In this study we explore a novel approach at capturing connectivity though nutrient spiraling along several short reaches (less than 100-meter) within the highly urbanized Fanno Creek watershed (4400 hectares). We measure channel complexity-sinuosity, bed material texture, organic matter-and use these measurements to determine spatial autocorrelation of 50 reaches in Fanno Creek, a small, urban watershed in Portland, Oregon. Using ion-selective electrodes, the fluxes of nitrate and ammonia are measured within each reach, which when combined with channel geometry and velocity measurements allow us to transform the values of nitrate and ammonia fluxes into spiraling metrics. Along each sampled reach, we collected three surface water samples to characterize nutrient amounts at the upstream, midstream, and downstream position of the reach. Two additional water samples were taken from the left and right bank hyporheic zones at a depth just below the armor layer of the channel bed using mini-piezometers and a hand-pumped vacuum device, which we constructed for this purpose. Adjacent to the hyporheic samples soil cores were collected and analyzed for organic matter composition, bulk density, and texture. We hypothesize that spiral metrics will respond significantly to the measured channel complexity values and will be a more robust predictor of nutrient flux than land cover characteristics in the area draining to each reach. Initial results show significant differences in hyporheic and surface water concentrations within the same reach indicating that sources and sinks of mineral nitrogen can be found within stream channels over very short distances. The implication of this study is that channel complexity is an important driver of nutrient flux in a watershed, and that this technique can be applied in future studies to better characterize the ecosystem services of stream channels over short reaches to entire catchments.

INTERREGIONAL COMPARISON OF NUTRIENT UPTAKE RATES IN MANAGED AND OLD-GROWTH WATERSHEDS

EPA Science Inventory

We compared nutrient uptake rates to examine the effect of timber harvest on streams. From 1999-2002, nutrient additions were conducted in 50 stream reaches in 4 ecoregions (southern Blue Ridge, NC, Ouachita Mountains, AR, Cascade Mountains, OR, and the redwood forests of the Co...

AN INTERREGIONAL COMPARISON OF CHANNEL STRUCTURE, TRANSIENT STORAGE AND NUTRIENT UPTAKE IN STREAMS DRAINING MANAGED AND OLD GROWTH WATERSHEDS

EPA Science Inventory

We compared stream channel structure (width, depth, substrate composition) and riparian canopy with transient storage and nutrient uptake in 32 streams draining old-growth and managed watersheds in the Appalachian Mountains (North Carolina), Ouachita Mountains (Arkansas), Cascade...

The Effect of Catchment Urbanization on Nutrient Uptake and Biofilm Enzyme Activity in Lake Superior (USA) Tributary Streams

EPA Science Inventory

We used landscape, habitat, and chemistry variables, along with nutrient spiraling metrics and biofilm extracellular enzyme activity (EEA), to assess the response of streams to the level of urbanization within their catchments. For this study nine streams of similar catchment are...

Influence of catchment land cover on stoichiometry and stable isotope compositions of basal resources and macroinvertebrate consumers in headwater streams

EPA Science Inventory

Anthropogenic land use affects aquatic landscapes. For example, landscape-level conversion to urban or agricultural land can heavily influence nutrient cycles in headwater streams via increased nutrient loading and altered hydrologic patterns. Recent studies in headwater streams ...

NUTRIENT UPTAKE AND COMMUNITY METABOLISM IN STREAMS DRAINING HARVESTED AND OLD GROWTH WATERSHEDS: A PRELIMINARY ASSESSMENT

EPA Science Inventory

The effect of timber harvesting on streams is assessed using two measures of ecosystem function: nutrient ad community metabolism. This research is being conducted in streams of the southern Appalachian Mountains of North Carolina, the Ouachita Mountains of Arkansas, the Cascad...

Water-resources appraisal of the Lake Traverse Indian Reservation in South Dakota

USGS Publications Warehouse

Lawrence, S.J.

1989-01-01

The water resources within the Lake Traverse Indian Reservation consist of streams, lakes, wetlands, and groundwater stored in alluvium and glacial outwash deposits. Streamflow may cease during dry periods and during the winter. Lakes and ponds within the reservation are found predominantly within an internally drained basin. Dissolved-solids concentrations in the lakes generally range from 500 to 10,000 mg/L. Dissolved-solids concentrations in the streams generally ranging from 500 to 1 ,000 mg/L. However, nutrient concentrations tend to be larger than natural background levels in both lakes and streams and indicate unidentified sources of nutrients that effect the quality of water. Major development of surface-water resources is hindered by the lack of storage capacity within the numerous lakes, the lack of sustained streamflow, and the lack of suitable sites for construction or reservoirs. Water within the Coteau des Prairies, a glacial upland, occurs in outwash deposits. The sand and gravel deposits in the Coteau may be as thick as 70 ft. The quality of water from these aquifers generally is suitable for most uses, with calcium, magnesium, and bicarbonate the dominant ions. Water in sand and gravel deposits within the Red River and Minnesota River lowlands tends to have larger concentrations of dissolved solids than the sand and gravel deposits in the Coteau des Prairies. The quality of water in these deposits tends to be more mineralized than water in the sand and gravel deposits in the Coteau des Prairies. The regional flow of groundwater generally is to the east towards the Minnesota and Red River basins and west in the Coteau des Prairies. (USGS)

Estimates of long-term mean-annual nutrient loads considered for use in SPARROW models of the Midcontinental region of Canada and the United States, 2002 base year

USGS Publications Warehouse

Saad, David A.; Benoy, Glenn A.; Robertson, Dale M.

2018-05-11

Streamflow and nutrient concentration data needed to compute nitrogen and phosphorus loads were compiled from Federal, State, Provincial, and local agency databases and also from selected university databases. The nitrogen and phosphorus loads are necessary inputs to Spatially Referenced Regressions on Watershed Attributes (SPARROW) models. SPARROW models are a way to estimate the distribution, sources, and transport of nutrients in streams throughout the Midcontinental region of Canada and the United States. After screening the data, approximately 1,500 sites sampled by 34 agencies were identified as having suitable data for calculating the long-term mean-annual nutrient loads required for SPARROW model calibration. These final sites represent a wide range in watershed sizes, types of nutrient sources, and land-use and watershed characteristics in the Midcontinental region of Canada and the United States.

Influence of Channel Geomorphology on Retention of Dissolved and Particulate Matter in a Cascade Mountain Stream

Treesearch

Gary A. Lamberti; Stan V. Gregory; Linda R. Ashkenas; Randall C. Wildman; Alan G. Steinman

1989-01-01

Retention of particulate and dissolved nutrients in streams is a major determinant of food avail-ability to stream biota. Retention of particulate matter (leaves) and dissolved nutrients (nitrogen) was studied experimentally during summer 1987 in four 300-500 m reaches of Lookout Creek, a fifth-order stream in the Cascade Mountains of Oregon. Constrained (narrow valley...

Effects of livestock grazing on morphology, hydrology and nutrient retention in four riparian/stream ecosystems, New Mexico, USA

Treesearch

James R. Thibault; Douglas L. Moyer; Clifford N. Dahm; H. Maurice Valett; Michael C. Marshall

1999-01-01

Land-use practices such as livestock grazing influence the structure and function of riparian/stream ecosystems. In New Mexico, four streams were selected to determine the impact of moderate livestock grazing on morphology, solute transport, and nutrient retention. Each stream contained a reach currently exposed to grazing and an exclosed, ungrazed reach. Channel width...

Reduced nutrient pollution in a rural stream following septic tank upgrade and installation of runoff retention measures.

PubMed

Ockenden, M C; Quinton, J N; Favaretto, N; Deasy, C; Surridge, B

2014-07-01

Surface water quality in the UK and much of Western Europe has improved in recent decades, in response to better point source controls and the regulation of fertilizer, manure and slurry use. However, diffuse sources of pollution, such as leaching or runoff of nutrients from agricultural fields, and micro-point sources including farmyards, manure heaps and septic tank sewerage systems, particularly systems without soil adsorption beds, are now hypothesised to contribute a significant proportion of the nutrients delivered to surface watercourses. Tackling such sources in an integrated manner is vital, if improvements in freshwater quality are to continue. In this research, we consider the combined effect of constructing small field wetlands and improving a septic tank system on stream water quality within an agricultural catchment in Cumbria, UK. Water quality in the ditch-wetland system was monitored by manual sampling at fortnightly intervals (April-October 2011 and February-October 2012), with the septic tank improvement taking place in February 2012. Reductions in nutrient concentrations were observed through the catchment, by up to 60% when considering total phosphorus (TP) entering and leaving a wetland with a long residence time. Average fluxes of TP, soluble reactive phosphorus (SRP) and ammonium-N (NH4-N) at the head of the ditch system in 2011 (before septic tank improvement) compared to 2012 (after septic tank improvement) were reduced by 28%, 9% and 37% respectively. However, TP concentration data continue to show a clear dilution with increasing flow, indicating that the system remained point source dominated even after the septic tank improvement.

A multi-agency nutrient dataset used to estimate loads, improve monitoring design, and calibrate regional nutrient SPARROW models

USGS Publications Warehouse

Saad, David A.; Schwarz, Gregory E.; Robertson, Dale M.; Booth, Nathaniel

2011-01-01

Stream-loading information was compiled from federal, state, and local agencies, and selected universities as part of an effort to develop regional SPAtially Referenced Regressions On Watershed attributes (SPARROW) models to help describe the distribution, sources, and transport of nutrients in streams throughout much of the United States. After screening, 2,739 sites, sampled by 73 agencies, were identified as having suitable data for calculating long-term mean annual nutrient loads required for SPARROW model calibration. These sites had a wide range in nutrient concentrations, loads, and yields, and environmental characteristics in their basins. An analysis of the accuracy in load estimates relative to site attributes indicated that accuracy in loads improve with increases in the number of observations, the proportion of uncensored data, and the variability in flow on observation days, whereas accuracy declines with increases in the root mean square error of the water-quality model, the flow-bias ratio, the number of days between samples, the variability in daily streamflow for the prediction period, and if the load estimate has been detrended. Based on compiled data, all areas of the country had recent declines in the number of sites with sufficient water-quality data to compute accurate annual loads and support regional modeling analyses. These declines were caused by decreases in the number of sites being sampled and data not being entered in readily accessible databases.

Emerging contaminants and nutrients synergistically affect the spread of class 1 integron-integrase (intI1) and sul1 genes within stable streambed bacterial communities.

PubMed

Subirats, Jèssica; Timoner, Xisca; Sànchez-Melsió, Alexandre; Balcázar, José Luis; Acuña, Vicenç; Sabater, Sergi; Borrego, Carles M

2018-07-01

Wastewater effluents increase the nutrient load of receiving streams while introducing a myriad of anthropogenic chemical pollutants that challenge the resident aquatic (micro)biota. Disentangling the effects of both kind of stressors and their potential interaction on the dissemination of antibiotic resistance genes in bacterial communities requires highly controlled manipulative experiments. In this work, we investigated the effects of a combined regime of nutrients (at low, medium and high concentrations) and a mixture of emerging contaminants (ciprofloxacin, erythromycin, sulfamethoxazole, diclofenac, and methylparaben) on the bacterial composition, abundance and antibiotic resistance profile of biofilms grown in artificial streams. In particular, we investigated the effect of this combined stress on genes encoding resistance to ciprofloxacin (qnrS), erythromycin (ermB), sulfamethoxazole (sul1 and sul2) as well as the class 1 integron-integrase gene (intI1). Only genes conferring resistance to sulfonamides (sul1 and sul2) and intI1 gene were detected in all treatments during the study period. Besides, bacterial communities exposed to emerging contaminants showed higher copy numbers of sul1 and intI1 genes than those not exposed, whereas nutrient amendments did not affect their abundance. However, bacterial communities exposed to both emerging contaminants and a high nutrient concentration (1, 25 and 1 mg L -1 of phosphate, nitrate and ammonium, respectively) showed the highest increase on the abundance of sul1 and intI1 genes thus suggesting a factors synergistic effect of both stressors. Since none of the treatments caused a significant change on the composition of bacterial communities, the enrichment of sul1 and intI1 genes within the community was caused by their dissemination under the combined pressure exerted by nutrients and emerging contaminants. To the best of our knowledge, this is the first study demonstrating the contribution of nutrients on the maintenance and spread of antibiotic resistance genes in streambed biofilms under controlled conditions. Our results also highlight that nutrients could enhance the effect of emerging contaminants on the dissemination of antibiotic resistance. Copyright © 2018 Elsevier Ltd. All rights reserved.

Persistent Influences of the 2002 Hayman Fire on Stream Nitrate and Dissolved Organic Carbon

NASA Astrophysics Data System (ADS)

Rhoades, C.; Pierson, D. N.; Fegel, T. S., II; Chow, A. T.; Covino, T. P.

2016-12-01

Large, high severity wildfires alter the physical and biological conditions that determine how watersheds retain and release nutrients and regulate stream water quality. For five years after the 2002 Hayman Fire burned in Colorado conifer forests, stream nitrate concentrations and export increased steadily in watersheds with extensive high-severity burning. Stream temperature and turbidity also increased in relation to the extent of high-severity burning and remained elevated above background levels throughout the initial five year post-fire period. Our recent sampling documents that 14 years after the Hayman Fire stream nitrate remains an order of magnitude higher in extensively-burned (35-90%) compared to unburned watersheds (0.2 vs 2.8 mg L-1). Nitrate represents 83% of the total dissolved N in extensively-burned watersheds compared to 29% in unburned watersheds. In contrast, dissolved organic carbon (DOC), was highest in watersheds that burned to a moderate extent (10-20%) and lowest in those with extensive burning. Catchments with a moderate extent burned had DOC concentrations 2.5 and 1.7 times more than those with extensive burning and unburned catchments, respectively. Peak concentrations of DOC and nitrate track the rising limb of the streamflow hydrograph and reach a maximum in May, but patterns among burn extent categories were seasonally consistent. Current riparian conditions are linked to stream nitrate in burned watersheds. For example, stream nitrate increases proportionally to the extent of riparian zones with low shrub cover (R2 = 0.76). We found signs of watershed recovery compared to the initial post-fire period; stream temperature and turbidity remained elevated in extensively burned catchments, but increases were only significant during the spring season. The persistent stream nitrate concentrations as well as the relation between riparian cover and post-fire stream nitrate may help prioritize restoration planting efforts and mitigate chronic, elevated nitrate export from burned watersheds.

Bacterial Cellulose Production from Industrial Waste and by-Product Streams

PubMed Central

Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis

2015-01-01

The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102–138 g·water/g·dry bacterial cellulose, viscosities of 4.7–9.3 dL/g, degree of polymerization of 1889.1–2672.8, stress at break of 72.3–139.5 MPa and Young’s modulus of 0.97–1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients. PMID:26140376

Bacterial Cellulose Production from Industrial Waste and by-Product Streams.

PubMed

Tsouko, Erminda; Kourmentza, Constantina; Ladakis, Dimitrios; Kopsahelis, Nikolaos; Mandala, Ioanna; Papanikolaou, Seraphim; Paloukis, Fotis; Alves, Vitor; Koutinas, Apostolis

2015-07-01

The utilization of fermentation media derived from waste and by-product streams from biodiesel and confectionery industries could lead to highly efficient production of bacterial cellulose. Batch fermentations with the bacterial strain Komagataeibacter sucrofermentans DSM (Deutsche Sammlung von Mikroorganismen) 15973 were initially carried out in synthetic media using commercial sugars and crude glycerol. The highest bacterial cellulose concentration was achieved when crude glycerol (3.2 g/L) and commercial sucrose (4.9 g/L) were used. The combination of crude glycerol and sunflower meal hydrolysates as the sole fermentation media resulted in bacterial cellulose production of 13.3 g/L. Similar results (13 g/L) were obtained when flour-rich hydrolysates produced from confectionery industry waste streams were used. The properties of bacterial celluloses developed when different fermentation media were used showed water holding capacities of 102-138 g · water/g · dry bacterial cellulose, viscosities of 4.7-9.3 dL/g, degree of polymerization of 1889.1-2672.8, stress at break of 72.3-139.5 MPa and Young's modulus of 0.97-1.64 GPa. This study demonstrated that by-product streams from the biodiesel industry and waste streams from confectionery industries could be used as the sole sources of nutrients for the production of bacterial cellulose with similar properties as those produced with commercial sources of nutrients.

Relating nutrient and herbicide fate with landscape features and characteristics of 15 subwatersheds in the Choptank River watershed

USGS Publications Warehouse

Hively, W. Dean; Hapeman, Cathleen J.; McConnell, Laura L.; Fisher, Thomas R.; Rice, Clifford P.; McCarty, Gregory W.; Sadeghi, Ali M.; Whitall, David R.; Downey, Peter M.; de Guzman, Gabriela T. Nino; Bialek-Kalinski, Krystyna; Lang, Megan W.; Gustafson, Anne B.; Sutton, Adrienne J.; Sefton, Kerry A.; Harman Fetcho, Jennifer A.

2011-01-01

Excess nutrients and agrochemicals from non-point sources contribute to water quality impairment in the Chesapeake Bay watershed and their loading rates are related to land use, agricultural practices, hydrology, and pollutant fate and transport processes. In this study, monthly baseflow stream samples from 15 agricultural subwatersheds of the Choptank River in Maryland USA (2005 to 2007) were characterized for nutrients, herbicides, and herbicide transformation products. High-resolution digital maps of land use and forested wetlands were derived from remote sensing imagery. Examination of landscape metrics and water quality data, partitioned according to hydrogeomorphic class, provided insight into the fate, delivery, and transport mechanisms associated with agricultural pollutants. Mean Nitrate-N concentrations (4.9 mg/L) were correlated positively with percent agriculture (R2 = 0.56) and negatively with percent forest (R2 = 0.60). Concentrations were greater (p = 0.0001) in the well-drained upland (WDU) hydrogeomorphic region than in poorly drained upland (PDU), reflecting increased denitrification and reduced agricultural land use intensity in the PDU landscape due to the prevalence of hydric soils. Atrazine and metolachlor concentrations (mean 0.29 μg/L and 0.19 μg/L) were also greater (p = 0.0001) in WDU subwatersheds than in PDU subwatersheds. Springtime herbicide concentrations exhibited a strong, positive correlation (R2 = 0.90) with percent forest in the WDU subwatersheds but not in the PDU subwatersheds. In addition, forested riparian stream buffers in the WDU were more prevalent than in the PDU where forested patches are typically not located near streams, suggesting an alternative delivery mechanism whereby volatilized herbicides are captured by the riparian forest canopy and subsequently washed off during rainfall. Orthophosphate, CIAT (6-chloro-N-(1-methylethyl)-1,3,5-triazine-2,4-diamine), CEAT (6-chloro-N-ethyl-1,3,5-triazine-2,4-diamine), and MESA (2-[(2-ethyl-6-methylphenyl) (2-methoxy-1-methylethyl)amino]-2-oxoethanesulfonic acid) were also analyzed. These findings will assist efforts in targeting implementation of conservation practices to the most environmentally-critical areas within watersheds to achieve water quality improvements in a cost-effective manner.

Assessment of water quality, road runoff, and bulk atmospheric deposition, Guanella Pass area, Clear Creek and Park Counties, Colorado, water years 1995-97

USGS Publications Warehouse

Stevens, Michael R.

2001-01-01

The Guanella Pass road, located about 40 miles west of Denver, Colorado, between the towns of Georgetown and Grant, has been designated a scenic byway and is being considered for reconstruction. The purpose of this report is to present an assessment of hydrologic and water-quality conditions in the Guanella Pass area and provide baseline data for evaluation of the effects of the proposed road reconstruction. The data were collected during water years 1995-97 (October 1, 1995, to September 30, 1997).Based on Colorado water-quality standards, current surface-water quality near Guanella Pass road was generally acceptable for specified use classifications of recreation, water supply, agriculture, and aquatic life. Streams had small concentrations of dissolved solids, nutrients, trace elements, and suspended sediment. An exception was upper Geneva Creek, which was acidic and had relatively large concentrations of iron, zinc, and other trace elements related to acid-sulfate weathering. Concentrations of many water-quality constituents, especially particle-related phases and suspended sediment, increased during peak snowmelt and rainstorm events and decreased to prerunoff concentrations at the end of runoff periods. Some dissolved (filtered) trace-element loads in Geneva Creek decreased during rainstorms when total recoverable loads remained generally static or increased, indicating a phase change that might be explained by adsorption of trace elements to suspended sediment during storm runoff.Total recoverable iron and dissolved zinc exceeded Colorado stream-water-quality standards most frequently. Exceedances for iron generally occurred during periods of high suspended-sediment transport in several streams. Zinc standards were exceeded in about one-half the samples collected in Geneva Creek 1.5 miles upstream from Grant.Lake-water quality was generally similar to that of area streams. Nitrogen and phosphorus ratios calculated for Clear and Duck Lakes indicated that phytoplankton in the lakes were probably phosphorus-limited. Measures of trophic status (secchi depth, total phosphorus, and chlorophyll-a) indicated that Duck and Clear Lakes were oligotrophic in 1997.Ground water had relatively low specific conductance (range 24 to 584 microsiemens per centimeter) and did not exceed U.S. Environmental Protection Agency drinking-water standards, except for samples collected from a single well, which exceeded the Proposed Maximum Contaminant Level for uranium.Runoff from the Guanella Pass road enters streams through surface channels connected to culverts and roadside ditches. Fifty-six percent of the total number of culvert and roadside-ditch drainage features on the Guanella Pass road showed evidence of recent surface runoff connection to an adjacent stream. Road runoff is generated during snowmelt and during summer rainstorms.At a road cross-drain culvert monitored continuously for discharge (water years 1996-97), most runoff (77 to 96 percent) was a result of snowmelt, and runoff from the road preceded the basinwide peak streamflow, resulting in sediment and water-quality constituent inputs to the stream when the stream?s capacity for dilution of the road runoff was low. Specific conductance of road-runoff samples ranged from 14 to 468 microsiemens per centimeter. Major-ion composition of some samples indicated effects from deicing salt (sodium chloride) and dust inhibitor (magnesium chloride) applied to sections of the road, but changes in the stream concentrations that might be attributed to the runoff were brief and relatively small.Nutrients were commonly measured in road-runoff samples at larger concentrations than in streamflow. Concentrations of nitrate and ammonia, especially during rainfall-generated road runoff, were more similar to the concentrations in precipitation than to the concentrations in stream water. Concentrations of ammonia plus organic nitrogen (total as N) (range less than 0.2 to 24 milligrams per liter) and t

Riparian shrub buffers reduce surface water pollutant loads

Treesearch

W. A. Geyer; C. Barden; K. Mankin; D. Devlin

2003-01-01

Surface water resources in Kansas often contain concentrations of pesticides, nutrients, and sediments that are of concern to local citizens. The United States Geological Survey reported in 1999 that 97 percent of streams and 82 percent of lakes in Kansas would not fully support all uses as designated by state statutes (U.S. Geological Survey 1999). Bacteria and...

Influence of storm characteristics on soil erosion and storm runoff

Treesearch

Johnny M. III Grace

2008-01-01

Unpaved forest roads can be major sources of sediment from forested watersheds. Storm runoff from forest roads are a concern due to their potential delivery of sediments and nutrients to stream systems resulting in degraded water quality. The volume and sediment concentrations of stormwater runoff emanating from forest roads can be greatly influenced by storm...

Water quality of two first order forested watersheds in coastal South Carolina

Treesearch

Devendra Amatya; Charles Harrison; Carl Trettin

2007-01-01

Understanding watershed hydrology and the concentrations of nutrients in stream waters are fundamental considerations for assessing water quality. Despite the fact that forests are generally recognized for providing clean water and used as a baseline for assessing the effects of other land uses, especially urbanization, there are ongoing concerns about the effects of...

Proximate and ultimate controls on carbon and nutrient dynamics of small agricultural catchments

NASA Astrophysics Data System (ADS)

Thomas, Zahra; Abbott, Benjamin W.; Troccaz, Olivier; Baudry, Jacques; Pinay, Gilles

2016-03-01

Direct and indirect effects from human activity have dramatically increased nutrient loading to aquatic inland and estuarine ecosystems. Despite an abundance of studies investigating the impact of agricultural activity on water quality, our understanding of what determines the capacity of a watershed to remove or retain nutrients remains limited. The goal of this study was to identify proximate and ultimate controls on dissolved organic carbon and nutrient dynamics in small agricultural catchments by investigating the relationship between catchment characteristics, stream discharge, and water chemistry. We analyzed a 5-year, high-frequency water chemistry data set from three catchments in western France ranging from 2.3 to 10.8 km2. The relationship between hydrology and solute concentrations differed between the three catchments and was associated with hedgerow density, agricultural activity, and geology. The catchment with thicker soil and higher surface roughness had relatively invariant carbon and nutrient chemistry across hydrologic conditions, indicating high resilience to human disturbance. Conversely, the catchments with smoother, thinner soils responded to both intra- and interannual hydrologic variation with high concentrations of phosphate (PO43-) and ammonium (NH4+) in streams during low flow conditions and strong increases in dissolved organic carbon (DOC), sediment, and particulate organic matter during high flows. Despite contrasting agricultural activity between catchments, the physical context (geology, topography, and land-use configuration) appeared to be the most important determinant of catchment solute dynamics based on principle components analysis. The influence of geology and accompanying topographic and geomorphological factors on water quality was both direct and indirect because the distribution of agricultural activity in these catchments is largely a consequence of the geologic and topographic context. This link between inherent catchment buffering capacity and the probability of human disturbance provides a useful perspective for evaluating vulnerability of aquatic ecosystems and for managing systems to maintain agricultural production while minimizing leakage of nutrients.

Identifying dissolved oxygen variability and stress in tidal freshwater streams of northern New Zealand.

PubMed

Wilding, Thomas K; Brown, Edmund; Collier, Kevin J

2012-10-01

Tidal streams are ecologically important components of lotic network, and we identify dissolved oxygen (DO) depletion as a potentially important stressor in freshwater tidal streams of northern New Zealand. Other studies have examined temporal DO variability within rivers and we build on this by examining variability between streams as a basis for regional-scale predictors of risk for DO stress. Diel DO variability in these streams was driven by: (1) photosynthesis by aquatic plants and community respiration which produced DO maxima in the afternoon and minima early morning (range, 0.6-4.7 g/m(3)) as a product of the solar cycle and (2) tidal variability as a product of the lunar cycle, including saline intrusions with variable DO concentrations plus a small residual effect on freshwater DO for low-velocity streams. The lowest DO concentrations were observed during March (early autumn) when water temperatures and macrophyte biomass were high. Spatial comparisons indicated that low-gradient tidal streams were at greater risk of DO depletions harmful to aquatic life. Tidal influence was stronger in low-gradient streams, which typically drain more developed catchments, have lower reaeration potential and offer conditions more suitable for aquatic plant proliferation. Combined, these characteristics supported a simple method based on the extent of low-gradient channel for identifying coastal streams at risk of DO depletion. High-risk streams can then be targeted for riparian planting, nutrient limits and water allocation controls to reduce potential ecological stress.

Solute-specific scaling of inorganic nitrogen and phosphorus uptake in streams

NASA Astrophysics Data System (ADS)

Hall, R. O., Jr.; Baker, M. A.; Rosi-Marshall, E. J.; Tank, J. L.; Newbold, J. D.

2013-11-01

Stream ecosystem processes such as nutrient cycling may vary with stream position in the network. Using a scaling approach, we examined the relationship between stream size and nutrient uptake length, which represents the mean distance that a dissolved solute travels prior to removal from the water column. Ammonium (NH4+) uptake length increased proportionally with stream size measured as specific discharge (discharge/stream width) with a scaling exponent = 1.01. In contrast, uptake lengths for nitrate (NO3-) and soluble reactive phosphorus (SRP) increased more rapidly than increases in specific discharge (scaling exponents = 1.19 for NO3- and 1.35 for SRP). Additionally, the ratio of inorganic nitrogen (N) uptake length to SRP uptake length declined with stream size; there was relatively lower demand for SRP compared to N as stream size increased. Finally, we related the scaling of uptake length with specific discharge to that of stream length using Hack's law and downstream hydraulic geometry. Ammonium uptake length increased less than proportionally with distance from the headwaters, suggesting a strong role for larger streams and rivers in regulating nutrient transport.

Predator-Driven Nutrient Recycling in California Stream Ecosystems

PubMed Central

Munshaw, Robin G.; Palen, Wendy J.; Courcelles, Danielle M.; Finlay, Jacques C.

2013-01-01

Nutrient recycling by consumers in streams can influence ecosystem nutrient availability and the assemblage and growth of photoautotrophs. Stream fishes can play a large role in nutrient recycling, but contributions by other vertebrates to overall recycling rates remain poorly studied. In tributaries of the Pacific Northwest, coastal giant salamanders (Dicamptodon tenebrosus) occur at high densities alongside steelhead trout (Oncorhynchus mykiss) and are top aquatic predators. We surveyed the density and body size distributions of D. tenebrosus and O. mykiss in a California tributary stream, combined with a field study to determine mass-specific excretion rates of ammonium (N) and total dissolved phosphorus (P) for D. tenebrosus. We estimated O. mykiss excretion rates (N, P) by bioenergetics using field-collected data on the nutrient composition of O. mykiss diets from the same system. Despite lower abundance, D. tenebrosus biomass was 2.5 times higher than O. mykiss. Mass-specific excretion summed over 170 m of stream revealed that O. mykiss recycle 1.7 times more N, and 1.2 times more P than D. tenebrosus, and had a higher N:P ratio (8.7) than that of D. tenebrosus (6.0), or the two species combined (7.5). Through simulated trade-offs in biomass, we estimate that shifts from salamander biomass toward fish biomass have the potential to ease nutrient limitation in forested tributary streams. These results suggest that natural and anthropogenic heterogeneity in the relative abundance of these vertebrates and variation in the uptake rates across river networks can affect broad-scale patterns of nutrient limitation. PMID:23520520

Measuring and Monitoring HydroBiogeochemical Flux in a Forested Riparian Floodplain of the Missouri Ozarks

NASA Astrophysics Data System (ADS)

Chinnasamy, P.; Hubbart, J. A.

2009-12-01

Forested riparian buffers play a vital role in protecting riparian ecosystems from natural and anthropogenic disturbances. Quantifying effective reach and catchment scale buffer designs is critical to achieve economic and riparian wetland natural resource sustainability. Advances in management of riparian wetlands require innovative reach-scale experimental studies and subsequent improvements in riparian modeling. Riparian recommended best management practices (BMPs) in Missouri (MO) have not been validated. Studies are therefore warranted to describe subsurface interactions between the stream, hyporheic zone (HZ), and adjoining riparian wetland/floodplain. Within the HZ groundwater discharge through highly permeable Karst geology can dramatically affect water quality. The following research is on-going in the Baskett Research and Education Area (BREA), a 9.17 km2 preserved wildland watershed located 8 km east of Ashland, in the Ozark border region of south-central MO. The climate at BREA is generally described as warm, humid, and continental, with mean January and August temperatures of -2.4 °C and 24.5 °C, respectively, and 1,022 mm mean annual precipitation. Limestone geology of Ordovician and Mississippian age underlies the BREA with dominant soils of Weller silt loam and Clinkenbeard clay loam. Vegetation at the BREA consists of northern and southern division oak dominated hickory forests. BREA offers a distinct opportunity to study wildland watershed processes to validate contemporary best management practices (BMP) in MO. To quantify hydrobiogeochemical flux, spatial and temporal (3 water years) variability in stream water temperatures, key nutrients (NO3, P, K, NH3) and hyporheic exchange are being monitored. Key hydrologic variables approaching a mass balance, plus groundwater monitoring (via piezometric arrays) are being studied. Results (beginning summer and fall 2009) will provide the necessary information to quantify the relationships between riparian buffer density and floodplain efficacy in ameliorating hydrologic and biogeochemical processes. Previous studies show that highest nutrient concentrations tend to occur in the smallest streams. In Iowa, watershed study results (areas 47 to 2774 km2) showed that NO3 concentrations in surface water ranged from 0.4-10.8 mg/L in larger watersheds while in smaller watersheds it ranged from 3.1-10 mg/L. Nitrate was shown to travel 5-10 times as farther than other constituents of concern including ammonia (NH3), which can travel tens to hundreds of meters. Given results from previous studies, it is expected that headwater streams of the BREA will supply nutrients at higher concentrations. It is further expected that nutrient flux will originate from surrounding hillslopes through the floodplain to streams (spatially and temporally variable). Riparian floodplains of the BREA will be characterized with respect to the pools and fluxes of water and nutrients, from which BMP efficacy can be assessed. This work will provide regionally specific and scientifically validated information that will justify the use of current or modified BMPs. Published results will better equip agencies and citizens to better protect these complex and critically important fresh water ecosystems.

Nutrient additions to mitigate for loss of Pacific salmon: consequences for stream biofilm and nutrient dynamics

USGS Publications Warehouse

Marcarelli, Amy M.; Baxter, Colden V.; Wipfli, Mark S.

2014-01-01

Mitigation activities designed to supplement nutrient and organic matter inputs to streams experiencing decline or loss of Pacific salmon typically presuppose that an important pathway by which salmon nutrients are moved to fish (anadromous and/or resident) is via nutrient incorporation by biofilms and subsequent bottom-up stimulation of biofilm production, which is nutrient-limited in many ecosystems where salmon returns have declined. Our objective was to quantify the magnitude of nutrient incorporation and biofilm dynamics that underpin this indirect pathway in response to experimental additions of salmon carcasses and pelletized fish meal (a.k.a., salmon carcass analogs) to 500-m reaches of central Idaho streams over three years. Biofilm standing crops increased 2–8-fold and incorporated marine-derived nutrients (measured using 15N and 13C) in the month following treatment, but these responses did not persist year-to-year. Biofilms were nitrogen (N) limited before treatments, and remained N limited in analog, but not carcass-treated reaches. Despite these biofilm responses, in the month following treatment total N load was equal to 33–47% of the N added to the treated reaches, and N spiraling measurements suggested that as much as 20%, but more likely 2–3% of added N was taken up by microbes. Design of biologically and cost-effective strategies for nutrient addition will require understanding the rates at which stream microbes take up nutrients and the downstream distance traveled by exported nutrients.

Analysis of nutrients in the surface waters of the Georgia-Florida Coastal Plain study unit, 1970-91

USGS Publications Warehouse

Ham, L.K.; Hatzell, H.H.

1996-01-01

During the early phase of the Georgia-Florida National Water Quality Assessment study, existing information on nutrients was compiled and analyzed in order to evaluate the nutrient concentrations within the 61,545 square mile study unit. Evaluation of the nutrient concentrations collected at surface- water sites between October 1, 1970, and September 30,1991, utilized the environmental characteristics of land resource provinces, land use, and nonpoint and point-source discharges within the study unit. Long-term trends were investigated to determine the temporal distribution of nutrient concentrations. In order to determine a level of concern for nutrient concentrations, the U.S. Environmental Protection Agency (USEPA) guidelines were used-(1) for nitrate concentrations, the maximum contaminant level in public-drinking water supplies (10 mg/L); (2) for ammonia concentrations, the chronic exposure of aquatic organisms to un-ionized ammonia (2.1 mg/L); (3) for total-phosphorus concentrations, the recommended concentration in flowing water to discourage excessive growth of aquatic plants (0.1 mg/L); and (4) for kjeldahl concentrations, however, no guidelines were available. For sites within the 10 major river basins, median nutrient concentrations were generally below USEPA guidelines, except for total-phosphorus concentrations where 45 percent of the medians exceeded the guideline. The only median ammonia concentration that exceeded the guideline occurred at the Swift Creek site (3.4 mg/L), in the Suwannee River basin, perhaps due to wastewater discharges. For all sites within the Withlacoochee, Aucilla, and St. Marys River basins, median concentrations of nitrate, ammonia, and total phosphorus were below the USEPA guidelines. Nutrient data at each monitoring site within each major basin were aggregated for comparisons of median nutrient concentrations among major basins. The Ochlockonee and Hillsborough River basins had the highest median nutrient concentrations, the Aucilla River basin had the lowest. Median concentrations of nitrate and ammonia among all major basins were below USEPA guidelines. The median total-phosphorus concentrations for the following river basins exceeded the USEPA guideline-Hillsborough, St. Johns, Suwannee, Ochlockonee, Satilla, Altamaha, and Ogeechee. Although nutrient concentrations within the study unit were low, long-term increasing trends were found in all four nutrients. All 18 study-unit wide nitrate trends had increasing slopes ranging from less than 0.01 to 0.07 (mg/L)/yr. The range in slope for the 13 ammonia trends was -0.03 to 0.01 (mg/L)/yr with 6 increasing trends in the northern part of the study unit. Of the 17 total-phosphorus trends found in the study unit, 10 were found at sites where the median concentration exceeded the USEPA guideline. At these 10 sites, 4 sites had increasing trends with slopes ranging from less than 0.01 to 0.07 (mg/L)/yr, 5 sites had decreasing trends with slopes ranging from -0.01 to -0.24 (mg/L)/yr, and one site showed a seasonal concentration trend. Median nutrient concentrations were significantly different among the four land resource provinces-Southern Piedmont, Southern Coastal Plain, Coastal Flatwoods, and Central Florida Ridge. As a result, nutrient concentrations among basins with similar nutrient inputs but located within different land resource provinces are not expected to be the same due to differences in the combination of factors such as soil permeability, runoff rates, and stream channel slopes. This concept is an important consideration in designing a surface-water quality network within the study area. For the most part, the Coastal Flatwoods showed the lowest median nutrient concentrations and the Southern Coastal Plain had the highest median nutrient concentrations. Lower median nitrate concentrations in surface-water basins were associated with the forest/wetland land-use category and higher median concentrations of nitrate and ammonia with

Concentrations, and Estimated Loads and Yields of Total Nitrogen and Total Phosphorus at Selected Stations in Kentucky, 1979-2004

USGS Publications Warehouse

Crain, Angela S.; Martin, Gary R.

2009-01-01

To evaluate the State's water quality, the Kentucky Division of Water collects data from a statewide network of primary ambient stream water-quality monitoring stations and flexible, rotating watershed-monitoring stations. This ambient stream water-quality monitoring network program is directed to assess the conditions of surface waters throughout Kentucky. Water samples were collected monthly for the majority of the stations from 1979 to 1998, which represented agricultural, undeveloped (mainly forested), and areas of mixed land use/land cover. In 1998, the number of water samples collected was reduced to a collection frequency of six times per year (every 2 months) every 4 of 5 years, because a new monitoring network was implemented involving a 5-year rotating Basin Management Unit scheme of monitoring. This report presents the results of a study conducted by the U.S. Geological Survey, in cooperation with the Kentucky Energy and Environment Cabinet-Kentucky Division of Water, to summarize concentrations of total nitrogen and total phosphorus and provide estimates of total nitrogen and total phosphorus loads and yields in 55 selected streams in Kentucky's ambient stream water-quality monitoring network, which was operated from 1979 through 2004. Streams in predominately agricultural basins had higher concentrations of total nitrogen (TN) and concentrations of total phosphorus (TP) than streams in predominately undeveloped (forested) basins. Streams in basins in intensely developed karst areas characterized by caves, springs, sinkholes, and sinking streams had a higher median concentration of TN (1.5 milligrams per liter [mg/L]) than streams in basins with limited or no karst areas (0.63 mg/L). As with TN, median concentrations of TP also were higher in areas of intense karst (0.05 mg/L) than in areas with limited or no karst (0.02 mg/L). The U.S. Environmental Protection Agency (USEPA) has recommended ecoregional nutrient water-quality criteria as a starting point for States to establish more precise numeric water-quality criteria for nutrients to protect aquatic life and recreational and other uses of rivers and streams. On the basis of the 25th percentile of concentration data from reference stations aggregated by ecoregion, the USEPA established recommended water-quality criteria for TN and TP in the two Aggregated Ecoregions (IX and XI) in Kentucky waters. The 25th percentile median values for TN and TP from this study exceeded the USEPA's recommendations in both aggregated ecoregions in the agricultural and mixed land-use/land-cover basins, and for TN in the undeveloped land-use/land-cover basins in Aggregated Ecoregion XI. However, the 25th percentile median values for TN (Aggregated Ecoregion IX) and TP in both aggregated ecoregions did not exceed the USEPA's recommendations in the undeveloped land-use/land-cover basins. Estimated loads and yields of TN and TP varied substantially among the individual stations. Estimated mean annual yields of TN ranged from 0.10 [tons per year per square mile (ton/yr)/mi2] to 7.2 (ton/yr)/mi2, and estimated mean annual yields of TP ranged from 0.02 (ton/yr)/mi2 to 1.4 (ton/yr)/mi2. Estimated mean annual yields of TN and TP were generally highest at stations in predominately agricultural basins, and lowest at stations in undeveloped land-use/land-cover basins.

Effects of the herbicide metazachlor on macrophytes and ecosystem function in freshwater pond and stream mesocosms.

PubMed

Mohr, S; Berghahn, R; Feibicke, M; Meinecke, S; Ottenströer, T; Schmiedling, I; Schmiediche, R; Schmidt, R

2007-05-01

The chloroacetamide metazachlor is a commonly used pre-emergent herbicide to inhibit growth of plants especially in rape culture. It occurs in surface and ground water due to spray-drift or run-off in concentrations up to 100 microgL(-1). Direct and indirect effects of metazachlor on aquatic macrophytes were investigated at oligo- to mesotrophic nutrient levels employing eight stream and eight pond indoor mesocosms. Five systems of each type were dosed once with 5, 20, 80, 200 and 500 microgL(-1) metazachlor and three ponds and three streams served as controls. Pronounced direct negative effects on macrophyte biomass of Potamogeton natans, Myriophyllum verticillatum and filamentous green algae as well as associated changes in water chemistry were detected in the course of the summer 2003 in both pond and stream mesocosms. Filamentous green algae dominated by Cladophora glomerata were the most sensitive organisms in both pond and stream systems with EC(50) ranging from 3 (streams) to 9 (ponds) microgL(-1) metazachlor. In the contaminated pond mesocosms with high toxicant concentrations (200 and 500 microgL(-1)), a species shift from filamentous green algae to the yellow-green alga Vaucheria spec. was detected. The herbicide effects for the different macrophyte species were partly masked by interspecific competition. No recovery of macrophytes was observed at the highest metazachlor concentrations in both pond and stream mesocosms until the end of the study after 140 and 170 days. Based on the lowest EC(50) value of 4 microgL(-1) for total macrophyte biomass, it is argued that single exposure of aquatic macrophytes to metazachlor to nominal concentrations >5 microgL(-1) is likely to have pronounced long-term effects on aquatic biota and ecosystem function.

PREDICTING PRESENCE OF NUTRIENTS AND PESTICIDES IN BASE FLOW CONDITIONS OF FIRST ORDER STREAMS IN THE MID-ATLANTIC COASTAL PLAIN

EPA Science Inventory

Excess nutrients and pesticides in the environment can cause a variety of ecological and human-health effects. When nutrients are unused by plants, or pesticides remain after use on their intended target, these compounds can be transported to streams, either directly through over...

Streamside Management Zones Affect Movement of Silvicultural Nitrogen and Phosphorus Fertilizers to Piedmont Streams

Treesearch

Joseph M. Secoges; Wallace M. Aust; John R. Seiler; C. Andrew Dolloff; William A. Lakel

2013-01-01

Forestry best management practices (BMP) recommendations for streamside management zones (SMZs) are based on limited data regarding SMZ width, partial harvests, and nutrient movements after forest fertilization. Agricultural fertilization is commonly linked to increased stream nutrients. However, less is known about effectiveness of SMZ options for controlling nutrient...

Temperature and Nutrients Interact to Control Nitrogen Fixation in a Subalpine Stream: An Experimental Examination

NASA Astrophysics Data System (ADS)

Marcarelli, A. M.

2005-05-01

To test the importance of factors controlling N-fixation in subalpine streams, I conducted a stream-side mesocosm experiment with epilithic communities and nutrient diffusing substrates (NDS) to test how temperature and nutrients interact to influence algal communities. Within two days, warm temperature (18°C) stimulated N-fixation by Calothrix in the epilithic community 2X above cold temperature (13°C), indicating a strong physiological response. Community responses measured on NDS indicated that cold-water diatoms dominated by day 45 in the cold treatment, while diatoms containing N-fixing endosymbionts dominated only in warm treatments with added phosphorus. There was a significant interaction between nutrient supply and temperature on N-fixation rates in the experiment. On nutrient controls, warm temperature boosted fixation 2X above cold temperature, but when P was added, temperature increased fixation 20X. This study indicates that N-fixation is stimulated both by temperature and nutrients in this stream, but the magnitude of response to phosphorus was much greater than to temperature. Furthermore, our results support the hypothesis that biological characteristics in streams, including community structure and biogeochemical processes, can be altered in complex ways by disturbances like grazing and logging that alter multiple controlling factors simultaneously.

Nutrient Retention in Restored Streams and Floodplains: A ...

EPA Pesticide Factsheets

Abstract: Excess nitrogen (N) and phosphorus (P) from human activities have contributed to degradation of coastal waters globally. A growing body of work suggests that hydrologically restoring streams and floodplains in agricultural and urban watersheds has potential to increase nitrogen and phosphorus retention, but rates and mechanisms have not yet been synthesized and compared across studies. We conducted a review of nutrient retention within hydrologically reconnected streams and floodplains including 79 studies. Overall, 62% of results were positive, 26% were neutral, and 12% were negative. The studies we reviewed used a variety of methods to analyze nutrients cycling. We did a further intensive meta-analysis on nutrient spiraling studies because this method was the most consistent and comparable between studies. A meta-analysis of 240 experimental additions of ammonium (NH4+), nitrate (NO3-), and soluble reactive phosphorus (SRP) was synthesized from 15 nutrient spiraling studies. Overall, we found that rates of uptake were variable along stream reaches over space and time. Our results indicate that the size of the stream restoration (total surface area) and hydrologic residence time can be key drivers in influencing N and P uptake at broader watershed scales or along the urban watershed continuum. Excess nitrogen and phosphorus from human activities contributes to the degradation of water quality in streams and coastal areas nationally and globally.

Complex Catchment Processes that Control Stream Nitrogen and Organic Matter Concentrations in a Northeastern USA Upland Catchment

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Pellerin, B.; Saraceno, J.; Aiken, G. R.; Boyer, E. W.; Doctor, D. H.; Kendall, C.

2009-05-01

There is a need to understand the coupled biogeochemical and hydrological processes that control stream hydrochemistry in upland forested catchments. At watershed 9 (W-9) of the Sleepers River Research Watershed in the northeastern USA, we use high-frequency sampling, environmental tracers, end-member mixing analysis, and stream reach mass balances to understand dynamic factors affect forms and concentrations of nitrogen and organic matter in streamflow. We found that rates of stream nitrate processing changed during autumn baseflow and that up to 70% of nitrate inputs to a stream reach were retained. At the same time, the stream reach was a net source of the dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) fractions of dissolved organic matter (DOM). The in-stream nitrate loss and DOM gains are examples of hot moments of biogeochemical transformations during autumn when deciduous litter fall increases DOM availability. As hydrological flowpaths changed during rainfall events, the sources and transformations of nitrate and DOM differed from baseflow. For example, during storm flow we measured direct inputs of unprocessed atmospheric nitrate to streams that were as large as 30% of the stream nitrate loading. At the same time, stream DOM composition shifted to reflect inputs of reactive organic matter from surficial upland soils. The transport of atmospheric nitrate and reactive DOM to streams underscores the importance of quantifying source variation during short-duration stormflow events. Building upon these findings we present a conceptual model of interacting ecosystem processes that control the flow of water and nutrients to streams in a temperate upland catchment.

Sources of trends in water-quality data for selected streams in Texas, 1975-89 water years

USGS Publications Warehouse

Schertz, T.L.; Wells, F.C.; Ohe, D.J.

1994-01-01

The probable source of trend patterns in nutrients and measures of oxygen in the Trinity River Basin was changes in the wastewater treatment facilities in the Dallas-Fort Worth metropolitan area. A pattern of increased concentrations of inorganic constituents in the upper Colorado River Basin resulted from emergency releases of water from the Natural Darn Lake, a salinity control structure. Trend patterns in inorganic constituents in the Rio Grande Basin were a result of increasing concentrations in the Pecos River and, to a lesser extent, the Rio Grande above the Amistad Reservoir, combined with the effects of reservoir regulation. A pattern of increasing concentrations of organic plus ammonia nitrogen and ammonia nitrogen was detected for the 1975-86 water years for stations with low concentrations (generally less than 5 milligrams per liter) of these nitrogen species. The trends were no longer evident when the period of trend analysis was extended to the 1989 water year. A positive bias in the data caused by the addition of mercuric chloride tablets to preserve nutrient samples during 1980-86 was the probable source of this trend pattern. A pattern of increasing concentrations in dissolved sulfate in the eastern part of the State was a result of a positive bias in the analytical results of a turbidimetric method of sulfate analysis. The source of a statewide pattern of increased pH in streams could not be identified.

Land use and nutrient concentrations and yields in selected streams in the Albemarle-Pamlico drainage basin, North Carolina and Virginia

USGS Publications Warehouse

Woodside, M.D.; Simerl, B.R.

1995-01-01

Because nutrients can cause water-quaiity degradation, a major focus of NAWQA is to investigate effects of nutrients on surface- and ground-water quality. This report summarizes surface-water quality study design and land uses in the NAWQA Albemarle-Pamlico Drainage Basin study unit, one of 60 study units nationwide, and shows how nutrient concentrations are related to land uses at selected basins in the study unit. The study area encompasses about 28,000 square miles (mi2) in central and eastern North Carolina and southern Virginia. The major river basins in the Albemarle-Pamlico Drainage Basin are the Chowan, Roanoke, Tar, and Neuse. The barrier islands, estuaries, and the AlbemarIe, Pamlico, and associated sounds are not included in the study-unit area. The Albemarle-Pamlico Drainage Basin covers four physiographic provinces:Valley and Ridge, Blue Ridge, Piedmont, and Coastal Plain. About 50 percent of the land in the study areais forested, 30 percent is cropland, 15 percent is wetland, and 5 percent is developed. The population--of the study unit is about 3 million people.

Periphyton response to increased light and salmon carcass introduction in northern California streams

USGS Publications Warehouse

Ambrose, H.E.; Wilzbach, M.A.; Cummins, K.W.

2004-01-01

Periphyton response to riparian canopy opening and salmon carcass addition in coastal streams of northern California was evaluated in a manipulative field experiment. The experiment followed a split-plot design, with streams as whole plots and two 100-m reaches in each of 6 streams as subplots. At the subplot level, riparian hardwoods were removed from one reach in each stream. At the whole-plot level, carcasses were added to both open- and closed-canopy reaches of 3 of the streams. Thus, treatments consisted of reaches with open or closed canopies, in the presence and absence of carcasses. Nutrient limitation of the periphyton was assessed in 2 streams (1 with carcasses and 1 without carcasses) using nutrient-diffusing clay saucers (N-enriched, P-enriched, N+P-enriched, or unenriched control) incubated in open- and closed-canopy reaches in the streams. Canopy and carcass treatments did not affect gross primary productivity or periphyton biomass on natural substrates. The periphyton assemblage consisted primarily of diatoms in all reaches on all dates. N amendment of agar in nutrient-diffusing, clay saucers and canopy removal increased biofilm ash-free dry mass on the saucers, but carcass introduction did not. Failure of periphyton to respond to carcass addition may have reflected overriding light limitation, inadequate within-stream retention of carcass nutrients, and/or limitations of the study design.

Effects of Urbanization on Stream Water Quality in the City of Atlanta, Georgia, USA

NASA Astrophysics Data System (ADS)

Peters, N. E.

2009-05-01

A long-term stream water-quality monitoring network was established in the City of Atlanta (COA) during 2003 to assess baseline water-quality conditions and the effects of urbanization on stream water quality. Routine hydrologically-based manual stream sampling, including several concurrent manual point and equal width increment sampling, was conducted approximately 12 times per year at 21 stations, with drainage areas ranging from 3.7 to 232 km2. Eleven of the stations are real-time (RT) water-quality stations having continuous measures of stream stage/discharge, pH, dissolved oxygen, specific conductance, water temperature, and turbidity, and automatic samplers for stormwater collection. Samples were analyzed for field parameters, and a broad suite of water-quality and sediment-related constituents. This paper summarizes an evaluation of field parameters and concentrations of major ions, minor and trace metals, nutrient species (nitrogen and phosphorus), and coliform bacteria among stations and with respect to watershed characteristics and plausible sources from 2003 through September 2007. The concentrations of most constituents in the COA streams are statistically higher than those of two nearby reference streams. Concentrations are statistically different among stations for several constituents, despite high variability both within and among stations. The combination of routine manual sampling, automatic sampling during stormflows, and real-time water-quality monitoring provided sufficient information about the variability of urban stream water quality to develop hypotheses for causes of water-quality differences among COA streams. Fecal coliform bacteria concentrations of most individual samples at each station exceeded Georgia's water-quality standard for any water-usage class. High chloride concentrations occur at three stations and are hypothesized to be associated with discharges of chlorinated combined sewer overflows, drainage of swimming pool(s), and dissolution and transport during rainstorms of CaCl2, a deicing salt applied to roads during winter storms. Water quality of one stream was highly affected by the dissolution and transport of ammonium alum [NH4Al(SO4)2] from an alum manufacturing plant in the watershed; streamwater has low pH (<5), low alkalinity and high concentrations of minor and trace metals. Several trace metals (Cu, Pb and Zn) exceed acute and chronic water-quality standards and the high concentrations are attributed to washoff from impervious surfaces.

Simulation of stream discharge and transport of nitrate and selected herbicides in the Mississippi River Basin

NASA Astrophysics Data System (ADS)

Broshears, Robert E.; Clark, Gregory M.; Jobson, Harvey E.

2001-05-01

Stream discharge and the transport of nitrate, atrazine, and metolachlor in the Mississippi River Basin were simulated using the DAFLOW/BLTM hydrologic model. The simulated domain for stream discharge included river reaches downstream from the following stations in the National Stream Quality Accounting Network: Mississippi River at Clinton, IA; Missouri River at Hermann, MO; Ohio River at Grand Chain, IL; and Arkansas River at Little Rock, AR. Coefficients of hydraulic geometry were calibrated using data from water year 1996; the model was validated by favourable simulation of observed discharges in water years 1992-1994. The transport of nitrate, atrazine, and metolachlor was simulated downstream from the Mississippi River at Thebes, IL, and the Ohio River at Grand Chain. Simulated concentrations compared favourably with observed concentrations at Baton Rouge, LA. Development of this model is a preliminary step in gaining a more quantitative understanding of the sources and fate of nutrients and pesticides delivered from the Mississippi River Basin to the Gulf of Mexico. Published in 2001 by John Wiley & Sons, Ltd.

Vulnerability of streams to legacy nitrate sources

USGS Publications Warehouse

Tesoriero, Anthony J.; Duff, John H.; Saad, David A.; Spahr, Norman E.; Wolock, David M.

2013-01-01

The influence of hydrogeologic setting on the susceptibility of streams to legacy nitrate was examined at seven study sites having a wide range of base flow index (BFI) values. BFI is the ratio of base flow to total streamflow volume. The portion of annual stream nitrate loads from base flow was strongly correlated with BFI. Furthermore, dissolved oxygen concentrations in streambed pore water were significantly higher in high BFI watersheds than in low BFI watersheds suggesting that geochemical conditions favor nitrate transport through the bed when BFI is high. Results from a groundwater-surface water interaction study at a high BFI watershed indicate that decades old nitrate-laden water is discharging to this stream. These findings indicate that high nitrate levels in this stream may be sustained for decades to come regardless of current practices. It is hypothesized that a first approximation of stream vulnerability to legacy nutrients may be made by geospatial analysis of watersheds with high nitrogen inputs and a strong connection to groundwater (e.g., high BFI).

Nutrient mass balance and trends, Mobile River Basin, Alabama, Georgia, and Mississippi

USGS Publications Warehouse

Harned, D.A.; Atkins, J.B.; Harvill, J.S.

2004-01-01

A nutrient mass balance - accounting for nutrient inputs from atmospheric deposition, fertilizer, crop nitrogen fixation, and point source effluents; and nutrient outputs, including crop harvest and storage - was calculated for 18 subbasins in the Mobile River Basin, and trends (1970 to 1997) were evaluated as part of the U.S. Geological Survey National Water Quality Assessment (NAWQA) Program. Agricultural nonpoint nitrogen and phosphorus sources and urban nonpoint nitrogen sources are the most important factors associated with nutrients in this system. More than 30 percent of nitrogen yield in two basins and phosphorus yield in eight basins can be attributed to urban point source nutrient inputs. The total nitrogen yield (1.3 tons per square mile per year) for the Tombigbee River, which drains a greater percentage of agricultural (row crop) land use, was larger than the total nitrogen yield (0.99 tons per square mile per year) for the Alabama River. Decreasing trends of total nitrogen concentrations in the Tombigbee and Alabama Rivers indicate that a reduction occurred from 1975 to 1997 in the nitrogen contributions to Mobile Bay from the Mobile River. Nitrogen concentrations also decreased (1980 to 1995) in the Black Warrior River, one of the major tributaries to the Tombigbee River. Total phosphorus concentrations increased from 1970 to 1996 at three urban influenced sites on the Etowah River in Georgia. Multiple regression analysis indicates a distinct association between water quality in the streams of the Mobile River drainage basin and agricultural activities in the basin.

Contributions of Phosphorus from Groundwater to Streams in the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces, Eastern United States

USGS Publications Warehouse

Denver, Judith M.; Cravotta,, Charles A.; Ator, Scott W.; Lindsey, Bruce D.

2011-01-01

Phosphorus from natural and human sources is likely to be discharged from groundwater to streams in certain geochemical environments. Water-quality data collected from 1991 through 2007 in paired networks of groundwater and streams in different hydrogeologic and land-use settings of the Piedmont, Blue Ridge, and Valley and Ridge Physiographic Provinces in the eastern United States were compiled and analyzed to evaluate the sources, fate, and transport of phosphorus. The median concentrations of phosphate in groundwater from the crystalline and siliciclastic bedrock settings (0.017 and 0.020 milligrams per liter, respectively) generally were greater than the median for the carbonate setting (less than 0.01 milligrams per liter). In contrast, the median concentrations of dissolved phosphate in stream base flow from the crystalline and siliciclastic bedrock settings (0.010 and 0.014 milligrams per liter, respectively) were less than the median concentration for base-flow samples from the carbonate setting (0.020 milligrams per liter). Concentrations of phosphorus in many of the stream base-flow and groundwater samples exceeded ecological criteria for streams in the region. Mineral dissolution was identified as the dominant source of phosphorus in the groundwater and stream base flow draining crystalline or siliciclastic bedrock in the study area. Low concentrations of dissolved phosphorus in groundwater from carbonate bedrock result from the precipitation of minerals and (or) from sorption to mineral surfaces along groundwater flow paths. Phosphorus concentrations are commonly elevated in stream base flow in areas underlain by carbonate bedrock, however, presumably derived from in-stream sources or from upland anthropogenic sources and transported along short, shallow groundwater flow paths. Dissolved phosphate concentrations in groundwater were correlated positively with concentrations of silica and sodium, and negatively with alkalinity and concentrations of calcium, magnesium, chloride, nitrate, sulfate, iron, and aluminum. These associations can result from the dissolution of alkali feldspars containing phosphorus; the precipitation of apatite; the precipitation of calcite, iron hydroxide, and aluminum hydroxide with associated sorption of phosphate ions; and the potential for release of phosphate from iron-hydroxide and other iron minerals under reducing conditions. Anthropogenic sources of phosphate such as fertilizer and manure and processes such as biological uptake, evapotranspiration, and dilution also affect phosphorus concentrations. The phosphate concentrations in surface water were not correlated with the silica concentration, but were positively correlated with concentrations of major cations and anions, including chloride and nitrate, which could indicate anthropogenic sources and effects of evapotranspiration on surface-water quality. Mixing of older, mineralized groundwater with younger, less mineralized, but contaminated groundwater was identified as a critical factor affecting the quality of stream base flow. In-stream processing of nutrients by biological processes also likely increases the phosphorus concentration in surface waters. Potential geologic contributions of phosphorus to groundwater and streams may be an important watershed-management consideration in certain hydrogeologic and geochemical environments. Geochemical controls effectively limit phosphorus transport through groundwater to streams in areas underlain by carbonate rocks; however, in crystalline and siliciclastic settings, phosphorus from mineral or human sources may be effectively transported by groundwater and contribute a substantial fraction to base-flow stream loads.

Predicting nitrate discharge dynamics in mesoscale catchments using the lumped StreamGEM model and Bayesian parameter inference

NASA Astrophysics Data System (ADS)

Woodward, Simon James Roy; Wöhling, Thomas; Rode, Michael; Stenger, Roland

2017-09-01

The common practice of infrequent (e.g., monthly) stream water quality sampling for state of the environment monitoring may, when combined with high resolution stream flow data, provide sufficient information to accurately characterise the dominant nutrient transfer pathways and predict annual catchment yields. In the proposed approach, we use the spatially lumped catchment model StreamGEM to predict daily stream flow and nitrate concentration (mg L-1 NO3-N) in four contrasting mesoscale headwater catchments based on four years of daily rainfall, potential evapotranspiration, and stream flow measurements, and monthly or daily nitrate concentrations. Posterior model parameter distributions were estimated using the Markov Chain Monte Carlo sampling code DREAMZS and a log-likelihood function assuming heteroscedastic, t-distributed residuals. Despite high uncertainty in some model parameters, the flow and nitrate calibration data was well reproduced across all catchments (Nash-Sutcliffe efficiency against Log transformed data, NSL, in the range 0.62-0.83 for daily flow and 0.17-0.88 for nitrate concentration). The slight increase in the size of the residuals for a separate validation period was considered acceptable (NSL in the range 0.60-0.89 for daily flow and 0.10-0.74 for nitrate concentration, excluding one data set with limited validation data). Proportions of flow and nitrate discharge attributed to near-surface, fast seasonal groundwater and slow deeper groundwater were consistent with expectations based on catchment geology. The results for the Weida Stream in Thuringia, Germany, using monthly as opposed to daily nitrate data were, for all intents and purposes, identical, suggesting that four years of monthly nitrate sampling provides sufficient information for calibration of the StreamGEM model and prediction of catchment dynamics. This study highlights the remarkable effectiveness of process based, spatially lumped modelling with commonly available monthly stream sample data, to elucidate high resolution catchment function, when appropriate calibration methods are used that correctly handle the inherent uncertainties.

Seasonal Progression and Interannual Variability of Nutrient and Chlorophyll-a Distributions in the Northern Gulf of Alaska, 1998-2010

NASA Astrophysics Data System (ADS)

Trahanovsky, K.; Whitledge, T. E.

2016-02-01

We examined nutrient and chlorophyll-a (chl) concentrations from bottle samples collected from 0-50 m depth in the Northern Gulf of Alaska along the Seward Line transect on 56 cruises from 1998-2010. We computed monthly average concentrations of macronutrients (N, P, and Si) and chlorophyll-a by depth at four major stations along the transect to describe the regular seasonal progression of the nutricline and typical water column distributions of chlorophyll-a in this seasonally productive, downwelling coastal zone. The across-shelf transect displayed two different patterns of seasonal progression clearly associated with the Alaska Coastal Current (ACC) and Alaskan Stream (AS) current systems. The annual cycle of nutrient drawdown and replenishment is remarkably consistent from year to year within each system and is well correlated with chl measurements. The spring bloom begins earlier and nutrient depletion is sustained longer in the near-shore ACC then in the AS system centered over the shelf break. Chlorophyll-a concentrations frequently peak at 10-20m depth in both systems during July through October, as nutrients remain depleted in the top 10m. Subsurface nutrients (20 - 50 m depth) begin to recover between July and August and then experience a secondary drawdown between August and October, consistent with higher chl levels observed during the fall bloom. Interannual variability in the progression of the nutricline and the relative contribution of subsurface chl to total chl is presented. Physical data demonstrate increasing stratification in this region due to climate change; the implications for nutrient dynamics and primary production are discussed.

Comparison of stream nutrient conditions in a subtropical lowland watershed to EPA suggested criteria

Treesearch

April Mason; Y. Jun Xu; Johnny M. Grace

2007-01-01

Nutrients such as nitrogen, phosphorus and organic carbon are essential to the health and diversity of stream ecosystems. However, excess nutrients can cause eutrophication, resulting in overgrowth of aquatic plants and decline of the ecosystem diversity. A paired-watershed study was initiated in a subtropical forested watershed within the Ouachita River Basin in...

Does diet influence consumer nutrient cycling? Macroinvertebrate and fish excretion in streams

Treesearch

Ryan McManamay; Jackson Webster; H. Valett; C. Dolloff

2011-01-01

Consumer nutrient cycling supplies limiting elements to autotrophic and heterotrophic organisms in aquatic systems. However, the role of consumers in supplying nutrients may change depending on their diet and their own stoichiometry. We evaluated the stoichiometry, N and P excretion, and diets of the dominant macroinvertebrates and fish at 6 stream sites to determine...

Water uptake and nutrient concentrations under a floodplain oak savanna during a non-flood period, lower Cedar River, Iowa

USGS Publications Warehouse

Schilling, K.E.; Jacobson, P.

2009-01-01

Floodplains during non-flood periods are less well documented than when flooding occurs, but non-flood periods offer opportunities to investigate vegetation controls on water and nutrient cycling. In this study, we characterized water uptake and nutrient concentration patterns from 2005 to 2007 under an oak savanna located on the floodplain of the Cedar River in Muscatine County, Iowa. The water table ranged from 0.5 to 2.5 m below ground surface and fluctuated in response to stream stage, plant water demand and rainfall inputs. Applying the White method to diurnal water table fluctuations, daily ET from groundwater averaged more than 3.5 mm/day in June and July and approximately 2 mm/day in May and August. Total annual ET averaged 404 mm for a growing season from mid-May to mid-October. Savanna groundwater concentrations of nitrate-N, ammonium-N, and phosphate-P were very low (mean <0.18, <0.14, <0.08 mg/l, respectively), whereas DOC concentrations were high (7.1 mg/l). Low concentrations of N and P were in contrast to high nutrient concentrations in the nearby Cedar River, where N and P averaged 7.5 mg/ l and 0.13, respectively. In regions dominated by intensive agriculture, study results document valuable ecosystem services for native floodplain ecosystems in reducing watershed-scale nutrient losses and providing an oasis for biological complexity. Improved understanding of the environmental conditions of regionally significant habitats, including major controls on water table elevations and water quality, offers promise for better management aimed at preserving the ecology of these important habitats. Copyright ?? 2009 John Wiley & Sons, Ltd.

Interaction of Substrate and Nutrient Availability on wood Biofilm Processes in Streams

Treesearch

Jennifer L. Tank; J.R. Webster

1998-01-01

We examined the effect of decomposing leaf litter and dissolved inorganic nutrients on the heterotrophic biofilm of submerged wood in streams with and without leaves. Leaf litter was excluded from one headwater stream in August 1993 at Coweeta Hydrologic Laboratory in the southern Appalachian Mountains. We compared microbial processes on wood in the litter-excluded...

Reality check of socio-hydrological interactions in water quality and ecosystem management

NASA Astrophysics Data System (ADS)

Destouni, Georgia; Fischer, Ida; Prieto, Carmen

2017-04-01

Socio-hydrological interactions in water management for improving water quality and ecosystem status include as key components both (i) the societal measures taken for mitigation and control, and (ii) the societal characterization and monitoring efforts made for choosing management targets and checking the effects of measures taken to reach the targets. This study investigates such monitoring, characterization and management efforts and effects over the first six-year management cycle of the EU Water Framework Directive (WFD). The investigation uses Sweden and the WFD-regulated management of its stream and lake waters as a concrete quantification example, with focus on the nutrient and eutrophication conditions that determine the most prominent water quality and ecosystem problems in need of mitigation in the Swedish waters. The case results show a relatively small available monitoring base for determination of these nutrient and eutrophication conditions, even though they constitute key parts in the overall WFD-based approach to classification and management of ecosystem status. Specifically, actual nutrient monitoring exists in only around 1% (down to 0.2% for nutrient loads) of the Swedish stream and lake water bodies; modeling is used to fill the gaps for the remaining unmonitored fraction of classified and managed waters. The available data show that the hydro-climatically driven stream water discharge is a primary explanatory variable for the resulting societal classification of ecosystem status in Swedish waters; this may be due to the discharge magnitude being dominant in determining nutrient loading to these waters. At any rate, with such a hydro-climatically related, rather than human-pressure related, determinant of the societal ecosystem-status classification, the main human-driven causes and effects of eutrophication may not be appropriately identified, and the measures taken for mitigating these may not be well chosen. The available monitoring data from Swedish waters support this hypothesis, by showing that the first WFD management cycle 2009-2015 has led to only slight changes in measured nutrient concentrations, with moderate-to-bad status waters mostly undergoing concentration increases. These management results are in direct contrast to the WFD management goals that ecosystem status in all member-state waters must be improved to at least good level, and in any case not be allowed to further deteriorate. In general, the present results show that societal approaches to ecosystem status classification, monitoring and improvement may need a focus shift for improved identification and quantification of the human-driven components of nutrient inputs, concentrations and loads in water environments. Dominant hydro-climatic change drivers and effects must of course also be understood and accounted for. However, adaptation to hydro-climatic changes should be additional to and aligned with, rather than instead of, necessary mitigation of human-driven eutrophication. The present case results call for further science-based testing and evidence of societal water quality and ecosystem management actually targeting and following up the potential achievement of such mitigation.

Nutrient and Suspended-Sediment Trends in the Missouri River Basin, 1993-2003

USGS Publications Warehouse

Sprague, Lori A.; Clark, Melanie L.; Rus, David L.; Zelt, Ronald B.; Flynn, Jennifer L.; Davis, Jerri V.

2007-01-01

Trends in streamflow and concentration of total nitrogen, nitrite plus nitrate, ammonia, total phosphorus, orthophosphorus, and suspended sediment were determined for the period from 1993 to 2003 at selected stream sites in the Missouri River Basin. Flow-adjusted trends in concentration (the trends that would have occurred in the absence of natural changes in streamflow) and non-flow-adjusted trends in concentration (the overall trends resulting from natural and human factors) were determined. In the analysis of flow-adjusted trends, the removal of streamflow as a variable affecting concentration allowed trends caused by other factors such as implementation of best management practices to be identified. In the analysis of non-flow-adjusted trends, the inclusion of any and all factors affecting concentration allowed trends affecting aquatic ecosystems and the status of streams relative to water-quality standards to be identified. Relations between the flow-adjusted and non-flow-adjusted trends and changes in streamflow, nutrient sources, ground-water inputs, and implementation of management practices also were examined to determine the major factors affecting the trends. From 1993 to 2003, widespread downward trends in streamflow indicated that drought conditions from about 2000 to 2003 led to decreasing streamflow throughout much of the Missouri River Basin. Flow-adjusted trends in nitrite plus nitrate and ammonia concentrations were split nearly equally between nonsignificant and downward; at about one-half of the sites, management practices likely were contributing to measurable decreases in concentrations of nitrite plus nitrate and ammonia. Management practices had less of an effect on concentrations of total nitrogen; downward flow-adjusted trends in total nitrogen concentrations occurred at only 2 of 19 sites. The pattern of non-flow-adjusted trends in nitrite plus nitrate concentrations was similar to the pattern of flow-adjusted trends; non-flow-adjusted trends were split nearly equally between nonsignificant and downward. A substantial source of nitrite plus nitrate to these streams likely was ground water; because of the time required for ground water to travel to streams, there may have been a lag time between the implementation of some pollution-control strategies and improvement in stream quality, contributing to the nonsignificant trends in nitrite plus nitrate. There were more sites with downward non-flow-adjusted trends than flow-adjusted trends in both ammonia and total nitrogen concentrations, possibly a result of decreased surface runoff from nonpoint sources associated with the downward trends in streamflow. No strong relations between any of the nitrogen trends and changes in nutrient sources or landscape characteristics were identified. Although there were very few upward trends in nitrogen from 1993 to 2003, there were upward flow-adjusted trends in total phosphorus concentrations at nearly one-half of the sites. At these sites, not only were pollution-control strategies not contributing to measurable decreases in total phosphorus concentrations, there was likely an increase in phosphorus loading on the land surface. There were fewer upward non-flow-adjusted than flow-adjusted trends in total phosphorus concentrations; at the majority of sites, overall total phosphorus concentrations did not change significantly during this period. The preponderance of upward flow-adjusted trends and nonsignificant non-flow-adjusted trends indicates that in some areas of the Missouri River Basin, overall concentrations of total phosphorus would have been higher without the decrease in streamflow and the associated decrease in surface runoff during the study period. During the study period, phosphorus loads from fertilizer generally increased at over one-half of the sites in the basin. Upward flow-adjusted trends were related to increasing fertilizer use in the upstream drainage area, particularly in the 10 percent

The Effect of Restored and Native Oxbows on Hydraulic Loads ...

EPA Pesticide Factsheets

The use of oxbow wetlands has been identified as a potential strategy to reduce nutrient transport from agricultural drainage tiles to streams in Iowa. In 2013 and 2014, a study was conducted in north central Iowa in a native oxbow in the Lyons Creek watershed and two reconstructed oxbows in the Prairie Creek watershed (Smeltzer west and Smeltzer east) to assess their effectiveness at reducing nitrogen and phosphorus loads. The tile line inlets carrying agricultural runoff to the oxbows, the outfall from the oxbows and the surface waters in the streams receiving the outfall water were monitored for discharge and nutrients from February 2013 to September 2015. Smeltzer west and east also had four monitoring wells each, two in the upland and two between the oxbow and Prairie Creek to monitor surface water groundwater interaction. The Smeltzer west and east oxbow sites also were instrumented to continuously measure the nitrate concentration. Rainfall was measured at one Lyons Creek and one Smeltzer site. Daily mean nitrate-N concentrations in Lyons Creek in 2013 ranged from 41 mg/L to 11.8 mg/L, the median daily mean nitrate-N concentration was 33 mg/L. Daily mean nitrate-N concentrations in Prairie Creek in 2013 ranged from 15.0 mg/L to 32 mg/L in June. The median daily mean nitrate-N concentration for the sampled period was 11.2 mg/L. In 2014, daily mean nitrate-N concentrations in Prairie Creek ranged from 0.17 mg/L to 26.7 mg/L in July; the daily mean

Surface-water nutrient conditions and sources in the United States Pacific Northwest

USGS Publications Warehouse

Wise, D.R.; Johnson, H.M.

2011-01-01

The SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was used to perform an assessment of surface-water nutrient conditions and to identify important nutrient sources in watersheds of the Pacific Northwest region of the United States (U.S.) for the year 2002. Our models included variables representing nutrient sources as well as landscape characteristics that affect nutrient delivery to streams. Annual nutrient yields were higher in watersheds on the wetter, west side of the Cascade Range compared to watersheds on the drier, east side. High nutrient enrichment (relative to the U.S. Environmental Protection Agency's recommended nutrient criteria) was estimated in watersheds throughout the region. Forest land was generally the largest source of total nitrogen stream load and geologic material was generally the largest source of total phosphorus stream load generated within the 12,039 modeled watersheds. These results reflected the prevalence of these two natural sources and the low input from other nutrient sources across the region. However, the combined input from agriculture, point sources, and developed land, rather than natural nutrient sources, was responsible for most of the nutrient load discharged from many of the largest watersheds. Our results provided an understanding of the regional patterns in surface-water nutrient conditions and should be useful to environmental managers in future water-quality planning efforts.

The contribution of volunteer-based monitoring data to the assessment of harmful phytoplankton blooms in Brazilian urban streams.

PubMed

Cunha, Davi Gasparini Fernandes; Casali, Simone Pereira; de Falco, Patrícia Bortoletto; Thornhill, Ian; Loiselle, Steven Arthur

2017-04-15

Urban streams are vulnerable to a range of impacts, leading to the impairment of ecosystem services. However, studies on phytoplankton growth in tropical lotic systems are still limited. Citizen science approaches use trained volunteers to collect environmental data. We combined data on urban streams collected by volunteers with data obtained by professional scientists to identify potential drivers of phytoplankton community and determine thresholds for Cyanobacteria development. We combined datasets (n=117) on water quality and environmental observations in 64 Brazilian urban streams with paired data on phytoplankton. Sampling activities encompassed dry (July 2013 and July 2015) and warm (February and November 2014) seasons. Volunteers quantified phosphate (PO 4 3- ), nitrate (NO 3 - ) and turbidity in each stream using colorimetric and optical methods and recorded environmental conditions in the immediate surroundings of the sites through visual observations. We used non-parametric statistics to identify correlations among nutrients, turbidity and phytoplankton. We also looked for thresholds with respect to high Cyanobacteria abundance (>50,000cells/mL). The streams were characterized by relatively high nutrient concentrations (PO 4 3- : 0.11mg/L; NO 3 - : 2.6mg/L) and turbidity (49 NTU). Phytoplankton densities reached 189,000cells/mL, mainly potentially toxic Cyanobacteria species. Moderate but significant (p<0.05) correlations were observed between phytoplankton density and turbidity (ρ=0.338, Spearman) and PO 4 3- (ρ=0.292), but not with NO 3 - . Other important variables (river flow, temperature and light) were not assessed. Volunteers' observations covaried with phytoplankton density (p<0.05, Kruskal-Wallis), positively with increasing number of pollution sources and negatively with presence of vegetation in the riparian zone. Our results indicate that thresholds for PO 4 3- (0.11mg/L) can be used to separate systems with high Cyanobacteria density. The number of pollution sources provided a good indicator of waterbodies with potential cyanobacteria problems. Our findings reinforced the need for nutrient abatement and restoration of local streams and highlighted the benefits of volunteer-based monitoring to support decision-making. Copyright © 2017 Elsevier B.V. All rights reserved.

Plan of study to determine the effect of changes in herbicide use on herbicide concentrations in Midwestern streams, 1989-94

USGS Publications Warehouse

Goolsby, Donald A.; Boyer, Laurie L.; Battaglin, William A.

1994-01-01

An approach was developed to determine if recent changes in the use of herbicides has affected herbicide concentrations in Midwestern streams. This approach also provides a plan to determine if the abnormally high rainfall and flooding in 1993 has an effect on nitrate concentrations in 1994 in streams that flooded in 1993. The approach involves sampling 53 stream sites, 50 of which were sampled in 1989 and 1990 as part of a reconnaissance to determine the geographic and seasonal distribution of herbicides in 10 Midwestern States. Sites will be sampled twice, once prior to application of herbicides, in March or early April, and once during the first runoff event after application of herbicides. Samples will be analyzed for 11 herbicide and 2 atrazine metabolites by gas chromatography/mass spectrometry. Samples will also be analyzed for ESA (an alachlor metabolite), two cyanazine metabolites, and nutrients. Changes to the manufacturers' label have decreased the maximum recommended application rate for atrazine on com and sorghum by about 50 percent since the 1989-90 study. Conversely, the use of other herbicides, such as cyanazine, has increased by more than 25 percent since 1989. Statistical procedures such as Wilcoxon signed rank tests for paired samples will be used to determine if the distributions of herbicide and nitrate concentrations in 1994 are different from those measured in 1989 and 1990.

Evaluation of nutrient retention in vegetated filter strips using the SWAT model.

PubMed

Elçi, Alper

2017-11-01

Nutrient fluxes in stream basins need to be controlled to achieve good water quality status. In stream basins with intensive agricultural activities, nutrients predominantly come from diffuse sources. Therefore, best management practices (BMPs) are increasingly implemented to reduce nutrient input to streams. The objective of this study is to evaluate the impact of vegetated filter strip (VFS) application as an agricultural BMP. For this purpose, SWAT is chosen, a semi-distributed water quality assessment model that works at the watershed scale, and applied on the Nif stream basin, a small-sized basin in Western Turkey. The model is calibrated with an automated procedure against measured monthly discharge data. Nutrient loads for each sub-basin are estimated considering basin-wide data on chemical fertilizer and manure usage, population data for septic tank effluents and information about the land cover. Nutrient loads for 19 sub-basins are predicted on an annual basis. Average total nitrogen and total phosphorus loads are estimated as 47.85 t/yr and 13.36 t/yr for the entire basin. Results show that VFS application in one sub-basin offers limited retention of nutrients and that a selection of 20-m filter width is most effective from a cost-benefit perspective.

Experimental nutrient additions accelerate terrestrial carbon loss from stream ecosystems

Treesearch

Amy D. Rosemond; Jonathan P. Benstead; Phillip M. Bumpers; Vladislav Gulis; John S. Kominoski; David W.P. Manning; Keller Suberkropp; J. Bruce Wallace

2015-01-01

Nutrient pollution of freshwater ecosystems results in predictable increases in carbon (C) sequestration by algae. Tests of nutrient enrichment on the fates of terrestrial organic C, which supports riverine food webs and is a source of CO2, are lacking. Using whole-stream nitrogen (N) and phosphorus (P) additions spanning the equivalent of 27 years, we found that...

Sea lamprey carcasses exert local and variable food web effects in a nutrient-limited Atlantic coastal stream

USGS Publications Warehouse

Weaver, Daniel M.; Coghlan, Stephen M.; Zydlewski, Joseph D.

2016-01-01

Resource flows from adjacent ecosystems are critical in maintaining structure and function of freshwater food webs. Migrating sea lamprey (Petromyzon marinus) deliver a pulsed marine-derived nutrient subsidy to rivers in spring when the metabolic demand of producers and consumers are increasing. However, the spatial and temporal dynamics of these nutrient subsidies are not well characterized. We used sea lamprey carcass additions in a small stream to examine changes in nutrients, primary productivity, and nutrient assimilation among consumers. Algal biomass increased 57%–71% immediately adjacent to carcasses; however, broader spatial changes from multiple-site carcass addition may have been influenced by canopy cover. We detected assimilation of nutrients (via δ13C and δ15N) among several macroinvertebrate families including Heptageniidae, Hydropsychidae, and Perlidae. Our research suggests that subsidies may evoke localized patch-scale effects on food webs, and the pathways of assimilation in streams are likely coupled to adjacent terrestrial systems. This research underscores the importance of connectivity in streams, which may influence sea lamprey spawning and elicit varying food web responses from carcass subsidies due to fine-scale habitat variables.

Techniques of fisheries management: water quality assessment with stream insects

Treesearch

A. Dennis Lemly

2000-01-01

Nutrient enrichment of streams is a long-standing problem that continues to have substantial local and regional consequences. For example, water quality of streams in the southern Appalachian Mountains of the U.S. can be seriously degraded by organic nutrients leached from animal wastes if cattle or other livestock are allowed to graze in the riparian zone. Local...

Impact of wildfire on stream nutrient chemistry and ecosystem metabolism in boreal forest catchments of interior Alaska

Treesearch

Emma F. Betts; Jeremy B. Jones

2009-01-01

With climatic warming, wildfire occurrence is increasing in the boreal forest of interior Alaska. Loss of catchment vegetation during fire can impact streams directly through altered solute and debris inputs and changed light and temperature regimes. Over longer time scales, fire can accelerate permafrost degradation, altering catchment hydrology and stream nutrient...

Nutrient uptake and community metabolism in streams draining harvested and old-growth watersheds: A preliminary assessment

Treesearch

Brian H. Hill; Frank H. McCormick

2004-01-01

The effect of timber harvesting on streams is assessed using two measures of ecosystem function: nutrient spiraling and community metabolism. This research is being conducted in streams of the southern Appalachian Mountains of North Carolina, the Ouachita Mountains of Arkansas, the Cascade Mountains of Oregon, and the redwood forests of northern California, in order to...

Quantifying and Predicting Three-Dimensional Heterogeneity in Transient Storage Using Roving Profiling

NASA Astrophysics Data System (ADS)

Kaplan, D. A.; Reaver, N.; Hensley, R. T.; Cohen, M. J.

2017-12-01

Hydraulic transport is an important component of nutrient spiraling in streams. Quantifying conservative solute transport is a prerequisite for understanding the cycling and fate of reactive solutes, such as nutrients. Numerous studies have modeled solute transport within streams using the one-dimensional advection, dispersion and storage (ADS) equation calibrated to experimental data from tracer experiments. However, there are limitations to the information about in-stream transient storage that can be derived from calibrated ADS model parameters. Transient storage (TS) in the ADS model is most often modeled as a single process, and calibrated model parameters are "lumped" values that are the best-fit representation of multiple real-world TS processes. In this study, we developed a roving profiling method to assess and predict spatial heterogeneity of in-stream TS. We performed five tracer experiments on three spring-fed rivers in Florida (USA) using Rhodamine WT. During each tracer release, stationary fluorometers were deployed to measure breakthrough curves for multiple reaches within the river. Teams of roving samplers moved along the rivers measuring tracer concentrations at various locations and depths within the reaches. A Bayesian statistical method was used to calibrate the ADS model to the stationary breakthrough curves, resulting in probability distributions for both the advective and TS zone as a function of river distance and time. Rover samples were then assigned a probability of being from either the advective or TS zone by comparing measured concentrations to the probability distributions of concentrations in the ADS advective and TS zones. A regression model was used to predict the probability of any in-stream position being located within the advective versus TS zone based on spatiotemporal predictors (time, river position, depth, and distance from bank) and eco-geomorphological feature (eddies, woody debris, benthic depressions, and aquatic vegetation). Results confirm that TS is spatially variable as a function of spatiotemporal and eco-geomorphological features. A substantial number of samples with nearly equivalent chances of being from the advective or TS zones suggests that the distinction between zones is often poorly defined.

A hydrologic network supporting spatially referenced regression modeling in the Chesapeake Bay watershed

USGS Publications Warehouse

Brakebill, J.W.; Preston, S.D.

2003-01-01

The U.S. Geological Survey has developed a methodology for statistically relating nutrient sources and land-surface characteristics to nutrient loads of streams. The methodology is referred to as SPAtially Referenced Regressions On Watershed attributes (SPARROW), and relates measured stream nutrient loads to nutrient sources using nonlinear statistical regression models. A spatially detailed digital hydrologic network of stream reaches, stream-reach characteristics such as mean streamflow, water velocity, reach length, and travel time, and their associated watersheds supports the regression models. This network serves as the primary framework for spatially referencing potential nutrient source information such as atmospheric deposition, septic systems, point-sources, land use, land cover, and agricultural sources and land-surface characteristics such as land use, land cover, average-annual precipitation and temperature, slope, and soil permeability. In the Chesapeake Bay watershed that covers parts of Delaware, Maryland, Pennsylvania, New York, Virginia, West Virginia, and Washington D.C., SPARROW was used to generate models estimating loads of total nitrogen and total phosphorus representing 1987 and 1992 land-surface conditions. The 1987 models used a hydrologic network derived from an enhanced version of the U.S. Environmental Protection Agency's digital River Reach File, and course resolution Digital Elevation Models (DEMs). A new hydrologic network was created to support the 1992 models by generating stream reaches representing surface-water pathways defined by flow direction and flow accumulation algorithms from higher resolution DEMs. On a reach-by-reach basis, stream reach characteristics essential to the modeling were transferred to the newly generated pathways or reaches from the enhanced River Reach File used to support the 1987 models. To complete the new network, watersheds for each reach were generated using the direction of surface-water flow derived from the DEMs. This network improves upon existing digital stream data by increasing the level of spatial detail and providing consistency between the reach locations and topography. The hydrologic network also aids in illustrating the spatial patterns of predicted nutrient loads and sources contributed locally to each stream, and the percentages of nutrient load that reach Chesapeake Bay.

Effects of Nitrogen Inputs and Watershed Characteristics on ...

EPA Pesticide Factsheets

Nitrogen (N) inputs to the landscape have been linked previously to N loads exported from watersheds at the national scale; however, stream N concentration is arguably more relevant than N load for drinking water quality, freshwater biological responses and establishment of nutrient criteria. In this study, we combine national-scale anthropogenic N input data, including synthetic fertilizer, crop biological N fixation, manure applied to farmland, atmospheric N deposition, and point source inputs, with data from the 2008-09 National Rivers and Streams Assessment to quantify the relationship between N inputs and in-stream concentrations of total N (TN), dissolved inorganic N (DIN), and total organic N (TON) (calculated as TN – DIN). In conjunction with simple linear regression, we use multiple regression to understand how watershed and stream reach attributes modify the effect of N inputs on N concentrations. Median TN was 0.50 mg N L-1 with a maximum of 25.8 mg N L-1. Total N inputs to the watershed ranged from less than 1 to 196 kg N ha-1 y-1, with a median of 14.4 kg N ha-1 y-1. Atmospheric N deposition was the single largest anthropogenic N source in the majority of sites, but, agricultural sources generally dominate total N inputs in sites with elevated N concentrations. The sum of all N inputs were positively correlated with concentrations of all forms of N [r2 = 0.44, 0.43, and 0.18 for TN, DIN, and TON, respectively (all log-transformed), n = 1112], indi

Water-quality and ancillary data collected from the Arroyo Colorado near Rio Hondo, Texas, 2006

USGS Publications Warehouse

Roussel, Meghan C.; Canova, Michael G.; Asquith, William H.; Kiesling, Richard L.

2007-01-01

The Arroyo Colorado is in the lower Rio Grande Valley of southern Texas and extends from near Mission, Texas, eastward to the Laguna Madre estuarine and coastal marine system, which separates Padre Island from the Texas mainland. Streamflow in the Arroyo Colorado primarily is sustained by effluent from municipal wastewater-treatment plants along the stream banks. Since 1986, the tidal segment of the Arroyo Colorado from the port of Harlingen to the Laguna Madre has been designated by the State of Texas as an impaired water body because of low dissolved oxygen concentrations. Efforts to develop predictive water-quality models for the tidal segment of the Arroyo Colorado have been hampered by a lack of physical, biological, and biochemical data. Specifically, data on primary algal productivity, nutrient cycling, sediment deposition rates, and the relations between these processes and dissolved oxygen dynamics in the stream have been inadequate to support water-quality modeling efforts. The U.S. Geological Survey, in cooperation with the Texas Commission on Environmental Quality, did a study in 2006 to collect data associated with primary algal productivity, nutrient cycling, and dissolved oxygen dynamics in the tidal segment (2201) of the Arroyo Colorado near Rio Hondo. Specific objectives of the study were to (1) characterize water quality by measuring basic properties; (2) characterize the concentrations of carbon and nutrients, biochemical oxygen demand, total organic carbon, total suspended solids, and volatile suspended solids; (3) measure the seasonal differences of nutrient-dependent algal growth and algal production in the water column; (4) measure oxygen respiration or production rates; and (5) measure rates of sediment deposition.

Periphyton dynamics in a subalpine mountain stream during winter

USGS Publications Warehouse

Gustina, G.W.; Hoffmann, J.P.

2000-01-01

We conducted two experiments to determine the activity of and factors which control periphyton during winter in Stevensville Brook, Vermont. The first experiment during winter/spring 1994 examined the effect of a 300 to 450% difference in light and doubling of flow (low and high light, slow and fast flow) on periphyton chlorophyll a (chl a) and ash-free dry mass (AFDM) from stream rocks and artificial substrata. A second experiment was performed to determine whether periphyton was nitrogen or phosphorus limited. In addition, stream water was sampled during fall/winter 1994/95 for nitrate (NO3), ammonia (NH4), soluble reactive phosphorus (SRP), and total phosphorus (TP) to determine the availability of nutrients in Stevensville Brook. Increases of up to 250% for AFDM and 600% for chl a during the first study indicated robust activity throughout the winter despite low temperatures and light. Flow had a negative effect and sampling date was found to have a significant effect on periphyton biomass (chl a and AFDM) while light was found to influence increases in AFDM on clay tiles only. Water analyses showed that SRP was less than 0.001 mg L-1, NH4 and TP were low and often undetectable, and NO3 remained at about 0.20 mg L-1. Results from the nutrient enrichment experiment showed a significant response of chl a to P but not N and no response of AFDM to enrichment with either N or P. In Stevensville Brook during winter, the algal community, as represented by the chl a concentration, is predominantly controlled by phosphorus concentrations and is influenced to a lesser extent by flow; the periphyton community as a whole, represented by AFDM, is controlled mostly by stream flow and light.

Modeling nutrient in-stream processes at the watershed scale using Nutrient Spiralling metrics

NASA Astrophysics Data System (ADS)

Marcé, R.; Armengol, J.

2009-01-01

One of the fundamental problems of using large-scale biogeochemical models is the uncertainty involved in aggregating the components of fine-scale deterministic models in watershed applications, and in extrapolating the results of field-scale measurements to larger spatial scales. Although spatial or temporal lumping may reduce the problem, information obtained during fine-scale research may not apply to lumped categories. Thus, the use of knowledge gained through fine-scale studies to predict coarse-scale phenomena is not straightforward. In this study, we used the nutrient uptake metrics defined in the Nutrient Spiralling concept to formulate the equations governing total phosphorus in-stream fate in a watershed-scale biogeochemical model. The rationale of this approach relies on the fact that the working unit for the nutrient in-stream processes of most watershed-scale models is the reach, the same unit used in field research based on the Nutrient Spiralling concept. Automatic calibration of the model using data from the study watershed confirmed that the Nutrient Spiralling formulation is a convenient simplification of the biogeochemical transformations involved in total phosphorus in-stream fate. Following calibration, the model was used as a heuristic tool in two ways. First, we compared the Nutrient Spiralling metrics obtained during calibration with results obtained during field-based research in the study watershed. The simulated and measured metrics were similar, suggesting that information collected at the reach scale during research based on the Nutrient Spiralling concept can be directly incorporated into models, without the problems associated with upscaling results from fine-scale studies. Second, we used results from our model to examine some patterns observed in several reports on Nutrient Spiralling metrics measured in impaired streams. Although these two exercises involve circular reasoning and, consequently, cannot validate any hypothesis, this is a powerful example of how models can work as heuristic tools to compare hypotheses and stimulate research in ecology.

Hyporheic zone influences on concentration-discharge relationships in a headwater sandstone stream

NASA Astrophysics Data System (ADS)

Hoagland, Beth; Russo, Tess A.; Gu, Xin; Hill, Lillian; Kaye, Jason; Forsythe, Brandon; Brantley, Susan L.

2017-06-01

Complex subsurface flow dynamics impact the storage, routing, and transport of water and solutes to streams in headwater catchments. Many of these hydrogeologic processes are indirectly reflected in observations of stream chemistry responses to rain events, also known as concentration-discharge (CQ) relations. Identifying the relative importance of subsurface flows to stream CQ relationships is often challenging in headwater environments due to spatial and temporal variability. Therefore, this study combines a diverse set of methods, including tracer injection tests, cation exchange experiments, geochemical analyses, and numerical modeling, to map groundwater-surface water interactions along a first-order, sandstone stream (Garner Run) in the Appalachian Mountains of central Pennsylvania. The primary flow paths to the stream include preferential flow through the unsaturated zone ("interflow"), flow discharging from a spring, and groundwater discharge. Garner Run stream inherits geochemical signatures from geochemical reactions occurring along each of these flow paths. In addition to end-member mixing effects on CQ, we find that the exchange of solutes, nutrients, and water between the hyporheic zone and the main stream channel is a relevant control on the chemistry of Garner Run. CQ relationships for Garner Run were compared to prior results from a nearby headwater catchment overlying shale bedrock (Shale Hills). At the sandstone site, solutes associated with organo-mineral associations in the hyporheic zone influence CQ, while CQ trends in the shale catchment are affected by preferential flow through hillslope swales. The difference in CQ trends document how the lithology and catchment hydrology control CQ relationships.

Minimal ecosystem uptake of selenium from Westland petrels, a forest-breeding seabird.

PubMed

Hawke, David J; Gamlen-Greene, Roseanna; Harding, Jon S; Leishman, Dana

2017-01-01

Endemic Westland petrels (Procellaria westlandica) are a remnant of extensive seabird populations that occupied the forested hill country of prehuman New Zealand. Because seabird guano is rich in Se, an often-deficient essential element, we proposed that Westland petrels enhance Se concentrations in ecosystems associated with their breeding grounds. We sampled terrestrial (soil, plants, riparian spiders) and freshwater (benthic invertebrates, fish) components from Westland petrel-enriched and non-seabird forests on the western coast of New Zealand's South Island, an area characterised by highly leached, nutrient-poor soils. Median seabird soil Se was an order of magnitude higher than soil from non-seabird sites (2.2mgkg -1 compared to 0.2mgkg -1 ), but corresponding plant foliage concentrations (0.06mgkg -1 ; 0.05mgkg -1 ) showed no difference between seabird and non-seabird sites. In streams, Se ranged from 0.05mgkg -1 (riparian foliage) to 3.1mgkg -1 (riparian spiders and freshwater mussels). However, there was no difference between seabird and non-seabird streams. Stoichiometric ratios (N:Se, P:Se) showed Se loss across all ecosystem components relative to seabird guano, except in seabird colony soil where N was lost preferentially. Seabirds therefore did not enrich the terrestrial plants and associated stream ecosystems in Se. We conclude that incorporation of trace elements brought ashore by seabirds cannot be assumed, even though seabirds are a significant source of marine-derived nutrients and trace elements to coastal ecosystems world-wide. Copyright © 2016 Elsevier B.V. All rights reserved.

Stream restoration and sewers impact sources and fluxes of water, carbon, and nutrients in urban watersheds

NASA Astrophysics Data System (ADS)

Pennino, Michael J.; Kaushal, Sujay S.; Mayer, Paul M.; Utz, Ryan M.; Cooper, Curtis A.

2016-08-01

An improved understanding of sources and timing of water, carbon, and nutrient fluxes associated with urban infrastructure and stream restoration is critical for guiding effective watershed management globally. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P) shift in response to differences in urban stream restoration and sewer infrastructure. We compared an urban restored stream with two urban degraded streams draining varying levels of urban development and one stream with upland stormwater management systems over a 3-year period. We found that there was significantly decreased peak discharge in response to precipitation events following stream restoration. Similarly, we found that the restored stream showed significantly lower (p < 0.05) monthly peak runoff (9.4 ± 1.0 mm day-1) compared with two urban degraded streams (ranging from 44.9 ± 4.5 to 55.4 ± 5.8 mm day-1) draining higher impervious surface cover, and the stream-draining stormwater management systems and less impervious surface cover in its watershed (13.2 ± 1.9 mm day-1). The restored stream exported most carbon, nitrogen, and phosphorus at relatively lower streamflow than the two more urban catchments, which exported most carbon and nutrients at higher streamflow. Annual exports of total carbon (6.6 ± 0.5 kg ha-1 yr-1), total nitrogen (4.5 ± 0.3 kg ha-1 yr-1), and total phosphorus (161 ± 15 kg ha-1 yr-1) were significantly lower in the restored stream compared to both urban degraded streams (p < 0.05), but statistically similar to the stream draining stormwater management systems, for N exports. However, nitrate isotope data suggested that 55 ± 1 % of the nitrate in the urban restored stream was derived from leaky sanitary sewers (during baseflow), statistically similar to the urban degraded streams. These isotopic results as well as additional tracers, including fluoride (added to drinking water) and iodide (contained in dietary salt), suggested that groundwater contamination was a major source of urban nutrient fluxes, which has been less considered compared to upland sources. Overall, leaking sewer pipes are a problem globally and our results suggest that combining stream restoration with restoration of aging sewer pipes can be critical to more effectively minimizing urban nonpoint nutrient sources. The sources, fluxes, and flowpaths of groundwater should be prioritized in management efforts to improve stream restoration by locating hydrologic hot spots where stream restoration is most likely to succeed.

Understanding the influence of nutrients on stream ecosystems in agricultural landscapes

USGS Publications Warehouse

Munn, Mark D.; Frey, Jeffrey W.; Tesoriero, Anthony J.; Black, Robert W.; Duff, John H.; Lee, Kathy E.; Maret, Terry R.; Mebane, Christopher A.; Waite, Ian R.; Zelt, Ronald B.

2018-06-06

Sustaining the quality of the Nation’s water resources and the health of our diverse ecosystems depends on the availability of sound water-resources data and information to develop effective, science-based policies. Effective management of water resources also brings more certainty and efficiency to important economic sectors. Taken together, these actions lead to immediate and long-term economic, social, and environmental benefits that make a difference to the lives of the almost 400 million people projected to live in the United States by 2050.In 1991, Congress established the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) to address where, when, why, and how the Nation’s water quality has changed, or is likely to change in the future, in response to human activities and natural factors. Since then, NAWQA has been a leading source of scientific data and knowledge used by national, regional, State, and local agencies to develop science-based policies and management strategies to improve and protect water resources used for drinking water, recreation, irrigation, energy development, and ecosystem needs (https://water.usgs.gov/nawqa/applications/). Plans for the third decade of NAWQA (2013–23) address priority water-quality issues and science needs identified by NAWQA stakeholders, such as the Advisory Committee on Water Information and the National Research Council, and are designed to meet increasing challenges related to population growth, increasing needs for clean water, and changing land-use and weather patterns.Excess nutrients are a pervasive problem of streams, lakes, and coastal waters. The current report, “The Quality of Our Nation’s Waters—Understanding the Effects of Nutrients on Stream Ecosystems in Agricultural Landscapes,” presents a summary of results from USGS investigations conducted from 2003 to 2011 on processes that influence nutrients and how nutrient enrichment can alter biological components of agricultural streams. This study included collecting data from 232 sites distributed among eight study areas. This report summarizes findings on processes that influence nutrients and how nutrient enrichment can alter biological communities in agricultural streams. These findings are relevant to local, State, regional, and national decision-makers involved in efforts to (1) better understand the influence of nutrients on agricultural streams, (2) develop nutrient criteria for streams and rivers, (3) reduce nutrients to streams and downstream receiving waters, and (4) develop tools for tracking nutrient and biological conditions following nutrient reduction strategies. All NAWQA reports are available online at https://water.usgs.gov/nawqa/bib/.We hope this publication will provide you with insights and information to meet your water-resource needs and will foster increased citizen awareness and involvement in the protection and restoration of our Nation’s waters. The information in this report is intended primarily for those interested or involved in resource management and protection, conservation, regulation, and policymaking at the regional and national levels.

Trends in the quality of water in New Jersey streams, water years 1971–2011

USGS Publications Warehouse

Hickman, R. Edward; Hirsch, Robert M.

2017-02-27

In a study conducted by the U.S. Geological Survey in cooperation with the New Jersey Department of Environmental Protection and the Delaware River Basin Commission, trend tests were conducted on selected water-quality characteristics measured at stations on streams in New Jersey during selected periods over water years 1971‒2011. Tests were conducted on 3 nutrients (total nitrogen, filtered nitrate plus nitrite, and total phosphorus) at 28 water-quality stations. At 4 of these stations, tests were also conducted on 3 measures of major ions (specific conductance, filtered chloride, and total dissolved solids).Two methods were used to identify trends—Weighted Regressions on Time, Discharge, and Season (WRTDS) models and seasonal rank-sum tests. For this report, the use of WRTDS models included the use of the WRTDS Bootstrap Test (WBT). WRTDS models identified trends in flow-normalized annual concentrations and flow-normalized annual fluxes over water years 1980‒2011 and 2000‒11 for each nutrient, filtered chloride, and total dissolved solids. WRTDS models were developed for each nutrient at the 20 or 21 stations at which streamflow was measured or estimated. Trends in nutrient concentration were reported for these stations; trends in nutrient fluxes were reported only for 15–17 of these stations.The results of WRTDS models for water years 1980‒2011 identified more stations with downward trends in concentrations of either total nitrogen or total phosphorus than upward trends. For total nitrogen, there were downward trends at 9 stations and an upward trend at 1 station. For total phosphorus, there were downward trends at 8 stations and an upward trend at 1 station. For filtered nitrate plus nitrite, there were downward trends at 6 stations and upward trends at 6 stations. The result of the trend test in flux for a selected nutrient at a selected station (downward trend, no trend, or upward trend) usually matched the trend result in concentration.Seasonal rank-sum tests, the second method used, identified step trends in water-quality measured in different decades—1970s, 1980s, 1990s, and 2000s. Tests were conducted on all nutrients at 28 stations and on all measures of major ions at the 4 selected stations. Results of seasonal rank-sum tests between the 1980s and the 2000s identified more stations with downward trends in concentrations of total nitrogen (14) than stations with upward trends (2) and more stations with downward trends in concentrations of total phosphorus (18) than stations with upward trends (1).A combined dataset of trend results for concentrations over water years 1980‒2011 was created from the results of the two tests for the period. Results of WRTDS models were included in this combined dataset, if available. Otherwise, the results of the seasonal rank-sum tests between water-quality characteristics measured in the 1980s and 2000s were included.Trend results over water years 1980‒2011 in the combined dataset show that few of the 28 stations had upward trends in concentrations of either total nitrogen or total phosphorus. There were only 2 stations with upward trends in total nitrogen concentration and 1 station with an upward trend in total phosphorus concentration. Results for filtered nitrate plus nitrite show about the same number of stations with upward trends (9) as stations with downward trends (7). Results for all measures of major ions show upward trends at the four stations tested.

A Bayesian methodological framework for accommodating interannual variability of nutrient loading with the SPARROW model

NASA Astrophysics Data System (ADS)

Wellen, Christopher; Arhonditsis, George B.; Labencki, Tanya; Boyd, Duncan

2012-10-01

Regression-type, hybrid empirical/process-based models (e.g., SPARROW, PolFlow) have assumed a prominent role in efforts to estimate the sources and transport of nutrient pollution at river basin scales. However, almost no attempts have been made to explicitly accommodate interannual nutrient loading variability in their structure, despite empirical and theoretical evidence indicating that the associated source/sink processes are quite variable at annual timescales. In this study, we present two methodological approaches to accommodate interannual variability with the Spatially Referenced Regressions on Watershed attributes (SPARROW) nonlinear regression model. The first strategy uses the SPARROW model to estimate a static baseline load and climatic variables (e.g., precipitation) to drive the interannual variability. The second approach allows the source/sink processes within the SPARROW model to vary at annual timescales using dynamic parameter estimation techniques akin to those used in dynamic linear models. Model parameterization is founded upon Bayesian inference techniques that explicitly consider calibration data and model uncertainty. Our case study is the Hamilton Harbor watershed, a mixed agricultural and urban residential area located at the western end of Lake Ontario, Canada. Our analysis suggests that dynamic parameter estimation is the more parsimonious of the two strategies tested and can offer insights into the temporal structural changes associated with watershed functioning. Consistent with empirical and theoretical work, model estimated annual in-stream attenuation rates varied inversely with annual discharge. Estimated phosphorus source areas were concentrated near the receiving water body during years of high in-stream attenuation and dispersed along the main stems of the streams during years of low attenuation, suggesting that nutrient source areas are subject to interannual variability.

Sewage pollution: genotoxicity assessment and phytoremediation of nutrients excess with Hydrocotyle ranunculoides.

PubMed

Basílico, Gabriel; Magdaleno, Anahí; Paz, Marta; Moretton, Juan; Faggi, Ana; de Cabo, Laura

2017-04-01

The discharge of sewage effluents into low-order streams has negative effects on water quality. Macrophytes can be efficient in the treatment of this wastewater due to the removal of the main pollutants. The genotoxicity of sewage-polluted water discharging into La Choza stream was evaluated by testing with Allium cepa. Also, a phytoremediation assay with continuous recirculation of the residual water was conducted for 12 days. Three treatments were carried out. One treatment (Hr) was performed with a macrophyte (Hydrocotyle ranunculoides), and two treatments were conducted without macrophytes: with lighting (Ai) and without lighting (Ao). The wastewater was toxic according to all the evaluated indexes (mitotic index, frequency of chromosomal aberrations and micronucleus). High concentrations of ammonium, dissolved inorganic nitrogen (DIN), total (TP) and soluble reactive phosphorous (SRP) and indicators of faecal contamination were determined in the wastewater. The ammonium, DIN, SRP and TP loads at the end of the assay were significantly lower in the treatments with light (Hr and Ai). So, the nutrient removal was due to their absorption and adsorption by the periphyton and H. ranunculoides. Our results lead us to recommend the maintenance and planting of macrophytes in lowland streams subject to sewage pollution.

Riparian plant litter quality increases with latitude.

PubMed

Boyero, Luz; Graça, Manuel A S; Tonin, Alan M; Pérez, Javier; J Swafford, Andrew; Ferreira, Verónica; Landeira-Dabarca, Andrea; A Alexandrou, Markos; Gessner, Mark O; McKie, Brendan G; Albariño, Ricardo J; Barmuta, Leon A; Callisto, Marcos; Chará, Julián; Chauvet, Eric; Colón-Gaud, Checo; Dudgeon, David; Encalada, Andrea C; Figueroa, Ricardo; Flecker, Alexander S; Fleituch, Tadeusz; Frainer, André; Gonçalves, José F; Helson, Julie E; Iwata, Tomoya; Mathooko, Jude; M'Erimba, Charles; Pringle, Catherine M; Ramírez, Alonso; Swan, Christopher M; Yule, Catherine M; Pearson, Richard G

2017-09-05

Plant litter represents a major basal resource in streams, where its decomposition is partly regulated by litter traits. Litter-trait variation may determine the latitudinal gradient in decomposition in streams, which is mainly microbial in the tropics and detritivore-mediated at high latitudes. However, this hypothesis remains untested, as we lack information on large-scale trait variation for riparian litter. Variation cannot easily be inferred from existing leaf-trait databases, since nutrient resorption can cause traits of litter and green leaves to diverge. Here we present the first global-scale assessment of riparian litter quality by determining latitudinal variation (spanning 107°) in litter traits (nutrient concentrations; physical and chemical defences) of 151 species from 24 regions and their relationships with environmental factors and phylogeny. We hypothesized that litter quality would increase with latitude (despite variation within regions) and traits would be correlated to produce 'syndromes' resulting from phylogeny and environmental variation. We found lower litter quality and higher nitrogen:phosphorus ratios in the tropics. Traits were linked but showed no phylogenetic signal, suggesting that syndromes were environmentally determined. Poorer litter quality and greater phosphorus limitation towards the equator may restrict detritivore-mediated decomposition, contributing to the predominance of microbial decomposers in tropical streams.

Stream-Groundwater Interaction Buffers Seasonal Changes in Urban Stream Water Quality

NASA Astrophysics Data System (ADS)

Ledford, S. H.; Lautz, L. K.

2013-12-01

Urban streams in the northeastern United States have large road salt inputs during winter, increased nonpoint sources of inorganic nitrogen, and decreased short-term and permanent storage of nutrients. Meadowbrook Creek, a first order stream in Syracuse, New York, flows along a negative urbanization gradient, from a channelized and armored stream running through the middle of a roadway to a pool-riffle stream meandering through a broad, vegetated floodplain with a riparian aquifer. In this study we investigated how reconnection to groundwater and introduction of riparian vegetation impacted surface water chemistry by making bi-weekly longitudinal surveys of stream water chemistry in the creek from May 2012 until June 2013. Chloride concentrations in the upstream, urban reach of Meadowbrook Creek were strongly influenced by discharge of road salt to the creek during snow melt events in winter and by the chemistry of water draining an upstream retention basin in summer. Chloride concentrations ranged from 161.2 mg/L in August to 2172 mg/L in February. Chloride concentrations in the downstream, 'connected' reach had less temporal variation, ranging from 252.0 mg/L in August to 1049 mg/L in January, and were buffered by groundwater discharge, as the groundwater chloride concentrations during the sampling period ranged from 84.0 to 655.4 mg/L. Groundwater discharge resulted in higher chloride concentrations in summer and lower concentrations in winter in the connected reach relative to the urban reach, minimizing annual variation. In summer, there was little-to-no nitrate in the urban reach due to a combination of limited sources and high primary productivity. In contrast, during the summer, nitrate concentrations reached over 1 mg N/L in the connected reach due to the presence of riparian vegetation and lower nitrate uptake due to cooler temperatures and shading. During the winter, when temperatures fell below freezing, nitrate concentrations in the urban reach increased to around 0.58 mg N/L, but were still lower than the connected reach, which averaged 0.88 mg N/L. Groundwater discharge rates were measured longitudinally along the creek during a constant rate Rhodamine WT injection and also confirmed qualitatively by longitudinal changes in stream sulfate and δ18O. The buffering capability of groundwater discharge in urban systems has implications for managers trying to mitigate the effects of urbanization on surface water.

Data to support statistical modeling of instream nutrient load based on watershed attributes, southeastern United States, 2002

USGS Publications Warehouse

Hoos, Anne B.; Terziotti, Silvia; McMahon, Gerard; Savvas, Katerina; Tighe, Kirsten C.; Alkons-Wolinsky, Ruth

2008-01-01

This report presents and describes the digital datasets that characterize nutrient source inputs, environmental characteristics, and instream nutrient loads for the purpose of calibrating and applying a nutrient water-quality model for the southeastern United States for 2002. The model area includes all of the river basins draining to the south Atlantic and the eastern Gulf of Mexico, as well as the Tennessee River basin (referred to collectively as the SAGT area). The water-quality model SPARROW (SPAtially-Referenced Regression On Watershed attributes), developed by the U.S. Geological Survey, uses a regression equation to describe the relation between watershed attributes (predictors) and measured instream loads (response). Watershed attributes that are considered to describe nutrient input conditions and are tested in the SPARROW model for the SAGT area as source variables include atmospheric deposition, fertilizer application to farmland, manure from livestock production, permitted wastewater discharge, and land cover. Watershed and channel attributes that are considered to affect rates of nutrient transport from land to water and are tested in the SAGT SPARROW model as nutrient-transport variables include characteristics of soil, landform, climate, reach time of travel, and reservoir hydraulic loading. Datasets with estimates of each of these attributes for each individual reach or catchment in the reach-catchment network are presented in this report, along with descriptions of methods used to produce them. Measurements of nutrient water quality at stream monitoring sites from a combination of monitoring programs were used to develop observations of the response variable - mean annual nitrogen or phosphorus load - in the SPARROW regression equation. Instream load of nitrogen and phosphorus was estimated using bias-corrected log-linear regression models using the program Fluxmaster, which provides temporally detrended estimates of long-term mean load well-suited for spatial comparisons. The detrended, or normalized, estimates of load are useful for regional-scale assessments but should be used with caution for local-scale interpretations, for which use of loads estimated for actual time periods and employing more detailed regression analysis is suggested. The mean value of the nitrogen yield estimates, normalized to 2002, for 637 stations in the SAGT area is 4.7 kilograms per hectare; the mean value of nitrogen flow-weighted mean concentration is 1.2 milligrams per liter. The mean value of the phosphorus yield estimates, normalized to 2002, for the 747 stations in the SAGT area is 0.66 kilogram per hectare; the mean value of phosphorus flow-weighted mean concentration is 0.17 milligram per liter. Nutrient conditions measured in streams affected by substantial influx or outflux of water and nutrient mass across surface-water basin divides do not reflect nutrient source and transport conditions in the topographic watershed; therefore, inclusion of such streams in the SPARROW modeling approach is considered inappropriate. River basins identified with this concern include south Florida (where surface-water flow paths have been extensively altered) and the Oklawaha, Crystal, Lower Sante Fe, Lower Suwanee, St. Marks, and Chipola River basins in central and northern Florida (where flow exchange with the underlying regional aquifer may represent substantial nitrogen influx to and outflux from the surface-water basins).

Characterization of major-ion chemistry and nutrients in headwater streams along the Appalachian National Scenic Trail and within adjacent watersheds, Maine to Georgia

USGS Publications Warehouse

Argue, Denise M.; Pope, Jason P.; Dieffenbach, Fred

2012-01-01

An inventory of water-quality data on field parameters, major ions, and nutrients provided a summary of water quality in headwater (first- and second-order) streams within watersheds along the Appalachian National Scenic Trail (Appalachian Trail). Data from 1,817 sampling sites in 831 catchments were used for the water-quality summary. Catchment delineations from NHDPlus were used as the fundamental geographic units for this project. Criteria used to evaluate sampling sites for inclusion were based on selected physical attributes of the catchments adjacent to the Appalachian Trail, including stream elevation, percentage of developed land cover, and percentage of agricultural land cover. The headwater streams of the Appalachian Trail are generally dilute waters, with low pH, low acid neutralizing capacity (ANC), and low concentrations of nutrients. The median pH value was slightly acidic at 6.7; the median specific conductance value was 23.6 microsiemens per centimeter, and the median ANC value was 98.7 milliequivalents per liter (μeq/L). Median concentrations of cations (calcium, magnesium, sodium, and potassium) were each less than 1.5 milligrams per liter (mg/L), and median concentrations of anions (bicarbonate, chloride, fluoride, sulfate, and nitrate) were less than 10 mg/L. Differences in water-quality constituent levels along the Appalachian Trail may be related to elevation, atmospheric deposition, geology, and land cover. Spatial variations were summarized by ecological sections (ecosections) developed by the U.S. Forest Service. Specific conductance, pH, ANC, and concentrations of major ions (calcium, chloride, magnesium, sodium, and sulfate) were all negatively correlated with elevation. The highest elevation ecosections (White Mountains, Blue Ridge Mountains, and Allegheny Mountains) had the lowest pH, ANC, and concentrations of major ions. The lowest elevation ecosections (Lower New England and Hudson Valley) generally had the highest pH, ANC, and concentrations of major ions. The geology in discrete portions of these two ecosections was classified as containing carbonate minerals which has likely influenced the chemical character of the streamwater. Specific conductance, pH, ANC, and concentrations of major ions (calcium, chloride, magnesium, sodium, and sulfate) were all positively correlated with percentages of developed and agricultural land uses at the lower elevations of the central region of the Appalachian Trail (including the Green-Taconic-Berkshire Mountains, Lower New England, Hudson Valley, and Northern Ridge and Valley ecosections). The distinctly different chemical character of the streams in the central sections of the Appalachian Trail is likely related to the lower elevations, the presence of carbonate minerals in the geology, higher percentages of developed and agricultural land uses, and possibly the higher inputs of sulfate and nitrate from atmospheric deposition. Acid deposition of sulfate and nitrate are important influences on the acid-base chemistry of the surface waters of the Appalachian Trail. Atmospheric deposition estimates are consistently high (more than 18 kilograms per hectare (kg/ha) for sulfate, and more than 16 kg/ha for nitrate) at both the highest and lowest elevations. However, the lowest elevation (Green-Taconic-Berkshire Mountains, Lower New England, Hudson Valley, Northern Glaciated Allegheny Plateau, and Northern Ridge and Valley ecosections) included the largest spatial area of sustained high estimates of atmospheric deposition. Calcium-bicarbonate was the most frequently calculated water type in the Lower New England and Hudson Valley ecosections. In the northern and southern sections of the Appalachian Trail mix-cation water types were most prevalent and sulfate was the predominate anion. The predominance of the sulfate anion in the surface waters of the northern and southern ecosections likely reflects the influence of sulfate deposition. Although the central portion of the Appalachian Trail has the largest spatial area of high atmospheric acid deposition, the lower ionic strength waters in the northern and southern ecosections of the Appalachian Trail may have been more adversely affected by acid deposition. The low ionic strength of the streams in the White Mountains, Blue Ridge Mountains, and Allegheny Mountains ecosections makes parts of these regions susceptible to seasonal or event-driven episodic acidification, which can be detrimental to health of aquatic and terrestrial ecosystems. Median catchment ANC values were classified into three groups - acidic, sensitive, and insensitive. The White Mountains, Blue Ridge Mountains, and Allegheny Mountains ecosections included the highest frequency of catchments classified as acidic or sensitive. More than 56 percent of the catchments from the White Mountains ecosection were classified as sensitive to acidic inputs. In the Blue Ridge ecosection, 1.6 percent of the catchments were classified as acidic, and 38.2 percent of the catchments were classified as sensitive to acidic inputs. In the Allegheny Mountains ecosection, 17.6 percent of the catchments were classified as acidic, and 29.4 percent of the catchments were classified as sensitive to acidic inputs. Median concentrations of nitrogen species were less than 0.4 mg/L, and median concentrations of total phosphorus were less than 0.02 mg/L along the Appalachian Trail. A comparison of median catchment concentrations of nutrients to estimated national background concentrations demonstrated that concentrations along the Appalachian Trail are generally lower. A comparison of median concentrations of total nitrogen and total phosphorus to the U.S. Environmental Protection Agency's (USEPA) nutrient criteria for the Eastern U.S. ecoregions showed that the concentrations of total nitrogen in the northern section of the Appalachian Trail were generally higher than the USEPA criterion. Similarly, median concentrations of total phosphorus in the southern regions of the Appalachian Trail were approximately twice as high as USEPA criteria. Sections of the Appalachian Trail are adjacent to modest amounts of agricultural and developed land areas. These nonforested land areas may be contributing to the percentage of catchments in which concentrations of total nitrogen and total phosphorus are higher than USEPA nutrient ecoregion criteria.

Review of Phosphorus Control Measures in the United States and Their Effects on Water Quality

USGS Publications Warehouse

Litke, David W.

1999-01-01

Historical information on phosphorus loadings to the environment and the effect on water quality are summarized in this report, which was produced as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. Phosphorus is a water-quality constituent of concern because it is often the limiting nutrient responsible for accelerated eutrophication in water bodies. Phosphorus inputs to the environment have increased since 1950 as the use of phosphate fertilizer, manure, and phosphate laundry detergent increased; however, the manufacture of phosphate detergent for household laundry was ended voluntarily in about 1994 after many States had established phosphate detergent bans. Total phosphorus concentrations in raw wastewater effluent contained about 3 milligrams per liter of total phosphorus during the 1940's, increased to about 11 milligrams per liter at the height of phosphate detergent use (1970), and have currently declined to about 5 milligrams per liter. However, in some cases, tertiary wastewater treatment still is needed to effectively improve water quality of streams. Downward trends in phosphorus concentrations since 1970 have been identified in many streams, but median total phosphorus concentrations still exceed the recommended limit of 0.1 milligram per liter across much of the Nation. Data from the NAWQA Program are representative of a variety of phosphorus-control measures, and, therefore, may be used to evaluate the effects of various control strategies. Current areas of concern include: evaluation of the effects of increased manure loadings of phosphorus on soil phosphorus and, subsequently, on ground water and subsurface runoff; determination of point-source and nonpoint-source components of phosphorus loads by geographic modeling and hydrologic separation techniques; and development of methods or indices to evaluate nutrient impairment in streams and rivers to serve as a basis for developing phosphorus criteria or standards.

Trophic state, eutrophication and nutrient criteria in streams.

PubMed

Dodds, Walter K

2007-12-01

Trophic state is the property of energy availability to the food web and defines the foundation of community integrity and ecosystem function. Describing trophic state in streams requires a stoichiometric (nutrient ratio) approach because carbon input rates are linked to nitrogen and phosphorus supply rates. Light determines the source of carbon. Cross system analyses, small experiments and ecosystem level manipulations have recently advanced knowledge about these linkages, but not to the point of building complex predictive models that predict all effects of nutrient pollution. Species diversity could indicate the natural distribution of stream trophic status over evolutionary time scales. Delineation of factors that control trophic state and relationships with biological community properties allows determination of goals for management of stream biotic integrity.

Factors affecting stream nutrient loads: A synthesis of regional SPARROW model results for the continental United States

USGS Publications Warehouse

Preston, Stephen D.; Alexander, Richard B.; Schwarz, Gregory E.; Crawford, Charles G.

2011-01-01

We compared the results of 12 recently calibrated regional SPARROW (SPAtially Referenced Regressions On Watershed attributes) models covering most of the continental United States to evaluate the consistency and regional differences in factors affecting stream nutrient loads. The models - 6 for total nitrogen and 6 for total phosphorus - all provide similar levels of prediction accuracy, but those for major river basins in the eastern half of the country were somewhat more accurate. The models simulate long-term mean annual stream nutrient loads as a function of a wide range of known sources and climatic (precipitation, temperature), landscape (e.g., soils, geology), and aquatic factors affecting nutrient fate and transport. The results confirm the dominant effects of urban and agricultural sources on stream nutrient loads nationally and regionally, but reveal considerable spatial variability in the specific types of sources that control water quality. These include regional differences in the relative importance of different types of urban (municipal and industrial point vs. diffuse urban runoff) and agriculture (crop cultivation vs. animal waste) sources, as well as the effects of atmospheric deposition, mining, and background (e.g., soil phosphorus) sources on stream nutrients. Overall, we found that the SPARROW model results provide a consistent set of information for identifying the major sources and environmental factors affecting nutrient fate and transport in United States watersheds at regional and subregional scales. ?? 2011 American Water Resources Association. This article is a U.S. Government work and is in the public domain in the USA.

Monitoring design for assessing compliance with numeric nutrient standards for rivers and streams using geospatial variables.

PubMed

Williams, Rachel E; Arabi, Mazdak; Loftis, Jim; Elmund, G Keith

2014-09-01

Implementation of numeric nutrient standards in Colorado has prompted a need for greater understanding of human impacts on ambient nutrient levels. This study explored the variability of annual nutrient concentrations due to upstream anthropogenic influences and developed a mathematical expression for the number of samples required to estimate median concentrations for standard compliance. A procedure grounded in statistical hypothesis testing was developed to estimate the number of annual samples required at monitoring locations while taking into account the difference between the median concentrations and the water quality standard for a lognormal population. For the Cache La Poudre River in northern Colorado, the relationship between the median and standard deviation of total N (TN) and total P (TP) concentrations and the upstream point and nonpoint concentrations and general hydrologic descriptors was explored using multiple linear regression models. Very strong relationships were evident between the upstream anthropogenic influences and annual medians for TN and TP ( > 0.85, < 0.001) and corresponding standard deviations ( > 0.7, < 0.001). Sample sizes required to demonstrate (non)compliance with the standard depend on the measured water quality conditions. When the median concentration differs from the standard by >20%, few samples are needed to reach a 95% confidence level. When the median is within 20% of the corresponding water quality standard, however, the required sample size increases rapidly, and hundreds of samples may be required. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Nutrient and sediment concentrations and corresponding loads during the historic June 2008 flooding in eastern Iowa

USGS Publications Warehouse

Hubbard, L.; Kolpin, D.W.; Kalkhoff, S.J.; Robertson, Dale M.

2011-01-01

A combination of above-normal precipitation during the winter and spring of 2007-2008 and extensive rainfall during June 2008 led to severe flooding in many parts of the midwestern United States. This resulted in transport of substantial amounts of nutrients and sediment from Iowa basins into the Mississippi River. Water samples were collected from 31 sites on six large Iowa tributaries to the Mississippi River to characterize water quality and to quantify nutrient and sediment loads during this extreme discharge event. Each sample was analyzed for total nitrogen, dissolved nitrate plus nitrite nitrogen, dissolved ammonia as nitrogen, total phosphorus, orthophosphate, and suspended sediment. Concentrations measured near peak flow in June 2008 were compared with the corresponding mean concentrations from June 1979 to 2007 using a paired t test. While there was no consistent pattern in concentrations between historical samples and those from the 2008 flood, increased flow during the flood resulted in near-peak June 2008 flood daily loads that were statistically greater (p < 0.05) than the median June 1979 to 2007 daily loads for all constituents. Estimates of loads for the 16-d period during the flood were calculated for four major tributaries and totaled 4.95 x 10(7) kg of nitrogen (N) and 2.9 x 10(6) kg of phosphorus (P) leaving Iowa, which accounted for about 22 and 46% of the total average annual nutrient yield, respectively. This study demonstrates the importance of large flood events to the total annual nutrient load in both small streams and large rivers.

Sources and transport of algae and nutrients in a Californian river in a semi-arid climate

USGS Publications Warehouse

Ohte, N.; Dahlgren, R.A.; Silva, S.R.; Kendall, C.; Kratzer, C.R.; Doctor, D.H.

2007-01-01

1. To elucidate factors contributing to dissolved oxygen (DO) depletion in the Stockton Deep Water Ship Channel in the lower San Joaquin River, spatial and temporal changes in algae and nutrient concentrations were investigated in relation to flow regime under the semiarid climate conditions. 2. Chlorophyll-a (chl-a) concentration and loads indicated that most algal biomass was generated by in-stream growth in the main stem of the river. The addition of algae from tributaries and drains was small (c.15% of total chl-a load), even though high concentrations of chl-a were measured in some source waters. 3. Nitrate and soluble-reactive phosphorus (SRP) were available in excess as a nutrient source for algae. Although nitrate and SRP from upstream tributaries contributed (16.9% of total nitrate load and 10.8% of total SRP load), nutrients derived from agriculture and other sources in the middle and lower river reaches were mostly responsible (20.2% for nitrate and 48.0% for SRP) for maintaining high nitrate and SRP concentrations in the main stem. 4. A reduction in nutrient discharge would attenuate the algal blooms that accelerate DO depletion in the Stockton Deep Water Ship Channel. The N : P ratio, in the main stem suggests that SRP reduction would be a more viable option for algae reduction than nitrogen reduction. 5. Very high algal growth rates in the main stem suggest that reducing the algal seed source in upstream areas would also be an effective strategy. ?? 2007 Blackwell Publishing Ltd.

Nutrient and sediment concentrations and corresponding loads during the historic June 2008 flooding in eastern Iowa.

PubMed

Hubbard, L; Kolpin, D W; Kalkhoff, S J; Robertson, D M

2011-01-01

A combination of above-normal precipitation during the winter and spring of 2007-2008 and extensive rainfall during June 2008 led to severe flooding in many parts of the midwestern United States. This resulted in transport of substantial amounts of nutrients and sediment from Iowa basins into the Mississippi River. Water samples were collected from 31 sites on six large Iowa tributaries to the Mississippi River to characterize water quality and to quantify nutrient and sediment loads during this extreme discharge event. Each sample was analyzed for total nitrogen, dissolved nitrate plus nitrite nitrogen, dissolved ammonia as nitrogen, total phosphorus, orthophosphate, and suspended sediment. Concentrations measured near peak flow in June 2008 were compared with the corresponding mean concentrations from June 1979 to 2007 using a paired t test. While there was no consistent pattern in concentrations between historical samples and those from the 2008 flood, increased flow during the flood resulted in near-peak June 2008 flood daily loads that were statistically greater (p < 0.05) than the median June 1979 to 2007 daily loads for all constituents. Estimates of loads for the 16-d period during the flood were calculated for four major tributaries and totaled 4.95 x 10(7) kg of nitrogen (N) and 2.9 x 10(6) kg of phosphorus (P) leaving Iowa, which accounted for about 22 and 46% of the total average annual nutrient yield, respectively. This study demonstrates the importance of large flood events to the total annual nutrient load in both small streams and large rivers.

Catchment Legacies and Time Lags: A Parsimonious Watershed Model to Predict the Effects of Legacy Storage on Nitrogen Export

PubMed Central

Van Meter, Kimberly J.; Basu, Nandita B.

2015-01-01

Nutrient legacies in anthropogenic landscapes, accumulated over decades of fertilizer application, lead to time lags between implementation of conservation measures and improvements in water quality. Quantification of such time lags has remained difficult, however, due to an incomplete understanding of controls on nutrient depletion trajectories after changes in land-use or management practices. In this study, we have developed a parsimonious watershed model for quantifying catchment-scale time lags based on both soil nutrient accumulations (biogeochemical legacy) and groundwater travel time distributions (hydrologic legacy). The model accurately predicted the time lags observed in an Iowa watershed that had undergone a 41% conversion of area from row crop to native prairie. We explored the time scales of change for stream nutrient concentrations as a function of both natural and anthropogenic controls, from topography to spatial patterns of land-use change. Our results demonstrate that the existence of biogeochemical nutrient legacies increases time lags beyond those due to hydrologic legacy alone. In addition, we show that the maximum concentration reduction benefits vary according to the spatial pattern of intervention, with preferential conversion of land parcels having the shortest catchment-scale travel times providing proportionally greater concentration reductions as well as faster response times. In contrast, a random pattern of conversion results in a 1:1 relationship between percent land conversion and percent concentration reduction, irrespective of denitrification rates within the landscape. Our modeling framework allows for the quantification of tradeoffs between costs associated with implementation of conservation measures and the time needed to see the desired concentration reductions, making it of great value to decision makers regarding optimal implementation of watershed conservation measures. PMID:25985290

Catchment legacies and time lags: a parsimonious watershed model to predict the effects of legacy storage on nitrogen export.

PubMed

Van Meter, Kimberly J; Basu, Nandita B

2015-01-01

Nutrient legacies in anthropogenic landscapes, accumulated over decades of fertilizer application, lead to time lags between implementation of conservation measures and improvements in water quality. Quantification of such time lags has remained difficult, however, due to an incomplete understanding of controls on nutrient depletion trajectories after changes in land-use or management practices. In this study, we have developed a parsimonious watershed model for quantifying catchment-scale time lags based on both soil nutrient accumulations (biogeochemical legacy) and groundwater travel time distributions (hydrologic legacy). The model accurately predicted the time lags observed in an Iowa watershed that had undergone a 41% conversion of area from row crop to native prairie. We explored the time scales of change for stream nutrient concentrations as a function of both natural and anthropogenic controls, from topography to spatial patterns of land-use change. Our results demonstrate that the existence of biogeochemical nutrient legacies increases time lags beyond those due to hydrologic legacy alone. In addition, we show that the maximum concentration reduction benefits vary according to the spatial pattern of intervention, with preferential conversion of land parcels having the shortest catchment-scale travel times providing proportionally greater concentration reductions as well as faster response times. In contrast, a random pattern of conversion results in a 1:1 relationship between percent land conversion and percent concentration reduction, irrespective of denitrification rates within the landscape. Our modeling framework allows for the quantification of tradeoffs between costs associated with implementation of conservation measures and the time needed to see the desired concentration reductions, making it of great value to decision makers regarding optimal implementation of watershed conservation measures.

Water Quality Conditions Associated with Cattle Grazing and Recreation on National Forest Lands

PubMed Central

Roche, Leslie M.; Kromschroeder, Lea; Atwill, Edward R.; Dahlgren, Randy A.; Tate, Kenneth W.

2013-01-01

There is substantial concern that microbial and nutrient pollution by cattle on public lands degrades water quality, threatening human and ecological health. Given the importance of clean water on multiple-use landscapes, additional research is required to document and examine potential water quality issues across common resource use activities. During the 2011 grazing-recreation season, we conducted a cross sectional survey of water quality conditions associated with cattle grazing and/or recreation on 12 public lands grazing allotments in California. Our specific study objectives were to 1) quantify fecal indicator bacteria (FIB; fecal coliform and E. coli), total nitrogen, nitrate, ammonium, total phosphorus, and soluble-reactive phosphorus concentrations in surface waters; 2) compare results to a) water quality regulatory benchmarks, b) recommended maximum nutrient concentrations, and c) estimates of nutrient background concentrations; and 3) examine relationships between water quality, environmental conditions, cattle grazing, and recreation. Nutrient concentrations observed throughout the grazing-recreation season were at least one order of magnitude below levels of ecological concern, and were similar to U.S. Environmental Protection Agency (USEPA) estimates for background water quality conditions in the region. The relative percentage of FIB regulatory benchmark exceedances widely varied under individual regional and national water quality standards. Relative to USEPA’s national E. coli FIB benchmarks–the most contemporary and relevant standards for this study–over 90% of the 743 samples collected were below recommended criteria values. FIB concentrations were significantly greater when stream flow was low or stagnant, water was turbid, and when cattle were actively observed at sampling. Recreation sites had the lowest mean FIB, total nitrogen, and soluble-reactive phosphorus concentrations, and there were no significant differences in FIB and nutrient concentrations between key grazing areas and non-concentrated use areas. Our results suggest cattle grazing, recreation, and provisioning of clean water can be compatible goals across these national forest lands. PMID:23826370

Urbanization and nutrient retention in freshwater riparian wetlands

USGS Publications Warehouse

Hogan, D.M.; Walbridge, M.R.

2007-01-01

Urbanization can degrade water quality and alter watershed hydrology, with profound effects on the structure and function of both riparian wetlands (RWs) and aquatic ecosystems downstream. We used freshwater RWs in Fairfax County, Virginia, USA, as a model system to examine: (1) the effects of increasing urbanization (indexed by the percentage of impervious surface cover [%ISC] in the surrounding watershed) on nitrogen (N) and phosphorus (P) concentrations in surface soils and plant tissues, soil P saturation, and soil iron (Fe) chemistry; and (2) relationships between RW soil and plant nutrient chemistries vs. the physical and biotic integrity of adjacent streams. Soil total P and NaOH-extractable P (representing P bound to aluminum [Al] and Fe hydrous oxides) varied significantly but nonlinearly with %ISC (r2 = 0.69 and 0.57, respectively); a similar pattern was found for soil P saturation but not for soil total N. Relationships were best described by second-order polynomial equations. Riparian wetlands appear to receive greater P loads in moderately (8.6-13.3% ISC) than in highly (25.1-29.1% ISC) urbanized watersheds. These observations are consistent with alterations in watershed hydrology that occur with increasing urbanization, directing water and nutrient flows away from natural RWs. Significant increases in total and crystalline soil Fe (r 2 = 0.57 and 0.53, respectively) and decreases in relative soil Fe crystallinity with increasing %ISC suggest the mobilization and deposition of terrestrial sediments in RWs, likely due to construction activities in the surrounding watershed. Increases in RW plant tissue nutrient concentrations and %ISC in the surrounding watershed were negatively correlated with standard indices of the physical and biotic integrity of adjacent streams. In combination, these data suggest that nutrient and sediment inputs associated with urbanization and storm-water management are important variables that affect wetland ecosystem services, such as water quality improvement, in urbanizing landscapes. ?? 2007 by the Ecological Society of America.

Carcass analog provides marine subsidies for macroinvertebrates and juvenile Atlantic 8 salmon in temperate oligotrophic streams

USGS Publications Warehouse

Guyette, Margaret Q.; Loftin, Cynthia S.; Zydlewski, Joseph D.; Cunjak, Richard

2014-01-01

Assimilation of nutrients from carcass analogues was both direct and indirect, and a nutrient legacy was evident in the second year of sampling. Incorporation of nutrients from the pellets at a range of heights in the food web demonstrated the potential for marine-derived subsidies to contribute to freshwater ecosystem processes in Atlantic salmon nursery streams.

Turbidity - a Semi-Continuous Monitoring Option for Suspended Solids

NASA Astrophysics Data System (ADS)

Lendvay, J. M.; Rosasco, M. V.; David, K. E.

2012-12-01

Redwood Creek, a third order coastal stream flowing through Muir Woods National Monument and Golden Gate National Recreation Area in Marin County, California, was once the spawning grounds for a relatively large population of Coho Salmon (Oncorhynchus kisutch). In recent years less than 1% of historic populations have been returning to the stream. Redwood creek is currently undergoing extensive ecological restoration in an attempt to improve the spawning habitat for the salmon. The original stream path has been altered in the past to make way for development and the National Park Service has been working towards restoring much of the stream's natural functionality with the hope that the salmon population will increase. The restoration process has altered the surrounding riparian landscape in the Redwood Creek watershed. Riparian disturbance caused by vegetation and levee removal as a part of the restoration process followed by installation of seedlings raises concern about the concentration of sediments in the water. Throughout 2011-2012 three parameters for water quality were monitored at Redwood Creek. Suspended sediment concentration (SSC) and total suspended solids (TSS) measurements to determine the concentration of suspended particles in the water column at a given point in time. Turbidity, measured in Nephelometric Turbidity Units (NTU) is a measure of the water's cloudiness caused by suspended particles. Turbidity measurements are favored as they provide a semi-automated monitoring option. Therefore, development of a relationship between turbidity and SSC and TSS is desired. Water samples were analyzed for TSS and SSC using the EPA standard methods, and Turbidity was measured using a Hach 2100Q portable turbidimeter. Additional semi-continuous monitoring of turbidity was completed in situ using Hydrolab DS5X datasondes (with self-cleaning turbidity sensor). The relationship between TSS, SSC and turbidity was determined using a linear regression model for two separate sites within Redwood creek. The linear correlation coefficient values for the two sites were high for both TSS vs. Turbidity (R2=0.929) and SSC vs. Turbidity (R2=0.929). Measures of suspended particle concentrations in the water column are important indicators of water quality, as sediments can be transporters of both nutrients and contaminants alike, particularly those with high binding affinities for soils. Moreover, the relationships between TSS, SSC and turbidity may serve as an important predictor when developing a model for nutrient and contaminant dynamics in coastal California streams. Determining the best way to measure suspended solids in the water column will help elucidate the most practicable in-stream monitoring methods.

Vulnerability Assessment of Groundwater Resources by Nutrient Source Apportionment to Individual Groundwater Wells: A Case Study in North Carolina

NASA Astrophysics Data System (ADS)

Ayub, R.; Obenour, D. R.; Keyworth, A. J.; Genereux, D. P.; Mahinthakumar, K.

2016-12-01

Groundwater contamination by nutrients (nitrogen and phosphorus) is a major concern in water table aquifers that underlie agricultural areas in the mid-Atlantic Coastal Plain of the United States. High nutrient concentrations leaching into shallow groundwater can lead to human health problems and eutrophication of receiving surface waters. Liquid manure from concentrated animal feeding operations (CAFOs) stored in open-air lagoons and applied to spray fields can be a significant source of nutrients to groundwater, along with septic waste. In this study, we developed a model-based methodology for source apportionment and vulnerability assessment using sparse groundwater quality sampling measurements for Duplin County, North Carolina (NC), obtained by the NC Department of Environmental Quality (NC DEQ). This model provides information relevant to management by estimating the nutrient transport through the aquifer from different sources and addressing the uncertainty of nutrient contaminant propagation. First, the zones of influence (dependent on nutrient pathways) for individual groundwater monitoring wells were identified using a two-dimensional vertically averaged groundwater flow and transport model incorporating geologic uncertainty for the surficial aquifer system. A multiple linear regression approach is then applied to estimate the contribution weights for different nutrient source types using the nutrient measurements from monitoring wells and the potential sources within each zone of influence. Using the source contribution weights and their uncertainty, a probabilistic vulnerability assessment of the study area due to nutrient contamination is performed. Knowledge of the contribution of different nutrient sources to contamination at receptor locations (e.g., private wells, municipal wells, stream beds etc.) will be helpful in planning and implementation of appropriate mitigation measures.

Surface-Water Nutrient Conditions and Sources in the United States Pacific Northwest1

PubMed Central

Wise, Daniel R; Johnson, Henry M

2011-01-01

Abstract The SPAtially Referenced Regressions On Watershed attributes (SPARROW) model was used to perform an assessment of surface-water nutrient conditions and to identify important nutrient sources in watersheds of the Pacific Northwest region of the United States (U.S.) for the year 2002. Our models included variables representing nutrient sources as well as landscape characteristics that affect nutrient delivery to streams. Annual nutrient yields were higher in watersheds on the wetter, west side of the Cascade Range compared to watersheds on the drier, east side. High nutrient enrichment (relative to the U.S. Environmental Protection Agency's recommended nutrient criteria) was estimated in watersheds throughout the region. Forest land was generally the largest source of total nitrogen stream load and geologic material was generally the largest source of total phosphorus stream load generated within the 12,039 modeled watersheds. These results reflected the prevalence of these two natural sources and the low input from other nutrient sources across the region. However, the combined input from agriculture, point sources, and developed land, rather than natural nutrient sources, was responsible for most of the nutrient load discharged from many of the largest watersheds. Our results provided an understanding of the regional patterns in surface-water nutrient conditions and should be useful to environmental managers in future water-quality planning efforts. PMID:22457584

Stream structure at low flow: biogeochemical patterns in intermittent streams over space and time

NASA Astrophysics Data System (ADS)

MacNeille, R. B.; Lohse, K. A.; Godsey, S.; McCorkle, E. P.; Parsons, S.; Baxter, C.

2017-12-01

Climate change in the western United States is projected to lead to earlier snowmelt, increasing fire risk and potentially transitioning perennial streams to intermittent ones. Differences between perennial and intermittent streams, especially the temporal and spatial patterns of carbon and nutrient dynamics during periods of drying, are understudied. We examined spatial and temporal patterns in surface water biogeochemistry during a dry (2016) and a wet (2017) water year in southwest Idaho. We hypothesized that as streams dry, carbon concentrations would increase due to evapoconcentration and/or increased in-stream production, and that the heterogeneity of constituents within each stream would increase. We expected these patterns to differ in a high water year compared to a low water year due to algae scour. Finally, we expected that the spatial heterogeneity of biogeochemistry would decrease with time following fire. To test these hypotheses, in 2016 we collected surface water samples at 50 meter intervals from two intermittent headwater streams over 2,500 meter reaches in April, May, and June. One stream is burned and one remains unburned. In 2017, we collected surface water at the 50, 25 and 10 meter intervals from each stream once during low flow. 2016 results showed average concentrations of dissolved inorganic carbon (DIC) and dissolved organic carbon (DOC) increased 3-fold from April to June in the burned site compared to the unburned site. Interestingly, average concentrations of total nitrogen (TN) dropped substantially for the burned site over these three months, but only decreased slightly for the unburned site over the same time period. Between wet and dry water years, we observed a decrease in the spatial heterogeneity as measured by the standard deviation (SD) in conductivity at 50 meter intervals; the burned stream had a SD of 23.08 in 2016 and 11.40 in 2017 whereas the unburned stream had similar SDs. We conclude that the burned stream experienced more inter and intra-annual surface water change in chemistry patterns than did the unburned stream.

Quantitative measurement of stream respiration using the resazurin-resorufin system

NASA Astrophysics Data System (ADS)

Gonzalez Pinzon, R. A.; Acker, S.; Haggerty, R.; Myrold, D.

2011-12-01

After three decades of active research in hydrology and stream ecology, the relationship between stream solute transport, metabolism and nutrient dynamics is still unresolved. These knowledge gaps obscure the function of stream ecosystems and how they interact with other landscape processes. To date, measuring rates of stream metabolism is accomplished with techniques that have vast uncertainties and are not spatially representative. These limitations mask the role of metabolism in nutrient processing. Clearly, more robust techniques are needed to develop mechanistic relationships that will ultimately improve our fundamental understanding of in-stream processes and how streams interact with other ecosystems. We investigated the "metabolic window of detection" of the Resazurin (Raz)-Resorufin (Rru) system (Haggerty et al., 2008, 2009). Although previous results have shown that the transformation of Raz to Rru is strongly correlated with respiration, a quantitative relationship between them is needed. We investigated this relationship using batch experiments with pure cultures (aerobic and anaerobic) and flow-through columns with incubated sediments from four different streams. The results suggest that the Raz-Rru system is a suitable approach that will enable hydrologists and stream ecologists to measure in situ and in vivo respiration at different scales, thus opening a reliable alternative to investigate how solute transport and stream metabolism control nutrient processing.

Influences of Geomorphic Complexity and Rehabilitation on Nutrient Uptake in an Urban Stream

NASA Astrophysics Data System (ADS)

Mueller, J. S.; Baker, D. W.; Bledsoe, B. P.

2006-12-01

Headwater streams, which are highly vulnerable to anthropogenic impacts associated with land use change, have large surface-to-volume ratios that favor retention and removal of nitrogen. We describe a study focused on how geomorphic complexity is related to nutrient retention in impacted and restored headwater streams along a gradient of human land use. A key element of the study is a detailed protocol for characterizing the spatial distribution of physical habitat units composed of relatively distinct combinations of flow hydraulics and textural facies. We are using the detailed physical characterization and nutrient injections in paired segments of a Colorado Front Range urban stream to examine associations among geomorphic complexity, nitrogen uptake, and the degree and style of channel rehabilitation. The results of the study have implications for the viability of stream rehabilitation as a tool for reducing N delivery to downstream aquatic systems that are vulnerable to eutrophication.

Tundra fire alters stream water chemistry and benthic invertebrate communities, North Slope, Alaska

NASA Astrophysics Data System (ADS)

Allen, A. R.; Bowden, W. B.; Kling, G. W.; Schuett, E.; Kostrzewski, J. M.; Kolden Abatzoglou, C.; Findlay, R. H.

2010-12-01

Increased fire frequency and severity are potentially important consequences of climate change in high latitude ecosystems. The 2007 Anaktuvuk River fire, which burned from July until October, is the largest recorded tundra fire from Alaska's north slope (≈1,000 km2). The immediate effects of wildfire on water chemistry and biotic assemblages in tundra streams are heretofore unknown. We hypothesized that a tundra fire would increase inorganic nutrient inputs to P-limited tundra streams, increasing primary production and altering benthic macroinvertebrate community structure. We examined linkages among: 1) percentage of riparian zone and overall watershed vegetation burned, 2) physical, chemical and biological stream characteristics, and 3) macroinvertebrate communities in streams draining burned and unburned watersheds during the summers of 2008 and 2009. Streams in burned watersheds contained higher mean concentrations of soluble reactive phosphorus (SRP), ammonium (NH4+), and dissolved organic carbon (DOC). In contrast, stream nitrate (NO3-) concentrations were lower in burned watersheds. The net result was that the tundra fire did not affect concentrations of dissolved inorganic nitrogen (NH4+ + NO3-). In spite of increased SRP, benthic chlorophyll-a biomass was not elevated. Macroinvertebrate abundances were 1.5 times higher in streams draining burned watersheds; Chironomidae midges, Nematodes, and Nemoura stoneflies showed the greatest increases in abundance. Multivariate multiple regression identified environmental parameters associated with the observed changes in the macroinvertebrate communities. Since we identified stream latitude as a significant predictor variable, latitude was included in the model as a covariate. After removing the variation associated with latitude, 67.3 % of the variance in macroinvertebrate community structure was explained by a subset of 7 predictor variables; DOC, conductivity, mean temperature, NO3-, mean discharge, SRP and NH4+. The percentage of riparian vegetation burned, the percentage of watershed vegetation burned and total suspended solids were not included in the model as these parameters correlated with DOC concentration at r > 0.90. These results indicate that tundra fire not only alters stream water chemistry, it also affects benthic macroinvertebrate community structure.

Nutrient recovery from the dry grind process using sequential micro and ultrafiltration of thin stillage.

PubMed

Arora, Amit; Dien, Bruce S; Belyea, Ronald L; Singh, Vijay; Tumbleson, M E; Rausch, Kent D

2010-06-01

The effectiveness of microfiltration (MF) and ultrafiltration (UF) for nutrient recovery from a thin stillage stream was determined. When a stainless steel MF membrane (0.1microm pore size) was used, the content of solids increased from 7.0% to 22.8% with a mean permeate flux rate of 45L/m(2)/h (LMH), fat increased and ash content decreased. UF experiments were conducted in batch mode under constant temperature and flow rate conditions. Permeate flux profiles were evaluated for regenerated cellulose membranes (YM1, YM10 and YM100) with molecular weight cut offs of 1, 10 and 100kDa. UF increased total solids, protein and fat and decreased ash in retentate stream. When permeate streams from MF were subjected to UF, retentate total solids concentrations similar to those of commercial syrup (23-28.8%) were obtained. YM100 had the highest percent permeate flux decline (70% of initial flux) followed by YM10 and YM1 membranes. Sequential filtration improved permeate flux rates of the YM100 membrane (32.6-73.4LMH) but the percent decline was also highest in a sequential MF+YM100 system. Protein recovery was the highest in YM1 retentate. Removal of solids, protein and fat from thin stillage may generate a permeate stream that may improve water removal efficiency and increase water recycling. Copyright 2010 Elsevier Ltd. All rights reserved.

Dual nitrate isotopes clarify the role of biological processing and hydrologic flow paths on nitrogen cycling in subtropical low-gradient watersheds

DOE PAGES

Griffiths, Natalie A.; Jackson, C. Rhett; McDonnell, Jeffrey J.; ...

2016-02-08

Nitrogen (N) is an important nutrient as it often limits productivity but in excess can impair water quality. Most studies on watershed N cycling have occurred in upland forested catchments where snowmelt dominates N export; fewer studies have focused on low-relief watersheds that lack snow. We examined watershed N cycling in three adjacent, low-relief watersheds in the Upper Coastal Plain of the southeastern United States to better understand the role of hydrological flow paths and biological transformations of N at the watershed scale. Groundwater was the dominant source of nitrified N to stream water in two of the three watersheds,more » while atmospheric deposition comprised 28% of stream water nitrate in one watershed. The greater atmospheric contribution may have been due to the larger stream channel area relative to total watershed area or the dominance of shallow subsurface flow paths contributing to stream flow in this watershed. There was a positive relationship between temperature and stream water ammonium concentrations and a negative relationship between temperature and stream water nitrate concentrations in each watershed suggesting that N cycling processes (i.e., nitrification and denitrification) varied seasonally. However, there were no clear patterns in the importance of denitrification in different water pools possibly because a variety of factors (i.e., assimilatory uptake, dissimilatory uptake, and mixing) affected nitrate concentrations. In conclusion, together, these results highlight the hydrological and biological controls on N cycling in low-gradient watersheds and variability in N delivery flow paths among adjacent watersheds with similar physical characteristics.« less

The case for regime-based water quality standards

USGS Publications Warehouse

Poole, Geoffrey C.; Dunham, J.B.; Keenan, D.M.; Sauter, S.T.; McCullough, D.A.; Mebane, Christopher; Lockwood, Jeffrey C.; Essig, Don A.; Hicks, Mark P.; Sturdevant, Debra J.; Materna, E.J.; Spalding, M.; Risley, John; Deppman, Marianne

2004-01-01

Conventional water quality standards have been successful in reducing the concentration of toxic substances in US waters. However, conventional standards are based on simple thresholds and are therefore poorly structured to address human-caused imbalances in dynamic, natural water quality parameters, such as nutrients, sediment, and temperature. A more applicable type of water quality standarda??a a??regime standarda??a??would describe desirable distributions of conditions over space and time within a stream network. By mandating the protection and restoration of the aquatic ecosystem dynamics that are required to support beneficial uses in streams, well-designed regime standards would facilitate more effective strategies for management of natural water quality parameters.

Stream Sediment Sources in Midwest Agricultural Basins with Land Retirement along Channel.

PubMed

Williamson, T N; Christensen, V G; Richardson, W B; Frey, J W; Gellis, A C; Kieta, K A; Fitzpatrick, F A

2014-09-01

Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses were that sediment from cropland, retired land, stream banks, and roads would be discernible using isotopic and elemental concentrations and that source contributions would vary with land retirement distribution along tributaries of West Fork Beaver Creek in Minnesota. Channel-bed and suspended sediment were sampled at nine locations and compared with local source samples by using linear discriminant analysis and a four-source mixing model that evaluated seven tracers: In, P, total C, Be, Tl, Th, and Ti. The proportion of sediment sources differed significantly between suspended and channel-bed sediment. Retired land contributed to channel-bed sediment but was not discernible as a source of suspended sediment, suggesting that retired-land material was not mobilized during high-flow conditions. Stream banks were a large contributor to suspended sediment; however, the percentage of stream-bank sediment in the channel bed was lower in basins with more continuous retired land along the riparian corridor. Cropland sediments had the highest P concentrations; basins with the highest cropland-sediment contributions also had the highest P concentrations. Along stream reaches with retired land, there was a lower proportion of cropland material in suspended sediment relative to sites that had almost no land retirement, indicating less movement of nutrients and sediment from cropland to the channel as a result of land retirement. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Stream sediment sources in midwest agricultural basins with land retirement along channel

USGS Publications Warehouse

Williamson, Tanja N.; Christensen, Victoria G.; Richardson, William B.; Frey, Jeffrey W.; Gellis, Allen C.; Kieta, K. A.; Fitzpatrick, Faith A.

2014-01-01

Documenting the effects of agricultural land retirement on stream-sediment sources is critical to identifying management practices that improve water quality and aquatic habitat. Particularly difficult to quantify are the effects from conservation easements that commonly are discontinuous along channelized streams and ditches throughout the agricultural midwestern United States. Our hypotheses were that sediment from cropland, retired land, stream banks, and roads would be discernible using isotopic and elemental concentrations and that source contributions would vary with land retirement distribution along tributaries of West Fork Beaver Creek in Minnesota. Channel-bed and suspended sediment were sampled at nine locations and compared with local source samples by using linear discriminant analysis and a four-source mixing model that evaluated seven tracers: In, P, total C, Be, Tl, Th, and Ti. The proportion of sediment sources differed significantly between suspended and channel-bed sediment. Retired land contributed to channel-bed sediment but was not discernible as a source of suspended sediment, suggesting that retired-land material was not mobilized during high-flow conditions. Stream banks were a large contributor to suspended sediment; however, the percentage of stream-bank sediment in the channel bed was lower in basins with more continuous retired land along the riparian corridor. Cropland sediments had the highest P concentrations; basins with the highest cropland-sediment contributions also had the highest P concentrations. Along stream reaches with retired land, there was a lower proportion of cropland material in suspended sediment relative to sites that had almost no land retirement, indicating less movement of nutrients and sediment from cropland to the channel as a result of land retirement.

Simulating Streamflow and Dissolved Organic Matter Export from small Forested Watersheds

NASA Astrophysics Data System (ADS)

Xu, N.; Wilson, H.; Saiers, J. E.

2010-12-01

Coupling the rainfall-runoff process and solute transport in catchment models is important for understanding the dynamics of water-quality-relevant constituents in a watershed. To simulate the hydrologic and biogeochemical processes in a parametrically parsimonious way remains challenging. The purpose of this study is to quantify the export of water and dissolved organic matter (DOM) from a forested catchment by developing and testing a coupled model for rainfall-runoff and soil-water flushing of DOM. Natural DOM plays an important role in terrestrial and aquatic systems by affecting nutrient cycling, contaminant mobility and toxicity, and drinking water quality. Stream-water discharge and DOM concentrations were measured in a first-order stream in Harvard Forest, Massachusetts. These measurements show that stream water DOM concentrations are greatest during hydrologic events induced by rainfall or snowmelt and decline to low, steady levels during periods of baseflow. Comparison of the stream-discharge data to calculations of a simple rainfall-runoff model reveals a hysteretic relationship between stream-flow rates and the storage of water within the catchment. A modified version of the rainfall-runoff model that accounts for hysteresis in the storage-discharge relationship in a parametrically simple way is capable of describing much, but not all, of the variation in the time-series data on stream discharge. Our ongoing research is aimed at linking the new rainfall-runoff formulation with coupled equations that predict soil-flushing and stream-water concentrations of DOM as functions of the temporal change in catchment water storage. This model will provide a predictive tool for examining how changes in climatic variables would affect the runoff generation and DOM fluxes from terrestrial landscape.

Assessing impacts of land-applied manure from concentrated animal feeding operations on fish populations and communities.

PubMed

Leet, Jessica K; Lee, Linda S; Gall, Heather E; Goforth, Reuben R; Sassman, Stephen; Gordon, Denise A; Lazorchak, James M; Smith, Mark E; Jafvert, Chad T; Javfert, Chad T; Sepúlveda, Maria S

2012-12-18

Concentrated animal feeding operation (CAFO) manure is a cost-effective fertilizer. In the Midwest, networks of subsurface tile-drains expedite transport of animal hormones and nutrients from land-applied CAFO manure to adjacent waterways. The objective of this study was to evaluate impacts of land-applied CAFO manure on fish populations and communities. Water chemistry including hormone, pesticide, and nutrient concentrations was characterized from study sites along with fish assemblage structure, growth, and endocrine disruption assessed in selected fish species. Although most CAFO water samples had hormone concentrations <1 ng/L, equivalent concentrations for 17β-E2 and 17α-TB peaked at >30 ng/L each during the period of spawning, hatching, and development for resident fishes. CAFO sites had lower fish species richness, and fishes exhibited faster somatic growth and lower reproductive condition compared to individuals from the reference site. Fathead minnows (Pimephales promelas) exposed to CAFO ditchwater during early developmental stages exhibited significantly skewed sex ratios toward males. Maximum observed hormone concentrations were well above the lowest observable effect concentrations for these hormones; however, complexities at the field scale make it difficult to directly relate hormone concentration and impacts on fish. Complicating factors include the consistent presence of pesticides and nutrients, and the difference in temperature and stream architecture of the CAFO-impacted ditches compared to the reference site (e.g., channelization, bottom substrate, shallow pools, and riparian cover).

The Effectiveness of Cattlemans Detention Basin, South Lake Tahoe, California

USGS Publications Warehouse

Green, Jena M.

2006-01-01

Lake Tahoe (Nevada-California) has been designated as an 'outstanding national water resource' by the U.S. Environmental Protection Agency, in part, for its exceptional clarity. Water clarity in Lake Tahoe, however, has been declining at a rate of about one foot per year for more than 35 years. To decrease the amount of sediment and nutrients delivered to the lake by way of alpine streams, wetlands and stormwater detention basins have been installed at several locations around the lake. Although an improvement in stormwater and snowmelt runoff quality has been measured, the effectiveness of the detention basins for increasing the clarity of Lake Tahoe needs further study. It is possible that poor ground-water quality conditions exist beneath the detention basins and adjacent wetlands and that the presence of the basins has altered ground-water flow paths to nearby streams. A hydrogeochemical and ground-water flow modeling study was done at Cattlemans detention basin, situated adjacent to Cold Creek, a tributary to Lake Tahoe, to determine whether the focusing of storm and snowmelt runoff into a confined area has (1) modified the ground-water flow system beneath the detention basin and affected transport of sediment and nutrients to nearby streams and (2) provided an increased source of solutes which has changed the distribution of nutrients and affected nutrient transport rates beneath the basin. Results of slug tests and ground-water flow modeling suggest that ground water flows unrestricted northwest across the detention basin through the meadow. The modeling also indicates that seasonal flow patterns and flow direction remain similar from year to year under transient conditions. Model results imply that about 34 percent (0.004 ft3/s) of the total ground water within the model area originates from the detention basin. Of the 0.004 ft3/s, about 45 percent discharges to Cold Creek within the modeled area downstream of the detention basin. The remaining 55 percent of ground water is either consumed by evapotranspiration, is discharged to Cold Creek outside the modeled area downstream of the detention basin, or is discharged directly to Lake Tahoe. Of the 45 percent discharging to Cold Creek, about 9 percent enters directly downstream of the detention basin and 36 percent enters further downstream. Geochemical and microbial data suggest that a seasonal variation of chemical constituents and microbe population size is present at most wells. The geochemical data also indicate that construction of Cattlemans detention basin has not substantially changed the composition of the ground water in the area. High concentrations of ammonia, iron, and dissolved organic carbon, low concentrations of sulfate and nitrate, and large populations of sulfate-reducing microbes imply that the major geochemical process controlling nutrient concentrations beneath the detention basin is sulfate reduction. High concentrations of total nitrogen indicate that oxidation of organic carbon is a second important geochemical process occurring beneath the basin. The influx of surface runoff during spring 2002 apparently provided sufficient oxidized organic carbon to produce iron-reducing conditions and an increase in reduced iron, sulfate, and iron-reducing microorganisms. The increase in recharge of oxygenated water to the ground water system beneath the basin in future intervals of increased recharge may eventually redistribute nutrients and speed up transport of dissolved nutrients from the ground water system to Cold Creek.

The biogeochemical fingerprint of urbanization: increasing carbon quality in Maine headwater streams

NASA Astrophysics Data System (ADS)

Parr, T.; Cronan, C.; Ohno, T.; Simon, K. S.

2012-12-01

Conversion of land cover to urban use is an accelerating global phenomenon. Physical landscape change manifests as the replacement of forests, grasslands, and wetlands with buildings, novel vegetation, and infrastructure. This physical change also brings with it a change in the human management of the landscape for aesthetic and practical purposes (i.e. road salt applications). Although urbanization's effects on inorganic nutrients have been well studied, far less is known about the interactive influences of urbanization and urban landscape management practices on dissolved organic matter (DOM), a key energy source essential to ecosystem function. We examined the seasonal abundance and composition of DOM, nutrients, and common cations in 116 small streams along a gradient of urbanization (0-60% total watershed imperviousness, TWI), in Maine, USA. Dissolved organic carbon concentration ranged from 0.5 to 20 ppm with no clear relationship to watershed urbanization. In contrast, DOM composition, quantified with specific ultra violet absorbance at 254 nm (SUVA_{254}), fluorescence indices, and parallel factor analysis (PARAFAC), changed considerably with increasing urbanization. SUVA_{254} indicated a shift from higher molecular weight humic compounds (SUVA_{254}>4) toward lower molecular weight compounds (SUVA_{254}<2.5) with increasing urbanization. Fluorescence indices (Fluorescence Index, Humification Index, and α:β) indicated DOM source shifted from allochthonous sources (e.g. plant and soil carbon) toward autochthonously derived compounds (e.g. derivatives of in-stream algal and microbial production). Humic acid-like compounds decreased from 40% to 10% of the fluorescent DOM pool, while fluorescence of more labile compounds increased from 10 to 25% with increasing urbanization. Laboratory bioassays of DOM degradation rates showed that increasing urbanization doubled the bioavailability of DOM. Ratios of DOC:DON declined from 20-50 at TWI<8% to <20 above 8% TWI. Changes in the DOM pool were unrelated to inorganic nutrient concentrations, but were related to base cation concentrations. Concentrations of base cations (Ca^{2+}, Mg^{2+}, K^+, Na^+) increased 3-100 fold with increasing impervious cover. The stoichiometric relationships among Na^+, Cl^- and other base cations suggest road salt application may mobilize base cations into streams draining urbanized watersheds. There was a strong negative relationship between humic-like DOM components and Ca^{2+} (R^2=0.3-0.5, p<0.01) across streams. Bottle incubations of ^1+ and ^{2+} base cation salts over a natural range (0 - 6 mM) showed that ^{2+} cations (esp. Ca^{2+}) preferentially flocculated the humic fraction of DOM (R^2=0.6-0.9, p<0.01). These results indicate that the carbon composition change observed with urbanization in Maine may be controlled by multiple concurrent processes linked to the creation and maintenance of urban landscapes. Our data suggest that a key biogeochemical consequence of urbanization may be an increase in abundance of labile carbon which may have important consequences for ecosystem function in urban systems. This process may be driven by a combination of altered landscape C sources reducing terrestrial C inputs, enhancement of in-stream C production, and base cation enrichment that removing terrestrial C from the aquatic DOM pool in urban landscapes.

Ecosystem and physiological scales of microbial responses to nutrients in a detritus-based stream: results of a 5-year continuous enrichment

Treesearch

Keller Suberkropp; Vladislav Gulis; Amy D. Rosemond; Jonathan Benstead

2010-01-01

Our study examined the response of leaf detritus–associated microorganisms (both bacteria and fungi) to a 5-yr continuous nutrient enrichment of a forested headwater stream. Leaf litter dominates detritus inputs to such streams and, on a system wide scale, serves as the key substrate for microbial colonization. We determined physiological responses as microbial biomass...

Microbial Enzyme Activity, Nutrient Uptake, and Nutrient Limitation in Forested Streams

EPA Science Inventory

We measured NH4 + and PO4 -3 uptake length (Sw), uptake velocity (Vf), uptake rate (U), biofilm enzyme activity (BEA), and channel geomorphology in streams draining forested catchments in the Northwestern (Northern California Coast Range and Cascade Mountains) and Southeastern (A...

Nutrient dynamics and decomposition of riparian Arundinaria gigantea (Walt.)Muhl. leaves in southern Illinois

USDA-ARS?s Scientific Manuscript database

Leaf litter quality and quantity can influence soil nutrient dynamics and stream productivity through decomposition and serving as allochthonous stream inputs. Leaf deposition, nitrogen (N)-resorption efficiency and proficiency, and decomposition rates were analyzed in riparian stands of Arundinaria...

Water resources of the Makah Indian Reservation, Washington

USGS Publications Warehouse

Dion, N.P.; Walters, Kenneth Lyle; Nelson, L.M.

1980-01-01

The residents of the Makah Indian Reservation, Wash., depend on the stream of the area for their fisheries and domestic water supply. The temporal distribution of streamflow in the study area is closely related to the amount and distribution of rainfall. In a year of average precipitation about three-quarters of the streamflow can be expected to occur during the 6-month period October-March. Although the chemical quality of water in streams is suitable for domestic puposes, State water-quality standards are not met by most streams at certain times of the year because of excessibe fecal-coliform bacteria and turbidity levels. Nutrient concentrations in the Waatch and Sail Rivers are sometimes high enough to cause nuisance-plant growth. Suspended-sediment concentrations were low in all streams sampled. Groundwater is known to occur only in sand and gravel layers that underlie the lowlands of the reservation. Individual wells are capable of yield as much as 90 gallons per minute. Several wells in the Neah Bay area have been abandoned because of inferior water quality. In coastal areas, and individual domestic well on each 10-acre allotment should provide sufficient water for the occupants without danger of seawater intrusion. (UGS)

Water-Quality Characterization of Surface Water in the Onondaga Lake Basin, Onondaga County, New York, 2005-08

USGS Publications Warehouse

Coon, William F.; Hayhurst, Brett A.; Kappel, William M.; Eckhardt, David A.V.; Szabo, Carolyn O.

2009-01-01

Water-resources managers in Onondaga County, N.Y., have been faced with the challenge of improving the water-quality of Onondaga Lake. To assist in this endeavor, the U.S. Geological Survey undertook a 3-year basinwide study to assess the water quality of surface water in the Onondaga Lake Basin. The study quantified the relative contributions of nonpoint sources associated with the major land uses in the basin and also focused on known sources (streams with large sediment loads) and presumed sinks (Onondaga Reservoir and Otisco Lake) of sediment and nutrient loads, which previously had not been evaluated. Water samples were collected and analyzed for nutrients and suspended sediment at 26 surface-water sites and 4 springs in the 285-square-mile Onondaga Lake Basin from October 2005 through December 2008. More than 1,060 base-flow, stormflow, snowmelt, spring-water, and quality-assurance samples collected during the study were analyzed for ammonia, nitrite, nitrate-plus-nitrite, ammonia-plus-organic nitrogen, orthophosphate, phosphorus, and suspended sediment. The concentration of total suspended solids was measured in selected samples. Ninety-one additional samples were collected, including 80 samples from 4 county-operated sites, which were analyzed for suspended sediment or total suspended solids, and 8 precipitation and 3 snowpack samples, which were analyzed for nutrients. Specific conductance, salinity, dissolved oxygen, and water temperature were periodically measured in the field. The mean concentrations of selected constituents in base-flow, stormflow, and snowmelt samples were related to the land use or land cover that either dominated the basin or had a substantial effect on the water quality of the basin. Almost 40 percent of the Onondaga Lake Basin is forested, 30 percent is in agricultural uses, and almost 21 percent, including the city of Syracuse, is in developed uses. The data indicated expected relative differences among the land types for concentrations of nitrate, ammonia-plus-organic nitrogen, and orthophosphate. The data departed from the expected relations for concentrations of phosphorus and suspended sediment, and plausible explanations for these departures were posited. Snowmelt concentrations of dissolved constituents generally were greater and those of particulate constituents were less than concentrations of these constituents in storm runoff. Presumably, the snowpack acted as a short-term sink for dissolved constituents that had accumulated from atmospheric deposition, and streambed erosion and resuspension of previously deposited material, rather than land-surface erosion, were the primary sources of particulate constituents in snowmelt flows. Longitudinal assessments documented the changes in the median concentrations of constituents in base flows and event flows (combined stormflow and snowmelt) from upstream to downstream monitoring sites along the two major tributaries to Onondaga Lake - Onondaga Creek and Ninemile Creek. Median base-flow concentrations of ammonia and phosphorus and event concentrations of ammonia increased in the downstream direction in both streams. Whereas median event concentrations of other constituents in Onondaga Creek displayed no consistent trends, concentrations of ammonia-plus-organic nitrogen, orthophosphate, phosphorus, and suspended sediment in Ninemile Creek decreased from upstream to downstream sites. Springs discharging from the Onondaga and Bertie Limestone had measureable effects on water temperatures in the receiving streams and increased salinity and values of specific conductance in base flows. Loads of selected nutrients and suspended sediment transported in three tributaries of Otisco Lake were compared with loads from 1981-83. Loads of ammonia-plus-organic nitrogen and orthophosphate decreased from 1981-83 to 2005-08, but those of nitrate-plus-nitrite, phosphorus, and suspended sediment increased. The largest load increase was for suspende

Nutrient transport to the Swan-Canning Estuary, Western Australia

NASA Astrophysics Data System (ADS)

Peters, Norman E.; Donohue, Robert

2001-09-01

Catchment nutrient availability in Western Australia is primarily controlled by the disposal of animal waste and the type and rate of fertilizer application, particularly on the relatively narrow (25 km wide), sandy coastal plain. Nitrogen (N) and phosphorus (P) concentrations and fluxes during the wet season of 15 tributaries, including four urban drains to the Swan-Canning Estuary, were evaluated from 1986 to 1992 and additionally concentrations only were evaluated throughout the year from 1993 to 1996. Concentrations of filtered reactive P (FRP) and total P (TP) were generally low, with the volume-weighted means for all sites being 0·06 mg l-1 and 0·12 mg l-1 respectively. The urban drains had higher TP concentrations (volume-weighted mean of 0·21 mg l-1) than the streams (0·12 mg l-1), with the high concentrations associated with particulate matter. Total inorganic N (TIN, NH4N plus NO3N) and total N (TN), which is of interest to eutrophic status of the N-limited estuary, were likewise low, compared with other developed areas having a similar climate. Both TIN and TN were higher in the urban drains (0·76 mg l-1 and 1·5 mg l-1 respectively) than the streams (0·31 mg l-1 and 1·2 mg l-1 respectively). The Avon River, which drains 98·5% of the 121 000 km2 catchment area, contributes most of the N (0·03 kg ha-1 year-1 or 65%) and a high percentage of the P (<0·01 kg ha-1

Nutrient transport to the Swan - Canning Estuary, Western Australia

USGS Publications Warehouse

Peters, N.E.; Donohue, R.

2001-01-01

Catchment nutrient availability in Western Australia is primarily controlled by the disposal of animal waste and the type and rate of fertilizer application, particularly on the relatively narrow (~25 km wide), sandy coastal plain. Nitrogen (N) and phosphorous (P) concentrations and fluxes during the wet season of 15 tributaries, including four urban drains to the Swan-Canning Estuary, were evaluated from 1986 to 1992 and additionally concentrations only were evaluated throughout the year from 1993 to 1996. Concentrations of filtered reactive P (FRP) and total P (TP) were generally low, with the volume-weighted means for all sites being 0.06 mg 1-1 and 0.12 mg 1-1 respectively. The urban drains had higher TP concentrations (volume-weighted mean of 0.21 mg 1-1) than the streams (0.12 mg 1-1), with the high concentrations associated with particulate matter. Total inorganic N (TIN, NH4N plus NO3N) and total N (TN), which is of interest to eutrophic status of the N-limited estuary, were likewise low, compared with other developed areas having a similar climate. Both TIN and TN were higher in the urban drains (0.76 mg 1-1 and 1.5 mg 1-1 respectively) than the streams (0.31 mg 1-1 and 1.2 mg 1-1 respectively). The Avon River, which drains 98.5% of the 121 000 km2 catchment area, contributes most of the N (0.03 kg ha-1 year-1 or 65%) and a high percentage of the P (<0.01 kg ha-1 year-1 or 32%) to the estuaries. The Avon River nutrient fluxes are much less than other tributaries closer to the estuary. The coastal plain receives significantly higher rainfall (1,200 mm year-1) and has more intense horticulture and animal production than inland areas (<300 mm year-1). Annual rainfall is seasonal, occuring primarily from May through December. The surficial aquifers on the coastal plain generally are sandy with a low nutrient retention capacity, and rapidly transmit soluble and colloidal material in subsurface flow. Ellen Brook, on the coastal plain, drains pastures treated with superphosphate and has the highest FRP (0.51 mg 1-1), TP (0.7 mg 1-1) and TN (2.1 mg 1-1) of any tributary to the estuary. The coastal plain is also undergoing urbanization, particularly in areas adjacent to the estuary. Nutrients are subsequently available for transport during the onset of seasonal wet weather. Perennial baseflow from urban areas is an important source of nutrients. Water yield from the urban areas was high, being as much as 50% of annual rainfall. The timing of the nutrients delivered by the tributaries may be an important control on estuarine ecology. Copyright ?? 2001 John Wiley and Sons, Ltd.

Discontinuities in stream nutrient uptake below lakes in mountain drainage networks

USGS Publications Warehouse

Arp, C.D.; Baker, M.A.

2007-01-01

In many watersheds, lakes and streams are hydrologically linked in spatial patterns that influence material transport and retention. We hypothesized that lakes affect stream nutrient cycling via modifications to stream hydrogeomorphology, source-waters, and biological communities. We tested this hypothesis in a lake district of the Sawtooth Mountains, Idaho. Uptake of NO3- and PO4-3 was compared among 25 reaches representing the following landscape positions: lake inlets and outlets, reaches >1-km downstream from lakes, and reference reaches with no nearby lakes. We quantified landscape-scale hydrographic and reach-scale hydrogeomorphic, source-water, and biological variables to characterize these landscape positions and analyze relationships to nutrient uptake. Nitrate uptake was undetectable at most lake outlets, whereas PO4-3 uptake was higher at outlets as compared to reference and lake inlet reaches. Patterns in nutrient demand farther downstream were similar to lake outlets with a gradual shift toward reference-reach functionality. Nitrate uptake was most correlated to sediment mobility and channel morphology, whereas PO 4-3 uptake was most correlated to source-water characteristics. The best integrated predictor of these patterns in nutrient demand was % contributing area (the proportion of watershed area not routing through a lake). We estimate that NO3- and PO 4-3 demand returned to 50% of pre-lake conditions within 1-4-km downstream of a small headwater lake and resetting of nutrient demand was slower downstream of a larger lake set lower in a watershed. Full resetting of these nutrient cycling processes was not reached within 20-km downstream, indicating that lakes can alter stream ecosystem functioning at large spatial scales throughout mountain watersheds. ?? 2007, by the American Society of Limnology and Oceanography, Inc.

Restoring hydrological and biogeochemical ecosystem services in streams: how can science inform practice?

NASA Astrophysics Data System (ADS)

Lautz, L.; Gordon, R.; Daniluk, T.; Zimmer, M. A.; Endreny, T. A.; McGrath, K.

2014-12-01

Society is increasingly recognizing the value of stream ecosystem functions, as evidenced by the enormous economic investment being made in stream restoration across the United States. Stream restoration projects have a variety of goals, including improvement in water quality and in-stream habitat. Popular approaches to restoration (such as Natural Channel Design, or NCD) aim to move degraded streams along a trajectory toward a dynamic ecological endpoint that represents natural conditions. Project designs primarily focus on channel form and function, but stream-groundwater exchanges of water and solutes are not typically a design consideration, although a primary component of fully functioning stream ecosystems. Here, we synthesize results from field investigations of the impact of NCD stream restoration on stream-groundwater exchanges by (1) comparing restored sites to reference reaches, which serve as the basis for the restoration design, (2) characterizing multiple restored sites to determine universal characteristics of streams restored by NCD, and (3) monitoring a stream pre- and post- restoration. NCD restoration creates hot spots of rapid hyporheic exchange upstream of channel spanning structures, with water fluxes across the bed interface up to an order of magnitude higher than at pre-restoration or reference reaches. Elevated flux rates result in short hyporheic residence times, which are not sufficiently long to generate net changes in nutrient concentrations. Hot spots of biogeochemical transformations are instead located around secondary bedforms, such as pool-riffle sequences, where gross water exchange rates are more moderate. Reference reaches show greater evidence of groundwater discharge to the hyporheic zone relative to restored reaches, although observations before and after restoration suggest NCD can modify the spatial extent of groundwater discharge zones. Gross water exchange across the streambed interface along restored reaches is a small percentage of stream discharge, suggesting the primary impact of restoration on stream-groundwater exchange is promoting biochemical heterogeneity in the subsurface, rather than longitudinal net changes in stream solute concentrations. Results inform future design to achieve restoration goals.

Water-quality assessment of the Sacramento River basin, California : water quality of fixed sites, 1996-1998

USGS Publications Warehouse

Domagalski, Joseph L.; Dileanis, Peter D.

2000-01-01

Water-quality samples were collected from 12 sites in the Sacramento River Basin, Cali-fornia, from February 1996 through April 1998. Field measurements (dissolved oxygen, pH, specific conductance, alkalinity, and water tem-perature) were completed on all samples, and laboratory analyses were done for suspended sediments, nutrients, dissolved and particulate organic carbon, major ions, trace elements, and mercury species. Samples were collected at four types of locations on the Sacramento River?large tributaries to the Sacramento River, agricul-tural drainage canals, an urban stream, and a flood control channel. The samples were collected across a range of flow conditions representative of those sites during the timeframe of the study. The water samples from the Sacramento River indi-cate that specific conductance increases slightly downstream but that the water quality is indicative of dilute water. Water temperature of the Sacramento River increases below Shasta Lake during the spring and summer irrigation season owing to diversion of water out of the river and subsequent lower flow. All 12 sites had generally low concentrations of nutrients, but chlorophyll concentrations were not measured; therefore, the actual consequences of nutrient loading could not be adequately assessed. Concentrations of dis-solved organic carbon in samples from the Sacramento River and the major tributaries were generally low; the formation of trihalomethanes probably does not currently pose a problem when water from the Sacramento River and its major tributaries is chlorinated for drinking-water purposes. However, dissolved organic carbon concentrations were higher in the urban stream and in agricultural drainage canals, but were diluted upon mixing with the Sacramento River. The only trace element that currently poses a water-quality problem in the Sacramento River is mercury. A federal criterion for the protection of aquatic life was exceeded during this study, and floodwater concentrations of mercury were mostly higher than the criterion. Exceedances of water-quality standards happened most frequently during winter when suspended-sediment concen-trations also were elevated. Most mercury is found in association with suspended sediment. The greatest loading or transport of mercury out of the Sacramento River Basin to the San Francisco Bay occurs in the winter and principally follows storm events.

Measuring variability in trophic status in the Lake Waco/Bosque River Watershed

PubMed Central

Rodriguez, Angela D; Matlock, Marty D

2008-01-01

Background Nutrient management in rivers and streams is difficult due to the spatial and temporal variability of algal growth responses. The objectives of this project were to determine the spatial and seasonal in situ variability of trophic status in the Lake Waco/Bosque River watershed, determine the variability in the lotic ecosystem trophic status index (LETSI) at each site as indicators of the system's nutrient sensitivity, and determine if passive diffusion periphytometers could provide threshold algal responses to nutrient enrichment. Methods We used the passive diffusion periphytometer to measure in-situ nutrient limitation and trophic status at eight sites in five streams in the Lake Waco/Bosque River Watershed in north-central Texas from July 1997 through October 1998. The chlorophyll a production in the periphytometers was used as an indicator of baseline chlorophyll a productivity and of maximum primary productivity (MPP) in response to nutrient enrichment (nitrogen and phosphorus). We evaluated the lotic ecosystem trophic status index (LETSI) using the ratio of baseline primary productivity to MPP, and evaluated the trophic class of each site. Results The rivers and streams in the Lake Waco/Bosque River Watershed exhibited varying degrees of nutrient enrichment over the 18-month sampling period. The North Bosque River at the headwaters (NB-02) located below the Stephenville, Texas wastewater treatment outfall consistently exhibited the highest degree of water quality impact due to nutrient enrichment. Sites at the outlet of the watershed (NB-04 and NB-05) were the next most enriched sites. Trophic class varied for enriched sites over seasons. Conclusion Seasonality played a significant role in the trophic class and sensitivity of each site to nutrients. Managing rivers and streams for nutrients will require methods for measuring in situ responses and sensitivities to nutrient enrichment. Nutrient enrichment periphytometers show significant potential for use in nutrient gradient studies. PMID:18271947

Measuring variability in trophic status in the Lake Waco/Bosque River Watershed.

PubMed

Rodriguez, Angela D; Matlock, Marty D

2008-01-11

Nutrient management in rivers and streams is difficult due to the spatial and temporal variability of algal growth responses. The objectives of this project were to determine the spatial and seasonal in situ variability of trophic status in the Lake Waco/Bosque River watershed, determine the variability in the lotic ecosystem trophic status index (LETSI) at each site as indicators of the system's nutrient sensitivity, and determine if passive diffusion periphytometers could provide threshold algal responses to nutrient enrichment. We used the passive diffusion periphytometer to measure in-situ nutrient limitation and trophic status at eight sites in five streams in the Lake Waco/Bosque River Watershed in north-central Texas from July 1997 through October 1998. The chlorophyll a production in the periphytometers was used as an indicator of baseline chlorophyll a productivity and of maximum primary productivity (MPP) in response to nutrient enrichment (nitrogen and phosphorus). We evaluated the lotic ecosystem trophic status index (LETSI) using the ratio of baseline primary productivity to MPP, and evaluated the trophic class of each site. The rivers and streams in the Lake Waco/Bosque River Watershed exhibited varying degrees of nutrient enrichment over the 18-month sampling period. The North Bosque River at the headwaters (NB-02) located below the Stephenville, Texas wastewater treatment outfall consistently exhibited the highest degree of water quality impact due to nutrient enrichment. Sites at the outlet of the watershed (NB-04 and NB-05) were the next most enriched sites. Trophic class varied for enriched sites over seasons. Seasonality played a significant role in the trophic class and sensitivity of each site to nutrients. Managing rivers and streams for nutrients will require methods for measuring in situ responses and sensitivities to nutrient enrichment. Nutrient enrichment periphytometers show significant potential for use in nutrient gradient studies.

Geochemistry and characteristics of nitrogen transport at a confined animal feeding operation in a coastal plain agricultural watershed, and implications for nutrient loading in the Neuse River basin, North Carolina, 1999-2002

USGS Publications Warehouse

Spruill, T.B.; Tesoriero, A.J.; Mew, H.E.; Farrell, K.M.; Harden, S.L.; Colosimo, A.B.; Kraemer, S.R.

2005-01-01

Chemical, geologic, hydrologic, and age-dating information collected between 1999 and 2002 were used to examine the transport of contaminants, primarily nitrogen, in ground water and the pathways to surface water in a coastal plain setting in North Carolina. Data were collected from more than 35 wells and 4 surface-water sampling sites located in a 0.59 square-mile basin to examine detailed hydrogeology and geochemical processes affecting nutrient fate and transport. Two additional surface-water sampling sites were located downstream from the primary study site to evaluate basin-scale effects. Chemical and flow data also were collected at an additional 10 sites in the Coastal Plain portion of the Neuse River basin located between Kinston and New Bern, North Carolina, to evaluate loads transported in the Neuse River and primary tributary basins. At the Lizzie Research Station study site in North Carolina, horizontal flow is induced by the presence of a confining unit at shallow depth. Age-dating, chemical, and piezometric data indicate that horizontal flow from the surficial aquifer is the dominant source of ground water to streamflow. Nitrogen applied on cultivated fields at the Lizzie Research Station is substantially reduced as it moves from recharge to discharge areas. Denitrification in deeper parts of the aquifer and in riparian zones is indicated by a characterization of redox conditions in the aquifer and by the presence of excess nitrogen gas. Direct ground-water discharge of nitrate to surface water during base-flow conditions is unlikely to be significant because of strongly reducing conditions that occur in the riparian zones of these streams. Nitrate loads from a drainage tile at the study site may account for much of the nitrate load in the receiving stream, indicating that a major source of nutrients from ground water to this stream is artificial drainage. During base-flow conditions when the streams are not flowing, it is hypothesized that the mineralization of organic matter on the streambed is the source of nitrate and(or) ammonium in the stream. Base flow is a small contributor to nitrogen loads, because both flows and inorganic nitrogen concentrations are low during summer months. Effects of a confined hog operation on ground-water quality also were evaluated. The use of sprayed swine wastes to fertilize crops at the Lizzie Research Station study site since 1995 resulted in increased concentrations of nitrate and other chemical constituents in ground water beneath spray fields when compared to ground water beneath fields treated with commercial fertilizer. The nitrate concentration in ground water from the spray field well increased by a factor of 3.5 after 4 years of spray applications. Nitrate concentrations ranged from 10 to 35 milligrams per liter, and one concentration as high as 56 milligrams per liter was observed in water from this well in spring 2002. This finding is in agreement with findings of other studies conducted in the Coastal Plain of North Carolina that nitrate concentrations were significantly higher in ground water from cultivated fields sprayed with swine wastes than from fields treated with commercial fertilizer. Loads and yields of nitrogen and phosphorus in 14 streams in the Neuse River basin were evaluated for calendar years 2000 and 2001. Data indicate that anthropogenic effects on nitrogen yields were greatest in the first-order stream studied (yields were greater than 2 tons per square mile [ton/mi2] and 1 ton/mi2 or less in second- and higher-order streams) in the Little Contentnea Creek subbasin. Nitrogen yields in streams in the Contentnea Creek subbasin ranged from 0.59 to 2 ton/mi2 with typical yields of approximately 1 ton/mi2. Contentnea Creek near Evansdale had the highest yield (2 ton/mi2), indicating that a major source of nitrogen is upstream from this station. Nitrogen yields were lower at Contentnea Creek at Hookerton in 2000 and 2001 compared to previous yi

Recycle of Inorganic Nutrients for Hydroponic Crop Production Following Incineration of Inedible Biomass

NASA Technical Reports Server (NTRS)

Bubenheim, David L.; Wignarajah, Kanapathipillai; Kliss, Mark H. (Technical Monitor)

1996-01-01

Recovery of resources from waste streams is essential for future implementation and reliance on a regenerative life support system. The major waste streams of concern are from human activities and plant wastes. Carbon, water and inorganics are the primary desired raw materials of interest. The goal of resource recovery is maintenance of product quality to insure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. Today, reagent grade nutrients are used to make nutrient solutions for hydroponic culture and these solutions are frequently changed during the life cycle or sometimes managed for only one crop life cycle. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration in all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match control, and ash only quality formulated with reagent grade chemicals. When nutrient solutions are formulated using only ash following-incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in suppression of crop growth. When the ash is supplemented with nutrients to establish the same balance as in the control, growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals but matching the quality of the ash only treatment resulted in growth similar to that of the ash only treatment. The ash product resulting from incineration of inedible biomass appears to be a suitable form for recycle of inorganic nutrients to crop production.

Nutrients, Dissolved Organic Carbon, Color, and Disinfection Byproducts in Base Flow and Stormflow in Streams of the Croton Watershed, Westchester and Putnam Counties, New York, 2000-02

USGS Publications Warehouse

Heisig, Paul M.

2009-01-01

The Croton Watershed is unique among New York City's water-supply watersheds because it has the highest percentages of suburban development (52 percent) and wetland area (6 percent). As the City moves toward filtration of this water supply, there is a need to document water-quality contributions from both human and natural sources within the watershed that can inform watershed-management decisions. Streamwater samples from 24 small (0.1 to 1.5 mi2) subbasins and three wastewater-treatment plants (2000-02) were used to document the seasonal concentrations, values, and formation potentials of selected nutrients, dissolved organic carbon (DOC), color, and disinfection byproducts (DBPs) during stormflow and base-flow conditions. The subbasins were categorized by three types of drainage efficiency and a range of land uses and housing densities. Analyte concentrations in subbasin streams differed in response to the subbasin charateristics. Nutrient concentrations were lowest in undeveloped, forested subbasins that were well drained and increased with all types of development, which included residential, urban commercial/industrial, golf-course, and horse-farm land uses. These concentrations were further modified by subbasin drainage efficiency. DOC, in contrast, was highly dependent on drainage efficiency. Color intensity and DBP formation potentials were, in turn, associated with DOC and thus showed a similar response to drainage efficiency. Every constituent exhibited seasonal changes in concentration. Nutrients. Total (unfiltered) phosphorus (TP), soluble reactive phosphorus (SRP), and nitrate were associated primarily with residential development, urban, golf-course, and horse-farm land uses. Base-flow and stormflow concentrations of the TP, SRP, and nitrate generally increased with increasing housing density. TP and SRP concentrations were nearly an order of magnitude higher in stormflow than in base flow, whereas nitrate concentrations showed little difference between these flow conditions. Organic nitrogen concentrations (calculated as the difference between concentrations of total dissolved N and of all other N species) was the dominant form of nitrogen in undeveloped and moderately to poorly drained subbasins. High TP concentrations in stormflows (800-1,750 ug/L) were associated with well drained and moderately drained residential subbasins with high- and medium-density housing and with the moderately drained golf-course subbasin. Areas with medium to high housing densities favor TP transport because they provide extensive impervious surfaces, storm sewers, and local relief, which together can rapidly route stormwater to streams. SRP concentrations were highest in the same types of subbasins as TP, but also in sewered residential and horse-farm subbasins. The ratio of SRP to TP was typically a smaller in stormflow than in base flow. Base-flow TP and SRP concentrations were highest during the warm-weather months (May to October). The highest nitrate concentrations (3.0-4.5 mg/L) were associated with the urban subbasin and the three well drained, high-density residential subbasins. The two moderately drained lake subbasins and the two poorly drained (colored-water wetland) subbasins had consistently low nitrate concentrations despite low and medium housing densities. Nitrate concentrations were generally highest during the winter months and lowest during the autumn leaf-fall period. Organic N concentrations were highest during the leaf-fall period. Dissolved Organic Carbon. DOC concentration was consistently highest in the two poorly drained (colored-water-wetland) subbasins and lowest in the well drained subbasins. Base-flow DOC concentration increased with decreasing drainage efficiency, except in the well drained sewered subbasin with high-density housing, where slightly elevated DOC concentrations throughout the year may indicate leakage from a nearby sewer main. Seasonal changes in stormflow DOC concentrat

NUTRIENT UPTAKE LENGTH, CHANNEL STRUCTURE, AND TRANSIENT STORAGE IN STREAMS DRAINING HARVESTED AND OLD GROWTH WATERSHEDS

EPA Science Inventory

Channel structure and transient storage were correlated with nutrient uptake length in streams draining old-growth and harvested watersheds in the Cascade Mountains of Oregon, and the redwood forests of northwestern California. Channel width and riparian canopy were measured at 1...

Stream restoration and sewers impact sources and fluxes of water,carbon, and nutrients in urban watersheds

EPA Science Inventory

An improved understanding of sources and timing of water and nutrient fluxes associated with urban stream restoration is critical for guiding effective watershed management. We investigated how sources, fluxes, and flowpaths of water, carbon (C), nitrogen (N), and phosphorus (P)...

LANDSCAPE INDICATORS FOR PESTICIDES, NUTRIENTS, EMERGING CONTAMINANTS, AND AQUATIC BIOLOGY IN MIDWESTERN CORN BELT STREAMS

EPA Science Inventory

This study is part of a long-term cooperative national research project among the US EPA and the USGS to collect comparable water-quality data from small streams and to develop regional predicitive models that use landscape characteristics to estimate pesticide and nutrient conce...

Quantifying spatial differences in metabolism in headwater streams

Treesearch

Ricardo González-Pinzón; Roy Haggerty; Alba Argerich

2014-01-01

Stream functioning includes simultaneous interaction among solute transport, nutrient processing, and metabolism. Metabolism is measured with methods that have limited spatial representativeness and are highly uncertain. These problems restrict development of methods for up-scaling biological processes that mediate nutrient processing. We used the resazurin–resorufin (...

ESTIMATION OF TOTAL DISSOLVED NITRATE LOAD IN NATURAL STREAM FLOWS USING AN IN-STREAM MONITOR

EPA Science Inventory

Estuaries respond rapidly to rain events and the nutrients carried by inflowing rivers such that discrete samples at weekly or monthly intervals are inadequate to catch the maxima and minima in nutrient variability. To acquire data with sufficient sampling frequency to realistica...

Evaluation of stream water quality in Atlanta, Georgia, and the surrounding region (USA)

USGS Publications Warehouse

Peters, N.E.; Kandell, S.J.

1999-01-01

A water-quality index (WQI) was developed from historical data (1986-1995) for streams in the Atlanta Region and augmented with 'new' and generally more comprehensive biweekly data on four small urban streams, representing an industrial area, a developed medium-density residential area and developing and developed low-density residential areas. Parameter WQIs were derived from percentile ranks of individual water-quality parameter values for each site by normalizing the constituent ranks for values from all sites in the area for a base period, i.e. 1990-1995. WQIs were developed primarily for nutrient-related parameters due to data availability. Site WQIs, which were computed by averaging the parameter WQIs, range from 0.2 (good quality) to 0.8 (poor quality), and increased downstream of known nutrient sources. Also, annual site WQI decreases from 1986 to 1995 at most long-term monitoring sites. Annual site WQI for individual parameters correlated with annual hydrological characteristics, particularly runoff, precipitation quantity, and water yield, reflecting the effect of dilution on parameter values. The WQIs of the four small urban streams were evaluated for the core-nutrient-related parameters, parameters for specific dissolved trace metal concentrations and sediment characteristics, and a species diversity index for the macro-invertebrate taxa. The site WQI for the core-nutrient-related parameters used in the retrospective analysis was, as expected, the worst for the industrial area and the best for the low-density residential areas. However, macro-invertebrate data indicate that although the species at the medium-density residential site were diverse, the taxa at the site were for species tolerant of degraded water quality. Furthermore, although a species-diversity index indicates no substantial difference between the two low-density residential areas, the number for macro-invertebrates for the developing area was much less than that for the developed area, consistent with observations of recent sediment problems probably associated with construction in the basin. However, sediment parameters were similar for the two sites suggesting that the routine biweekly measurements may not capture the short-term increases in sediment transport associated with rainstorms. The WQI technique is limited by the number and types of parameters included in it, the general conditions of those parameters for the range of conditions in area streams, and by the effects of external factors, such as hydrology, and therefore, should be used with caution.

A Bayesian changepoint-threshold model to examine the effect of TMDL implementation on the flow-nitrogen concentration relationship in the Neuse River basin.

PubMed

Alameddine, Ibrahim; Qian, Song S; Reckhow, Kenneth H

2011-01-01

In-stream nutrient concentrations are well known to exhibit a strong relationship with river flow. The use of flow measurements to predict nutrient concentrations and subsequently nutrient loads is common in water quality modeling. Nevertheless, most adopted models assume that the relationship between flow and concentration is fixed across time as well as across different flow regimes. In this study, we developed a Bayesian changepoint-threshold model that relaxes these constraints and allows for the identification and quantification of any changes in the underlying flow-concentration relationship across time. The results from our study support the occurrence of a changepoint in time around the year 1999, which coincided with the period of implementing nitrogen control measures as part of the TMDL program developed for the Neuse Estuary in North Carolina. The occurrence of the changepoint challenges the underlying assumption of temporal invariance in the flow-concentrations relationship. The model results also point towards a transition in the river nitrogen delivery system from a point source dominated loading system towards a more complicated nonlinear system, where non-point source nutrient delivery plays a major role. Moreover, we use the developed model to assess the effectiveness of the nitrogen reduction measures in achieving a 30% drop in loading. The results indicate that while there is a strong evidence of a load reduction, there still remains a high level of uncertainty associated with the mean nitrogen load reduction. We show that the level of uncertainty around the estimated load reduction is not random but is flow related. Copyright © 2010 Elsevier Ltd. All rights reserved.

Before and After Integrated Catchment Management in a Headwater Catchment: Changes in Water Quality

NASA Astrophysics Data System (ADS)

Hughes, Andrew O.; Quinn, John M.

2014-12-01

Few studies have comprehensively measured the effect on water quality of catchment rehabilitation measures in comparison with baseline conditions. Here we have analyzed water clarity and nutrient concentrations and loads for a 13-year period in a headwater catchment within the western Waikato region, New Zealand. For the first 6 years, the entire catchment was used for hill-country cattle and sheep grazing. An integrated catchment management plan was implemented whereby cattle were excluded from riparian areas, the most degraded land was planted in Pinus radiata, channel banks were planted with poplar trees and the beef cattle enterprise was modified. The removal of cattle from riparian areas without additional riparian planting had a positive and rapid effect on stream water clarity. In contrast, the water clarity decreased in those sub-catchments where livestock was excluded but riparian areas were planted with trees and shrubs. We attribute the decrease in water clarity to a reduction in groundcover vegetation that armors stream banks against preparatory erosion processes. Increases in concentrations of forms of P and N were recorded. These increases were attributed to: (i) the reduction of instream nutrient uptake by macrophytes and periphyton due to increased riparian shading; (ii) uncontrolled growth of a nitrogen fixing weed (gorse) in some parts of the catchment, and (iii) the reduction in the nutrient attenuation capacity of seepage wetlands due to the decrease in their areal coverage in response to afforestation. Our findings highlight the complex nature of the water quality response to catchment rehabilitation measures.

Nutrient contributions and biogas potential of co-digestion of feedstocks and dairy manure.

PubMed

Ma, Guiling; Neibergs, J Shannon; Harrison, Joseph H; Whitefield, Elizabeth M

2017-06-01

This study focused on collection of data on nutrient flow and biogas yield at a commercial anaerobic digester managed with dairy manure from a 1000 cow dairy and co-digestion of additional feedstocks. Feedstocks included: blood, fish, paper pulp, out of date beverages and grease trap waste. Mass flow of inputs and outputs, nutrient concentration of inputs and outputs, and biogas yield were obtained. It was determined that manure was the primary source of nutrients to the anaerobic digester when co-digested with feedstocks. The percentage of contribution from manure to the total nutrient inputs for total nitrogen, ammonia-nitrogen, phosphorus and total solids was 46.3%, 67.7%, 32.8% and 23.4%, respectively. On average, manure contributed the greatest amount of total nitrogen and ammonia-nitrogen. Grease trap waste contributed the greatest amount of phosphorus and total solids at approximately 50%. Results demonstrated that a reliable estimate of nutrient inflow could be obtained from the product of the nutrient analyses of a single daily composite of influent subsamples times the total daily flow estimated with an in-line flow meter. This approach to estimate total daily nutrient inflow would be more cost effective than testing and summing the contribution of individual feedstocks. Data collected after liquid-solid separation confirmed that the majority (>75%) of nutrients remain with the liquid effluent portion of the manure stream. It was demonstrated that the ash concentration in solids before and after composting could be used to estimate the mass balance of total solids during the compost process. This data confirms that biogas or methane yield could be accurately measured from the ratio of % volatile solids to % total solids. Copyright © 2017 Elsevier Ltd. All rights reserved.

The differing biogeochemical and microbial signatures of glaciers and rock glaciers

USGS Publications Warehouse

Fegel, Timothy S.; Baron, Jill S.; Fountain, Andrew G.; Johnson, Gunnar F.; Hall, Edward K.

2016-01-01

Glaciers and rock glaciers supply water and bioavailable nutrients to headwater mountain lakes and streams across all regions of the American West. Here we present a comparative study of the metal, nutrient, and microbial characteristics of glacial and rock glacial influence on headwater ecosystems in three mountain ranges of the contiguous U.S.: The Cascade Mountains, Rocky Mountains, and Sierra Nevada. Several meltwater characteristics (water temperature, conductivity, pH, heavy metals, nutrients, complexity of dissolved organic matter (DOM), and bacterial richness and diversity) differed significantly between glacier and rock glacier meltwaters, while other characteristics (Ca2+, Fe3+, SiO2 concentrations, reactive nitrogen, and microbial processing of DOM) showed distinct trends between mountain ranges regardless of meltwater source. Some characteristics were affected both by glacier type and mountain range (e.g. temperature, ammonium (NH4+) and nitrate (NO3- ) concentrations, bacterial diversity). Due to the ubiquity of rock glaciers and the accelerating loss of the low latitude glaciers our results point to the important and changing influence that these frozen features place on headwater ecosystems.

Concentration-Discharge Responses to Storm Events in Coastal California Watersheds

NASA Astrophysics Data System (ADS)

Aguilera, Rosana; Melack, John M.

2018-01-01

Storm events in montane catchments are the main cause of mobilization of solutes and particulates into and within stream channels in coastal California. Nonlinear behavior of nutrients and suspended sediments during storms is evident in the hysteresis that arises in concentration-discharge (C-Q) relationships. We examined patterns in the C-Q hysteresis of nutrients (NO3-, NH4+, DON, and PO43-) and total suspended solids (TSS) during storms across 10 sites and water years 2002-2015 by quantifying the slope of the C-Q relationship and the rotational pattern of the hysteresis loop. We observed several hysteresis types in the ˜400 storms included in our study. Concentrations of constituents associated with sediment transport (PO43- and TSS) peaked during high flows. Conversely, nitrogen species had hysteretic responses such as dilution with clockwise rotation in urban sites and enrichment with anticlockwise rotation in undeveloped sites. The wide range of C-Q responses that occurred among sites and seasons reflected the variable hydrological and biogeochemical characteristics of catchments and storms. Responses for nitrate in nested catchments differed in slope and rotation of C-Q hysteresis. Upland undeveloped and lowland urban sites had anticlockwise rotation at the onset of the rainy season following a dry year, which implied a delay in the transport of this solute to the streams. Slopes by the middle of the rainy season showed that the urban site switched from dilution to enrichment, and then again to dilution with clockwise rotation at the end of the season, which implied high initial concentrations and proximal sources.

Analysis of stream quality in the Yampa River Basin, Colorado and Wyoming

USGS Publications Warehouse

Wentz, Dennis A.; Steele, Timothy Doak

1980-01-01

Historic data show no significant water-temperature changes since 1951 for the Little Snake or Yampa Rivers, the two major streams of the Yampa River basin in Colorado and Wyoming. Regional analyses indicate that harmonic-mean temperature is negatively correlated with altitude. No change in specific conductance since 1951 was noted for the Little Snake River; however, specific conductance in the Yampa River has increaed 14 % since that time and is attributed to increased agricultural and municipal use of water. Site-specific relationships between major inorganic constituents and specific conductance for the Little Snake and Yampa Rivers were similar to regional relationships developed from both historic and recent (1975) data. These relationships provide a means for estimating concentrations of major inorganic constituents from specific conductance, which is easily measured. Trace-element and nutrient data collected from August 1975 through September 1976 at 92 sites in the Yampa River basin indicate that water-quality degradation occurred upstream from 3 sites. The degradation resulted from underground drainage from pyritic materials that probably are associated with coal at one site, discharge from powerplant cooling-tower blowdown water at a second site, and runoff from a small watershed containing a gas field at the third site. Ambient concentrations of dissolved and total iron and manganese frequently exceeded proposed Colorado water-quality standards. The concentrations of many dissolved and total trace elements and nutrients were greatest during March 1976. These were associated with larger suspended-sediment concentrations and smaller pH values than at other times of the year. (USGS)

Water-quality assessment of White River between Lake Sequoyah and Beaver Reservoir, Washington County, Arkansas

USGS Publications Warehouse

Terry, J.E.; Morris, E.E.; Bryant, C.T.

1982-01-01

The Arkansas Department of Pollution Control and Ecology and U.S. Geological Survey conducted a water quality assessment be made of the White River and, that a steady-state digital model be calibrated and used as a tool for simulating changes in nutrient loading. The city of Fayetteville 's wastewater-treatment plant is the only point-source discharger of waste effluent to the river. Data collected during synoptic surveys downstream from the wastewater-treatment plan indicate that temperature, dissolved oxygen, dissolved solids, un-ionized ammonia, total phosphorus, and floating solids and depositable materials did not meet Arkansas stream standards. Nutrient loadings below the treatment plant result in dissolved oxygen concentrations as low as 0.0 milligrams per liter. Biological surveys found low macroinvertebrate organism diversity and numerous dead fish. Computed dissolved oxygen deficits indicate that benthic demands are the most significant oxygen sinks in the river downstream from the wastewater-treatment plant. Benthic oxygen demands range from 2.8 to 11.0 grams per meter squared per day. Model projections indicate that for 7-day, 10-year low-flow conditions and water temperature of 29 degrees Celsius, daily average dissolved oxygen concentrations of 6.0 milligrams per liter can be maintained downstream from the wastewater-treatment plant if effluent concentrations of ultimate carbonaceous biochemical oxygen demand and ammonia nitrogen are 7.5 (5.0 5-day demand) and 2 milligrams per liter respectively. Model sensitivity analysis indicate that dissolved oxygen concentrations were most sensitive to changes in stream temperature. (USGS)

Trace elements in stormflow, ash, and burned soil following the 2009 station fire in southern California

USGS Publications Warehouse

Burton, Carmen; Hoefen, Todd M.; Plumlee, Geoffrey S.; Baumberger, Katherine L.; Backlin, Adam R.; Gallegos, Elizabeth; Fisher, Robert N.

2016-01-01

Most research on the effects of wildfires on stream water quality has focused on suspended sediment and nutrients in streams and water bodies, and relatively little research has examined the effects of wildfires on trace elements. The purpose of this study was two-fold: 1) to determine the effect of the 2009 Station Fire in the Angeles National Forest northeast of Los Angeles, CA on trace element concentrations in streams, and 2) compare trace elements in post-fire stormflow water quality to criteria for aquatic life to determine if trace elements reached concentrations that can harm aquatic life. Pre-storm and stormflow water-quality samples were collected in streams located inside and outside of the burn area of the Station Fire. Ash and burned soil samples were collected from several locations within the perimeter of the Station Fire. Filtered concentrations of Fe, Mn, and Hg and total concentrations of most trace elements in storm samples were elevated as a result of the Station Fire. In contrast, filtered concentrations of Cu, Pb, Ni, and Se and total concentrations of Cu were elevated primarily due to storms and not the Station Fire. Total concentrations of Se and Zn were elevated as a result of both storms and the Station Fire. Suspended sediment in stormflows following the Station Fire was an important transport mechanism for trace elements. Cu, Pb, and Zn primarily originate from ash in the suspended sediment. Fe primarily originates from burned soil in the suspended sediment. As, Mn, and Ni originate from both ash and burned soil. Filtered concentrations of trace elements in stormwater samples affected by the Station Fire did not reach levels that were greater than criteria established for aquatic life. Total concentrations for Fe, Pb, Ni, and Zn were detected at concentrations above criteria established for aquatic life.

Trace Elements in Stormflow, Ash, and Burned Soil following the 2009 Station Fire in Southern California

PubMed Central

Burton, Carmen A.; Hoefen, Todd M.; Plumlee, Geoffrey S.; Baumberger, Katherine L.; Backlin, Adam R.; Gallegos, Elizabeth; Fisher, Robert N.

2016-01-01

Most research on the effects of wildfires on stream water quality has focused on suspended sediment and nutrients in streams and water bodies, and relatively little research has examined the effects of wildfires on trace elements. The purpose of this study was two-fold: 1) to determine the effect of the 2009 Station Fire in the Angeles National Forest northeast of Los Angeles, CA on trace element concentrations in streams, and 2) compare trace elements in post-fire stormflow water quality to criteria for aquatic life to determine if trace elements reached concentrations that can harm aquatic life. Pre-storm and stormflow water-quality samples were collected in streams located inside and outside of the burn area of the Station Fire. Ash and burned soil samples were collected from several locations within the perimeter of the Station Fire. Filtered concentrations of Fe, Mn, and Hg and total concentrations of most trace elements in storm samples were elevated as a result of the Station Fire. In contrast, filtered concentrations of Cu, Pb, Ni, and Se and total concentrations of Cu were elevated primarily due to storms and not the Station Fire. Total concentrations of Se and Zn were elevated as a result of both storms and the Station Fire. Suspended sediment in stormflows following the Station Fire was an important transport mechanism for trace elements. Cu, Pb, and Zn primarily originate from ash in the suspended sediment. Fe primarily originates from burned soil in the suspended sediment. As, Mn, and Ni originate from both ash and burned soil. Filtered concentrations of trace elements in stormwater samples affected by the Station Fire did not reach levels that were greater than criteria established for aquatic life. Total concentrations for Fe, Pb, Ni, and Zn were detected at concentrations above criteria established for aquatic life. PMID:27144270

Water-quality parameters and benthic algal communities at selected streams in Minnesota, August 2000 - Study design, methods and data

USGS Publications Warehouse

Lee, K.E.

2002-01-01

This report describes the study design, sampling methods, and summarizes the physical, chemical, and benthic algal data for a component of the multiagency study that was designed to document diurnal water-quality measurements (specific conductance, pH, water temperature, and dissolved oxygen), benthic algal community composition and chlorophyll-a content, and primary productivity at 12 stream sites on 6 streams in Minnesota during August 2000. Specific conductance, pH, water temperature, dissolved oxygen concentrations and percent dissolved oxygen saturation measurements were made with submersible data recorders at 30 minute intervals for a period of 3-6 days during August 2000. Benthic algae collected from wood and rock substrate were identified and enumerated. Biovolume (volume of algal cells per unit area), density (number of cells per unit area), and chlorophyll-a content from benthic algae were determined. These data can be used as part of the multiagency study to develop an understanding of the relations among nutrient concentrations, algal abundance, algal community composition, and primary production and respiration processes in rivers of differing ecoregions in Minnesota.

Climate change and wetland loss impacts on a Western river's water quality

NASA Astrophysics Data System (ADS)

Records, R. M.; Arabi, M.; Fassnacht, S. R.; Duffy, W. G.; Ahmadi, M.; Hegewisch, K. C.

2014-05-01

An understanding of potential stream water quality conditions under future climate is critical for the sustainability of ecosystems and protection of human health. Changes in wetland water balance under projected climate could alter wetland extent or cause wetland loss. This study assessed the potential climate-induced changes to in-stream sediment and nutrients loads in the historically snow melt-dominated Sprague River, Oregon, Western United States. Additionally, potential water quality impacts of combined changes in wetland water balance and wetland area under future climatic conditions were evaluated. The study utilized the Soil and Water Assessment Tool (SWAT) forced with statistical downscaling of general circulation model (GCM) data from the Coupled Model Intercomparison Project 5 (CMIP5) using the Multivariate Adaptive Constructed Analogs (MACA) method. Our findings suggest that in the Sprague River (1) mid-21st century nutrient and sediment loads could increase significantly during the high flow season under warmer-wetter climate projections, or could change only nominally in a warmer and somewhat drier future; (2) although water quality conditions under some future climate scenarios and no wetland loss may be similar to the past, the combined impact of climate change and wetland losses on nutrient loads could be large; (3) increases in stream total phosphorus (TP) concentration with wetland loss under future climate scenarios would be greatest at high-magnitude, low-probability flows; and (4) loss of riparian wetlands in both headwaters and lowlands could increase outlet TP loads to a similar degree, but this could be due to distinctly different mechanisms in different parts of the watershed.

Assessing the chemical contamination dynamics in a mixed land use stream system.

PubMed

Sonne, Anne Th; McKnight, Ursula S; Rønde, Vinni; Bjerg, Poul L

2017-11-15

Traditionally, the monitoring of streams for chemical and ecological status has been limited to surface water concentrations, where the dominant focus has been on general water quality and the risk for eutrophication. Mixed land use stream systems, comprising urban areas and agricultural production, are challenging to assess with multiple chemical stressors impacting stream corridors. New approaches are urgently needed for identifying relevant sources, pathways and potential impacts for implementation of suitable source management and remedial measures. We developed a method for risk assessing chemical stressors in these systems and applied the approach to a 16-km groundwater-fed stream corridor (Grindsted, Denmark). Three methods were combined: (i) in-stream contaminant mass discharge for source quantification, (ii) Toxic Units and (iii) environmental standards. An evaluation of the chemical quality of all three stream compartments - stream water, hyporheic zone, streambed sediment - made it possible to link chemical stressors to their respective sources and obtain new knowledge about source composition and origin. Moreover, toxic unit estimation and comparison to environmental standards revealed the stream water quality was substantially impaired by both geogenic and diffuse anthropogenic sources of metals along the entire corridor, while the streambed was less impacted. Quantification of the contaminant mass discharge originating from a former pharmaceutical factory revealed that several 100 kgs of chlorinated ethenes and pharmaceutical compounds discharge into the stream every year. The strongly reduced redox conditions in the plume result in high concentrations of dissolved iron and additionally release arsenic, generating the complex contaminant mixture found in the narrow discharge zone. The fingerprint of the plume was observed in the stream several km downgradient, while nutrients, inorganics and pesticides played a minor role for the stream health. The results emphasize that future investigations should include multiple compounds and stream compartments, and highlight the need for holistic approaches when risk assessing these dynamic systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Controls on methane concentrations and fluxes in streams draining human-dominated landscapes

USGS Publications Warehouse

Crawford, John T.; Stanley, Emily H.

2016-01-01

Streams and rivers are active processors of carbon, leading to significant emissions of CO2 and possibly CH4 to the atmosphere. Patterns and controls of CH4 in fluvial ecosystems remain relatively poorly understood. Furthermore, little is known regarding how major human impacts to fluvial ecosystems may be transforming their role as CH4 producers and emitters. Here, we examine the consequences of two distinct ecosystem changes as a result of human land use: increased nutrient loading (primarily as nitrate), and increased sediment loading and deposition of fine particles in the benthic zone. We did not find support for the hypothesis that enhanced nitrate loading down-regulates methane production via thermodynamic or toxic effects. We did find strong evidence that increased sedimentation and enhanced organic matter content of the benthos lead to greater methane production (diffusive + ebullitive flux) relative to pristine fluvial systems in northern Wisconsin (upper Midwest, USA). Overall, streams in a human-dominated landscape of southern Wisconsin were major regional sources of CH4 to the atmosphere, equivalent to ~20% of dairy cattle emissions, or ~50% of a landfill’s annual emissions. We suggest that restoration of the benthic environment (reduced fine deposits) could lead to reduced CH4 emissions, while decreasing nutrient loading is likely to have limited impacts to this ecosystem process.

Relationships between ecosystem metabolism, benthic macroinvertebrate densities, and environmental variables in a sub-arctic Alaskan river

USGS Publications Warehouse

Benson, Emily R.; Wipfli, Mark S.; Clapcott, Joanne E.; Hughes, Nicholas F.

2013-01-01

Relationships between environmental variables, ecosystem metabolism, and benthos are not well understood in sub-arctic ecosystems. The goal of this study was to investigate environmental drivers of river ecosystem metabolism and macroinvertebrate density in a sub-arctic river. We estimated primary production and respiration rates, sampled benthic macroinvertebrates, and monitored light intensity, discharge rate, and nutrient concentrations in the Chena River, interior Alaska, over two summers. We employed Random Forests models to identify predictor variables for metabolism rates and benthic macroinvertebrate density and biomass, and calculated Spearman correlations between in-stream nutrient levels and metabolism rates. Models indicated that discharge and length of time between high water events were the most important factors measured for predicting metabolism rates. Discharge was the most important variable for predicting benthic macroinvertebrate density and biomass. Primary production rate peaked at intermediate discharge, respiration rate was lowest at the greatest time since last high water event, and benthic macroinvertebrate density was lowest at high discharge rates. The ratio of dissolved inorganic nitrogen to soluble reactive phosphorus ranged from 27:1 to 172:1. We found that discharge plays a key role in regulating stream ecosystem metabolism, but that low phosphorous levels also likely limit primary production in this sub-arctic stream.

Chapter A. Effects of urbanization on stream ecosystems in the South Platte River basin, Colorado and Wyoming

USGS Publications Warehouse

Sprague, Lori A.; Zuellig, Robert E.; Dupree, Jean A.

2006-01-01

This report describes the effects of urbanization on physical, chemical, and biological characteristics of stream ecosystems in 28 basins along an urban land-use gradient in the South Platte River Basin, Colorado and Wyoming, from 2002 through 2003. Study basins were chosen to minimize natural variability among basins due to factors such as geology, elevation, and climate and to maximize coverage of different stages of urban development among basins. Because land use or population density alone often are not a complete measure of urbanization, land use, land cover, infrastructure, and socioeconomic variables were integrated in a multimetric urban intensity index to represent the degree of urban development in each study basin. Physical characteristics studied included stream hydrology, stream temperature, and habitat; chemical characteristics studied included nutrients, pesticides, suspended sediment, sulfate, chloride, and fecal bacteria concentrations; and biological characteristics studied included algae, fish, and invertebrate communities. Semipermeable membrane devices (SPMDs), passive samplers that concentrate trace levels of hydrophobic organic contaminants like polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), also were used. The objectives of the study were to (1) examine physical, chemical, and biological responses along the gradient of urbanization; (2) determine the major physical, chemical, and landscape variables affecting the structure of aquatic communities; and (3) evaluate the relevance of the results to the management of water resources in the South Platte River Basin. Commonly observed effects of urbanization on instream physical, chemical, and biological characteristics, such as increased flashiness, higher magnitude and more frequent peak flows, increased concentrations of chemicals, and changes in aquatic community structure, generally were not observed in this study. None of the hydrologic, temperature, habitat, or chemical variables were correlated strongly (Spearman's rho greater than or equal to 0.7) with urban intensity, with the exception of some of the SPMD-based toxicity and chemical variables. SPMD-based measures of potential toxicity and PAH concentrations were positively correlated with urban intensity. The PAH concentrations also were positively correlated with measures of road density and negatively correlated with distance to the nearest road, indicating that automobile exhaust is a major source of these compounds in the study area. This source may be localized enough that the transport of PAHs would be minimally affected by water-management practices such as diversion or storage upstream. In contrast, the predominant sources of nutrients, bacteria, suspended sediment, sulfate, chloride, and pesticides may be more dispersed throughout the drainage area and, therefore, their transport to downstream sites may be subject to greater disruption by water regulation. Although no direct link was found between most water-chemistry characteristics and urbanization, invertebrate, algae, and fish-community characteristics were strongly associated with nutrients, pesticides, sulfate, chloride, and suspended sediment. None of the biological community variables were strongly correlated with the urban intensity index. Algal biomass predominantly was associated with total nitrogen concentrations, nitrite-plus-nitrate concentrations, and the duration of high flows. Fish communities predominantly were associated with housing age, the percentage of suspended sediment finer than 0.063 millimeters and chloride concentrations. Invertebrate communities predominantly were associated with the frequency of rising and falling flow events, the duration of high flows, total nitrogen concentrations, nitrite-plus-nitrate concentrations, and total herbicide concentrations. Historical records indicate that aquatic communities in the region may have been altered prior to any substantial urban development by early agricultural and water-management practices. Present-day aquatic communities are composed primarily of tolerant species even in areas of minimal urban development; when development does occur, the communities already may be resistant to disturbance. In addition to the effects of historical stressors on aquatic community structure, it is possible that current water-management practices in the study basins are having an effect. In the absence of natural, unaltered hydrologic conditions, more sensitive taxa may be unable to recolonize urban streams. The movement and storage of water also may lead to a disconnect between the land surface and streams, resulting in instream physical, chemical, and biological characteristics that, to some degree, are independent of land-cover characteristics.

Coupled Spatio-Temporal Patterns of Solute Transport, Metabolism and Nutrient Uptake in Streams

NASA Astrophysics Data System (ADS)

Kurz, M. J.; Schmidt, C.

2017-12-01

Slower flow velocities and longer residence times within stream transient storage (TS) zones facilitate interaction between solutes and microbial communities, potentially increasing local rates of metabolic activity. Multiple factors, including channel morphology and substrate, variable hydrology, and seasonal changes in biological and physical parameters, result in changes in the solute transport dynamics and reactivity of TS zones over time and space. These changes would be expected to, in turn, influence rates of whole-stream ecosystem functions such as metabolism and nutrient uptake. However, the linkages between solute transport and ecosystem functioning within TS zones, and the contribution of TS zones to whole-stream functioning, are not always so straight forward. This may be due, in part, to methodological challenges. In this study we investigated the influence of stream channel hydro-morphology and substrate type on reach (103 m) and sub-reach (102 m) scale TS and ecosystem functioning. Patterns in solute transport, metabolism and nitrate uptake were tracked from April through October in two contrasting upland streams using several methods. The two streams, located in the Harz Mountains, Germany, are characterized by differing size (0.02 vs. 0.3 m3/s), dominant stream channel substrate (bedrock vs. alluvium) and sub-reach morphology (predominance of pools, riffles and glides). Solute transport parameters and respiration rates at the reach and sub-reach scale were estimated monthly from coupled pulse injections of the reactive tracer resazurin (Raz) and conservative tracers uranine and salt. Raz, a weakly fluorescent dye, irreversibly transforms to resorufin (Rru) under mildly reducing conditions, providing a proxy for aerobic respiration. Daily rates of primary productivity, respiration and nitrate retention at the reach scale were estimated using the diel cycles in dissolved oxygen and nitrate concentrations measured by in-situ sensors. Preliminary results indicate distinct differences in common metrics of TS and Raz transformation rates within and between the two streams. However, transformation rates and TS metrics are not well correlated, indicating complexities in the relationship between solute transport dynamics and metabolism in streams.

Water quality of the St. Clair River, Lake St. Clair, and their U.S. tributaries, 1946-2005

USGS Publications Warehouse

Healy, Denis F.; Chambers, Douglas B.; Rachol, Cynthia M.; Jodoin, Richard S.

2007-01-01

The St. Clair River/Lake St. Clair waterway forms an international boundary between the United States and Canada. The waters of the area are an important part of the cultural heritage of the area and serves as an important water-supply and power-generating resource; the waterway also supports an economy based largely on recreation, agriculture, and manufacturing. This report was undertaken as part of the Lake St. Clair Regional Monitoring Project for the purpose of providing a comprehensive assessment of the hydrological, chemical, and physical state of the surface water of Lake St. Clair and its tributaries. The data varied in focus and density over the period of compilation which in many cases this variation prevented the completion of statistical analyses because data did not meet minimum comparability or quality requirements for those tests. Comparison of water quality of the Belle, Black, Clinton, and Pine River Basins, as well as basins of minor rivers in the study area, showed that water quality in many of the tributaries, particularly the Clinton River and some of the minor rivers, was degraded compared to the water quality of the St. Clair River/Lake St. Clair waterway. Data analyses included comparison of nutrients, chloride, specific conductance, turbidity, biochemical oxygen demand (BOD), and pesticides among the basins and the St. Clair River. Median concentrations of total nitrate were well below the recommended USEPA total nitrogen ambient water-quality criterion of 0.54 mg/L as N for nutrient ecoregion VII for all study-area streams except the Clinton River. More than 93 percent of the phosphorus concentrations for the Belle, Black, Pine and minor river basins and 84 percent of the phosphorus concentrations for the Clinton River Basin are greater than the USEPA recommended ambient total phosphorus criterion of 0.033 mg/L for rivers and streams. Nine chloride concentrations exceeded the USEPA criterion maximum concentration (CMC) for chloride set at 860 mg/L for all study-area streams, with the six largest being in the Belle River Basin. Higher chloride concentrations were increasingly common from 2002 to 2005. The urban minor river basins had the highest median specific conductance, whereas the agricultural Pine River Basin had the lowest median specific conductance. The median values of BOD for the five basins in the study area ranged from 2.4 mg/L for the Pine River Basin to 3.2 mg/L for the Black and Clinton River Basins, whereas the median for the St. Clair River was 0.5 mg/L. In 1985, the highest concentrations of pesticides were found in samples from the mouth of the Clinton River; however, in 1996–98, the majority of high pesticide concentrations were found in samples from the Black River. Changing land-use patterns, specifically conversion of agricultural lands to urban/residential lands in the Clinton River Basin, may explain this difference. Trend analysis was done for four stream sites where adequate data were available. These analyses identified no significant water-quality changes at a stream site on the Black River, where land-use patterns have changed little in the past few decades. This stands in marked contrast to trend analysis for three stream sites in the Clinton River Basin, which has undergone significant land-use change. The changes at the Clinton River stream sites, ranging from 5 to 13 significant trends, were generally decreases in nutrients and increases in total dissolved solids (TDS) and chloride. The greater flow volume of the St. Clair River/Lake St. Clair waterway is able to assimilate incoming dissolved and suspended constituents from tributaries with little effect upon its overall water quality, although incomplete mixing may result in localized water-quality impairment downstream from tributary confluences. Mixing effects on Lake St. Clair water quality was also demonstrated in analysis of Escherichia coli (E. coli) data collected at paired nearshore/offshore sites, which reflected similarity in water quality among many paired sites.

Concentration-discharge responses to storm events in coastal California watersheds

NASA Astrophysics Data System (ADS)

Aguilera, R.; Melack, J. M.

2017-12-01

Storm events in montane catchments are the main cause of mobilization of solutes and particulates into and within stream channels in coastal California. Non-linear behavior of nutrients and suspended sediments during storms is evident in the hysteresis that arises in concentration-discharge (C-Q) relationships. We examined patterns in the C-Q hysteresis of nutrients (NO3-, NH4+, DON and PO43-) and total suspended solids (TSS) during storms across ten sites and water years 2002 to 2015 by quantifying the slope of the C-Q relationship and the rotational pattern of the hysteresis loop. We observed several hysteresis types: constituents associated with sediment transport (PO43- and TSS) were flushed during storm events, whereas nitrogen species had hysteretic responses such as dilution with clockwise rotation in urban sites and enrichment with anti-clockwise rotation in undeveloped sites. The wide range of C-Q responses that occurred among sites and seasons reflected the variable hydrological and biogeochemical characteristics of catchments and storms. Storm responses for nitrate in nested catchments differed in slope and rotation of C-Q hysteresis. Upland undeveloped and lowland urban sites had anti-clockwise rotation at the onset of the rainy season following a dry year, which implied a delay in the transport of this solute to the streams. By the middle of the season, the urban site switched from dilution to enrichment, and then again to dilution with clockwise rotation, which implied high initial concentrations and proximal sources by the end of the season.

Contrasting response of stream detritivores to long-term nutrient enrichment

Treesearch

W.F. Cross; B.R. Johnson; J.R. Wallace; A.D. Rosemond

2005-01-01

We examined growth and production responses of two dominant stream detritivores (chironomids and Tallaperla spp. stoneflies) at opposite ends of the "slow-fast" life-history continuum and with distinct feeding characteristics (i.e., consumption of fine particulate organic matter vs. leaf litter) to a 2-yr experimental nutrient enrichment of...

STABLE ISOTOPE STUDIES ON THE USE OF MARINE-DERIVED NUTRIENTS BY COHO SALMON JUVENILES IN THE OREGON COAST RANGE

EPA Science Inventory

Greatly reduced spawning runs of anadromous salmon in streams of the Pacific Northwest (USA) have led to concerns about the effects of reduced marine derived nutrients (MDN's) on sustaining over-wintering juvenile salmon in those streams. In response to these concerns, state a...

Convergence of detrital stoichiometry predicts thresholds of nutrient-stimulated breakdown in streams

Treesearch

David W. P. Manning; Amy D. Rosemond; Vladislav Gulis; Jonathan P. Benstead; John S. Kominoski; John C. Maerz

2016-01-01

Nutrient enrichment of detritus-based streams increases detrital resource quality for consumers and stimulates breakdown rates of particulate organic carbon (C). The relative importance of dissolved inorganic nitrogen (N) vs. phosphorus (P) for detrital quality and their effects on microbial- vs. detritivore-mediated detrital breakdown are poorly understood....

Imaging of metal bioaccumulation in hay-scented fern (Dennstaedtia punctilobula) rhizomes growing on contaminated soils by laser ablation ICP-MS.

PubMed

Koelmel, Jeremy; Amarasiriwardena, Dulasiri

2012-09-01

Understanding Pb removal from the translocation stream is vital to engineering Pb hyperaccumulation in above ground organs, which would enhance the economic feasibility of Pb phytoextraction technologies. We investigated Cu, Pb, Sb and Zn distributions in Hay-scented fern (Dennstaedtia punctilobula) rhizomes on shooting range soils by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS), analyzing digested rhizomes, stems, and fronds using ICP-MS. Nutrients Cu and Zn concentrated in fronds while toxic elements Pb and Sb did not, showing potential Pb and Sb sequestration in the rhizome. Frond and rhizome concentration of Pb was 0.17 ± 0.10% and 0.32 ± 0.21% of dry biomass, respectively. The 208Pb/13C and 121Sb/13C determined by LA-ICP-MS increased from inner sclerotic cortex to the epidermis, while Pb concentrated in the starchy cortex only in contaminated sites. These results suggest that concentration dependent bioaccumulation in the rhizome outer cortex removes Pb from the vascular transport stream. Copyright © 2012 Elsevier Ltd. All rights reserved.

Residence times and nitrate transport in ground water discharging to streams in the Chesapeake Bay Watershed

USGS Publications Warehouse

Lindsey, Bruce D.; Phillips, Scott; Donnelly, Colleen A.; Speiran, Gary K.; Plummer, Niel; Bohlke, John Karl; Focazio, Michael J.; Burton, William C.; Busenberg, Eurybiades

2003-01-01

One of the major water-quality problems in the Chesapeake Bay is an overabundance of nutrients from the streams and rivers that discharge to the Bay. Some of these nutrients are from nonpoint sources such as atmospheric deposition, agricultural manure and fertilizer, and septic systems. The effects of efforts to control nonpoint sources, however, can be difficult to quantify because of the lag time between changes at the land surface and the response in the base-flow (ground water) component of streams. To help resource managers understand the lag time between implementation of management practices and subsequent response in the nutrient concentrations in the base-flow component of streamflow, a study of ground-water discharge, residence time, and nitrate transport in springs throughout the Chesapeake Bay Watershed and in four smaller watersheds in selected hydrogeomorphic regions (HGMRs) was conducted. The four watersheds were in the Coastal Plain Uplands, Piedmont crystalline, Valley and Ridge carbonate, and Valley and Ridge siliciclastic HGMRs.A study of springs to estimate an apparent age of the ground water was based on analyses for concentrations of chlorofluorocarbons in water samples collected from 48 springs in the Chesapeake Bay Watershed. Results of the analysis indicate that median age for all the samples was 10 years, with the 25th percentile having an age of 7 years and the 75th percentile having an age of 13 years. Although the number of samples collected in each HGMR was limited, there did not appear to be distinct differences in the ages between the HGMRs. The ranges were similar between the major HGMRs above the Fall Line (modern to about 50 years), with only two HGMRs of small geographic extent (Piedmont carbonate and Mesozoic Lowland) having ranges of modern to about 10 years. The median values of all the HGMRs ranged from 7 to 11 years. Not enough samples were collected in the Coastal Plain for comparison. Spring samples showed slightly younger water under wet conditions than under dry conditions. The apparent age of water from wells, springs, and other ground-water discharge points in the four targeted watersheds was modern to 60 years, which was similar to the apparent ages from the spring study. In the Pocomoke River Watershed in the Coastal Plain Uplands HGMR, the apparent age of ground-water samples ranged from 0 to 60 years; the ages in the vicinity of the streams ranged from 0 to 23 years.The apparent ages of ground water in the Polecat Creek Watershed in the Piedmont crystalline HGMR ranged from 2 to 30 years. The apparent ages of water from wells in the Muddy Creek Watershed in the Valley and Ridge carbonate HGMR ranged from 10 to 20 years (except for a single sample that was 45 years). The ages in the East Mahantango Creek Watershed in the Valley and Ridge siliciclastic HGMR ranged from 0 to 50 years. The distribution in apparent age of water from wells in the targeted watersheds, however, generally is older than that for water from the springs. The median age of water from wells in the Muddy Creek Watershed, for example, was 15 years, compared to 11 years for the water from the springs in that watershed, and less than 10 years for water from all springs in the spring study. The similarity in the ranges in apparent age of water from the wells and from the springs shows that the samples from the targeted watersheds and springs have bracketed the range of apparent ages that would be expected in the shallow ground-water-flow systems throughout the Chesapeake Bay Watershed.The apparent age of water from individual wells does not necessarily represent the entire distribution of ages of the discharging ground water, and it is this distribution of ages that affects the response of nutrient concentrations in stream base flow. Nutrient-reduction scenarios were modeled for two watersheds for which the distribution of apparent ground-water ages was available, the East Mahantango Creek Watershed in the Valley and Ridge siliciclastic HGMR and the Locust Grove Watershed in the Coastal Plain Uplands HGMR. A nutrient-reduction scenario was created for East Mahantango Creek, where the average residence time was determined to be approximately 10 years on the basis of the output of particle tracking from a ground-water-flow model. This scenario showed decreases of nearly 50 percent in base-flow concentrations of nitrate in streams within the first year after the reduction in nitrogen input; smaller reductions in nitrate concentration occurred in each subsequent year. A second scenario for that same watershed, in which the same 10-year average residence time was assumed and an exponential model was used for analysis, showed that a 50-percent reduction in base-flow concentrations of nitrate could take up to 5 years. For the Locust Grove Watershed, in which an average residence time of 32 years was assumed, simulation with the exponential model showed that it may take more than 20 years to achieve a 50-percent reduction in base-flow concentra-tions of nitrate. Although it was not possible to construct such scenarios for all watersheds, these examples show the range of possible responses to changes in nutrient inputs in two very different types of watersheds.Findings from this study include information on factors that affect ground-water age, spatial distribution of ages, and nitrogen transport. In the East Mahantango Creek Watershed and the Polecat Creek Watershed, the residence time varied spatially depending on the position of the flow path, and temporally depending on the recharge conditions. Generally, ground water in areas near the stream had short residence times and the water in upland areas had longer residence times. Water traveling through deep layers had longer residence times than water traveling through shallow layers, and residence times were faster under high recharge conditions than low recharge conditions. Ground water in the Pocomoke Watershed exhibits a similar pattern: younger water discharges to small order streams in headwater basins and older water discharges to larger streams near the basin outlet.Factors affecting nitrogen transport in ground water include spatial and temporal variation in input sources, ground-water age, and aquifer processes that lead to denitrification. Spatial and temporal variations in nitrogen sources affect all the watersheds. Tributaries with higher inputs of nitrogen have higher concentrations in stream base flow. Areas where nitrogen application rates have increased over time show an age-nitrate relation in ground-water samples. The age-nitrate relation can be affected by denitrification, which occurs in Pocomoke and East Mahantango Creeks but is not evident in Polecat and Muddy Creeks. In East Mahantango Creek, the level of denitrification is significant in water with residence times greater than 20 years, but because this is a small component of overall ground-water discharge to a stream, it may not remove a significant quantity of nitrogen from the system. Denitrification in Pocomoke Creek is significant and appears to affect mostly older water discharging to streams. Therefore, if most of the nitrogen entering these two streams is associated with the discharge of younger ground water, denitrification may not greatly affect the overall nitrogen delivery to these streams.Other findings of this study show that nitrate in ground water discharging along preferential flow paths may not be affected by natural processes, such as denitrification or uptake by riparian vegetation. Seeps to swales and ditches beneath the north uplands at Polecat Creek indicate a shallow water table and discharge of young ground water whereas the absence of such seeps on the south side indicates a deep water table and a lack of young ground water. Similarly, discharge at the base of the slope and to the valley wetland south of the creek but not north of the creek indicates a different role for the riparian forest on the two sides of the creek. In many of the systems where water discharges at the base of slopes to wetlands, ditches have been dug to drain the valley. Such drainage circumvents possible removal of nitrate by riparian vegetation.Because ground-water residence times do not appear directly related to the HGMRs, the targeting of management practices will achieve the most rapid response in water quality if directed at 1) watersheds with large agricultural sources of nitrate, 2) areas with the shortest ground-water-flow paths and 3) areas not affected by significant denitrification. The fastest response in stream base-flow concentrations of nitrogen to implementation of management practices would be to implement practices in those areas with the highest loads rather than attempt to target practices on the basis of HGMR stratification. Overall findings of the study indicate that 1) ground-water contributions to nitrogen in streamflow are significant, 2) some response to management practices should be evident in base-flow concentrations of nitrogen and loads within 1 to 5 years in watersheds with the shortest average residence times, but response time may be closer to 20 years in watersheds with longer average ground-water residence times, 3) the majority of the response in ground-water discharge to any changes in management practices will be distributed over a 10-year time period even in the watersheds with the fastest response times, and 4) given that half the streamflow is from ground-water discharge and the other half is runoff or soil water, about 90 percent of total water being discharged to a stream will be less than about a decade old; therefore, full implementation of nutrient reductions may result in improved streamwater quality in about a decade. In the more-likely scenario of gradual source reduction, the reduction in concentrations of nitrate in streams and aquifers would take longer than the examples shown here.

Estimation of Tile Drainage Contribution to Streamflow and Nutrient Export Loads

NASA Astrophysics Data System (ADS)

Schilling, K. E.; Arenas Amado, A.; Jones, C. S.; Weber, L. J.

2015-12-01

Subsurface drainage is a very common practice in the agricultural U.S. Midwest. It is typically installed in poorly drained soils in order to enhance crop yields. The presence of tile drains creates a route for agrichemicals to travel and therefore negatively impacts stream water quality. This study estimated through end-member analyses the contributions of tile drainage, groundwater, and surface runoff to streamflow at the watershed scale based on continuously monitored data. Especial attention was devoted to quantifying tile drainage impact on watershed streamflow and nutrient export loads. Data analyzed includes streamflow, rainfall, soil moisture, shallow groundwater levels, in-stream nitrate+nitrite concentrations and specific conductance. Data were collected at a HUC12 watershed located in Northeast Iowa, USA. Approximately 60% of the total watershed area is devoted to agricultural activities and forest and grassland are the other two predominant land uses. Results show that approximately 20% of total annual streamflow comes from tile drainage and during rainfall events tile drainage contribution can go up to 30%. Furthermore, for most of the analyzed rainfall events groundwater responded faster and in a more dramatic fashion than tile drainage. The State of Iowa is currently carrying out a plan to reduce nutrients in Iowa waters and the Gulf of Mexico (Iowa Nutrient Reduction Strategy). The outcome of this investigation has the potential to assist in Best Management Practice (BMP) scenario selection and therefore help the state achieve water quality goals.