THE INFLUENCE OF ECOLOGICAL AND ANTHROPOGENIC FACTORS ON PATTERNS IN THE FISH COMMUNITIES OF THE ALBEMARLE-PAMLICO BASIN

EPA Science Inventory

Data on fish abundance from the EPA, USGS, and states of North Carolina and Virginia were analyzed for patterns in the fish communities of the Albemarle-Pamlico Basin. The basin covers 72,500 square kilometers and five ecoregions in Virginia and North Carolina, including the wat...

Micropetrographic characteristics of peats from modern coal-forming environments in Okefenokee Swamp, Georgia and Albemarle-Pamlico Peninsular Swamps, North Carolina

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

Corvinus, D.A.

1982-01-01

The Okefenokee Swamp, over 400,000 acres, is a swamp-marsh complex dominated by Taxodium-swamp vegetaion on its west side and Nymphaea-marsh vegetation onits east side. The Albemarle-Pamlico Peninsular Swamps primarily support a pocosin-bay vegetation. The Taxodium-dominated peats of the Okefenokee are more similar botanically to the Albemarle-Pamlico bay peats than are the Okefenokee Nymphaea-dominated peats. Some petrographic characteristics are common to all three peat types. The majority of cell walls in the peat exhibit colors (yellow to orange to red) which they did not display in their living state. This is believed to be from impregnation by the various cell fillingsmore » present in the peats. Unoxidized fragmented (granular) material in all three peat types usually occurs in larger amounts than oxidized (darkened) material. In Taxodium-dominated and bay peats the fragmented matrix is also usually more prevalent than the preserved material (intact cell walls and cell fillings). On the other hand, preserved material is most common in Nymphaea-dominated peats. It is believed that the majority of fragmented material is derived from the surface litter and that swamp vegetation contributes more surface litter than does marsh vegetation.« less

Holistic impact assessment and cost savings of rainwater harvesting at the watershed scale

EPA Science Inventory

We evaluated the impacts of domestic and agricultural rainwater harvesting (RWH) systems in three watersheds within the Albemarle-Pamlico river basin (southeastern U.S.) using life cycle assessment (LCA) and life cycle cost assessment. Life cycle impact assessment (LCIA) categori...

The Response of Fish Habitat to Environmental Flows in the Albemarle-Pamlico Watershed

EPA Science Inventory

The provision of habitat for fish is an important service provided by rivers. Future land development and climate change will likely alter several aspects of habitat, including flow. We have used hierarchical models to predict the presence of 25 fish species within the Albemarle-...

Ecosystem Services Research Program (ESRP) Albemarle-Pamlico Watershed and Estuary Study (APWES) Research Plan

EPA Science Inventory

The APWES is a place-based study for the U.S. EPA Ecosystem Services Research Program conducted through the collaboration across the EPA Office of Research and Development. The mission of the APWES is to develop ecosystem services science to inform watershed and coastal manageme...

Shoreline Erosion in the Albemarle-Pamlico Estuarine System, Northeastern North Carolina

NASA Astrophysics Data System (ADS)

Murphy, M. A.; Riggs, S. R.

2002-12-01

Computer analysis of aerial photographic series demonstrates that the estuarine shorelines within the North Carolina Albemarle-Pamlico coastal system are eroding at 2-3 times greater rates than previous studies reported. Specific rates and amounts of shoreline recession vary tremendously depending upon local variables including: 1) shoreline type, geometry, and composition; 2) geographic location, size, and shape of associated estuary; 3) frequency, intensity, and fetch of storms; 4) type and abundance of associated vegetation; and locally 5) boat wakes. Organic or wetland shorelines (marsh and swamp forest) comprise approximately 62% of the estuarine margins in NE NC, whereas sediment banks (low, high, and bluff) constitute about 38%. The goals of this study were to determine the rates of recession for different shoreline types and the role of local variables in the erosion process. Shorelines were mapped using high precision GPS mapping techniques, digital orthographic quarter quadrangles, and other georeferenced aerial photographs from the early 1950's to 2001. Shoreline change was then calculated for 20 estuarine study sites. Field mapping of each site provided data on shoreline characteristics and erosional processes. Data synthesis suggests mean annual shoreline erosion rates are significantly different for shoreline types as follows: 1) marshes = 7.4 ft/yr (range 2.7-17.0 ft/yr), low sediment banks = 5.0 ft/yr (range 1.0-12.0 ft/yr), bluff sediment banks = 5.0 ft/yr (range = 3.9-6.0 ft/yr), swamp forests = 3.0 ft/yr (range = 1.7-4.0 ft/yr), high sediment banks = 2.8 ft/yr (range = 2.7-2.9 ft/yr). Modified shorelines continue to erode, however at lower mean annual rates that range from 0.9-2.7 ft/yr. Locally, specific marsh shorelines have eroded at rates up to 100 ft/yr during particularly stormy periods. Thus, about 1166 acres of land are lost each year along the 1593 miles of mapped estuarine shoreline in NE NC. If these erosion rates are representative of

Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia; characterization of suspended sediment, nutrients, and pesticides

USGS Publications Warehouse

Harned, Douglas; McMahon, Gerard; Spruill, T.B.; Woodside, M.D.

1995-01-01

The 28,000-square-mile Albemarle-Pamlico drainage basin includes the Roanoke, Dan, Chowan Tar, and Neuse Rivers. The basin extends through four physiographic provinces in North Carolina and Virginia-Valley and Ridge, Blue Ridge, Piedmont and Coastal Plain. The spatial and temporal trends in ground-water and riverine water quality in the study area were characterized by using readily available data sources The primary data sources that were used included the U.S. Geological Survey's National Water Data Storage and Retrieval System (WATSTORE) database, the U.S. Environmental Protection Agency's Storage and Retrieval System (STORET) database, and results of a few investigations of pesticide occurrence. The principal water-quality constituents examined were suspended sediment, nutrients, and pesticides. The data examined generally spanned the period from 1950 to 1993. The only significant trends in suspended sediment were detected at three Chowan River tributary sites which showed long-term decreases. Suspended- and total-solids concentrations have decreased throughout the Albemarle-Pamlico drainage basin. The decreases are probably a result of (1) construction of new lakes and ponds in the basin, which trap solids, (2) improved agricultural soil management, and (3) improved wastewater treatment. Nutrient point sources are much less than nonpoint nutrient sources at the eight NASQAN basins examined for nutrient loads. The greatest nitrogen inputs are associated with crop fertilizer and biological nitrogen fixation by soybeans and peanuts, whereas atmospheric and animal-related nitrogen inputs are comparable in magnitude. The largest phosphorus inputs are associated with animal wastes. The most commonly detected pesticides in surface water in the STORET database were atrazine and aldrin.Intensive organonitrogen herbicide sampling of Chicod Creek in 1992 showed seasonal variations in pesticide concentration. The most commonly detected herbicides were atrazine, alachlor

Water quality in the Albemarle-Pamlico drainage basin, North Carolina and Virginia, 1992-95

USGS Publications Warehouse

Spruill, Timothy B.; Harned, Douglas A.; Ruhl, Peter M.; Eimers, Jo Leslie; McMahon, Gerard; Smith, Kelly E.; Galeone, David R.; Woodside, Michael D.

1998-01-01

The NAWQA Program is assessing the water-quality conditions of more than 50 of the Nation's largest river basins and aquifers, known as Study Units. Collectively, these Study Units cover about one-half of the United States and include sources of drinking water used by about 70 percent of the U.S. population. Comprehensive assessments of about one-third of the Study Units are ongoing at a given time. Each Study Unit is scheduled to be revisited every decade to evaluate changes in water-quality conditions. NAWQA assessments rely heavily on existing information collected by the USGS and many other agencies as well as the use of nationally consistent study designs and methods of sampling and analysis. Such consistency simultaneously provides information about the status and trends in water-quality conditions in a particular stream or aquifer and, more importantly, provides the basis to make comparisons among watersheds and improve our understanding of the factors that affect water-quality conditions regionally and nationally. This report is intended to summarize major findings that emerged between 1992 and 1995 from the water-quality assessment of the Albemarle-Pamlico Drainage Study Unit and to relate these findings to water-quality issues of regional and national concern. The information is primarily intended for those who are involved in water-resource management. Indeed, this report addresses many of the concerns raised by regulators, water-utility managers, industry representatives, and other scientists, engineers, public officials, and members of stakeholder groups who provided advice and input to the USGS during this NAWQA Study-Unit investigation. Yet, the information contained here may also interest those who simply wish to know more about the quality of water in the rivers and aquifers in the area where they live.

Comparative impacts of two major hurricane seasons on the Neuse River and western Pamlico Sound ecosystems.

PubMed

Burkholder, JoAnn; Eggleston, David; Glasgow, Howard; Brownie, Cavell; Reed, Robert; Janowitz, Gerald; Posey, Martin; Melia, Greg; Kinder, Carol; Corbett, Reide; Toms, David; Alphin, Troy; Deamer, Nora; Springer, Jeffrey

2004-06-22

Ecosystem-level impacts of two hurricane seasons were compared several years after the storms in the largest lagoonal estuary in the U.S., the Albemarle-Pamlico Estuarine System. A segmented linear regression flow model was developed to compare mass-water transport and nutrient loadings to a major artery, the Neuse River Estuary (NRE), and to estimate mean annual versus storm-related volume delivery to the NRE and Pamlico Sound. Significantly less water volume was delivered by Hurricane Fran (1996), but massive fish kills occurred in association with severe dissolved oxygen deficits and high contaminant loadings (total nitrogen, total phosphorus, suspended solids, and fecal bacteria). The high water volume of the second hurricane season (Hurricanes Dennis, Floyd, and Irene in 1999) delivered generally comparable but more dilute contaminant loads, and no major fish kills were reported. There were no discernable long-term adverse impacts on water quality. Populations of undesirable organisms, such as toxic dinoflagellates, were displaced down-estuary to habitats less conducive for growth. The response of fisheries was species-dependent: there was no apparent impact of the hurricanes on commercial landings of bivalve molluscs or shrimp. In contrast, interacting effects of hurricane floodwaters in 1999 and intensive fishing pressure led to striking reductions in blue crabs. Overall, the data support the premise that, in shallow estuaries frequently disturbed by hurricanes, there can be relatively rapid recovery in water quality and biota, and benefit from the scouring activity of these storms.

Ecosystem impacts of three sequential hurricanes (Dennis, Floyd, and Irene) on the United States' largest lagoonal estuary, Pamlico Sound, NC

USGS Publications Warehouse

Paerl, H.W.; Bales, J.D.; Ausley, L.W.; Buzzelli, C.P.; Crowder, L.B.; Eby, L.A.; Fear, J.M.; Go, M.; Peierls, B.L.; Richardson, T.L.; Ramus, J.S.

2001-01-01

Three sequential hurricanes, Dennis, Floyd, and Irene, affected coastal North Carolina in September and October 1999. These hurricanes inundated the region with up to 1 m of rainfall, causing 50- to 500-year flooding in the watershed of the Pamlico Sound, the largest lagoonal estuary in the United States and a key West Atlantic fisheries nursery. We investigated the ecosystem-level impacts on and responses of the Sound to the floodwater discharge. Floodwaters displaced three-fourths of the volume of the Sound, depressed salinity by a similar amount, and delivered at least half of the typical annual nitrogen load to this nitrogen-sensitive ecosystem. Organic carbon concentrations in floodwaters entering Pamlico Sound via a major tributary (the Neuse River Estuary) were at least 2-fold higher than concentrations under prefloodwater conditions. A cascading set of physical, chemical, and ecological impacts followed, including strong vertical stratification, bottom water hypoxia, a sustained increase in algal biomass, displacement of many marine organisms, and a rise in fish disease. Because of the Sound's long residence time (???1 year), we hypothesize that the effects of the short-term nutrient enrichment could prove to be multiannual. A predicted increase in the frequency of hurricane activity over the next few decades may cause longer-term biogeochemical and trophic changes in this and other estuarine and coastal habitats.

Ecosystem impacts of three sequential hurricanes (Dennis, Floyd, and Irene) on the United States' largest lagoonal estuary, Pamlico Sound, NC

PubMed Central

Paerl, Hans W.; Bales, Jerad D.; Ausley, Larry W.; Buzzelli, Christopher P.; Crowder, Larry B.; Eby, Lisa A.; Fear, John M.; Go, Malia; Peierls, Benjamin L.; Richardson, Tammi L.; Ramus, Joseph S.

2001-01-01

Three sequential hurricanes, Dennis, Floyd, and Irene, affected coastal North Carolina in September and October 1999. These hurricanes inundated the region with up to 1 m of rainfall, causing 50- to 500-year flooding in the watershed of the Pamlico Sound, the largest lagoonal estuary in the United States and a key West Atlantic fisheries nursery. We investigated the ecosystem-level impacts on and responses of the Sound to the floodwater discharge. Floodwaters displaced three-fourths of the volume of the Sound, depressed salinity by a similar amount, and delivered at least half of the typical annual nitrogen load to this nitrogen-sensitive ecosystem. Organic carbon concentrations in floodwaters entering Pamlico Sound via a major tributary (the Neuse River Estuary) were at least 2-fold higher than concentrations under prefloodwater conditions. A cascading set of physical, chemical, and ecological impacts followed, including strong vertical stratification, bottom water hypoxia, a sustained increase in algal biomass, displacement of many marine organisms, and a rise in fish disease. Because of the Sound's long residence time (≈1 year), we hypothesize that the effects of the short-term nutrient enrichment could prove to be multiannual. A predicted increase in the frequency of hurricane activity over the next few decades may cause longer-term biogeochemical and trophic changes in this and other estuarine and coastal habitats. PMID:11344306

Water-quality assessment of the Albemarle-Pamlico drainage basin, North Carolina and Virginia; trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers, 1992-93

USGS Publications Warehouse

Ruhl, P.M.; Smith, K.E.

1996-01-01

The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, trace elements in Asiatic clam (Corbicula fluminea) soft tissues and redbreast sunfish (Lepomis auritus) livers were analyzed to obtain information about the occurrence and distribution of trace element contaminants in the Albemarle-Pamlico Drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. All but 3 of the 22 trace elements that were analyzed were detected. Although all 10 of the U.S. Environmental Protection Agency (U.S. EPA) priority pollutants were detected in the tissues sampled, they were present in relatively low concentrations. Concentrations of U.S. EPA priority pollutants in Asiatic clams collected in the Albemarle-Pamlico Drainage Basin are similar to concentrations observed in other NAWQA study units in the southeastern United States. Mercury (a U.S. EPA priority pollutant) was widely detected, being present in 29 of 30 tissue samples, but concentrations did not exceed the FDA action level for mercury of a risk-based screening value for the general public. Mercury concentrations in Asiatic clams were similar to concentrations in other NAWQA study areas in the Southeast.

ALBERMARLE PAMLICO IR 2002

EPA Science Inventory

The 2002 Albermarle Pamlico Implementation Review (IR) highlights recent successes and challenges with the estuary program. Various components within the IR include: CCMP implementation, outlining priority management actions, public involvement, stakeholder contribution, and limi...

Decadal-scale sediment dynamics and environmental change in the Albemarle Estuarine System, North Carolina

NASA Astrophysics Data System (ADS)

Corbett, D. Reide; Vance, Dave; Letrick, Erin; Mallinson, David; Culver, Stephen

2007-02-01

During the summer of 2001, several short cores (<50 cm) were collected in the Albemarle Estuarine System (AES). Down-core measurements for radiochemical tracers ( 210Pb, 137Cs) and organic matter signatures (δ 13C, δ 15N, C:N ratio, and LOI) have been used to elucidate potential temporal changes in fluxes and cycles of organic matter in the AES. Pb-210 geochronology indicates temporal and spatial variations in sediment deposition rates (0.08-0.57 cm y -1) with highest rates near the AES western limit relative to the rest of the estuary. Low accumulation rates, deficient excess 210Pb inventories, and near linear 137Cs profiles throughout the AES suggest that sediments are resuspended by wind-generated waves and currents and flushed from the system by river discharge and wind-tides, probably to Pamlico Sound to the south. Sediments in the AES are accumulating at rates less than the current rate of relative sea-level rise for this region except in protected portions of the estuary. Thus sediment accumulation in the AES is controlled in the short term by storm wave-base and in the long term by the creation of accommodation space by basin subsidence and sea-level rise. The geochemical and sedimentological data characterize the evolution of the Albemarle Sound and associated tributaries over the past 200-300 years. The majority of cores collected throughout the system show a significant decrease in 13C and increase in 15N isotopic signatures up-core. Thus, the estuarine system of eastern North Carolina has changed from a marine-influenced, high brackish environment to the modern-day system, which is a highly variable, terrestrially influenced, low brackish environment.

MERIS Retrieval of Water Quality Components in the Turbid Albemarle-Pamlico Sound Estuary, USA

EPA Science Inventory

Biological, geophysical and optical field observations carried out in the Neuse River Estuary, North Carolina, USA were used to develop a semi-empirical optical algorithm for assessing inherent optical properties associated with water quality components (WQCs). Three wavelengths ...

Simulation of hydrodynamics and solute transport in the Pamlico River estuary, North Carolina

USGS Publications Warehouse

Bales, Jerad; Robbins, Jeanne C.

1995-01-01

An investigation was conducted to characterize flow, circulation, and solute transport in the Pamlico River estuary, North Carolina. The study included a detailed field-measurement program and the calibration, validation, and application of a physically realistic numerical model of hydro- dynamics and transport. Water level, salinity, water temperature, wind speed and direction, and current data were collected during March 1988 through September 1992, and were used to characterize physical conditions in the estuary. Data from pre- existing streamflow gaging stations and meteoro- logical stations were also used. A two-dimensional vertically averaged hydrodynamic and solute transport model was applied to the 48-kilometer study reach. The model domain was discretized into 5,620 separate 200- by 200-meter computational cells. Model calibration was achieved through adjustment of parameters for June 14-30, 1991. Data from selected periods in 1989 and 1991 were used for model validation. Water levels used for model calibration and validation ranged from -0.052 to 0.698 meter; salinities ranged from 0.1 to 13.1 parts per thousand; and wind speeds ranged from calm to 22 meters per second. The model was tested for stratified and unstratified conditions. Simulated and observed data were used to evaluate model performance. The calibrated model was applied for selected periods in 1989 and 1991. Instantaneous flows were simulated at each boundary and at mid- estuary. Circulation patterns were characterized using vector plots, particle tracking, and solute transport. Particle tracks showed that materials released at mid-estuary may remain in the system for 25 days or longer.

National Guidebook for Application of Hydrogeomorphic Assessment to Tidal Fringe Wetlands

DTIC Science & Technology

1998-12-01

Wrighton Road Lothian, MD 20711 Ron Thorn Battele Marine Science Laboratory 1529 West Sequim Bay Road Sequim , WA 98382 Rena Weichenburg U.S. Army...This region includes the Delaware and Chesapeake Bay estuaries and, except for the exclusion of the microtidal Albemarle and Pamlico Sounds...Gulf (Pearl River, Mississippi, to Galveston Bay , Texas). Small tidal range (< 1 m), meteorologically dominated diurnal tides. Freshwater input

FROM LANDSCAPE ECOLOGY OF WATERSHEDS TO BENTHIC ECOLOGY OF ESTUARIES

EPA Science Inventory

Do land use/cover characteristics of watersheds associated with small estuaries (<260 km2) have a strong enough signal to make landscape metrics useful for finding impaired bottom communities? We tested this idea with 58 pairs of small estuaries and watersheds from Delaware Bay t...

Status of bottomland forests in the Albemarle Sound of North Carolina and Virginia, 1984-2012

Treesearch

Jean H. Lorber; Anita K. Rose

2015-01-01

The Albemarle Sound, a 6-million-acre watershed, contains some of the largest areas of bottomland hardwood habitat in the Eastern United States. Using close to 30 years of data from the Forest Inventory and Analysis Program, a study of the current status and trends in the Albemarle Sound’s bottomland forest system was conducted. In 2012, bottomlands totaled...

U.S. Geological Survey second national symposium on Water quality; abstracts of the technical sessions, Orlando, Florida, November 12-17, 1989

USGS Publications Warehouse

Pederson, G. L.; Smith, M.M.

1989-01-01

The U.S Geological Survey (USGS) compiled and analyzed existing hydrologic and water-quality data from over 200 stream and estuary stations of the Abemarle-Pamlico estuarine system (A/P) to identify long-term temporal and spatial trends. The dataset included seven stations of the USGS National Stream Quality Accounting Network, two stations of the National Atmospheric Precipitation Deposition monitoring network, stations of the N.C. Department of Natural Resources and Community Development, and stations from 25 reports by individual investigators. Regression-residuals analysis, the seasonal Kendall's Tau test for trends, and graphical analysis using annual box plots were employed to determine trends. Profound change has occurred in the water quality of the A/P area over the last 30 years. Analysis of water-quality data upstream from the estuaries indicates increases of discharge-adjusted values of specific conductance, alkalinity, phosphorous, hardness, chloride, and dissolved solids. In the estuaries, pH is increasing except in the Pamlico River, where it is decreasing. There is a generalized decrease in suspended inorganic material in the system. Salinities are decreasing for sections of the Pamlico River, and increasing for parts of Albemarle Sound. Nitrogen concentrations are decreasing except in the Pamlico River, where they are increasing. Phosphorus concentrations are increasing in the Pamlico River and decreasing elsewhere. Annual average data show that nitrogen is the limiting nutrient in the Neuse and Pamlico Rivers. Phosphorus is limiting in the rest of the area. Chlorophyll-a levels are increasing in parts of the Neuse and Pamlico Rivers and decreasing in parts of the Chowan River. To evaluate the effect of basin characteristics on water quality, linear correlation was used. Agricultural crop variables produced the most correlations with water-quality data. Fertilizer usage had little detectable relation to water quality in the study area. In the

Water-quality assessment of the Albemarle-Pamlico Drainage Basin, North Carolina and Virginia; organochlorine compounds in Asiatic clam (Corbicula fluminea) soft tissues and whole redbrest sunfish (Lepomis auritus) 1992-93

USGS Publications Warehouse

Smith, K.E.; Ruhl, P.M.

1996-01-01

The analysis of potential contaminants in biological tissues is an important part of many water-quality assessment programs, including the National Water-Quality Assessment (NAWQA) Program. Tissue analyses often are used to provide information about (1) direct threats to ecosystem integrity, and (2) the occurrence and distribution of potential contaminants in the environment. During 1992-93, Asiatic clam (Corbicula fluminea) soft tissues and whole redbreast sunfish (Lepomis auritus) samples were collected and analyzed to obtain information about the occurrence and distribution of organochlorine compounds in the Albemarle-Pamlico drainage Basin of North Carolina and Virginia. The investigation was conducted as part of the NAWQA Program. Relatively few organochlorine compounds were detected and of the compounds detected, all were detected in relatively low concentrations. The organochlorine compounds detected were p,p'-DDD, p,p'-DDE, p,p'-DDT, dieldrin, trans-nonachlor, PCB's, and toxaphene. Multiple compounds were detected at 16 of 19 sites sampled. Compared to Asiatic clams, redbreast sunfish appear to be better bioindicators of organochlorine contamination in aquatic systems. Except for one detection of toxaphene, pesticide concentrations are well below the National Academy of Sciences and National Academy of Engineering (NAS/NAE) guidelines for the protection of fish-eating wildlife.

San Juan Bay Estuary watershed urban forest inventory

Treesearch

Thomas J. Brandeis; Francisco J. Escobedo; Christina L. Staudhammer; David J. Nowak; Wayne C. Zipperer

2014-01-01

We present information on the urban forests and land uses within the watershed of Puerto Rico’s 21 658-ha San Juan Bay Estuary based on urban forest inventories undertaken in 2001 and 2011. We found 2548 ha of mangrove and subtropical moist secondary forests covering 11.8 percent of the total watershed area in 2011. Red, black, and white mangroves (Rhizophora...

AIRSHED DOMAINS FOR MODELING ATMOSPHERIC DEPOSITION OF OXIDIZED AND REDUCED NITROGEN TO THE NEUSE/PAMLICO SYSTEM OF NORTH CAROLINA

EPA Science Inventory

Atmospheric deposition is important to nutrient loadings to coastal estuaries. Atmospheric emissions of nitrogen travel hundreds of kilometers as they are removed via atmospheric deposition. Long-range transport from outside the Neuse/Pamlico system in North Carolina is an impo...

Albemarle County road orders, 1783-1816.

DOT National Transportation Integrated Search

1975-01-01

During the early stages of the pilot study of Albemarle County it was necessary to examine and extract all the road orders for the counties from which Albemarle was formed, as well as the orders for Albemarle when it still contained the counties of A...

Delineation and mapping of coastal shark habitat within a shallow lagoonal estuary.

PubMed

Bangley, Charles W; Paramore, Lee; Dedman, Simon; Rulifson, Roger A

2018-01-01

Estuaries function as important nursery and foraging habitats for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and provides a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitats within Pamlico Sound, shark catch and environmental data were analyzed from the 2007-2014 North Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys conducted within the estuary. Principal species were identified and environmental data recorded at survey sites (depth, temperature, salinity, dissolved oxygen, submerged aquatic vegetation (SAV) distance, and inlet distance) were interpolated across Pamlico Sound to create seasonal environmental grids with a 90-m2 cell size. Boosted Regression Tree (BRT) analysis was used to identify the most important environmental factors and ranges associated with presence of each principal species, and the resulting models were used to predict shark capture probability based on the environmental values within the grid cells. The Atlantic Sharpnose Shark (Rhizoprionodon terraenovae), Blacktip Shark (Carcharhinus limbatus), Bull Shark (Carcharhinus leucas), Sandbar Shark (Carcharhinus plumbeus), Smooth Dogfish (Mustelus canis), and Spiny Dogfish (Squalus acanthias) were the principal species in Pamlico Sound. Most species were associated with proximity to the inlet and/or high salinity, and warm temperatures, but the Bull Shark preferred greater inlet distances and the Spiny Dogfish preferred lower temperatures than the other species. Extensive Smooth Dogfish habitat overlap with seagrass beds suggests that seagrass may be a critical part of nursery habitat for this species. Spatial delineation of shark habitat within the estuary will allow for better protection of essential habitat and assessment of potential interactions with other species.

Water-quality assessment of the Albermarle-Pamlico drainage basin, North Carolina and Virginia; environmental setting and water-quality issues

USGS Publications Warehouse

McMahon, Gerard; Lloyd, Orville B.

1995-01-01

The Albemarle-Pamlico drainage study unit is one of 60 units of the U.S. Geological Survey's National Water-Quality Assessment Program, and includes the large river basins which drain into the Albemarle and Pamlico Sounds-the Chowan, Roanoke, Tar-Pamlico, and Neuse River Basins. The study unit includes about 28,000 square miles and has an interrelated set of environmental characteristics which strongly influence water quality. The chemical and physical nature of these characteristics are the dominant controls on baseline water quality in the study area. About 50 percent of the study area is forested, slightly more than 30 percent is agricultural, about 15 percent is wetlands, and less than 5 percent is developed. Three million people live in the study area, and activities related to agriculture and development have caused increased concentrations of constituents such as nutrients, pesticides, and suspended sediment. About two-thirds of the 36 to 52 inches of precipitation in the area reenters the atmosphere by evapotranspiration. About one-third of the remaining precipitation reaches streams by overland runoff; the remainder recharges the water table aquifer, where much of the water eventually discharges to streams as ground water. Thus, ground-water quality has a substantial influence on surface-water quality, particularly during dry weather. In 1990, about 152,900 tons of elemental nitrogen and 10,500 tons of elemental phosphorus either were applied to crops as fertilizer or fixed by biological processes, and in 1987, about 43,500 tons of nitrogen and 12,200 tons of phosphorus were produced as animal wastes. In addition, about 1,300 tons of selected herbicides and 400 tons of selected insecticides were applied to crops in 1990. Some 249 permitted point sources discharged 410 million gallons per day, containing an annual load of 5,800 tons of nitrogen and 1,800 tons of phosphorus, to the study area in 1990. Data from 1970-79 indicate that mean annual suspended

WestuRe: U.S. Pacific Coast estuary/watershed data and R tools

EPA Science Inventory

There are about 350 estuaries along the U.S. Pacific Coast. Basic descriptive data for these estuaries, such as their size and watershed area, are important for coastal-scale research and conservation planning. However, this information is spread among many sources and can be dif...

Adjustment of the San Francisco estuary and watershed to decreasing sediment supply in the 20th century

USGS Publications Warehouse

Schoellhamer, David H.; Wright, Scott A.; Drexler, Judith Z.

2013-01-01

The general progression of human land use is an initial disturbance (e.g., deforestation, mining, agricultural expansion, overgrazing, and urbanization) that creates a sediment pulse to an estuary followed by dams that reduce sediment supply. We present a conceptual model of the effects of increasing followed by decreasing sediment supply that includes four sequential regimes, which propagate downstream: a stationary natural regime, transient increasing sediment supply, transient decreasing sediment supply, and a stationary altered regime. The model features characteristic lines that separate the four regimes. Previous studies of the San Francisco Estuary and watershed are synthesized in the context of this conceptual model. Hydraulic mining for gold in the watershed increased sediment supply to the estuary in the late 1800s. Adjustment to decreasing sediment supply began in the watershed and upper estuary around 1900 and in the lower estuary in the 1950s. Large freshwater flow in the late 1990s caused a step adjustment throughout the estuary and watershed. It is likely that the estuary and watershed are still capable of adjusting but further adjustment will be as steps that occur only during greater floods than previously experienced during the adjustment period. Humans are actively managing the system to try to prevent greater floods. If this hypothesis of step changes occurring for larger flows is true, then the return interval of step changes will increase or, if humans successfully control floods in perpetuity, there will be no more step changes.

Delineation and mapping of coastal shark habitat within a shallow lagoonal estuary

PubMed Central

Paramore, Lee; Dedman, Simon; Rulifson, Roger A.

2018-01-01

Estuaries function as important nursery and foraging habitats for many coastal species, including highly migratory sharks. Pamlico Sound, North Carolina, is one of the largest estuaries in the continental United States and provides a variety of potential habitats for sharks. In order to identify and spatially delineate shark habitats within Pamlico Sound, shark catch and environmental data were analyzed from the 2007–2014 North Carolina Division of Marine Fisheries (NCDMF) gillnet and longline surveys conducted within the estuary. Principal species were identified and environmental data recorded at survey sites (depth, temperature, salinity, dissolved oxygen, submerged aquatic vegetation (SAV) distance, and inlet distance) were interpolated across Pamlico Sound to create seasonal environmental grids with a 90-m2 cell size. Boosted Regression Tree (BRT) analysis was used to identify the most important environmental factors and ranges associated with presence of each principal species, and the resulting models were used to predict shark capture probability based on the environmental values within the grid cells. The Atlantic Sharpnose Shark (Rhizoprionodon terraenovae), Blacktip Shark (Carcharhinus limbatus), Bull Shark (Carcharhinus leucas), Sandbar Shark (Carcharhinus plumbeus), Smooth Dogfish (Mustelus canis), and Spiny Dogfish (Squalus acanthias) were the principal species in Pamlico Sound. Most species were associated with proximity to the inlet and/or high salinity, and warm temperatures, but the Bull Shark preferred greater inlet distances and the Spiny Dogfish preferred lower temperatures than the other species. Extensive Smooth Dogfish habitat overlap with seagrass beds suggests that seagrass may be a critical part of nursery habitat for this species. Spatial delineation of shark habitat within the estuary will allow for better protection of essential habitat and assessment of potential interactions with other species. PMID:29649261

Estuary 2100 Project, Phase 2: Building Partnerships for Resilient Watersheds

EPA Pesticide Factsheets

Information about the SFBWQP Estuary 2100 Project, Phase 2: Building Partnerships for Resilient Watersheds, part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquat

Tropical land-sea couplings: Role of watershed deforestation, mangrove estuary processing, and marine inputs on N fluxes in coastal Pacific Panama.

PubMed

Valiela, Ivan; Elmstrom, Elizabeth; Lloret, Javier; Stone, Thomas; Camilli, Luis

2018-07-15

We review data from coastal Pacific Panama and other tropical coasts with two aims. First, we defined inputs and losses of nitrogen (N) mediating connectivity of watersheds, mangrove estuaries, and coastal sea. N entering watersheds-mainly via N fixation (79-86%)-was largely intercepted; N discharges to mangrove estuaries (3-6%), small compared to N inputs to watersheds, nonetheless significantly supplied N to mangrove estuaries. Inputs to mangrove estuaries (including watershed discharges, and marine inputs during flood tides) were matched by losses (mainly denitrification and export during ebb tides). Mangrove estuary subsidies of coastal marine food webs take place by export of forms of N [DON (62.5%), PN (9.1%), and litter N (12.9%)] that provide dissimilative and assimilative subsidies. N fixation, denitrification, and tidal exchanges were major processes, and DON was major form of N involved in connecting fluxes in and out of mangrove estuaries. Second, we assessed effects of watershed forest cover on connectivity. Decreased watershed forest cover lowered N inputs, interception, and discharge into receiving mangrove estuaries. These imprints of forest cover were erased during transit of N through estuaries, owing to internal N cycle transformations, and differences in relative area of watersheds and estuaries. Largest losses of N consisted of water transport of energy-rich compounds, particularly DON. N losses were similar in magnitude to N inputs from sea, calculated without considering contribution by intermittent coastal upwelling, and hence likely under-estimated. Pacific Panama mangrove estuaries are exposed to major inputs of N from land and sea, which emphasizes the high degree of bi-directional connectivity in these coupled ecosystems. Pacific Panama is still lightly affected by human or global changes. Increased deforestation can be expected, as well as changes in ENSO, which will surely raise watershed-derived loads of N, as well as significantly

Estuary 2100 Project, Phase 1: Resilient Watersheds for a Changing Climate

EPA Pesticide Factsheets

Information about the SFBWQP Estuary 2100 Project, Phase 1: Resilient Watersheds for a Changing Climate , part of an EPA competitive grant program to improve SF Bay water quality focused on restoring impaired waters and enhancing aquatic resources.

Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States

EPA Science Inventory

The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

Headwaters to estuaries: advances in watershed science and management - Proceedings of the Fifth Interagency Conference on Research in the Watersheds

Treesearch

Christina E. Stringer; Ken W. Krauss; James S. Latimer

2016-01-01

These proceedings contain the abstracts, manuscripts, and posters of presentations given at the Fifth Interagency Conference on Research in the Watersheds—Headwaters to estuaries: advances in watershed science and management, held at the Trident Technical College Conference Center in North Charleston, South Carolina, March 3-5, 2015. The conference was hosted...

Hyperspectral remote sensing and long term monitoring reveal watershed-estuary ecosystem interactions

NASA Astrophysics Data System (ADS)

Hestir, E. L.; Schoellhamer, D. H.; Santos, M. J.; Greenberg, J. A.; Morgan-King, T.; Khanna, S.; Ustin, S.

2016-02-01

Estuarine ecosystems and their biogeochemical processes are extremely vulnerable to climate and environmental changes, and are threatened by sea level rise and upstream activities such as land use/land cover and hydrological changes. Despite the recognized threat to estuaries, most aspects of how change will affect estuaries are not well understood due to the poorly resolved understanding of the complex physical, chemical and biological processes and their interactions in estuarine systems. Remote sensing technologies such as high spectral resolution optical systems enable measurements of key environmental parameters needed to establish baseline conditions and improve modeling efforts. The San Francisco Bay-Delta is a highly modified estuary system in a state of ecological crisis due to the numerous threats to its sustainability. In this study, we used a combination of hyperspectral remote sensing and long-term in situ monitoring records to investigate how water clarity has been responding to extreme climatic events, anthropogenic watershed disturbances, and submerged aquatic vegetation (SAV) invasions. From the long-term turbidity monitoring record, we found that water clarity underwent significant increasing step changes associated with sediment depletion and El Nino-extreme run-off events. Hyperspectral remote sensing data revealed that invasive submerged aquatic pant species have facultative C3 and C4-like photosynthetic pathways that give them a competitive advantage under the changing water clarity conditions of the Bay-Delta system. We postulate that this adaptation facilitated the rapid expansion of SAV following the significant step changes in increasing water clarity caused by watershed disturbances and the 1982-1983 El Nino events. Using SAV maps from hyperspectral remote sensing, we estimate that SAV-water clarity feedbacks were responsible for 20-70% of the increasing water clarity trend in the Bay-Delta. Ongoing and future developments in airborne and

Estuary Data Mapper: A Stand-Alone Tool for Geospatial Data Access, Visualization and Download for Estuaries and Coastal Watersheds of the United States. (UNH)

EPA Science Inventory

The US EPA Estuary Data Mapper (EDM; http://badger.epa.gov/rsig/edm/index.html) has been designed as a free stand-alone tool for geospatial data discovery, visualization, and data download for estuaries and their associated watersheds in the conterminous United States. EDM requi...

Holocene climates and connections between the San Francisco Bay Estuary and its watershed: A review

USGS Publications Warehouse

Malamud-Roam, F.; Dettinger, M.; Ingram, B. Lynn; Hughes, Malcolm K.; Florsheim, Joan

2007-01-01

This review of paleoclimate records reveals a gradual warming and drying in California from about 10,000 years to about 4,000 years before present. During this period, the current Bay and Delta were inundated by rising sea level so that by 4,000 years ago the Bay and Delta had taken on much of their present shape and extent. Between about 4,000 and 2,000 years ago, cooler and wetter conditions prevailed in the watershed, lowering salinity in the Estuary and altering local ecosystems. Those wetter conditions gave way to increasing aridity during the past 2,000 years, a general trend punctuated by occasional prolonged and severe droughts and occasional unusually wet, cool periods. California’s climate since A.D. 1850 has been unusually stable and benign, compared to climate variations during the previous 2,000 or more years. Thus, climate variations in California’s future may be even more (perhaps much more) challenging than those of the past 100 years. To improve our understanding of these past examples of climate variability in California, and of the linkages between watershed climate and estuarine responses, greater emphases on paleoclimate records in and around the Estuary, improved temporal resolutions in several record types, and linked watershed-estuary paleo-modeling capabilities are needed. 

Elevational dependence of projected hydrologic changes in the San Francisco Estuary and watershed

USGS Publications Warehouse

Knowles, N.; Cayan, D.R.

2004-01-01

California's primary hydrologic system, the San Francisco Estuary and its upstream watershed, is vulnerable to the regional hydrologic consequences of projected global climate change. Previous work has shown that a projected warming would result in a reduction of snowpack storage leading to higher winter and lower spring-summer streamflows and increased spring-summer salinities in the estuary. The present work shows that these hydrologic changes exhibit a strong dependence on elevation, with the greatest loss of snowpack volume in the 1300-2700 m elevation range. Exploiting hydrologic and estuarine modeling capabilities to trace water as it moves through the system reveals that the shift of water in mid-elevations of the Sacramento river basin from snowmelt to rainfall runoff is the dominant cause of projected changes in estuarine inflows and salinity. Additionally, although spring-summer losses of estuarine inflows are balanced by winter gains, the losses have a stronger influence on salinity since longer spring-summer residence times allow the inflow changes to accumulate in the estuary. The changes in inflows sourced in the Sacramento River basin in approximately the 1300-2200 m elevation range thereby lead to a net increase in estuarine salinity under the projected warming. Such changes would impact ecosystems throughout the watershed and threaten to contaminate much of California's freshwater supply.

EstuRe Project: U.S. Pacific Coast Estuary/Watershed Data and R Tools

EPA Science Inventory

The EstuRe Project is a collaborative effort of the U.S. EPA and USGS to standardize and improve the accessibility of data for U.S. Pacific Coast estuaries and their corresponding watersheds. We are presenting a preview of the datasets and tools that will soon be available from ...

Flood Tide Transport of Blue Crab Postlarvae: Limitations in a Lagoonal Estuary

NASA Astrophysics Data System (ADS)

Cudaback, C.; Eggleston, D.

2005-05-01

Blue crabs, an important commercial species, spend much of their life in estuaries along the east coast. The larvae spawn at or near the ocean, but the juveniles mature in the lower salinity waters of the estuary. It is generally believed that blue crab postlarvae migrate into near surface waters on flood, possibly cued by increasing salinity, and return to the bottom on ebb. Over several tidal cycles, the postlarvae travel a significant distance up-estuary. This model applies quite well to Chesapeake Bay, which has a strong along-estuary salinity gradient and large tides, but may not apply as well to Pamlico Sound, where circulation and salinity are more wind-driven than tidal. A recently completed study (N. Reyns, PhD), indicates that postlarval blue crabs use flood tides and wind-driven currents to cross Pamlico Sound. This study was based on observations with good spatial coverage, but limited vertical and temporal resolution. We have recently completed a complementary study, sampling crab larvae around the clock at four depths at a single location. Preliminary results from the new study suggest that the crab postlarvae do swim all the way to the surface, on flood only, and that flood currents are strongest slightly below the surface. These observations suggest the utility of flood tide transport in this system. However, near bottom salinity does not seem to be driven by tides; at this point it is unclear what cue might trigger the vertical migration of the postlarvae.

Financial Statement Audit Report of Pamlico Community College.

ERIC Educational Resources Information Center

Campbell, Ralph

This report presents the results of the Pamlico Community College financial statement audit for the fiscal year ending on June 30, 1998. Pamlico Community College is a component of the State of North Carolina, thus the authority to audit is granted by Article 5A of G.S. 147. The accounts and operations of the institution were subject to audit…

Processing watershed-derived nitrogen in a well-flushed New England estuary

USGS Publications Warehouse

Tobias, C.R.; Cieri, M.; Peterson, B.J.; Deegan, Linda A.; Vallino, J.; Hughes, J.

2003-01-01

Isotopically labeled nitrate (15NO3-) was added continuously to the Rowley estuary, Massachusetts, for 22 d to assess the transport, uptake, and cycling of terrestrially derived nitrogen during a period of high river discharge and low phytoplankton activity. Isotopic enrichment of the 3.5-km tidal prism (150,000 m3) was achieved for the 3 weeks and allowed us to construct a nitrogen mass balance model for the upper estuary. Mean ??15NO3- in the estuary ranged from 300??? to 600???, and approximately 75%-80% of the 15N was exported conservatively as 15NO 3- to the coastal ocean. Essentially all of the 20%-25% of the 15N processed in the estuary occurred in the benthos and was evenly split between direct denitrification and autotrophic assimilation. The lack of water-column 15N uptake was attributed to low phytoplankton stocks and short water residence times (1.2-1.4 d). Uptake of water-column NO3- by benthic autotrophs (enriched in excess of 100???) was a function of NO3- concentration and satisfied up to 15% and 25% of the total nitrogen demand for benthic microalgae and macroalgae, respectively. Approximately 10% of tracer assimilated by benthic autotrophs was mineralized and released back to the water column as 15NH4+. By the end of the study, 15N storage in sediments and marsh macrophytes accounted for 50%-70% of the 15N assimilated in the estuary. These compartments may sequester watershed-derived nitrogen in the estuary for time scales of months to years.

Estuarine monitoring programs in the Albemarle Sound study area, North Carolina

USGS Publications Warehouse

Moorman, Michelle; Kolb, Katharine R.; Supak, Stacy

2014-01-01

The purpose of this report is to identify major natural resource management issues for the region, provide information on current monitoring activities occurring within the Albemarle Sound study area, determine how the current monitoring network fits into the design of the NMN, and determine what additional monitoring data are needed to address these issues. In order to address these questions, a shapefile and data table were created to document monitoring and research programs in the Albemarle Sound study area with an emphasis on current monitoring programs within the region. This database was queried to determine monitoring gaps that existed in the Albemarle Sound by comparing current monitoring programs with the design indicated by the NMN. The report uses this information to provide recommendations on how monitoring could be improved in the Albemarle Sound study area.

Holistic Sustainability Assessment of Agricultural Rainwater Harvesting

EPA Science Inventory

We present a methodology for holistic sustainability assessment of green infrastructure, applied to agricultural rainwater harvesting (RWH) in the Albemarle-Pamlico river basin. It builds upon prior work in the region through the use of detailed, crop-level management information...

REMOTE SENSING OF PAMLICO SOUND PLANKTON COMMUNITIES USING AVIRIS DATA

EPA Science Inventory

The U.S. EPA, in cooperation with NASA, NOAA and the University of North Carolina, has acquired AVIRIS hyperspectral data and high altitude (ER2) color infrared aerial photography (1: 65,000-scale) for the Pamlico Sound in North Carolina on May 15, 2002. The Pamlico Sound is a hi...

A View from Albemarle

ERIC Educational Resources Information Center

Holt, Thaddeus

1977-01-01

This paper was originally delivered in July of 1975, within a few weeks of the Supreme Court's decision in the case of "Albemarle Paper Company v. Moody". Its intent is to shed light on the interrelationship between the practice of industrial psychology and the judicial process in operation. (Editor/RK)

Watershed-scale drivers of air-water CO2 exchanges in two lagoonal, North Carolina (USA) estuaries

NASA Astrophysics Data System (ADS)

Van Dam, B.; Crosswell, J.; Anderson, I. C.; Paerl, H. W.

2017-12-01

Riverine loading of nutrients and organic matter act in concert to modulate CO2 fluxes in estuaries, yet quantitative relationships between these factors remain poorly defined. This study explored watershed-scale mechanisms responsible for the relatively low CO2 fluxes observed in two microtidal, lagoonal estuaries. Air-water CO2 fluxes were quantified with 74 high-resolution spatial surveys in the neighboring New River Estuary (NewRE) and Neuse River Estuary (NeuseRE), North Carolina, which experience a common climatology, but differ in marine versus riverine influence. Annually, both estuaries were relatively small sources of CO2 to the atmosphere, 12.5 and 16.3 mmol C m2 d-1 in the NeuseRE and NewRE, respectively. Variations in riverine alkalinity and inorganic carbon loading caused zones of minimum buffering capacity to occur at different locations in each estuary, enhancing the sensitivity of estuarine inorganic C chemistry to acidification. Large-scale pCO2 variations were driven by changes in freshwater age (akin to residence time), which modulate nutrient and organic carbon supply and phytoplankton flushing. Greatest pCO2 under-saturation was observed at intermediate freshwater ages, between 2-3 weeks. Biological controls on CO2 fluxes were obscured by variable inputs of river-borne CO2, which drove CO2 degassing in the river-dominated NeuseRE. Internally produced CO2 exceeded river-borne CO2 in the marine-dominated NewRE, suggesting that net ecosystem heterotrophy, rather than riverine inputs, drove CO2 fluxes in this system. Although annual CO2 fluxes were similar between systems, watershed-specific hydrologic factors led to disparate controls on internal carbonate chemistry, which can influence overall ecosystem health and response to future perturbation.

Watershed-Scale Drivers of Air-Water CO2 Exchanges in Two Lagoonal North Carolina (USA) Estuaries

NASA Astrophysics Data System (ADS)

Van Dam, Bryce R.; Crosswell, Joseph R.; Anderson, Iris C.; Paerl, Hans W.

2018-01-01

Riverine loading of nutrients and organic matter act in concert to modulate CO2 fluxes in estuaries, yet quantitative relationships between these factors remain poorly defined. This study explored watershed-scale mechanisms responsible for the relatively low CO2 fluxes observed in two microtidal, lagoonal estuaries. Air-water CO2 fluxes were quantified with 74 high-resolution spatial surveys in the neighboring New River Estuary (NewRE) and Neuse River Estuary (NeuseRE), North Carolina, which experience a common climatology but differ in marine versus riverine influence. Annually, both estuaries were relatively small sources of CO2 to the atmosphere, 12.5 and 16.3 mmol C m-2 d-1 in the NeuseRE and NewRE, respectively. Large-scale pCO2 variations were driven by changes in freshwater age, which modulates nutrient and organic carbon supply and phytoplankton flushing. Greatest pCO2 undersaturation was observed at intermediate freshwater ages, between 2 and 3 weeks. Biological controls on CO2 fluxes were obscured by variable inputs of river-borne CO2, which drove CO2 degassing in the river-dominated NeuseRE. Internally produced CO2 exceeded river-borne CO2 in the marine-dominated NewRE, suggesting that net ecosystem heterotrophy, rather than riverine inputs, drove CO2 fluxes in this system. Variations in riverine alkalinity and inorganic carbon loading caused zones of minimum buffering capacity to occur at different locations in each estuary, enhancing the sensitivity of estuarine inorganic C chemistry to acidification. Although annual CO2 fluxes were similar between systems, watershed-specific hydrologic factors led to disparate controls on internal carbonate chemistry, which can influence ecosystem biogeochemical cycling, trophic state, and response to future perturbations.

CHAPTER 7: COASTAL ZONES.

EPA Science Inventory

The Mid-Atlantic's coastal areas, especially the Chesapeake Bay, Delaware Bay, and Albemarle/Pamlico Sounds (Figure 3), have important aesthetic and economic values. In Delaware, for example, Parsons and Powell (1998) estimated that $90,000 of the value of a $200,000 home along t...

75 FR 65278 - Pamlico Sound and Adjacent Waters, NC; Danger Zones for Marine Corps Operations

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

... DEPARTMENT OF DEFENSE Corps of Engineers, Department of the Army 33 CFR Part 334 Pamlico Sound and... (Corps) is proposing to amend its regulations to establish one new danger zone in Pamlico Sound near... described in Sec. 334.420(b)(1)(i)] in the Pamlico Sound and adjacent waters in Carteret County, North...

LIDAR vs. GEODAS land elevation data in hurricane induced inundation modelling

NASA Astrophysics Data System (ADS)

Peng, M.; Pietrafesa, L. J.; Bao, S.; Liu, H.; Xia, M.; Yan, T.

2007-04-01

LIDAR (Light Detection and Ranging) and GEODAS (GEOphysical DAta System) are respectively taken as the land elevation data for a 3-D storm surge and inundation model to investigate the subsequent inundation differences. Hilton Head, South Carolina, and Croatan-Albemarle-Pamlico Estuary System (CAPES), North Carolina, are the two investigated regions. Significant inundation differences with LIDAR versus GEODAS are found in both regions. The modeled inundation area with GEODAS is larger than with LIDAR. For Category 2-3 hypothetical hurricanes, the maximum inundation difference in Hilton Head region is 67%, while the difference in the CAPES is 156%. Generally, vertical precision difference of the two databases is the major reason for the inundation difference. Recently constructed man-made structures, not included in the GEODAS, but included in the LIDAR data sets may be another contributing reason.

Albemarle County roads, 1725-1816.

DOT National Transportation Integrated Search

1981-01-01

This publication is the result of an effort to write a history of the early road system of Albemarle County which could be used as a prototype for similar histories of other areas. This has involved research in such primary sources as court records, ...

THE ROLES OF ANTHROPOGENIC WATERSHED LOADING AND CLIMATE VARIABILITY ON NITROGEN FLUXES TO THE POTOMAC RIVER ESTUARY

EPA Science Inventory

To better anticipate responses of estuaries and coastal ecosystems to human activity and climate variation, it is useful to examine the historical record of nitrogen fluxes from watersheds to receiving waters and the factors affecting them. This study undertook a statistical exam...

An index to roads shown in the Albemarle County surveyors books, 1744-1853.

DOT National Transportation Integrated Search

1976-01-01

Albemarle County, formed from Goochland in 1744, is fortunate in having preserved in its records three volumes of surveys made by the surveyors of the county between 1744 and 1853. In a sense, Albemarle County's good fortune extends to several other ...

Estuary Data Mapper

EPA Science Inventory

The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools to support decision-making. To facilita...

Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

76 FR 78335 - North Carolina & Virginia Railroad Company, LLC, Chesapeake & Albemarle Railroad Division-Lease...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-16

... Carolina & Virginia Railroad Company, LLC, Chesapeake & Albemarle Railroad Division--Lease Amendment Exemption--Norfolk Southern Railway Company North Carolina & Virginia Railroad, LLC, Chesapeake & Albemarle Railroad Division (NCVR), a Class III carrier, has filed a verified notice of exemption under 49 CFR1150.41...

About Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions.

Creating a Population of 12-Digit Headwater Basins within the Albemarle-Pamlico Estuary System

EPA Science Inventory

Ecological research within the US Environmental Protection Agency's Office of Research and Development has recently changed its focus to quantifying and mapping ecosystem services provided to humans. Our local research group has been charged to develop a regional assessment of se...

Measurement of water colour using AVIRIS imagery to assess the potential for an operational monitoring capability in the Pamlico Sound Estuary, USA

PubMed Central

Ross, S. Lunetta; Joseph, F. Knight; Hans, W. Paerl; John, J. Streicher; Benjamin, L. Peierls; Tom, Gallo; John, G. Lyon; Thomas, H. Mace; Christopher, P. Buzzelli

2009-01-01

The monitoring of water colour parameters can provide an important diagnostic tool for the assessment of aquatic ecosystem condition. Remote sensing has long been used to effectively monitor chlorophyll concentrations in open ocean systems; however, operational monitoring in coastal and estuarine areas has been limited because of the inherent complexities of coastal systems, and the coarse spectral and spatial resolutions of available satellite systems. Data were collected using the National Aeronautics and Space Administration (NASA) Advanced Visible-Infrared Imaging Spectrometer (AVIRIS) flown at an altitude of approximately 20000 m to provide hyperspectral imagery and simulate both MEdium Resolution Imaging Spectrometer (MERIS) and Moderate Resolution Imaging Spectrometer (MODIS) data. AVIRIS data were atmospherically corrected using a radiative transfer modelling approach and analysed using band ratio and linear regression models. Regression analysis was performed with simultaneous field measurements data in the Neuse River Estuary (NRE) and Pamlico Sound on 15 May 2002. Chlorophyll a (Chl a) concentrations were optimally estimated using AVIRIS bands (9.5 nm) centred at 673.6 and 692.7 nm, resulting in a coefficient of determination (R2) of 0.98. Concentrations of Chromophoric Dissolved Organic Matter (CDOM), Total Suspended Solids (TSS) and Fixed Suspended Solids (FSS) were also estimated, resulting in coefficients of determination of R2=0.90, 0.59 and 0.64, respectively. Ratios of AVIRIS bands centred at or near those corresponding to the MERIS and MODIS sensors indicated that relatively good satellite-based estimates could potentially be derived for water colour constituents at a spatial resolution of 300 and 500 m, respectively. PMID:25937680

Collection and analysis of remotely sensed data from the Rhode River Estuary Watershed. [ecological parameters of Chesapeake Bay

NASA Technical Reports Server (NTRS)

Jenkins, D. W.

1972-01-01

NASA chose the watershed of Rhode River, a small sub-estuary of the Bay, as a representative test area for intensive studies of remote sensing, the results of which could be extrapolated to other estuarine watersheds around the Bay. A broad program of ecological research was already underway within the watershed, conducted by the Smithsonian Institution's Chesapeake Bay Center for Environmental Studies (CBCES) and cooperating universities. This research program offered a unique opportunity to explore potential applications for remote sensing techniques. This led to a joint NASA-CBCES project with two basic objectives: to evaluate remote sensing data for the interpretation of ecological parameters, and to provide essential data for ongoing research at the CBCES. A third objective, dependent upon realization of the first two, was to extrapolate photointerpretive expertise gained at the Rhode River watershed to other portions of the Chesapeake Bay.

Tillamook Estuary Case Study: Local Drivers Influencing Coastal Acidification

EPA Science Inventory

US EPA initiated a study in the Tillamook estuary and watershed focused on the impact of changes in watershed land use, ocean conditions, and weather on estuarine water quality and ecosystem goods and services production within the estuary. This project is a collaboration betwee...

Micropaleontologic record of late Pliocene and Quaternary paleoenvironments in the northern Albemarle Embayment, North Carolina, U.S.A.

USGS Publications Warehouse

Culver, S.J.; Farrell, K.M.; Mallinson, D.J.; Horton, B.P.; Willard, D.A.; Thieler, E.R.; Riggs, S.R.; Snyder, S.W.; Wehmiller, J.F.; Bernhardt, C.E.; Hillier, C.

2008-01-01

Micropaleontological data provide a strong actualistic basis for detailed interpretations of Quaternary paleoenvironmental change. The 90??m-thick Quaternary record of the Albemarle Embayment in the mid-Atlantic coastal plain of the USA provides an excellent opportunity to use such an approach in a region where the details of Quaternary environmental change are poorly known. The foraminiferal record in nine cores from the northern Outer Banks, east of Albemarle Sound, North Carolina, indicates the deposition of subhorizontal, mostly open-marine early to late Pleistocene units unconformably upon a basement of late Pliocene reduced-oxygen, fine-grained, shelf-basin deposits. Pollen data record several warm-cool fluctuations within the early to mid-Pleistocene deposits. Diatom data indicate that some fresh and brackish-water units occur within the generally open-marine Pleistocene succession. A channel cut by the paleo-Roanoke River during the last glacial sea-level lowstand occurs in the northern part of the study area. Pollen indicates that the basal fluvial valley fill accumulated in cooler than modern climate conditions in the latest Pleistocene. Overlying silts and muds accumulated under cool climatic, estuarine conditions according to diatom and pollen data. Radiocarbon ages from the estuarine deposits indicate that the bulk of these sediments accumulated during the latest Pleistocene. The estuarine channel-fill deposits are overlain by Holocene open-marine sands deposited as the rising sea transgressed into the estuary approximately 8.5 to 9.0??kyr BP. Within the barrier island drill cores of this study, fully marine sedimentation occurred throughout the Holocene. However, immediately west of the present barrier island, mid- to late Holocene estuarine deposits underlie the modern Albemarle Sound. The islands that currently form a continuous barrier across the mouth of Albemarle Sound have a complex history of Holocene construction and destruction and large

WATERSHED LANDSCAPE INDICATORS OF ESTUARINE BENTHIC CONDITION

EPA Science Inventory

Do land use/cover characteristics of watersheds associated with small estuaries exhibit a strong enough signal to make landscape metrics useful for identifying degraded bottom communities? We tested this idea with 58 pairs of small estuaries (<260 km2) and watersheds in the U.S. ...

A DATA SYSTEM FOR INTEGRATING DATA FROM LANDSCAPES, STREAMS AND ESTUARIES

EPA Science Inventory

Estuaries are natural integrators of substances and processes that occur internally and externally (watersheds, ocean, atmosphere). Watershed activities that contribute fresh water, nutrients, contaminants, and suspended solids have a strong effect on the health of estuaries. Res...

Downloading and Installing Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

Frequent Questions about Estuary Data Mapper (EDM)

EPA Pesticide Factsheets

Estuary Data Mapper is a tool for geospatial data discovery, visualization, and data download for any of the approximately 2,000 estuaries and associated watersheds in along the five US coastal regions

Albemarle County/City of Charlottesville transportation planning compact disc.

DOT National Transportation Integrated Search

1998-06-01

This report describes transportation planning data, available in numerous files and formats stored on the accompanying compact disc, that were compiled from planning studies for the Charlottesville/Albemarle area done in 1967, 1979, and 1990. These d...

Charlottesville-Albemarle Media Center: A Proposal for Implementation.

ERIC Educational Resources Information Center

Coleman, J. Gordon, Jr.

Initiated as a graduate school project in educational media administration and later distributed to administrative personnel in the Charlottesville and Albemarle County public school districts, this document presents a 5-year plan for merging the district-level library media centers and related services of these two neighboring Virginia school…

Identifying Local Factors that May Exacerbate Coastal Acidification in Pacific Northwest Estuaries

EPA Science Inventory

US EPA initiated a study in the Tillamook estuary and watershed focused on the impact of changes in watershed land use, ocean conditions, and weather on estuarine water quality and ecosystem goods and services production within the estuary. This project is a collaboration betwee...

Assessing the response of the Pamlico Sound, North Carolina, USA to human and climatic disturbances: Management implications

USGS Publications Warehouse

Paerl, H.W.; Peierls, B.L.; Hall, N. S.; Joyner, A. R.; Christian, R.R.; Bales, Jerad D.; Riggs, S.R.

2010-01-01

The Pamlico Sound (PS) with its sub-estuaries is the largest lagoonal ecosystem in the United States. It exhibits periodically strong salinity stratification and an average freshwater residence time of 1 year for the sound proper. This relatively long residence time promotes effective use and cycling of nutrients, allowing the system to support high rates of primary and secondary production, and serve as a vitally important fisheries nursery. This hydrologic characteristic also makes the system highly sensitive to nutrient over-enrichment and eutrophication. The PS is experiencing ecological change in response to increasing human activity and climatic perturbations. Human impacts include a rise in nutrient, sediment, and other pollutant loads that accompany urbanization and agricultural and industrial growth in its watersheds and airsheds. Since the mid-1990s, the PS has witnessed a sudden rise in tropical storm and hurricane impacts, with eight hurricanes and four tropical storms having made landfall in the PS watershed during the 1996 to 2007 period. Each of these storms had unique hydrologic, nutrient, and other pollutant loading effects. In addition, since the early 2000s, the region has experienced record droughts, which are continuing. Variable freshwater discharges from storms and droughts have caused large oscillations in nutrient enrichment, reflected ultimately in differential phytoplankton production, biomass, and community compositional responses. Floodwaters from the two wettest hurricanes, Fran (1996) and Floyd (1999), and from Tropical Storm Ernesto (2006) exerted long-term (months) effects on hydrology, nutrient loads, and algal production. Windy but relatively dry hurricanes, like Irene (1999) and Isabel (2003), caused strong vertical mixing, storm surges, but relatively minor changes in river flow, flushing, and nutrient loads. These contrasting effects are accompanied by biogeochemical (hypoxia, nutrient cycling) and habitat alterations, and

75 FR 11862 - Endangered Species; File No. 14759

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-12

... Fear) and estuaries (Albemarle Sound) using non-lethal sampling methods combining hydroacoustic surveys..., Neuse, Cape Fear river systems and Albemarle Sound, and up to 20 shortnose sturgeon from the Roanoke...

A COMPARATIVE ANALYSIS OF NUTRIENT LOADING, NUTRIENT RETENTION AND NET ECOSYSTEM METABOLISM IN THREE TIDAL RIVER ESTUARIES DIFFERING PREDOMINATELY BY THEIR WATERSHED LAND USE TYPES.

EPA Science Inventory

Abstract and oral presentation for the Estuarine Research Federation Conference.

Estuarine retention of watershed nutrient loads, system-wide nutrient biogeochemical fluxes, and net ecosystem metabolism (NEM) were determined in three estuaries exhibiting differing magnitud...

Impacts of pesticides in a Central California estuary.

PubMed

Anderson, Brian; Phillips, Bryn; Hunt, John; Siegler, Katie; Voorhees, Jennifer; Smalling, Kelly; Kuivila, Kathy; Hamilton, Mary; Ranasinghe, J Ananda; Tjeerdema, Ron

2014-03-01

Recent and past studies have documented the prevalence of pyrethroid and organophosphate pesticides in urban and agricultural watersheds in California. While toxic concentrations of these pesticides have been found in freshwater systems, there has been little research into their impacts in marine receiving waters. Our study investigated pesticide impacts in the Santa Maria River estuary, which provides critical habitat to numerous aquatic, terrestrial, and avian species on the central California coast. Runoff from irrigated agriculture constitutes a significant portion of Santa Maria River flow during most of the year, and a number of studies have documented pesticide occurrence and biological impacts in this watershed. Our study extended into the Santa Maria watershed coastal zone and measured pesticide concentrations throughout the estuary, including the water column and sediments. Biological effects were measured at the organism and community levels. Results of this study suggest the Santa Maria River estuary is impacted by current-use pesticides. The majority of water samples were highly toxic to invertebrates (Ceriodaphnia dubia and Hyalella azteca), and chemistry evidence suggests toxicity was associated with the organophosphate pesticide chlorpyrifos, pyrethroid pesticides, or mixtures of both classes of pesticides. A high percentage of sediment samples were also toxic in this estuary, and sediment toxicity occurred when mixtures of chlorpyrifos and pyrethroid pesticides exceeded established toxicity thresholds. Based on a Relative Benthic Index, Santa Maria estuary stations where benthic macroinvertebrate communities were assessed were degraded. Impacts in the Santa Maria River estuary were likely due to the proximity of this system to Orcutt Creek, the tributary which accounts for most of the flow to the lower Santa Maria River. Water and sediment samples from Orcutt Creek were highly toxic to invertebrates due to mixtures of the same pesticides measured

PECONIC ESTUARY PROGRAM COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

EPA Science Inventory

The Peconic Estuary, situated between the North and South Forks of eastern Long Island, New York, consists of more than 100 distinct bays, harbors, embayments, and tributaries. The area surrounding the Peconic Estuary's watershed is rich in rolling farmland, scenic beaches and cr...

Hydrology of major estuaries and sounds of North Carolina

USGS Publications Warehouse

Giese, G.L.; Wilder, Hugh B.; Parker, Garald G.

1985-01-01

Hydrology-related problems associated with North Carolina 's major estuaries and sounds include contamination of some estuaries with municipal and industrial wastes and drainage from adjacent, intensively farmed areas, and nuisance-level algal blooms. In addition, there is excessive shoaling in some navigation channels, salt-water intrusion into usually fresh estuarine reaches, too high or too-low salinities in nursery areas for various estuarine species, and flood damage due to hurricanes. The Cape Fear River is the only major North Carolina estuary having a direct connection to the sea. Short-term flow throughout most of its length is dominated by ocean tides. Freshwater entering the major estuaries is, where not contaminated, of acceptable quality for drinking with minimum treatment. However, iron concentrations in excess of 0.3 milligrams per liter sometimes occur and water draining from swampy areas along the Coastal Plain is often highly colored, but these problems may be remedied with proper treatment. Nuisance-level algal blooms have been a recurring problem on the lower estuarine reaches of the Neuse, Tar-Pamlico, and Chowan Rivers where nutrients (compounds of phosphorous and nitrogen) are abundant. The most destructive blooms tend to occur in the summer months during periods of low freshwater discharge and relatively high water temperatures. Saltwater intrusion occurs from time to time in all major estuaries except the Roanoke River, where releases from Roanoke Rapids Lake and other reservoirs during otherwise low-flow periods effectively block saline water from the estuary. New shoaling materials found in the lower channelized reaches of the Cape Fear and Northeast Cape Fear Rivers are primarily derived, not from upstream sources, but from nearby shore erosion, from slumping of material adjacent to the dredged channels, from old spoil areas, or from ocean-derived sediments carried upstream by near-bottom density currents.

Long-term Watershed Database for the Ridge and Valley Physiographic Province: Mahantango Creek Watershed, Pennsylvania, USA

USDA-ARS?s Scientific Manuscript database

Understanding agricultural effects on water quality in rivers and estuaries requires understanding of hydrometeorology and geochemical cycling at various scales over time. The USDA-ARS initiated a hydrologic research program at the Mahantango Creek Watershed (MCW) in 1968, a research watershed at t...

REGIONAL ASSESSMENT OF FISH HEALTH: A PROTOTYPE METHODOLOGY AND CASE STUDY FOR THE ALBEMARLE-PAMLICO RIVER BASIN, NORTH CAROLINA

EPA Science Inventory

BASE (Basin-Scale Assessments for Sustainable Ecosystems) is a research program developed by the Ecosystems Research Division of the National Exposure Research Laboratory to explore and formulate approaches for assessing the sustainability of ecological resources within watershed...

FerryMon: An Unattended Ferry-Based Observatory to Assess Human and Climatically- Induced Ecological Change in the Neuse River-Pamlico Sound System, North Carolina, USA

NASA Astrophysics Data System (ADS)

Guajardo, R.; Paerl, H. W.; Hall, N.; Whipple, A.; Luettich, R.

2007-12-01

In North Carolina's Neuse River Estuary (NRE)-Pamlico Sound (PS) System, nitrogen (N)-driven eutrophication, water quality and habitat decline have prompted the State and US EPA to mandate watershed-based N load reductions, including a total maximum daily allowable N load (TMDL). Chlorophyll a (chl-a), the indicator of algal biomass, is the measure for the efficacy of N reductions, with "acceptable" values being <40 μg chl- a L-1. However, algal blooms are patchy in time and space, making exceedances of 40 μ g L-1 difficult to track. The North Carolina ferry-based water quality monitoring program, FerryMon (www.ferrymon.org) addresses this and other environmental monitoring needs in the NRE-PS. FerryMon uses NC DOT ferries to provide continuous, space-time intensive, accurate measurements of chl-a and other key water quality criteria, using sensors placed in a flow-through system and discrete sampling of nutrients, organics, diagnostic photopigment and molecular indicators of major algal groups in a near real-time manner. Complementing FerryMon are automated vertical profilers (AVPs), which produce chl-a and other water quality indicator depth profiles with very high time and vertical resolution. In-line spectral fluorometers (Algae Online Analyzers (AOAs)) will be installed starting in late 2007, providing rapid early warning detection and quantification of algal blooms. FerryMon permits spatial characterization of trends in water quality conditions over a range of relevant physical, chemical and biological time scales. This enhanced capability is timely, given a protracted period of increased tropical storm and hurricane activity that, in combination with anthropogenic nutrient enrichment, affects water quality in unpredictable, yet significant ways. FerryMon also serves as a data source for calibrating and verifying remotely sensed indicators of water quality (photopigments, turbidity), nutrient-productivity and hydrologic modeling. Data management and

Nitrogen Source and Loading Data for EPA Estuary Data Mapper

EPA Science Inventory

Nitrogen source and loading data have been compiled and aggregated at the scale of estuaries and associated watersheds of the conterminous United States, using the spatial framework in EPA's Estuary Data Mapper (EDM) to provide system boundaries. Original sources of data include...

Demonstration and Hands-on Exercises with the Estuary Data Mapper

EPA Science Inventory

The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for applications of the Clean Water Act in coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools t...

Sources and Loading of Nitrogen to U.S. Estuaries

EPA Science Inventory

Previous assessments of land-based nitrogen loading and sources to U.S. estuaries have been limited to estimates for larger systems with watersheds at the scale of 8-digit HUCs and larger, in part due to the coarse resolution of available data, including estuarine watershed bound...

Micropaleontologic record of Quaternary paleoenvironments in the Central Albemarle Embayment, North Carolina, U.S.A.

USGS Publications Warehouse

Culver, Stephen J.; Farrell, Kathleen M.; Mallinson, David J.; Willard, Debra A.; Horton, Benjamin P.; Riggs, Stanley R.; Thieler, E. Robert; Wehmiller, John F.; Parham, Peter; Snyder, Scott W.; Hillier, Caroline

2011-01-01

To understand the temporal and spatial variation of eustatic sea-level fluctuations, glacio-hydro-isostacy, tectonics, subsidence, geologic environments and sedimentation patterns for the Quaternary of a passive continental margin, a nearly complete stratigraphic record that is fully integrated with a three dimensional chronostratigraphic framework, and paleoenvironmental information are necessary. The Albemarle Embayment, a Cenozoic regional depositional basin in eastern North Carolina located on the southeast Atlantic coast of the USA, is an ideal setting to unravel these dynamic, interrelated processes.Micropaleontological data, coupled with sedimentologic, chronostratigraphic and seismic data provide the bases for detailed interpretations of paleoenvironmental evolution and paleoclimates in the 90. m thick Quaternary record of the Albemarle Embayment. The data presented here come from a transect of cores drilled through a barrier island complex in the central Albemarle Embayment. This area sits in a ramp-like setting between late Pleistocene incised valleys.The data document the episodic infilling of the Albemarle Embayment throughout the Quaternary as a series of transgressive-regressive (T-R) cycles, characterized by inner shelf, midshelf, and shoreface assemblages, that overlie remnants of fluvial to estuarine valley-fill. Barrier island and marginal marine deposits have a low preservation potential. Inner to mid-shelf deposits of the early Pleistocene are overlain by similar middle Pleistocene shelf sediments in the south of the study area but entirely by inner shelf deposits in the north. Late Pleistocene marine sediments are of inner shelf origin and Holocene deposits are marginal marine in nature. Pleistocene marine sediments are incised, particularly in the northern half of the embayment by lowstand paleovalleys, partly filled by fluvial/floodplain deposits and in some cases, overlain by remnants of transgressive estuarine sediments. The shallowing

Environmental Assessment for Atlantic White Cedar Restoration Project at Dare County Range, Seymour Johnson Air Force Base, North Carolina

DTIC Science & Technology

2014-12-23

bond of$5,000 with ENR running to Stale of NC: conditional that n Permit to drill exploratory oil or gas well m1y well opened by drill operator shall...Native American Consultation B – U.S. Fish and Wildlife Service Endangered Species Consultation C – Greenhouse Gas Estimates D – Air Emissions...on the north by the Albemarle Sound, on the west by the Alligator River, on the east by the Croatan Sound, and on the southeast by the Pamlico Sound

Linking Data Access to Data Models to Applications: The Estuary Data Mapper

EPA Science Inventory

The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools to support decision-making. To facilita...

The role of watershed characteristics in estuarine condition: an empirical approach

Treesearch

James Latimer; Melissa Hughes; Michael Charpentier; Christine Tilburg

2016-01-01

Estuarine condition is a function of the nature of the estuary, ocean, and atmospheric systems, and the upstream watershed. To fully understand and predict how an estuary will respond to drivers and pressures,...

Approaches for Development of Nutrient Criteria in Oregon Estuaries With a Focus on Tillamook Estuary

EPA Science Inventory

Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

Rapid Holocene coastal change revealed by high-resolution micropaleontological analysis, Pamlico Sound, North Carolina, USA

USGS Publications Warehouse

Grand, Pre C.; Culver, S.J.; Mallinson, D.J.; Farrell, K.M.; Corbett, D.R.; Horton, B.P.; Hillier, C.; Riggs, S.R.; Snyder, S.W.; Buzas, M.A.

2011-01-01

Foraminiferal analyses of 404 contiguous samples, supported by diatom, lithologic, geochronologic and seismic data, reveal both rapid and gradual Holocene paleoenvironmental changes in an 8.21-m vibracore taken from southern Pamlico Sound, North Carolina. Data record initial flooding of a latest Pleistocene river drainage and the formation of an estuary 9000. yr ago. Estuarine conditions were punctuated by two intervals of marine influence from approximately 4100 to 3700 and 1150 to 500. cal. yr BP. Foraminiferal assemblages in the muddy sand facies that accumulated during these intervals contain many well-preserved benthic foraminiferal species, which occur today in open marine settings as deep as the mid shelf, and significant numbers of well-preserved planktonic foraminifera, some typical of Gulf Stream waters. We postulate that these marine-influenced units resulted from temporary destruction of the southern Outer Banks barrier islands by hurricanes. The second increase in marine influence is coeval with increased rate of sea-level rise and a peak in Atlantic tropical cyclone activity during the Medieval Climate Anomaly. This high-resolution analysis demonstrates the range of environmental variability and the rapidity of coastal change that can result from the interplay of changing climate, sea level and geomorphology in an estuarine setting. ?? 2011 University of Washington.

The Role of Watershed Characteristics in Estuarine Condition: An Empirical Approach

EPA Science Inventory

Estuarine condition is a function of the nature of the estuary, ocean, and atmospheric systems, and the upstream watershed. To fully understand and predict how an estuary will respond to drivers and pressures, each compartment must be characterized. For example, eutrophication ef...

Collaborative Potential between National Estuary Programs ...

EPA Pesticide Factsheets

Estuaries are among the most productive ecosystems in the world, providing unique habitat for freshwater and marine species as well as valuable social and economic benefits. The wealth of ecosystem goods and services from estuaries has led to growth and development of human communities in adjacent areas and an increase in human activities that can adversely affect water quality and critical habitat. Managing for sustainable estuaries requires a balance of environmental concerns with community social and economic values. This has created an opportunity to leverage Environmental Protection Agency (EPA) scientific knowledge and tools with National Estuary Program (NEP) planning and management expertise to address environmental challenges in important estuarine ecosystems. The non-regulatory National Estuary Program (NEP) was outlined in the Clean Water Act to provide stakeholders an opportunity to monitor and manage ‘nationally significant’ estuaries. Currently there are 28 estuaries in the NEP, broadly distributed across the Atlantic, Pacific and Gulf Coasts, and in Puerto Rico. The local NEP management conferences must address a variety of environmental issues, from water quality and natural resources to coastal and watershed development. While the underlying objectives of each NEP are quite similar, each has unique landscapes, land uses, waterbodies, habitats, biological resources, economies and social culture. Consequently, the effects and severity of anthr

78 FR 77590 - Drawbridge Operation Regulation; Albemarle Sound to Sunset Beach, Atlantic Intracoastal Waterway...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-24

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 [Docket No. USCG-2013-1020] Drawbridge Operation Regulation; Albemarle Sound to Sunset Beach, Atlantic Intracoastal Waterway (AICW), Wrightsville Beach, NC AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from drawbridge regulation. SUMMARY: The...

78 FR 47191 - Drawbridge Operation Regulation; Albemarle Sound to Sunset Beach, Atlantic Intracoastal Waterway...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-05

... DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 [Docket No. USCG-2013-0687] Drawbridge Operation Regulation; Albemarle Sound to Sunset Beach, Atlantic Intracoastal Waterway (AICW), Wrightsville Beach, NC AGENCY: Coast Guard, DHS. ACTION: Notice of deviation from drawbridge regulation. SUMMARY: The...

From headwaters to coast: Influence of human activities on water quality of the Potomac River Estuary

USGS Publications Warehouse

Bricker, Suzanne B.; Rice, Karen C.; Bricker, Owen P.

2014-01-01

The natural aging process of Chesapeake Bay and its tributary estuaries has been accelerated by human activities around the shoreline and within the watershed, increasing sediment and nutrient loads delivered to the bay. Riverine nutrients cause algal growth in the bay leading to reductions in light penetration with consequent declines in sea grass growth, smothering of bottom-dwelling organisms, and decreases in bottom-water dissolved oxygen as algal blooms decay. Historically, bay waters were filtered by oysters, but declines in oyster populations from overfishing and disease have led to higher concentrations of fine-sediment particles and phytoplankton in the water column. Assessments of water and biological resource quality in Chesapeake Bay and tributaries, such as the Potomac River, show a continual degraded state. In this paper, we pay tribute to Owen Bricker’s comprehensive, holistic scientific perspective using an approach that examines the connection between watershed and estuary. We evaluated nitrogen inputs from Potomac River headwaters, nutrient-related conditions within the estuary, and considered the use of shellfish aquaculture as an in-the-water nutrient management measure. Data from headwaters, nontidal, and estuarine portions of the Potomac River watershed and estuary were analyzed to examine the contribution from different parts of the watershed to total nitrogen loads to the estuary. An eutrophication model was applied to these data to evaluate eutrophication status and changes since the early 1990s and for comparison to regional and national conditions. A farm-scale aquaculture model was applied and results scaled to the estuary to determine the potential for shellfish (oyster) aquaculture to mediate eutrophication impacts. Results showed that (1) the contribution to nitrogen loads from headwater streams is small (about 2 %) of total inputs to the Potomac River Estuary; (2) eutrophic conditions in the Potomac River Estuary have improved in

The relative importance of oceanic nutrient inputs for Bass Harbor Marsh Estuary at Acadia National Park, Maine

USGS Publications Warehouse

Huntington, Thomas G.; Culbertson, Charles W.; Fuller, Christopher; Glibert, Patricia; Sturtevant, Luke

2014-01-01

The U.S. Geological Survey and Acadia National Park (ANP) collaborated on a study of nutrient inputs into Bass Harbor Marsh Estuary on Mount Desert Island, Maine, to better understand ongoing eutrophication, oceanic nutrient inputs, and potential management solutions. This report includes the estimation of loads of nitrate, ammonia, total dissolved nitrogen, and total dissolved phosphorus to the estuary derived from runoff within the watershed and oceanic inputs during summers 2011 and 2012. Nutrient outputs from the estuary were also monitored, and nutrient inputs in direct precipitation to the estuary were calculated. Specific conductance, water temperature, and turbidity were monitored at the estuary outlet. This report presents a first-order analysis of the potential effects of projected sea-level rise on the inundated area and estuary volume. Historical aerial photographs were used to investigate the possibility of widening of the estuary channel over time. The scope of this report also includes analysis of sediment cores collected from the estuary and fringing marsh surfaces to assess the sediment mass accumulation rate. Median concentrations of nitrate, ammonium, and total dissolved phosphorus on the flood tide were approximately 25 percent higher than on the ebb tide during the 2011 and 2012 summer seasons. Higher concentrations on the flood tide suggest net assimilation of these nutrients in biota within the estuary. The dissolved organic nitrogen fraction dominated the dissolved nitrogen fraction in all tributaries. The median concentration of dissolved organic nitrogen was about twice as high on the on the ebb tide than the flood tide, indicating net export of dissolved organic nitrogen from the estuary. The weekly total oceanic inputs of nitrate, ammonium, and total dissolved phosphorus to the estuary were usually much larger than inputs from runoff or direct precipitation. The estuary was a net sink for nitrate and ammonium in most weeks during both

Microbial Community Structure in Relation to Water Quality in a Eutrophic Gulf of Mexico Estuary

EPA Science Inventory

Weeks Bay is a shallow, microtidal, eutrophic sub-estuary of Mobile Bay, AL. High watershed nutrient inputs to the estuary contribute to a eutrophic condition characterized by frequent summertime diel-cycling hypoxia and dissolved oxygen (DO) oversaturation. Spatial and seasonal ...

Comparative Ecological Approach to Assess the Role of Watersheds in Estuarine Condition

EPA Science Inventory

Estuarine condition is a function of the nature of the estuary, ocean, and atmospheric systems, and the upstream watershed. To fully understand and predict how an estuary will respond to drivers and pressures, each compartment must be characterized. For example, eutrophication ef...

Proceedings Abstracts: American Water Resources Association's Symposium on the National Water-Quality Assessment (NAWQA) Program--November 7-9, 1994, Chicago, Illinois

USGS Publications Warehouse

Sorenson, Stephen K.

1994-01-01

Approximately 418,000 pounds of triazine herbicides are applied annually to control weeds in crops grown in the Albemarle-Pamilico Sound drainage basin, located in North Carolina and Virginia. An enzyme-linked immunosorbent assay was used to detect concentrations of total triazine herbicides in streams draining into Albemarle-Pamlico Sound. Water samples were collected in May and June during the application of triazine herbicides and in early September during low streamflows at approximately 40 sites on streams in the Coastal Plain and Piedmont Physiographic Provinces. Triazine concentrations exceeded 0.2 ?g/L (micrograms per liter) in 67 percent of the water samples collected In June, and 13 percent of the water samples exceeded 0.2 ?g/L in September during low streamflows. The enzyme-linked immunosorbent assay for total triazine herbicides provides a low-cost and rapid analytical method for screening water samples prior to sending them to a laboratory and for semiquantitatively assessing seasonal concentrations of triazine herbicides in streams throughout a large region.

Water quality and bed sediment quality in the Albemarle Sound, North Carolina, 2012–14

USGS Publications Warehouse

Moorman, Michelle C.; Fitzgerald, Sharon A.; Gurley, Laura N.; Rhoni-Aref, Ahmed; Loftin, Keith A.

2017-01-23

The Albemarle Sound region was selected in 2012 as one of two demonstration sites in the Nation to test and improve the design of the National Water Quality Monitoring Council’s National Monitoring Network (NMN) for U.S. Coastal Waters and Tributaries. The goal of the NMN for U.S. Coastal Waters and Tributaries is to provide information about the health of our oceans, coastal ecosystems, and inland influences on coastal waters for improved resource management. The NMN is an integrated, multidisciplinary, and multi-organizational program using multiple sources of data and information to augment current monitoring programs.This report presents and summarizes selected water-quality and bed sediment-quality data collected as part of the demonstration project conducted in two phases. The first phase was an occurrence and distribution study to assess nutrients, metals, pesticides, cyanotoxins, and phytoplankton communities in the Albemarle Sound during the summer of 2012 at 34 sites in Albemarle Sound, nearby sounds, and various tributaries. The second phase consisted of monthly sampling over a year (March 2013 through February 2014) to assess seasonality in a more limited set of constituents including nutrients, cyanotoxins, and phytoplankton communities at a subset (eight) of the sites sampled in the first phase. During the summer of 2012, few constituent concentrations exceeded published water-quality thresholds; however, elevated levels of chlorophyll a and pH were observed in the northern embayments and in Currituck Sound. Chlorophyll a, and metals (copper, iron, and zinc) were detected above a water-quality threshold. The World Health Organization provisional guideline based on cyanobacterial density for high recreational risk was exceeded in approximately 50 percent of water samples collected during the summer of 2012. Cyanobacteria capable of producing toxins were present, but only low levels of cyanotoxins below human health benchmarks were detected. Finally

Stable Isotope Identification of Nitrogen Sources for United States (U.S.) Pacific Coast Estuaries

NASA Astrophysics Data System (ADS)

Brown, C. A.; Kaldy, J. E.; Fong, P.; Fong, C.; Mochon Collura, T.; Clinton, P.

2016-02-01

Nutrients are the leading cause of water quality impairments in the United States, and as a result tools are needed to identify the sources of nutrients. We used natural abundance stable isotope data to evaluate nitrogen sources to U.S. west coast estuaries. We collected macroalgae and analyzed these samples for natural abundance of stable isotopes (δ15N) and supplemented this with available data from the literature for estuaries from Mexico to Alaska. Stable isotope ratios of green macroalgae were compared to δ15N of dissolved inorganic nitrogen of oceanic and watershed end members. There was a latitudinal gradient in δ15N of macroalgae with southern estuaries being 7 per mil heavier than northern estuaries. Gradients in isotope data were compared to nitrogen sources estimated by the USGS using the SPARROW model. In California estuaries, the elevation of isotope data appeared to be related to anthropogenic nitrogen sources. In Oregon systems, the nitrogen levels of streams flowing into the estuaries are related to forest cover, rather than to developed land classes. In Oregon estuaries, the δ15N of macroalgae suggested that the ocean and nitrogen-fixing trees in the watersheds were the dominant nitrogen sources with heavier sites located near the estuary mouth. In California estuaries, the gradient was reversed with heavier sites located upriver. In some Oregon estuaries, there was an elevation an elevation of δ15N above marine end members in the vicinity of wastewater treatment facility discharge locations, suggesting isotopes may be useful for distinguishing inputs along an estuarine gradient.

A Comparative Ecological Approach to Assess the Role of Watersheds in Estuarine Condition

EPA Science Inventory

Estuarine condition is a function of the geophysical nature of the estuary, the ocean (and atmospheric) system, and the upstream watershed. To fully understand and predict how an estuary will respond to a mixture of natural and anthropogenic drivers and pressures each compartment...

Nutrient budgets, marsh inundation under sea-level rise scenarios, and sediment chronologies for the Bass Harbor Marsh estuary at Acadia National Park

USGS Publications Warehouse

Huntington, Thomas G.; Culbertson, Charles W.; Fuller, Christopher C.; Glibert, Patricia; Sturtevant, Luke

2014-01-01

Eutrophication in the Bass Harbor Marsh estuary on Mount Desert Island, Maine, is an ongoing problem manifested by recurring annual blooms of green macroalgae species, principally Enteromorpha prolifera and Enteromorpha flexuosa, blooms that appear in the spring and summer. These blooms are unsightly and impair the otherwise natural beauty of this estuarine ecosystem. The macroalgae also threaten the integrity of the estuary and its inherent functions. The U.S. Geological Survey and Acadia National Park have collaborated for several years to better understand the factors related to this eutrophication problem with support from the U.S. Geological Survey and National Park Service Water Quality Assessment and Monitoring Program. The current study involved the collection of hydrologic and water-quality data necessary to investigate the relative contribution of nutrients from oceanic and terrestrial sources during summer 2011 and summer 2012. This report provides data on nutrient budgets for this estuary, sedimentation chronologies for the estuary and fringing marsh, and estuary bathymetry. The report also includes data, based on aerial photographs, on historical changes from 1944 to 2010 in estuary surface area and data, based on surface-elevation details, on changes in marsh area that may accompany sea-level rise. The LOADEST regression model was used to calculate nutrient loads into and out of the estuary during summer 2011 and summer 2012. During these summers, tidal inputs of ammonium to the estuary were more than seven times greater than the combined inputs in watershed runoff and precipitation. In 2011 tidal inputs of nitrate were about four times greater than watershed plus precipitation inputs, and in 2012 tidal inputs were only slightly larger than watershed plus precipitation inputs. In 2011, tidal inputs of total organic nitrogen were larger than watershed input by a factor of 1.6. By contrast, in 2012 inputs of total organic nitrogen in watershed runoff

A review of land–sea coupling by groundwater discharge of nitrogen to New England estuaries: Mechanisms and effects

USGS Publications Warehouse

2007-01-01

Hydrologists have long been concerned with the interface of groundwater flow into estuaries, but not until the end of the last century did other disciplines realize the major role played by groundwater transport of nutrients to estuaries. Mass balance and stable isotopic data suggest that land-derived NO3, NH4, and dissolved organic N do enter estuaries in amounts likely to affect the function of the receiving ecosystem. Because of increasing human occupancy of the coastal zone, the nutrient loads borne by groundwater have increased in recent decades, in spite of substantial interception of nutrients within the land and aquifer components of watersheds. Groundwater-borne nutrient loads have increased the N content of receiving estuaries, increased phytoplankton and macroalgal production and biomass, decreased the area of seagrasses, and created a cascade of associated ecological changes. This linkage between land use and eutrophication of estuaries occurs in spite of mechanisms, including uptake of land-derived N by riparian vegetation and fringing wetlands, “unloading” by rapid water removal, and direct N inputs to estuaries, that tend to uncouple the effects of land use on receiving estuaries. It can be expected that as human activity on coastal watersheds continues to increase, the role of groundwater-borne nutrients to the receiving estuary will also increase.

Estuarine environments as rearing habitats for juvenile Coho Salmon in contrasting south-central Alaska watersheds

USGS Publications Warehouse

Hoem Neher, Tammy D.; Rosenberger, Amanda E.; Zimmerman, Christian E.; Walker, Coowe M.; Baird, Steven J.

2013-01-01

For Pacific salmon, estuaries are typically considered transitional staging areas between freshwater and marine environments, but their potential as rearing habitat has only recently been recognized. The objectives of this study were two-fold: (1) to determine if Coho Salmon Oncorhynchus kisutch were rearing in estuarine habitats, and (2) to characterize and compare the body length, age, condition, and duration and timing of estuarine occupancy of juvenile Coho Salmon between the two contrasting estuaries. We examined use of estuary habitats with analysis of microchemistry and microstructure of sagittal otoliths in two watersheds of south-central Alaska. Juvenile Coho Salmon were classified as estuary residents or nonresidents (recent estuary immigrants) based on otolith Sr : Ca ratios and counts of daily growth increments on otoliths. The estuaries differed in water source (glacial versus snowmelt hydrographs) and in relative estuarine and watershed area. Juvenile Coho Salmon with evidence of estuary rearing were greater in body length and condition than individuals lacking evidence of estuarine rearing. Coho Salmon captured in the glacial estuary had greater variability in body length and condition, and younger age-classes predominated the catch compared with the nearby snowmelt-fed, smaller estuary. Estuary-rearing fish in the glacial estuary arrived later and remained longer (39 versus 24 d of summer growth) during the summer than did fish using the snowmelt estuary. Finally, we observed definitive patterns of overwintering in estuarine and near shore environments in both estuaries. Evidence of estuary rearing and overwintering with differences in fish traits among contrasting estuary types refute the notion that estuaries function as only staging or transitional habitats in the early life history of Coho Salmon.

Linking Data Access to Geospatial Data Models to Applications at Local to National Scales: The Estuary Data Mapper

EPA Science Inventory

The U.S. Environmental Protection Agency (US EPA) is developing e-Estuary, a decision-support system for Clean Water Act applications in coastal management. E-Estuary has three elements: an estuarine geo-referenced relational database, watershed GIS coverages, and tools to suppo...

76 FR 30023 - Pamlico Sound and Adjacent Waters, NC; Danger Zones for Marine Corps Operations

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-24

... DEPARTMENT OF DEFENSE Corps of Engineers, Department of the Army 33 CFR Part 334 Pamlico Sound and Adjacent Waters, NC; Danger Zones for Marine Corps Operations AGENCY: United States Army Corps of Engineers, DoD. ACTION: Final rule. SUMMARY: The U.S. Army Corps of Engineers is amending its regulations to...

Modeling Mitigation Activities in North Carolina Watersheds

NASA Astrophysics Data System (ADS)

Garcia, A. M.

2017-12-01

Nutrient enrichment and excessive sediment loadings have contributed to the degradation of rivers, lakes and estuaries in North Carolina. The North Carolina Department of Environmental Quality (NCDEQ) has implemented several basin-wide nutrient and sediment management strategies, yet gaps remain in understanding the impact of these strategies given the complexities in quantifying the processes that govern the transport of nutrient and sediment. In particular, improved assessment of the status of nutrient and sediment loadings to lakes and estuaries throughout the state is needed, including characterizing their sources and describing the relative contributions of different areas. The NCDEQ Division of Mitigation Services (DMS) uses watershed planning to identify and prioritize the best locations to implement stream, wetland, and riparian-buffer restoration to improve water quality. To support better decision-making for watershed restoration activities we are developing a SPARROW (SPAtially Referenced Regressions On Watershed attributes) model framework specifically for North Carolina. The SPARROW analysis (developed by the U.S. Geological Survey) relates water-quality monitoring data to better understand the effects of human activities and natural processes on surface-water quality. The core of the model consists of using a nonlinear-regression equation to describe the non-conservative transport of contaminants from point and nonpoint sources on land to rivers, lakes and estuaries through the stream and river network. In this presentation, preliminary total Nitrogen, total Phosphorus, and Total Suspended Solids (TSS) NC-SPARROW models are described that illustrate the SPARROW modeling framework incorporating specific restoration datasets and activity metrics, such as extent of riparian buffer and easements.

Approaches for Development of Nutrient Criteria in Oregon Estuaries

EPA Science Inventory

Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

Selected Pharmaceuticals Entering an Estuary: Concentrations, Temporal Trends, Partitioning and Fluxes

EPA Science Inventory

In many coastal watersheds and ecosystems, rivers discharging to estuaries receive waters from domestic wastewater-treatment plants resulting in the release and distribution of pharmaceuticals to the marine environment. In the present study, 15 active pharmaceutical ingredients w...

Impacts of domestic and and agricultural rainwater harvesting system on watershed hydrology: A case study of Albemarle-Pamlico Watershed basins (NC, VA, USA)

EPA Science Inventory

Rainwater harvesting (RWH) is increasingly relevant in the context of growing population and its demands on water quantity. Here, we present a method to better understand the hydrologic impacts of urban domestic and agricultural rainwater harvesting and apply the approach to thre...

Reference Condition Approach for Numeric Nutrient Criteria for Oregon Estuaries

EPA Science Inventory

Development of nutrient criteria for all water body types of the US remains a top priority for EPA. Estuaries in the Pacific Northwest receive nutrients from both the watershed and the coastal ocean, and thus are particularly complex systems in which to establish water quality c...

SUSPENDED AND BENTHIC SEDIMENT RELATIONSHIPS IN THE YAQUINA ESTUARY, OREGON: NUTRIENT PROCESSING

EPA Science Inventory

Measurements of nutrient loading and subsequent nutrient processing are fundamental for determining biogeochemical processes in rivers and estuaries. In Oregon coastal watersheds, nutrient transport is strongly seasonal with up to 94% of the riverine dissolved nitrate and silic...

Use of the USEPA Estuary Nitrogen Model to Estimate Concentrations of Total Nitrogen in Estuaries Using Loads Calculated by Watershed Models and Monitoring Data

EPA Science Inventory

We use USEPA’s Estuary Nitrogen Model (ENM) to calculate annual average concentrations of total nitrogen (TN) in ten estuaries or sub-estuaries along the Atlantic coast from New Hampshire to Florida. These include a variety of systems, ranging from strongly-flushed bays to weakly...

Comparison of sediment supply to San Francisco Bay from watersheds draining the Bay Area and the Central Valley of California

USGS Publications Warehouse

McKee, L.J.; Lewicki, M.; Schoellhamer, D.H.; Ganju, N.K.

2013-01-01

Quantifying suspended sediment loads is important for managing the world's estuaries in the context of navigation, pollutant transport, wetland restoration, and coastal erosion. To address these needs, a comprehensive analysis was completed on sediment supply to San Francisco Bay from fluvial sources. Suspended sediment, optical backscatter, velocity data near the head of the estuary, and discharge data obtained from the output of a water balance model were used to generate continuous suspended sediment concentration records and compute loads to the Bay from the large Central Valley watershed. Sediment loads from small tributary watersheds around the Bay were determined using 235 station-years of suspended sediment data from 38 watershed locations, regression analysis, and simple modeling. Over 16 years, net annual suspended sediment load to the head of the estuary from its 154,000 km2 Central Valley watershed varied from 0.13 to 2.58 (mean = 0.89) million metric t of suspended sediment, or an average yield of 11 metric t/km2/yr. Small tributaries, totaling 8145 km2, in the nine-county Bay Area discharged between 0.081 and 4.27 (mean = 1.39) million metric t with a mean yield of 212 metric t/km2/yr. The results indicate that the hundreds of urbanized and tectonically active tributaries adjacent to the Bay, which together account for just 5% of the total watershed area draining to the Bay and provide just 7% of the annual average fluvial flow, supply 61% of the suspended sediment. The small tributary loads are more variable (53-fold between years compared to 21-fold for the inland Central Valley rivers) and dominated fluvial sediment supply to the Bay during 10 out of 16 yr. If San Francisco Bay is typical of other estuaries in active tectonic or climatically variable coastal regimes, managers responsible for water quality, dredging and reusing sediment accumulating in shipping channels, or restoring wetlands in the world's estuaries may need to more carefully

Eco-Efficiency Analysis of Green Infrastructure Based Watershed Management: A Case Study of Raionwater Harvesting in the Albemarle-Pimlico Basins

EPA Science Inventory

Rising world population, rapid urbanization, and land development exacerbate the global challenge of protecting watersheds and their sustainability. The U.S. Environmental Protection Agency (EPA) has achieved significant progress in protecting and remediating national watersheds,...

Cross-system comparison of factors influencing chlorophyll-a concentration in Oregon estuaries

EPA Science Inventory

Water column chlorophyll-a (chla) is a proxy for phytoplankton biomass and is often used as a biological response indicator of eutrophication. Although watershed nutrient loading may influence chla concentration in estuaries, factors such as freshwater inflow, residence time, and...

Satellite Remote Sensing of Chlorophyll a in Support of Nutrient Management in the Neuse and Tar-Pamlico River Estuaries

EPA Science Inventory

The North Carolina Environmental Management Commission (EMC) has adopted as a water quality standard that chlorophyll a concentration should not exceed 40 ug/L in sounds, estuaries and other slow-moving waters. Exceedances require regulators to develop a Total Maximum Daily Limit...

Recent sediments of the St. Marks River coast, northwest Florida, a low-energy, sediment-starved estuary

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

Highly, A.B.; Donoghue, J.F.; Garrett, C.

1994-03-01

The St. Marks river of northwest Florida drains parts of the central panhandle of northwestern Florida, and a small area in southwestern Georgia. It traverses nearly 56.3 kilometers through a watershed of 1,711 square kilometers. The slow-moving river carries little sediment and terminates in Apalachee Bay, a low-energy embayment in the northeasternmost Gulf of Mexico. The coastal region is characterized by mudflats, seagrass beds, and an absence of sandy beaches and barrier islands. Clastic sediments of the coast and shelf rest on a shallow-dipping carbonate platform. The upper surface of the platform is locally karstic. As a result, like othermore » rivers in this region of northwest Florida, the St. Marks watershed is marked by sinkholes and disappearing streams. The fact that the river travels underground through part of its lower watershed serves to trap or sieve some of its clastic load. In the estuary, the undulating karst topography causes the estuarine sediments to vary in thickness from 0 to 4+ meters. The concave shape of the coastline and its orientation with respect to prevailing winds result in low average wave energy. Sedimentation is therefore controlled by riverine and tidal forces. The relatively low energy conditions result in good preservation of the sedimentary record in the St. Marks estuary. A suite of sediment cores has been collected in the lower river, estuary and adjacent Gulf of Mexico. Lead-210 dating results indicate a slow average sedimentation rate ([approximately] 1mm/yr). Investigation of sedimentation rates and sediment characteristics over time in the St. Marks estuary indicate that sedimentologic conditions in this low-energy environment have been relatively stable during the recent geologic history of the estuary.« less

33 CFR 334.420 - Pamlico Sound and adjacent waters, N.C.; danger zones for Marine Corps operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) Bombing and rocket firing area in Pamlico Sound in vicinity of Brant Island—(1) The area. The waters.... Upon being so warned vessels working in the area shall leave the area immediately. (b) Bombing, rocket... bombing, rocket firing, and strafing areas. Live and dummy ammunition will be used. The area shall be...

Application of advanced remote sensing techniques to improve modeling estuary water quality

USDA-ARS?s Scientific Manuscript database

Estuaries, the interface between terrestrial and coastal waters are an important component of complex and dynamic coastal watersheds. They are usually characterized by abrupt chemical gradients and complex dynamics, which can result in major transformations in the amount, chemical nature and timing ...

Potential Impacts and Management Implications of Climate Change on Tampa Bay Estuary Critical Coastal Habitats

NASA Astrophysics Data System (ADS)

Sherwood, Edward T.; Greening, Holly S.

2014-02-01

The Tampa Bay estuary is a unique and valued ecosystem that currently thrives between subtropical and temperate climates along Florida's west-central coast. The watershed is considered urbanized (42 % lands developed); however, a suite of critical coastal habitats still persists. Current management efforts are focused toward restoring the historic balance of these habitat types to a benchmark 1950s period. We have modeled the anticipated changes to a suite of habitats within the Tampa Bay estuary using the sea level affecting marshes model under various sea level rise (SLR) scenarios. Modeled changes to the distribution and coverage of mangrove habitats within the estuary are expected to dominate the overall proportions of future critical coastal habitats. Modeled losses in salt marsh, salt barren, and coastal freshwater wetlands by 2100 will significantly affect the progress achieved in "Restoring the Balance" of these habitat types over recent periods. Future land management and acquisition priorities within the Tampa Bay estuary should consider the impending effects of both continued urbanization within the watershed and climate change. This requires the recognition that: (1) the Tampa Bay estuary is trending towards a mangrove-dominated system; (2) the current management paradigm of "Restoring the Balance" may no longer provide realistic, attainable goals; (3) restoration that creates habitat mosaics will prove more resilient in the future; and (4) establishing subtidal and upslope "refugia" may be a future strategy in this urbanized estuary to allow sensitive habitat types (e.g., seagrass and salt barren) to persist under anticipated climate change and SLR impacts.

Potential impacts and management implications of climate change on Tampa Bay estuary critical coastal habitats.

PubMed

Sherwood, Edward T; Greening, Holly S

2014-02-01

The Tampa Bay estuary is a unique and valued ecosystem that currently thrives between subtropical and temperate climates along Florida's west-central coast. The watershed is considered urbanized (42 % lands developed); however, a suite of critical coastal habitats still persists. Current management efforts are focused toward restoring the historic balance of these habitat types to a benchmark 1950s period. We have modeled the anticipated changes to a suite of habitats within the Tampa Bay estuary using the sea level affecting marshes model under various sea level rise (SLR) scenarios. Modeled changes to the distribution and coverage of mangrove habitats within the estuary are expected to dominate the overall proportions of future critical coastal habitats. Modeled losses in salt marsh, salt barren, and coastal freshwater wetlands by 2100 will significantly affect the progress achieved in "Restoring the Balance" of these habitat types over recent periods. Future land management and acquisition priorities within the Tampa Bay estuary should consider the impending effects of both continued urbanization within the watershed and climate change. This requires the recognition that: (1) the Tampa Bay estuary is trending towards a mangrove-dominated system; (2) the current management paradigm of "Restoring the Balance" may no longer provide realistic, attainable goals; (3) restoration that creates habitat mosaics will prove more resilient in the future; and (4) establishing subtidal and upslope "refugia" may be a future strategy in this urbanized estuary to allow sensitive habitat types (e.g., seagrass and salt barren) to persist under anticipated climate change and SLR impacts.

Potential climate-induced runoff changes and associated uncertainty in four Pacific Northwest estuaries

USGS Publications Warehouse

Steele, Madeline O.; Chang, Heejun; Reusser, Deborah A.; Brown, Cheryl A.; Jung, Il-Won

2012-01-01

As part of a larger investigation into potential effects of climate change on estuarine habitats in the Pacific Northwest, we estimated changes in freshwater inputs into four estuaries: Coquille River estuary, South Slough of Coos Bay, and Yaquina Bay in Oregon, and Willapa Bay in Washington. We used the U.S. Geological Survey's Precipitation Runoff Modeling System (PRMS) to model watershed hydrological processes under current and future climatic conditions. This model allowed us to explore possible shifts in coastal hydrologic regimes at a range of spatial scales. All modeled watersheds are located in rainfall-dominated coastal areas with relatively insignificant base flow inputs, and their areas vary from 74.3 to 2,747.6 square kilometers. The watersheds also vary in mean elevation, ranging from 147 meters in the Willapa to 1,179 meters in the Coquille. The latitudes of watershed centroids range from 43.037 degrees north latitude in the Coquille River estuary to 46.629 degrees north latitude in Willapa Bay. We calibrated model parameters using historical climate grid data downscaled to one-sixteenth of a degree by the Climate Impacts Group, and historical runoff from sub-watersheds or neighboring watersheds. Nash Sutcliffe efficiency values for daily flows in calibration sub-watersheds ranged from 0.71 to 0.89. After calibration, we forced the PRMS models with four North American Regional Climate Change Assessment Program climate models: Canadian Regional Climate Model-(National Center for Atmospheric Research) Community Climate System Model version 3, Canadian Regional Climate Model-Canadian Global Climate Model version 3, Hadley Regional Model version 3-Hadley Centre Climate Model version 3, and Regional Climate Model-Canadian Global Climate Model version 3. These are global climate models (GCMs) downscaled with regional climate models that are embedded within the GCMs, and all use the A2 carbon emission scenario developed by the Intergovernmental Panel on

Editorial: Eutrophication and hypoxia and their impacts on the ecosystem of the Changjiang Estuary and adjacent coastal environment

NASA Astrophysics Data System (ADS)

Zhang, Jing; Xiao, Tian; Huang, Daji; Liu, Su Mei; Fang, Jianguang

2016-02-01

The Changjiang (Yangtze River) Estuary plays an important role in the land-ocean interactions of East Asia, particularly in regard to the fate of land-derived materials and their impact on marine ecosystems in the Northwest Pacific Ocean. The 12 papers included in this special issue describe results from the MEcoPAM Study, an IMBER-China project, which occurred in 2011-2015. This project used a multi-disciplinary approach to understand ecosystem function of the Changjiang Estuary in response to multiple stressors (i.e. combined external forcings). The results presented here show that human activities in the watersheds have greatly changed the flux and variation of dissolved and particulate materials from the river. Further interactions between the Changjiang Watersheds and the East China Sea can dramatically modify the pathways of biogeochemistry and food web dynamics of the estuary and adjacent coastal environment at seasonal and inter-annual scales.

Status and Trends of Nitrogen Loads to Estuaries of the Conterminous U.S.

EPA Science Inventory

We applied regional SPARROW (SPAtially Referenced Regressions On Watershed attributes) models to estimate status and trends of potential nitrogen loads to estuaries of the conterminous United States. The original SPARROW models predict average detrended loads by source based on ...

33 CFR 334.420 - Pamlico Sound and adjacent waters, N.C.; danger zones for Marine Corps operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) Bombing and rocket firing area in Pamlico Sound in vicinity of Brant Island—(1) The area. The waters.... Upon being so warned vessels working in the area shall leave the area immediately. (b) Bombing, rocket... regulations. (i) The area described in paragraph (b)(1) of this section will be used as bombing, rocket firing...

33 CFR 334.420 - Pamlico Sound and adjacent waters, N.C.; danger zones for Marine Corps operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) Bombing and rocket firing area in Pamlico Sound in vicinity of Brant Island—(1) The area. The waters.... Upon being so warned vessels working in the area shall leave the area immediately. (b) Bombing, rocket... regulations. (i) The area described in paragraph (b)(1) of this section will be used as bombing, rocket firing...

33 CFR 334.420 - Pamlico Sound and adjacent waters, N.C.; danger zones for Marine Corps operations.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) Bombing and rocket firing area in Pamlico Sound in vicinity of Brant Island—(1) The area. The waters.... Upon being so warned vessels working in the area shall leave the area immediately. (b) Bombing, rocket... regulations. (i) The area described in paragraph (b)(1) of this section will be used as bombing, rocket firing...

33 CFR 334.420 - Pamlico Sound and adjacent waters, N.C.; danger zones for Marine Corps operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Bombing and rocket firing area in Pamlico Sound in vicinity of Brant Island—(1) The area. The waters.... Upon being so warned vessels working in the area shall leave the area immediately. (b) Bombing, rocket... regulations. (i) The area described in paragraph (b)(1) of this section will be used as bombing, rocket firing...

Nutrient elements in large Chinese estuaries

NASA Astrophysics Data System (ADS)

Zhang, Jing

1996-07-01

Based on comprehensive observations since 1983, this study summarizes major features of nutrient elements (nitrogen, phosphorus and silicon) in large Chinese river/estuary systems. Elevated nutrient element levels were observed in Chinese rivers, when compared to large and less disturbed aquatic systems (e.g. the Amazon, Zaire and Orinoco). Data from this study are similar to those obtained from the polluted and/or eutrophic rivers in Europe and North America (e.g. the Rhóne and Loire). Nutrient elements may have either conservative or active distributions, or both, in the mixing zone, depending on the element and the estuary. For example, non-conservative behaviors were observed in the upper estuary, where nutrient elements may be remobilized due to the strong desorption and variations of the fresh water end-member, but conservative distributions were found afterwards in the lower estuary. Outside the riverine effluent plumes, nutrient elements may be depleted in surface waters relative to elevated bioproduction, whereas the regeneration with respect to decomposition of organic material and/or nitrification/denitrification offshore, may sustain high levels of nutrient elements in near-bottom waters. Laboratory experiment data generally compares well with field observations. The high fluxes and area] yields of nutrient elements from large Chinese rivers, indicate the extensive use of chemical fertilizers and domestic waste drainage over watersheds in China.

Baseline sediment trace metals investigation: Steinhatchee River estuary, Florida, Northeast Gulf of Mexico

USGS Publications Warehouse

Trimble, C.A.; Hoenstine, R.W.; Highley, A.B.; Donoghue, J.F.; Ragland, P.C.

1999-01-01

This Florida Geological Survey/U.S. Department of the Interior, Minerals Management Service Cooperative Study provides baseline data for major and trace metal concentrations in the sediments of the Steinhatchee River estuary. These data are intended to provide a benchmark for comparison with future metal concentration data measurements. The Steinhatchee River estuary is a relatively pristine bay located within the Big Bend Wildlife Management Area on the North Central Florida Gulf of Mexico coastline. The river flows 55 km through woodlands and planted pines before emptying into the Gulf at Deadman Harbor. Water quality in the estuary is excellent at present. There is minimal development within the watershed. The estuary is part of an extensive system of marshes that formed along the Florida Gulf coast during the Holocene marine transgression. Sediment accretion rate measurements range from 1.4 to 4.1 mm/yr on the basis of lead-210 measurements. Seventy-nine short cores were collected from 66 sample locations, representing four lithofacies: clay- and organic-rich sands, organic-rich sands, clean quartz sands, and oyster bioherms. Samples were analyzed for texture, total organic matter, total carbon, total nitrogen, clay mineralogy, and major and trace-metal content. Following these analyses, metal concentrations were normalized against geochemical reference elements (aluminum and iron) and against total weight percent organic matter. Metals were also normalized granulometrically against total weight percent fines (<0.062 mm). Concentrations were determined by inductively coupled plasma-atomic emission spectrometry (ICP-AES) for all metals except mercury. Mercury concentrations were determined by cold-flameless atomic absorption spectrometry (AAS). Granulometric measurements were made by sieve and pipette analyses. Organic matter was determined by two methods: weight loss upon ignition and elemental analysis (by Carlo-Erba Furnace) of carbon and nitrogen. X

Albemarle Sound demonstration study of the national monitoring network for US coastal waters and their tributaries

Treesearch

Michelle Moorman; Sharon Fitzgerald; Keith Loftin; Elizabeth Fensin

2016-01-01

The U.S. Geological Survey’s (USGS) is implementing a demonstration project in the Albemarle Sound for the National Monitoring Network for U.S. coastal waters and their tributaries. The goal of the National Monitoring Network is to provide information about the health of our oceans and coastal ecosystems and inland influences on coastal waters for improved resource...

A summary report of sediment processes in Chesapeake Bay and watershed

USGS Publications Warehouse

Langland, Michael J.; Cronin, Thomas

2003-01-01

The Chesapeake Bay, the Nation's largest estuary, has been degraded because of diminished water quality, loss of habitat, and over-harvesting of living resources. Consequently, the bay was listed as an impaired water body due to excess nutrients and sediment. The Chesapeake Bay Program (CBP), a multi-jurisdictional partnership, completed an agreement called "Chesapeake 2000" that revises and establishes new restoration goals through 2010 in the bay and its watershed. The goal of this commitment is the removal of the bay from the list of impaired waterbodies by the year 2010. The CBP is committed to developing sediment and nutrient allocations for major basins within the bay watershed and to the process of examining new and innovative management plans in the estuary itself and along the coastal zones of the bay. However, additional information is required on the sources, transport, and deposition of sediment that affect water clarity. Because the information and data on sediment processes in the bay were not readily accessible to the CBP or to state, and local managers, a Sediment Workgroup (SWGP) was created in 2001.The primary objective of this report, therefore, is to provide a review of the literature on the sources, transport, and delivery of sediment in Chesapeake Bay and its watershed with discussion of potential implications for various management alternatives. The authors of the report have extracted, discussed, and summarized the important aspects of sediment and sedimentation that are most relevant to the CBP and other sediment related-issues with which resources managers are involved. This report summarizes the most relevant studies concerning sediment sources, transport and deposition in the watershed and estuary, sediments and relation to water clarity, and provides an extensive list of references for those wanting more information.

A classification of U.S. estuaries based on physical and hydrologic attributes

USGS Publications Warehouse

Engle, V.D.; Kurtz, J.C.; Smith, L.M.; Chancy, C.; Bourgeois, P.

2007-01-01

A classification of U.S. estuaries is presented based on estuarine characteristics that have been identified as important for quantifying stressor-response relationships in coastal systems. Estuaries within a class have similar physical and hydrologic characteristics and would be expected to demonstrate similar biological responses to stressor loads from the adjacent watersheds. Nine classes of estuaries were identified by applying cluster analysis to a database for 138 U.S. estuarine drainage areas. The database included physical measures of estuarine areas, depth and volume, as well as hydrologic parameters (i.e., tide height, tidal prism volume, freshwater inflow rates, salinity, and temperature). The ability of an estuary to dilute or flush pollutants can be estimated using physical and hydrologic properties such as volume, bathymetry, freshwater inflow and tidal exchange rates which influence residence time and affect pollutant loading rates. Thus, physical and hydrologic characteristics can be used to estimate the susceptibility of estuaries to pollutant effects. This classification of estuaries can be used by natural resource managers to describe and inventory coastal systems, understand stressor impacts, predict which systems are most sensitive to stressors, and manage and protect coastal resources. ?? Springer Science+Business Media B.V. 2007.

Juvenile salmon usage of the Skeena River estuary.

PubMed

Carr-Harris, Charmaine; Gottesfeld, Allen S; Moore, Jonathan W

2015-01-01

Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2-8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations that

What’s Upstream? GIS’s critical role in developing nutrient reference conditions for estuaries

EPA Science Inventory

Eutrophication due to excess levels of nitrogen and phosphorus can seriously impair ecological function in estuaries. Protective criteria for nutrients are difficult to establish because the source can vary spatially and seasonally, originate either from the watershed or the oce...

THE EFFECTS OF LAND-USE/LAND-COVER, GEOMORPHOLOGY AND CLIMATE ON MAGNITUDE AND TIMING OF NUTRIENT EXPORT AND LOADING RATES IN THREE COASTAL PLAIN WATERSHEDS

EPA Science Inventory

Watershed nitrogen (N), phosphorus (P), organic carbon (OC), and total suspended sediment (TSS) export rates were determined in 18 sub-basins of three watershed-estuarine systems over two annual cycles (2000 and 2001). The three watersheds all drain to the Mobile Bay estuary and ...

Relating nutrient and herbicide fate with landscape features and characteristics of 15 subwatersheds in the Choptank River Watershed

USDA-ARS?s Scientific Manuscript database

The Choptank River is an estuary and tributary on the eastern shore of the Chesapeake Bay; it drains portions of the Delmarva Peninsula, located within the Mid-Atlantic region of the United States. Its watershed is an ARS Benchmark Watershed in the Conservation Effects Assessment Project (CEAP). M...

Economic Tools for Managing Nitrogen in Coastal Watersheds ...

EPA Pesticide Factsheets

Watershed managers are interested in using economics to communicate the value of estuarine resources to the wider community, determine the most cost-effective means to reduce nitrogen pollution, and evaluate the benefits of taking action to improve coastal ecosystems. We spoke to coastal watershed managers who had commissioned economic studies and found that they were largely satisfied with the information and their ability to communicate the importance of coastal ecosystems. However, while managers were able to use these studies as communication tools, methods used in some studies were inconsistent with what some economists consider best practices. In addition, many watershed managers are grappling with how to implement nitrogen management activities in a way that is both cost-effective and achieves environmental goals, while maintaining public support. These and other issues led to this project. Our intent is to provide information to watershed managers and others interested in watershed management – such as National Estuary Programs, local governments, or nongovernmental organizations – on economic tools for managing nitrogen in coastal watersheds, and to economists and other analysts who are interested in assisting them in meeting their needs. Watershed management requires balancing scientific, political, and social issues to solve environmental problems. This document summarizes questions that watershed managers have about using economic analysis, and g

Nutrient load summaries for major lakes and estuaries of the Eastern United States, 2002

USGS Publications Warehouse

Moorman, Michelle C.; Hoos, Anne B.; Bricker, Suzanne B.; Moore, Richard B.; García, Ana María; Ator, Scott W.

2014-01-01

Nutrient enrichment of lakes and estuaries across the Nation is widespread. Nutrient enrichment can stimulate excessive plant and algal growth and cause a number of undesirable effects that impair aquatic life and recreational activities and can also result in economic effects. Understanding the amount of nutrients entering lakes and estuaries, the physical characteristics affecting the nutrient processing within these receiving waterbodies, and the natural and manmade sources of nutrients is fundamental to the development of effective nutrient reduction strategies. To improve this understanding, sources and stream transport of nutrients to 255 major lakes and 64 estuaries in the Eastern United States were estimated using Spatially Referenced Regression on Watershed attributes (SPARROW) nutrient models.

A Corresponding Study of Water Quality Evaluation of the Pasquotank Watershed in Northeastern North Carolina

NASA Astrophysics Data System (ADS)

Stevenson, J.; Walthall, S.; McKenzie, R.; Dixon, R.

2015-12-01

The Pasquotank River Watershed covers 450 sq miles in the Coastal Plain of NE North Carolina. It flows from the Great Dismal Swamp at the VA/NC border into the Albemarle Sound. The watershed provides a transition between spawning grounds and waters of the Albemarle Sound. Forested swamp wetlands border much of the waterways. Increased agricultural and urban development has greatly affected water quality during recent years. Test were completed along the tributaries and the river itself, adding to the previously data from 2011, 2013, and 2014. Streams tested were the Newbegun Creek, Knobbs Creek, Areneuse Creek, Mill Dam Creek, and Sawyers Creek. These streams cover a large area of the watershed and provide a wide variety of shore development from swampland and farmland to industrial development. Samples were tested for pH, salinity, total dissolved solids, and conductivity. Air/water temperature, dissolved oxygen, wind speed/direction, and turbidity/clarity measurements were taken in the field. The results were placed into an online database and correlated to the location of the sample using Google Maps®. Analysis tools were developed to compare the data from all years. Excel spreadsheets were developed to look more closely at individual points and tests for each point. This database was connected to a data visualization page utilizing Google Maps®. The results show variations for the individual water quality scores, but the overall water quality score for all the tested water sources remained at a comparable level from previous years. Mill Dam Creek rose above the previous three scores of 48 (2011), 47 (2013), and 49 (2014) and achieved a medium water quality score of 57. Areneuse Creek improved in water quality with a medium water quality score of 60. Sawyers Creek became the lowest scoring waterway tested at 35. Knobbs Creek decreased from previous years with a water quality score of 42. For a fourth consecutive testing year, Newbegun Creek fell within the

Retrospective Review of Watershed Characteristics and a Framework for Future Research in the Sarasota Bay Watershed, Florida

USGS Publications Warehouse

Kish, George R.; Harrison, Arnell S.; Alderson, Mark

2008-01-01

The U.S. Geological Survey, in cooperation with the Sarasota Bay Estuary Program conducted a retrospective review of characteristics of the Sarasota Bay watershed in west-central Florida. This report describes watershed characteristics, surface- and ground-water processes, and the environmental setting of the Sarasota Bay watershed. Population growth during the last 50 years is transforming the Sarasota Bay watershed from rural and agriculture to urban and suburban. The transition has resulted in land-use changes that influence surface- and ground-water processes in the watershed. Increased impervious cover decreases recharge to ground water and increases overland runoff and the pollutants carried in the runoff. Soil compaction resulting from agriculture, construction, and recreation activities also decreases recharge to ground water. Conventional approaches to stormwater runoff have involved conveyances and large storage areas. Low-impact development approaches, designed to provide recharge near the precipitation point-of-contact, are being used increasingly in the watershed. Simple pollutant loading models applied to the Sarasota Bay watershed have focused on large-scale processes and pollutant loads determined from empirical values and mean event concentrations. Complex watershed models and more intensive data-collection programs can provide the level of information needed to quantify (1) the effects of lot-scale land practices on runoff, storage, and ground-water recharge, (2) dry and wet season flux of nutrients through atmospheric deposition, (3) changes in partitioning of water and contaminants as urbanization alters predevelopment rainfall-runoff relations, and (4) linkages between watershed models and lot-scale models to evaluate the effect of small-scale changes over the entire Sarasota Bay watershed. As urbanization in the Sarasota Bay watershed continues, focused research on water-resources issues can provide information needed by water

Comprehensive trends assessment of nitrogen sources and loads to estuaries of the coterminous United States

EPA Science Inventory

Sources of nitrogen and phosphorus to estuaries and estuarine watersheds of the coterminous United States have been compiled from a variety of publically available data sources (1985 – 2015). Atmospheric loading was obtained from two sources. Modelled and interpolated meas...

ESTIMATION OF INHERENT OPTICAL PROPERTIES AND WATER CONSTITUENT CONCENTRATIONS FROM THE REMOTE-SENSING REFLECTANCE SPECTRA IN THE ALBEMARLE-PAMLICO ESTUARY, USA

EPA Science Inventory

The decomposition of remote sensing reflectance (RSR) spectra into absorption, scattering and backscattering coefficients, and scattering phase function is an important issue for estimating water quality (WQ) components. For Case 1 waters RSR decomposition can be easily accompli...

Pesticides in streams in the Tar-Pamlico drainage basin, North Carolina, 1992-94

USGS Publications Warehouse

Woodside, Michael D.; Ruhl, Kelly E.

2001-01-01

From 1992 to 1994, 147 water samples were collected at 5 sites in the Tar-Pamlico drainage basin in North Carolina and analyzed for 46 herbicides, insecticides, and pesticide metabolites as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Based on a common adjusted detection limit of 0.01 microgram per liter, the most frequently detected herbicides were metolachlor (84 percent), atrazine (78 percent), alachlor (72 percent), and prometon (57 percent). The insecticides detected most frequently were carbaryl (12 percent), carbofuran (7 percent), and diazinon (4 percent). Although the pesticides with the highest estimated uses generally were the compounds detected most frequently, there was not a strong correlation between estimated use and detection frequency. The development of statistical correlations between pesticide use and detection frequency was limited by the lack of information on pesticides commonly applied in urban and agricultural areas, such as prometon, chlorpyrifos, and diazinon, and the small number of basins included in this study. For example, prometon had the fourth highest detection frequency, but use information was not available. Nevertheless, the high detection frequency of prometon indicates that nonagricultural uses also contribute to pesticide levels in streams in the Tar-Pamlico drainage basin.Concentrations of the herbicides atrazine, alachlor, and trifluralin varied seasonally, with elevated concentrations generally occurring in the spring, during and immediately following application periods, and in the summer. Seasonal concentration patterns were less evident for prometon, diazinon, and chlorpyrifos. Alachlor is the only pesticide detected in concentrations that exceeded current (2000) drinking-water standards.

Loads of suspended sediment and nutrients from local nonpoint sources to the tidal Potomac River and Estuary, Maryland and Virginia, 1979-81 water years

USGS Publications Warehouse

Hickman, R. Edward

1987-01-01

Loads of suspended sediment, phosphorus, nitrogen, biochemical oxygen demand, and dissolved silica discharged to the tidal Potomac River and Estuary during the !979-81 water years from three local nonpoint sources have been calculated. The loads in rain falling directly upon the tidal water surface and from overflows of the combined sewer system of the District of Columbia were determined from available information. Loads of materials in the streamflow from local watersheds draining directly to the tidal Potomac River and Estuary downstream from Chain Bridge in Washington, D.C., were calculated from samples of streamflow leaving five monitored watersheds. Average annual yields of substances leaving three urban watersheds (Rock Creek and the Northwest and Northeast Branches of the Anacostia River) and the rural Saint Clements Creek watershed were calculated either by developing relationships between concentration and streamflow or by using the mean of measured concentrations. Yields calculated for the 1979-81 water years are up to 2.3 times period-of-record yields because of greater than average streamflow and stormflow during this 3-year period. Period-of-record yields of suspended sediment from the three urban watersheds and the Saint Clements Creek watershed do not agree with yields reported by other studies. The yields from the urban watersheds are 17 to 51 percent of yields calculated using sediment-concentration data collected during the 1960-62 water years. Previous studies suggest that this decrease is at least partly due to the imposition of effective sediment controls at construction sites and to the construction of two multipurpose reservoirs. The yield calculated for the rural Saint Clements Creek watershed is at least twice the yields calculated for other rural watersheds, a result that may be due to most of the samples of this stream being taken during the summer of the 1981 water year, a very dry period. Loads discharged from all local tributary

Use of a metolachlor metabolite (MESA) to assess agricultural nitrate-n fate and transport in choptank river watershed, Maryland USA

USDA-ARS?s Scientific Manuscript database

A majority of streams in the Chesapeake Bay watershed have been rated as poor or very poor based on biological assessments. The Choptank River estuary, a Bay tributary on the eastern shore, is an example, where crop production in upland areas of the watershed contribute significant loads of nutrien...

Relation between inherent optical properties and land use and land cover across Gulf Coast estuaries

EPA Science Inventory

Land use and land cover (LULC) can affect the watershed exports of optically active constituents such as suspended particulate matter and colored dissolved organic matter, and in turn affect estuarine optical properties. We collected optical data from six estuaries in the northea...

Multi-timescale sediment responses across a human impacted river-estuary system

NASA Astrophysics Data System (ADS)

Chen, Yining; Chen, Nengwang; Li, Yan; Hong, Huasheng

2018-05-01

Hydrological processes regulating sediment transport from land to sea have been widely studied. However, anthropogenic factors controlling the river flow-sediment regime and subsequent response of the estuary are still poorly understood. Here we conducted a multi-timescale analysis on flow and sediment discharges during the period 1967-2014 for the two tributaries of the Jiulong River in Southeast China. The long-term flow-sediment relationship remained linear in the North River throughout the period, while the linearity showed a remarkable change after 1995 in the West River, largely due to construction of dams and reservoirs in the upland watershed. Over short timescales, rainstorm events caused the changes of suspended sediment concentration (SSC) in the rivers. Regression analysis using synchronous SSC data in a wet season (2009) revealed a delayed response (average 5 days) of the estuary to river input, and a box-model analysis established a quantitative relationship to further describe the response of the estuary to the river sediment input over multiple timescales. The short-term response is determined by both the vertical SSC-salinity changes and the sediment trapping rate in the estuary. However, over the long term, the reduction of riverine sediment yield increased marine sediments trapped into the estuary. The results of this study indicate that human activities (e.g., dams) have substantially altered sediment delivery patterns and river-estuary interactions at multiple timescales.

Satellite remote sensing of chlorophyll a in support of nutrient management in the Neuse and Tar-Pamlico River (North Carolina) estuaries

EPA Science Inventory

The North Carolina Environmental Management Commission (EMC) has adopted as a water quality standard that chlorophyll a concentration should not exceed 40 ug/L in sounds, estuaries and other slow-moving waters. Exceedances require regulators to develop a Total Maximum Daily Limit...

Status and Trends of Narragansett Bay and its Watershed: A Geographical Approach

EPA Science Inventory

The Narragansett Bay Estuary Program developed 24 environmental indicators for its 2017 State of the Bay and its Watershed report with the collaboration of over 50 bi-state and regional partners. A geographical approach was undertaken at different scales using an array of geospat...

Juvenile Salmon Usage of the Skeena River Estuary

PubMed Central

Carr-Harris, Charmaine; Gottesfeld, Allen S.; Moore, Jonathan W.

2015-01-01

Migratory salmon transit estuary habitats on their way out to the ocean but this phase of their life cycle is more poorly understood than other phases. The estuaries of large river systems in particular may support many populations and several species of salmon that originate from throughout the upstream river. The Skeena River of British Columbia, Canada, is a large river system with high salmon population- and species-level diversity. The estuary of the Skeena River is under pressure from industrial development, with two gas liquefaction terminals and a potash loading facility in various stages of environmental review processes, providing motivation for understanding the usage of the estuary by juvenile salmon. We conducted a juvenile salmonid sampling program throughout the Skeena River estuary in 2007 and 2013 to investigate the spatial and temporal distribution of different species and populations of salmon. We captured six species of juvenile anadromous salmonids throughout the estuary in both years, and found that areas proposed for development support some of the highest abundances of some species of salmon. Specifically, the highest abundances of sockeye (both years), Chinook in 2007, and coho salmon in 2013 were captured in areas proposed for development. For example, juvenile sockeye salmon were 2–8 times more abundant in the proposed development areas. Genetic stock assignment demonstrated that the Chinook salmon and most of the sockeye salmon that were captured originated from throughout the Skeena watershed, while some sockeye salmon came from the Nass, Stikine, Southeast Alaska, and coastal systems on the northern and central coasts of British Columbia. These fish support extensive commercial, recreational, and First Nations fisheries throughout the Skeena River and beyond. Our results demonstrate that estuary habitats integrate species and population diversity of salmon, and that if proposed development negatively affects the salmon populations

ASSESSING THE EFFECTS OF NATURAL AND ANTHROPOGENIC STRESSORS IN THE POTOMAC ESTUARY: IMPLICATIONS FOR LONG-TERM MONITORING

EPA Science Inventory

Ecological conditions in the Potomac Estuary are affected by a variety of natural and anthropogenic stressors. Natural climatic factors combined with anthropogenic activities affect fluxes of material through Potomac River watersheds and cause changes in ecological conditions in ...

Comprehensive Status and Trends of Nitrogen Loads to Estuaries in the Conterminous United States: Pacific Coast Results

EPA Science Inventory

We applied regional SPARROW (SPAtially Referenced Regressions On Watershed attributes) models to estimate status and trends of potential nitrogen loads to estuaries of the conterminous United States. The original Regional SPARROW models predict average detrended loads by source ...

Circulation and physical processes within the San Gabriel River Estuary during summer 2005

USGS Publications Warehouse

Rosenberger, Kurt J.; Xu, Jingping; Stein, Eric D.; Noble, Marlene A.; Gartner, Anne L.

2007-01-01

The Southern California Coastal Water Research Project (SCCWRP) is developing a hydrodynamic model of the SGR estuary, which is part of the comprehensive water-quality model of the SGR estuary and watershed investigated by SCCWRP and other local agencies. The hydrodynamic model will help understanding of 1) the exchange processes between the estuary and coastal ocean; 2) the circulation patterns in the estuary; 3) upstream natural runoff and the cooling discharge from PGS. Like all models, the SGR hydrodynamic model is only useful after it is fully calibrated and validated. In May 2005, SCCWRP requested the assistance of the U.S. geological Survey (USGS) Coastal and Marine Geology team (CMG) in collecting data on the hydrodynamic conditions in the estuary during the summer dry season. The summer was chosen for field data collection as this was assumed to be the season with the greatest potential for chronic degraded water quality due to low river flow and high thermal stratification within the estuary (due to both higher average air temperature and PGS output). Water quality can be degraded in winter as well, when higher river discharge events bring large volumes of water from the Los Angeles basin into the estuary. The objectives of this project were to 1) collect hydrodynamic data along the SGR estuary; 2) study exchange processes within the estuary through analysis of the hydrodynamic data; and 3) provide field data for model calibration and validation. As the data only exist for the summer season, the results herein only apply to summer conditions.

CHARACTERIZING THE ORGANIC MATTER IN SURFACE SEDIMENTS FROM THE SAN JUAN BAY ESTUARY.

EPA Science Inventory

The San Juan Bay Estuary (SJBE) is located on the north coast of Puerto Rico and includes the San Juan Bay, San José Lagoon, La Torrecilla Lagoon and Piñones Lagoon, as well as the Martín Peña and the Suárez Canals. The SJBE watershed has the highest...

Characterizing the Organic Matter in Surface Sediments from the San Juan Bay Estuary,

EPA Science Inventory

The San Juan Bay Estuary (SJBE) is located on the north coast of Puerto Rico and includes the San Juan Bay, San José Lagoon, La Torrecilla Lagoon and Piñones Lagoon, as well as the Martín Peña and the Suárez Canals. The SJBE watershed has the highest...

CHARACTERIZING THE ORGANIC MATTER IN SURFACE SEDIMENTS FROM THE SAN JUAN BAY ESTUARY

EPA Science Inventory

The San Juan Bay Estuary (SJBE) is located on the north coast of Puerto Rico and includes the San Juan Bay, San José Lagoon, La Torrecilla Lagoon and Piñones Lagoon, as well as the Martín Peña and the Suárez Canals. The SJBE watershed has the highest...

What’s Upstream? GIS’s critical role in developing nutrient reference conditions for estuaries - April 2, 2015

EPA Science Inventory

Eutrophication due to excess levels of nitrogen and phosphorus can seriously impair ecological function in estuaries. Protective criteria for nutrients are difficult to establish because the source can vary spatially and seasonally, originate either from the watershed or the oce...

Relating stream microbial ecology to land-use in the Choptank River Watershed

USDA-ARS?s Scientific Manuscript database

The Choptank River is an estuary and tributary on the Eastern Shore of the Chesapeake Bay whose mouth is a tidal embayment that spans 2057 km2. Approximately 60% of land use in the Choptank River Watershed is agricultural, with large acreages of corn (Zea mays), soybean (Glycine max), wheat (Tritic...

Importance of Watershed Land Use in Predicting Benthic Invertebrate Condition in the Virginian Biogeographic Province, USA.

EPA Science Inventory

Estuaries are dynamic transition zones linking freshwater and oceanic habitats. These productive ecosystems are threatened by a variety of stressors including human modification of coastal watersheds. In this study we examined potential linkages between estuarine condition and...

Estuary-ocean connectivity: fast physics, slow biology.

PubMed

Raimonet, Mélanie; Cloern, James E

2017-06-01

Estuaries are connected to both land and ocean so their physical, chemical, and biological dynamics are influenced by climate patterns over watersheds and ocean basins. We explored climate-driven oceanic variability as a source of estuarine variability by comparing monthly time series of temperature and chlorophyll-a inside San Francisco Bay with those in adjacent shelf waters of the California Current System (CCS) that are strongly responsive to wind-driven upwelling. Monthly temperature fluctuations inside and outside the Bay were synchronous, but their correlations weakened with distance from the ocean. These results illustrate how variability of coastal water temperature (and associated properties such as nitrate and oxygen) propagates into estuaries through fast water exchanges that dissipate along the estuary. Unexpectedly, there was no correlation between monthly chlorophyll-a variability inside and outside the Bay. However, at the annual scale Bay chlorophyll-a was significantly correlated with the Spring Transition Index (STI) that sets biological production supporting fish recruitment in the CCS. Wind forcing of the CCS shifted in the late 1990s when the STI advanced 40 days. This shift was followed, with lags of 1-3 years, by 3- to 19-fold increased abundances of five ocean-produced demersal fish and crustaceans and 2.5-fold increase of summer chlorophyll-a in the Bay. These changes reflect a slow biological process of estuary-ocean connectivity operating through the immigration of fish and crustaceans that prey on bivalves, reduce their grazing pressure, and allow phytoplankton biomass to build. We identified clear signals of climate-mediated oceanic variability in this estuary and discovered that the response patterns vary with the process of connectivity and the timescale of ocean variability. This result has important implications for managing nutrient inputs to estuaries connected to upwelling systems, and for assessing their responses to changing

Origins of sediment-associated contaminants to the Marais Vernier, the Seine Estuary, France

USGS Publications Warehouse

Van Metre, P.C.; Mesnage, V.; Laignel, B.; Motelay, A.; Deloffre, J.

2008-01-01

The Marais Vernier is the largest freshwater wetland in the Seine Estuary in northern France. It is in a heavily urbanized and industrialized region and could be affected by atmospheric deposition and by fluvial input of contaminants in water diverted from the Seine River. To evaluate contaminant histories in the wetland and the region, sediment cores were collected from two open-water ponds in the Marais Vernier: the Grand-Mare, which was connected to the Seine by a canal from 1950 to 1996, and the Petite Mare, which has a small rural watershed. Diversions from the Seine to the Grand-Mare increased sedimentation rates but mostly resulted in low contaminant concentrations and loading rates, indicating that the sediment from the Seine was predominantly brought upstream by tidal currents from the estuary and was not from the watershed. Atmospheric sources of metals dominate inputs to the Petite Mare; however, runoff of metals from vehicle-related sources in the watershed might contribute to the upward trends in concentrations of Cr, Cu, and Zn. Estimates of atmospheric deposition using the Petite Mare core are consistent with measured deposition in the region and are mixed (similar for Hg and Pb; larger for Cd, Cu, and Zn) compared with deposition estimated from sediment cores in the northeastern United States. A local source of PAHs in the watershed of the Petite Mare is indicated by higher concentrations, higher accumulation rates, and a different, more petrogenic, PAH assemblage than in the Grand-Mare. The study illustrates how diverse sources and transport pathways can affect wetlands in industrial regions and can be evaluated using sediment cores from the wetland ponds. ?? 2008 Springer Science+Business Media B.V.

Downscaling future climate projections to the watershed scale: A north San Francisco Bay estuary case study

USGS Publications Warehouse

Micheli, Elisabeth; Flint, Lorraine; Flint, Alan; Weiss, Stuart; Kennedy, Morgan

2012-01-01

We modeled the hydrology of basins draining into the northern portion of the San Francisco Bay Estuary (North San Pablo Bay) using a regional water balance model (Basin Characterization Model; BCM) to estimate potential effects of climate change at the watershed scale. The BCM calculates water balance components, including runoff, recharge, evapotranspiration, soil moisture, and stream flow, based on climate, topography, soils and underlying geology, and the solar-driven energy balance. We downscaled historical and projected precipitation and air temperature values derived from weather stations and global General Circulation Models (GCMs) to a spatial scale of 270 m. We then used the BCM to estimate hydrologic response to climate change for four scenarios spanning this century (2000–2100). Historical climate patterns show that Marin’s coastal regions are typically on the order of 2 °C cooler and receive five percent more precipitation compared to the inland valleys of Sonoma and Napa because of marine influences and local topography. By the last 30 years of this century, North Bay scenarios project average minimum temperatures to increase by 1.0 °C to 3.1 °C and average maximum temperatures to increase by 2.1 °C to 3.4 °C (in comparison to conditions experienced over the last 30 years, 1981–2010). Precipitation projections for the 21st century vary between GCMs (ranging from 2 to 15% wetter than the 20th-century average). Temperature forcing increases the variability of modeled runoff, recharge, and stream discharge, and shifts hydrologic cycle timing. For both high- and low-rainfall scenarios, by the close of this century warming is projected to amplify late-season climatic water deficit (a measure of drought stress on soils) by 8% to 21%. Hydrologic variability within a single river basin demonstrated at the scale of subwatersheds may prove an important consideration for water managers in the face of climate change. Our results suggest that in arid

2017 STATE OF NARRAGANSETT BAY AND ITS WATERSHED – MAPPING DRIVERS OF CHANGE AND VARIATION

EPA Science Inventory

The Narragansett Bay Estuary Program (NBEP) developed 24 environmental indicators for its 2017 State of Narragansett Bay and Its Watershed report with the collaboration of over 50 bi-state (MA and RI) and regional partners. The report presents and tracks the 24 indicators in ord...

Seasonal and Spatial Distribution of Freshwater Flow and Salinity in the Ten Thousand Islands Estuary, Florida, 2007-2009

USGS Publications Warehouse

Soderqvist, Lars E.; Patino, Eduardo

2010-01-01

The watershed of the Ten Thousand Islands (TTI) estuary has been substantially altered through the construction of canals and roads for the Southern Golden Gate Estates (SGGE), Barron River Canal, and U.S. 41 (Tamiami Trail). Two restoration projects designed to improve freshwater delivery to the estuary are the Picayune Strand Restoration Project, which includes the Southern Golden Gate Estates, and the Tamiami Trail Culverts Project; both are part of the Comprehensive Everglades Restoration Plan. To address hydrologic information needs critical for monitoring the effects of these restoration projects, the U.S. Geological Survey initiated a study in October 2006 to characterize freshwater outflows from the rivers, internal circulation and mixing within the estuary, and surface-water exchange between the estuary and Gulf of Mexico. The effort is conducted in cooperation with the South Florida Water Management District and complemented by monitoring performed by the Rookery Bay National Estuarine Research Reserve. Surface salinity was measured during moving boat surveys using a flow-through system that operated at planing speeds averaging 20 miles per hour. The data were logged every 10 seconds by a data recorder that simultaneously logged location information from a Global Positioning System. The major rivers, bays, and nearshore Gulf of Mexico region of the TTI area were surveyed in approximately 5 hours by two boats traversing about 200 total miles. Salinity and coordinate data were processed using inverse distance weighted interpolation to create salinity contour maps of the entire TTI region. Ten maps were created from salinity surveys performed between May 2007 and May 2009 and illustrate the dry season, transitional, and wet season salinity patterns of the estuarine rivers, inner bays, mangrove islands, and Gulf of Mexico boundary. The effects of anthropogenic activities are indicated by exceptionally low salinities associated with point discharge into the

Role of Geologic Framework, Paleotopography, Sediment Supply, and Human Modification in the Evolutionary Development of the Northeastern North Carolina Barrier Island System

NASA Astrophysics Data System (ADS)

Riggs, S. R.; Thieler, E. R.; Mallinson, D. A.; Culver, S. J.; Corbett, D. R.; Hoffman, C. W.

2002-12-01

The NE North Carolina coastal system contains an exceptionally thick and well preserved Quaternary stratigraphic record that is the focus of a five-year Cooperative Coastal Geology Program between the USGS, several academic institutions, and state agencies. The major goal is to map this Quaternary section on the inner continental shelf, Outer Banks barrier islands, Albemarle-Pamlico estuarine system, and adjacent land areas. The program objectives are to define the geologic framework, develop the detailed evolutionary history, and understand the ongoing process dynamics driving this large, complex, and rapidly changing, high-energy coastal system. Preliminary data synthesis demonstrates that the major controls dictating the present health and future evolution of this coastal system include the following. 1) The regional late Pleistocene morphology constitutes the underlying geologic framework that the Holocene system has inherited. 2) The controlling paleotopography is a series of lowstand drainage basins consisting of trunk and tributary streams and associated interstream divides that are being drowned. 3) Three major sediment sources dictate the highly variable sand resources available to specific barrier segments and include riverine channel and deltaic deposits associated with lowstand trunk streams, the large cross-shelf cape shoal sand deposits, and sand-rich units occurring within the adjacent shoreface and inner-self strata. 4) Wherever large sand supplies have historically been available, the barrier segments occur as complex islands with large sand volumes producing high and wide barriers, whereas barrier segments without adequate sand supplies are sediment starved and occur as simple overwash barriers. 5) Human modification of the barrier islands over the past seven decades represents a major force that has significantly changed the barrier island dynamics and evolution. 6) The Albemarle Embayment appears to have a slightly higher rate of sea-level rise

Linking Resilience of Aquatic Species to Watershed Condition

NASA Astrophysics Data System (ADS)

Flitcroft, R. L.

2017-12-01

Watershed condition means different things to different people. From the perspective of aquatic ecology, watershed condition may be interpreted to mean the capacity of a watershed to support life history diversity of native species. Diversity in expression of life history is thought to confer resilience allowing portions of the broader population to survive stressful conditions. Different species have different life history strategies, many of which were developed through adaptation to regional or local environmental conditions and natural disturbance regimes. By reviewing adaptation strategies for species of interest at regional scales, characteristics of watersheds that confer resilience may be determined. Such assessments must be completed at multiple levels of spatial organization (i.e. sub-watershed, watershed, region) allowing assessments to be inferred across broad spatial extents. In a project on the Wenatchee River watershed, we guided models of wildfire effects on bull trout and spring Chinook from a meta-population perspective to determine risks to survival at local and population scales over multiple extents of spatial organization. In other work in the Oregon Coast Range, we found that historic landslides continue to exert habitat-forming pressure at local scales, leading to patchiness in distribution of habitats for different life stages of coho salmon. Further, climate change work in Oregon estuaries identified different vulnerabilities in terms of juvenile rearing habitat depending on the species of interest and the intensity of future changes in climate. All of these studies point to the importance of considering physical conditions in watersheds at multiple spatial extents from the perspective of native aquatic species in order to understand risks to long-term survival. The broader implications of watershed condition, from this perspective, is the determination of physical attributes that confer resilience to native biota. This may require

Watershed processing of atmospheric polychlorinated biphenyl inputs.

PubMed

Rowe, Amy A; Totten, Lisa A; Cavallo, Gregory I; Yagecic, John R

2007-04-01

Indirect atmospheric deposition of PCBs was examined in subwatersheds of the Delaware River Estuary. Tributary PCB loads and atmospheric PCB concentrations were used to understand the pass-through efficiencies for nine rivers/ creeks for which PCB inputs appeared to be dominated by atmospheric deposition. The pass-through efficiency, E, was calculated from tributary loads and atmospheric deposition fluxes. Unfortunately, uncertainties in the gaseous and dry particle deposition velocities, vg and vd, respectively, render the calculated atmospheric deposition fluxes highly uncertain. In order to circumvent this problem, export of PCBs from the watershed was related directly to atmospheric PCB concentrations via a new mass transfer coefficient, the watershed delivery rate or vws, which describes the process by which the watershed transfers PCBs from the airto the River's main stem. vws increases with increasing chlorination and is significantly correlated with vapor pressure. This trend suggests that the transfer of PCBs from the atmosphere to the River via the watershed is more efficient for high molecular weight PCBs than for low molecular weight PCBs. This may indicate that the selected watersheds are at or close to equilibrium with respect to gaseous exchange of PCBs, such that lower molecular weight congeners undergo substantial revolatilization after deposition. The magnitude of the pass-through efficiency, E, depends on the deposition velocities used to calculate the atmospheric deposition flux, but when congener-specific deposition velocities are used, E is independent of vapor pressure and is relatively constant at about 3%.

Estuary-ocean connectivity: Fast physics, slow biology

USGS Publications Warehouse

Raimonet, Mélanie; Cloern, James E.

2017-01-01

Estuaries are connected to both land and ocean so their physical, chemical, and biological dynamics are influenced by climate patterns over watersheds and ocean basins. We explored climate-driven oceanic variability as a source of estuarine variability by comparing monthly time series of temperature and chlorophyll-a inside San Francisco Bay with those in adjacent shelf waters of the California Current System (CCS) that are strongly responsive to wind-driven upwelling. Monthly temperature fluctuations inside and outside the Bay were synchronous, but their correlations weakened with distance from the ocean. These results illustrate how variability of coastal water temperature (and associated properties such as nitrate and oxygen) propagates into estuaries through fast water exchanges that dissipate along the estuary. Unexpectedly, there was no correlation between monthly chlorophyll-a variability inside and outside the Bay. However, at the annual scale Bay chlorophyll-a was significantly correlated with the Spring Transition Index (STI) that sets biological production supporting fish recruitment in the CCS. Wind forcing of the CCS shifted in the late 1990s when the STI advanced 40 days. This shift was followed, with lags of 1–3 years, by 3- to 19-fold increased abundances of five ocean-produced demersal fish and crustaceans and 2.5-fold increase of summer chlorophyll-a in the Bay. These changes reflect a slow biological process of estuary–ocean connectivity operating through the immigration of fish and crustaceans that prey on bivalves, reduce their grazing pressure, and allow phytoplankton biomass to build. We identified clear signals of climate-mediated oceanic variability in this estuary and discovered that the response patterns vary with the process of connectivity and the timescale of ocean variability. This result has important implications for managing nutrient inputs to estuaries connected to upwelling systems, and for assessing their responses to

The Recent Microrelief Features of the Yangtze Estuary

NASA Astrophysics Data System (ADS)

Wu, S. H.

2016-02-01

Based on the bedforms date were made in the Yangtze estuary, China, during January 2010 and July 2015 with the acoustic multi-beam bathymetric and shallow sediment profiler and surface sediment samples collected recently, the microrelief features of the Yangtze Estuary under the human interference recently is studied. Results show that in addition to four types of common microrelief (smooth bedfloors , sandwaves, hollow and gully), but also there are two types of microrelief under the human interference (sand and dredging mark).Restricted by the nature of sediment, sand waves exist only in the local region of the South Channel, the North Channel the South Passage and the Hengsha passage whose main types of the surface sediment was fine sand. Under the combined effect of a series of large-scale engineering with watershed and estuary, the upper reach of North Channel, the Hengsha passage, the upper reach of south Channel and the upper reach of the South passage are subject to different degrees of erosion recently, so there are varying degrees of erosive microrelief (hollow and gully). Due to dredging engineering and artificial disordered mining, there are a huge range of dredging mark in the lower reach of South Channel, Yuanyuansha channel and North passage and there are a degree of sand in the main channel of south side of Ruifengsha.

Spatiotemporal change of phosphorous speciation and concentration in stormwater in the St. Lucie Estuary watershed, South Florida.

PubMed

Li, Liguang; He, Zhenli; Li, Zhigang; Li, Suli; Wan, Yongshan; Stoffella, Peter J

2017-04-01

Phosphorous (P) concentration in stormwater runoff varies at different spatial and temporal scales. Excessive P loading from agriculture system into the St. Lucie Estuary (SLE) contributed to water quality deterioration in southern Indian River Lagoon. This study examines the spatial and temporal shifts of different P forms in runoff and storm water under different land use, water management, and rainfall conditions. Storm water samplings were conducted monthly between April 2013 and December 2014 in typical farmland and along the waterway (Canal C-24) that connects lands to the SLE. Concentrations of different P forms and related water quality variables were measured. Approximately 89% of the collected water samples contained total P (TP) concentrations exceeding the total maximum daily load (TMDL) level (0.081 mg L -1 ). Concentrations of different P forms declined from agricultural field furrows to the canal and then increased from the upstream to the downstream in the canal where urban activities dominated land use. Total dissolved P (TDP) was the predominant form of TP, followed by PO 4 -P. Speciation and concentrations of P varied with sites and sampling times, but were significantly higher in the summer months (from June to September) than in the winter. Water pH explained ∼20% of TP variation. Spatiotemporal variations of P concentrations and compositions provide a data-based guide for development of best management practices (BMPs) to minimize P export from the SLE watershed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anthropogenic sea level rise and adaptation in the Yangtze estuary

NASA Astrophysics Data System (ADS)

Cheng, H.; Chen, J.; Chen, Z.; Ruan, R.; Xu, G.; Zeng, G.; Zhu, J.; Dai, Z.; Gu, S.; Zhang, X.; Wang, H.

2016-02-01

Sea level rise is a major projected threat of climate change. There are regional variations in sea level changes, depending on both naturally the tectonic subsidence, geomorphology, naturally changing river inputs and anthropogenic driven forces as artificial reservoir water impoundment within the watershed and urban land subsidence driven by ground water depletion in the river delta. Little is known on regional sea level fall in response to the channel erosion due to the sediment discharge decline by reservoir interception in the upstream watershed, and water level rise driven by anthropogenic measures as the land reclamation, deep waterway regulation and fresh water reservoir construction to the sea level change in estuaries. Changing coastal cities are situated in the delta regions expected to be threatened in various degrees. Shanghai belongs to those cities. Here we show that the anthropogenic driven sea level rise in the Yangtze estuary from the point of view of the continuous hydrodynamic system consisted of river catchment, estuary and coastal sea. Land subsidence is cited as 4 mm/a (2011-2030). Scour depth of the estuarine channel by upstream engineering as Three Gauge Dam is estimated at 2-10 cm (2011-2030). The rise of water level by deep waterway and land reclamation is estimated at 8-10 cm (2011-2030). The relative sea level rise will be speculated about 10 -16 cm (2011-2030), which these anthropogenic sea level changes will be imposed into the absolute sea level rise 2 mm/a and tectonic subsidence 1 mm/a measured in 1990s. The action guideline to the sea level rise strategy in the Shanghai city have been proposed to the Shanghai government as (1) recent actions (2012-2015) to upgrade the city water supply and drainage engineering and protective engineering; (2) interim actions (2016-2020) to improve sea level monitoring and early warning system, and then the special, city, regional planning considering sea level rise; (3) long term actions (2021

Sources and distribution of aromatic hydrocarbons in a tropical marine protected area estuary under influence of sugarcane cultivation.

PubMed

Arruda-Santos, Roxanny Helen de; Schettini, Carlos Augusto França; Yogui, Gilvan Takeshi; Maciel, Daniele Claudino; Zanardi-Lamardo, Eliete

2018-05-15

Goiana estuary is a well preserved marine protected area (MPA) located on the northeastern coast of Brazil. Despite its current state, human activities in the watershed represent a potential threat to long term local preservation. Dissolved/dispersed aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) were investigated in water and sediments across the estuarine salt gradient. Concentration of aromatic hydrocarbons was low in all samples. According to results, aromatic hydrocarbons are associated to suspended particulate matter (SPM) carried to the estuary by river waters. An estuarine turbidity maximum (ETM) was identified in the upper estuary, indicating that both sediments and contaminants are trapped prior to an occasional export to the adjacent sea. PAHs distribution in sediments were associated with organic matter and mud content. Diagnostic ratios indicated pyrolytic processes as the main local source of PAHs that are probably associated with sugarcane burning and combustion engines. Low PAH concentrations probably do not cause adverse biological effects to the local biota although their presence indicate anthropogenic contamination and pressure on the Goiana estuary MPA. Copyright © 2017 Elsevier B.V. All rights reserved.

A COMPREHENSIVE NONPOINT SOURCE FIELD STUDY FOR SEDIMENT, NUTRIENTS AND PATHOGENS IN THE SOUTH FORK BROAD RIVER WATERSHED, GEORGIA

EPA Science Inventory

There is an urgent need for EPA to develop protocols for establishing Total Maximum Daily Loads (TMDLs) in streams, lakes and estuaries. A cooperative TMDL field data collection project between ORD and Region 4 is ongoing in the South Fork Broad River Watershed (SFBR), a 245.18 ...

Development of a preliminary relative risk model for evaluating regional ecological conditions in the Delaware River Estuary, USA.

PubMed

Iannuzzi, Timothy J; Durda, Judi L; Preziosi, Damian V; Ludwig, David F; Stahl, Ralph G; DeSantis, Amanda A; Hoke, Robert A

2010-01-01

Effective environmental management and restoration of urbanized systems such as the Delaware River Estuary requires a holistic understanding of the relative importance of various stressor-related impacts throughout the watershed, both historical and ongoing. To that end, it is important to involve as many stakeholders as possible in the management process and to develop a system for sharing of scientific data and information, as well as effective technical tools for evaluating and disseminating the data needed to make management decisions. In this study, we describe a preliminary assessment that was undertaken to evaluate the relative risks for the variety of stressors currently operating within the Delaware Estuary using a relative risk model (RRM) framework. This model was constructed using existing data and information on the ecological conditions and stressors in the main-stem Delaware River below the head of tide at Trenton, New Jersey, USA. A large database was developed with pertinent data from a variety of library, scientific, and regulatory sources. Data were compiled, reviewed, and characterized before development of the Estuary-specific RRM. Our primary goals and objectives in developing this preliminary RRM for the Estuary were to 1) determine if the RRM framework can be adapted to a large complex estuarine system such as the Delaware River, 2) identify the issues associated with adapting the model framework to the various management issues and regional areas/habitats of the River, 3) help identify data needs and potential refinements that might be needed to more specifically quantify relative stressor risks in various areas and habitats of the Estuary to better inform future management goals/actions by Stakeholders. The key conclusions of our preliminary assessment are 1) a diverse suite of stressors is likely affecting the ecological conditions of the Delaware Estuary, 2) chemical (toxicants/contaminants) and physical (sedimentation, habitat loss

Denitrification rates in marsh soils and hydrologic and water quality data for Northeast Creek and Bass Harbor Marsh watersheds, Mount Desert Island, Maine

USGS Publications Warehouse

Huntington, Thomas G.; Culbertson, Charles W.; Duff, John H.

2011-01-01

Nutrient enrichment from atmospheric deposition, agricultural activities, wildlife, and domestic sources is a concern at Acadia National Park because of the potential problem of water-quality degradation and eutrophication in estuaries. Water-quality degradation has been observed at the park's Bass Harbor Marsh estuary but minimal degradation is observed in Northeast Creek estuary. Previous studies at Acadia National Park have estimated nutrient inputs to estuaries from atmospheric deposition and surface-water runoff, and have identified shallow groundwater as an additional potential nutrient source. Previous studies at Acadia National Park have assumed that a certain fraction of the nitrogen input was removed through microbial denitrification, but rates of denitrification (natural or maximum potential) in marsh soils have not been determined. The U.S. Geological Survey, in cooperation with Acadia National Park, measured in situ denitrification rates in marsh soils in Northeast Creek and Bass Harbor Marsh watersheds during the summer seasons of 2008 and 2009. Denitrification was measured under ambient conditions and following inorganic nitrogen and glucose additions. Laboratory incubations of marsh soils with and without acetylene were conducted to determine average ratios of nitrous oxide (N2O) to nitrogen (N2) produced during denitrification. Surface water and groundwater samples were analyzed for nutrients, specific conductance, temperature, and dissolved oxygen. Water level was recorded continuously during the growing season in Fresh Meadow Marsh in the Northeast Creek Watershed.

Quantifying nitrogen inputs to the Choptank River estuary

NASA Astrophysics Data System (ADS)

Mccarty, G.; Hapeman, C. J.; Sadeghi, A. M.; Hively, W. D.; Denver, J. M.; Lang, M. W.; Downey, P. M.; Rice, C. P.

2015-12-01

The Chesapeake Bay is the largest estuary in the US, and over 50% of its streams have been rated as poor or very poor, based on the biological integrity yearly index. The Choptank River, a Bay tributary on the Delmarva Peninsula, is dominated by intensive corn and soybean farming associated with poultry and some dairy production. The Choptank River is under Environmental Protection Agency (USEPA) total maximum daily load restrictions. However, reducing nonpoint source pollution contributions from agriculture requires that source predictions be improved and that mitigation and conservation measures be properly targeted. Therefore, new measurement strategies have been implemented. In-situ sensors have been deployed adjacent to US Geological Survey gauging stations in the Tuckahoe and Greensboro sub-basins of the Choptank River watershed. These sensors measure stream water concentrations of nitrate along and water quality parameters every 30 min. Initial results indicate that ~40% less nitrate is exported from the Greensboro sub-basin, even though the total amount of agricultural land use is similar to that in the Tuckahoe sub-basin. This is most likely due to more efficient nitrate processing in the Greensboro sub-basin where the amount of cropland on poorly-drained soils is much larger. Another potential nitrogen source to the Choptank River estuary is atmospheric deposition of ammonia. Over 550 million broilers are produced yearly on the Delmarva Peninsula potentially leading to the release of 20,000 Mtons of ammonia. USEPA recently estimated that as much as 22% of nitrogen in the Bay is due to ammonia deposition. We have initiated a collaborative effort within the LTAR network to increase coverage of ammonia sampling and to explore the spatial and temporal variability of ammonia, particularly in the Choptank River watershed. All these measurements will be useful in improving the handling of nitrogen sources and its fate and transport in the Chesapeake Bay model.

Pesticide-sampling equipment, sample-collection and processing procedures, and water-quality data at Chicod Creek, North Carolina, 1992

USGS Publications Warehouse

Manning, T.K.; Smith, K.E.; Wood, C.D.; Williams, J.B.

1994-01-01

Water-quality samples were collected from Chicod Creek in the Coastal Plain Province of North Carolina during the summer of 1992 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Chicod Creek is in the Albemarle-Pamlico drainage area, one of four study units designated to test equipment and procedures for collecting and processing samples for the solid-phase extraction of selected pesticides, The equipment and procedures were used to isolate 47 pesticides, including organonitrogen, carbamate, organochlorine, organophosphate, and other compounds, targeted to be analyzed by gas chromatography/mass spectrometry. Sample-collection and processing equipment equipment cleaning and set-up procedures, methods pertaining to collecting, splitting, and solid-phase extraction of samples, and water-quality data resulting from the field test are presented in this report Most problems encountered during this intensive sampling exercise were operational difficulties relating to equipment used to process samples.

Watershed Watch: Using undergraduate student-driven inquiry-based research projects as a means of engaging undeclared students in the biogeosciences

NASA Astrophysics Data System (ADS)

Rock, B. N.; Hale, S.; Graham, K.; Hayden, L. B.

2009-12-01

Watershed Watch (NSF 0525433) engages early undergraduate students from two-year and four-year colleges in student-driven full inquiry-based instruction in the biogeosciences. Program goals for Watershed Watch are to test if inquiry-rich student-driven projects sufficiently engage undeclared students (or noncommittal STEM majors) to declare a STEM major (or remain with their STEM major). The program is a partnership between two four-year campuses - the University of New Hampshire (UNH), and Elizabeth City State University (ECSU, in North Carolina); and two two-year campuses - Great Bay Community College (GBCC, in New Hampshire) and the College of the Albemarle (COA, in North Carolina). The program focuses on two watersheds: the Merrimack Ricer Watershed in New Hampshire and Massachusetts, and the Pasquotank River Watershed in Virginia and North Carolina. Both the terrestrial and aquatic components of both watersheds are evaluated using the student-driven projects. A significant component of this program is an intensive two-week Summer Research Institute (SRI), in which undeclared freshmen and sophomores investigate various aspects of their local watershed. Two Summer Research Institutes have been held on the UNH campus (2006 and 2008) and two on the ECSU campus (2007 and 2009). Students develop their own research questions and study design, collect and analyze data, and produce a scientific oral or poster presentation on the last day of the SRI. The course objectives, curriculum and schedule are presented as a model for dissemination for other institutions and programs seeking to develop inquiry-rich programs or courses designed to attract students into biogeoscience disciplines. Data from self-reported student feedback indicate the most important factors explaining high-levels of student motivation and research excellence in the program are: 1) working with committed, energetic, and enthusiastic faculty mentors, and 2) faculty mentors demonstrating high degrees of

Use of retrospective data to assess ecotoxicological monitoring needs for terrestrial vertebrates residing in Atlantic coast estuaries

USGS Publications Warehouse

Cohen, J.B.; Rattner, B.A.; Golden, N.H.

2003-01-01

The 'Contaminant Exposure and Effects--Terrestrial Vertebrates' (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n=2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The U.S. Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.

Use of retrospective data to assess ecotoxicological monitoring needs for terrestrial vertebrates residing in Atlantic coast estuaries.

PubMed

Cohen, Jonathan B; Rattner, Barnett A; Golden, Nancy H

2003-01-01

The "Contaminant Exposure and Effects-Terrestrial Vertebrates" (CEE-TV) database contains 4,336 records of ecotoxicological information for free-ranging amphibians, reptiles, birds, and mammals residing in Atlantic and Florida Gulf coast estuaries and their drainages. To identify spatial data gaps, those CEE-TV records for which the specific study location were known (n = 2,740) were combined with watershed and wildlife management unit boundaries using Geographic Information Systems software. The US Environmental Protection Agency's Index of Watershed Indicators (IWI), which classifies watersheds based on water quality and their vulnerability to pollution, was used to prioritize these data gaps. Of 136 watersheds in the study area, 15 that are classified by the IWI as having water quality problems or high vulnerability to pollution lacked terrestrial vertebrate ecotoxicological monitoring or research in the past decade. Older studies within some of these watersheds documented high levels of contaminants in wildlife tissues. Of 90 National Wildlife Refuge units, 42 without current data fall within watersheds of concern. Of 40 National Park units larger than 1 km2, 17 without current data fall within watersheds of concern. Issues encountered in this analysis highlighted the need for spatially and temporally replicated field monitoring programs that utilize random sampling. Without data from such studies, it will be difficult to perform unbiased assessments of regional trends in contaminant exposure and effects in terrestrial vertebrates.

Pollutant fate and spatio-temporal variability in the choptank river estuary: Factors influencing water quality

USGS Publications Warehouse

Whitall, D.; Hively, W.D.; Leight, A.K.; Hapeman, C.J.; McConnell, L.L.; Fisher, T.; Rice, C.P.; Codling, E.; McCarty, G.W.; Sadeghi, A.M.; Gustafson, A.; Bialek, K.

2010-01-01

Restoration of the Chesapeake Bay, the largest estuary in the United States, is a national priority. Documentation of progress of this restoration effort is needed. A study was conducted to examine water quality in the Choptank River estuary, a tributary of the Chesapeake Bay that since 1998 has been classified as impaired waters under the Federal Clean Water Act. Multiple water quality parameters (salinity, temperature, dissolved oxygen, chlorophyll a) and analyte concentrations (nutrients, herbicide and herbicide degradation products, arsenic, and copper) were measured at seven sampling stations in the Choptank River estuary. Samples were collected under base flow conditions in the basin on thirteen dates between March 2005 and April 2008. As commonly observed, results indicate that agriculture is a primary source of nitrate in the estuary and that both agriculture and wastewater treatment plants are important sources of phosphorus. Concentrations of copper in the lower estuary consistently exceeded both chronic and acute water quality criteria, possibly due to use of copper in antifouling boat paint. Concentrations of copper in the upstream watersheds were low, indicating that agriculture is not a significant source of copper loading to the estuary. Concentrations of herbicides (atrazine, simazine, and metolachlor) peaked during early-summer, indicating a rapid surface-transport delivery pathway from agricultural areas, while their degradation products (CIAT, CEAT, MESA, and MOA) appeared to be delivered via groundwater transport. Some in-river processing of CEAT occurred, whereas MESA was conservative. Observed concentrations of herbicide residues did not approach established levels of concern for aquatic organisms. Results of this study highlight the importance of continued implementation of best management practices to improve water quality in the estuary. This work provides a baseline against which to compare future changes in water quality and may be used

Head-of-tide bottleneck of particulate material transport from watersheds to estuaries

NASA Astrophysics Data System (ADS)

Ensign, Scott H.; Noe, Gregory B.; Hupp, Cliff R.; Skalak, Katherine J.

2015-12-01

We measured rates of sediment, C, N, and P accumulation at four floodplain sites spanning the nontidal through oligohaline Choptank and Pocomoke Rivers, Maryland, USA. Ceramic tiles were used to collect sediment for a year and sediment cores were collected to derive decadal sedimentation rates using 137Cs. The results showed highest rates of short- and long-term sediment, C, N, and P accumulation occurred in tidal freshwater forests at the head of tide on the Choptank and the oligohaline marsh of the Pocomoke River, and lowest rates occurred in the downstream tidal freshwater forests in both rivers. Presumably, watershed material was mostly trapped at the head of tide, and estuarine material was trapped in oligohaline marshes. This hydrologic transport bottleneck at the head of tide stores most available watershed sediment, C, N, and P creating a sediment shadow in lower tidal freshwater forests potentially limiting their resilience to sea level rise.

Head-of-tide bottleneck of particulate material transport from watersheds to estuaries

USGS Publications Warehouse

Ensign, Scott H.; Noe, Gregory; Hupp, Cliff R.; Skalak, Katherine

2015-01-01

We measured rates of sediment, C, N, and P accumulation at four floodplain sites spanning the nontidal through oligohaline Choptank and Pocomoke Rivers, Maryland, USA. Ceramic tiles were used to collect sediment for a year and sediment cores were collected to derive decadal sedimentation rates using 137Cs. The results showed highest rates of short- and long-term sediment, C, N, and P accumulation occurred in tidal freshwater forests at the head of tide on the Choptank and the oligohaline marsh of the Pocomoke River, and lowest rates occurred in the downstream tidal freshwater forests in both rivers. Presumably, watershed material was mostly trapped at the head of tide, and estuarine material was trapped in oligohaline marshes. This hydrologic transport bottleneck at the head of tide stores most available watershed sediment, C, N, and P creating a sediment shadow in lower tidal freshwater forests potentially limiting their resilience to sea level rise.

Long-Term Effects of Changing Land Use Practices on Surface Water Quality in a Coastal River and Lagoonal Estuary

NASA Astrophysics Data System (ADS)

Rothenberger, Meghan B.; Burkholder, Joann M.; Brownie, Cavell

2009-09-01

The watershed of the Neuse River, a major tributary of the largest lagoonal estuary on the U.S. mainland, has sustained rapid growth of human and swine populations. This study integrated a decade of available land cover and water quality data to examine relationships between land use changes and surface water quality. Geographic Information Systems (GIS) analysis was used to characterize 26 subbasins throughout the watershed for changes in land use during 1992-2001, considering urban, agricultural (cropland, animal as pasture, and densities of confined animal feed operations [CAFOs]), forested, grassland, and wetland categories and numbers of wastewater treatment plants (WWTPs). GIS was also used together with longitudinal regression analysis to identify specific land use characteristics that influenced surface water quality. Total phosphorus concentrations were significantly higher during summer in subbasins with high densities of WWTPs and CAFOs. Nitrate was significantly higher during winter in subbasins with high numbers of WWTPs, and organic nitrogen was higher in subbasins with higher agricultural coverage, especially with high coverage of pastures fertilized with animal manure. Ammonium concentrations were elevated after high precipitation. Overall, wastewater discharges in the upper, increasingly urbanized Neuse basin and intensive swine agriculture in the lower basin have been the highest contributors of nitrogen and phosphorus to receiving surface waters. Although nonpoint sources have been emphasized in the eutrophication of rivers and estuaries such as the Neuse, point sources continue to be major nutrient contributors in watersheds sustaining increasing human population growth. The described correlation and regression analyses represent a rapid, reliable method to relate land use patterns to water quality, and they can be adapted to watersheds in any region.

Understanding Sediment Processes of Los Laureles Canyon in the Binational Tijuana River Watershed

NASA Astrophysics Data System (ADS)

Yuan, Yongping; Biggs, Trent; Liden, Douglas

2015-04-01

Tijuana River Basin originates in Mexico and drains 4465 km2 into the Tijuana River Estuary National Research Reserve, a protected coastal wetland in California that supports 400 species of birds. Excessive erosion in Tijuana during storms produces sediment loads that bury native vegetation and block the tidal channels. Erosion also threatens human life, causing roads and houses in Mexico to collapse and the Tijuana River Valley in the U.S. to flood. Government agencies in US and Mexico spend millions annually to remove sediment. The EPA-SEMARNAT Border 2020 program identified the reduction of sediment to the Tijuana Estuary as a high priority. Gully formation on unpaved roads, channel erosion, and sheetwash and rill erosion from vacant lots in Tijuana are the primary sources of sediment (Biggs et al, 2009). Because 73% of the watershed is located in Mexico, the problem is likely to worsen as Tijuana continues to urbanize. EPA, with support from USDA, San Diego State University, and CICESE, is developing a model to estimate the sediment loss from a sub-basin of the watershed (Los Laureles Canyon) under existing conditions and under future development. This study will evaluate the reduction/prevention of sediment loss from green infrastructure projects, sediment basins, road paving, and conservation easements.

A COMPREHENISVE NONPOINT SOURCE FIELD STUDY FOR SEDIMENT, NUTRIENTS AND PATHOGENS IN THE SOUTH FORK BROAD RIVER WATERSHED IN NORTHEAST GEORGIA

EPA Science Inventory

There is an urgent need for EPA to develop protocols for establishing Total Maximum Daily Loads (TMDLs) in streams, lakes and estuaries. A cooperative TMDL field data collection project between ORD and Region 4 is ongoing in the South Fork Broad River Watershed (SFBR), a 245.18 ...

Latitudinal gradients in oceanic and watershed nitrogen sources to Pacific coast estuaries of North America

EPA Science Inventory

To assess the relative importance of terrestrial versus oceanic nutrient sources, we assembled natural abundance nitrogen stable isotope (δ15N) data for nitrate, green macroalgae, seagrass (Zostera marina) and mussels in the nearshore and in estuaries along the west coast o...

[Assessment system for watershed ecological health in the United States: development and application].

PubMed

Zhang, Hua; Luo, Yong-Ming

2013-07-01

To meet the water quality goals of the Clean Water Act, the environmental agencies in the United States (U.S.) have developed a comprehensive ecological assessment system of watershed health in the last two decades. The system employs a watershed approach, and includes a large set of hydrological, chemical, and biological indices, having become an essential part of the watershed water quality management system in the U.S. and provided strong support for the protection of water environment and the restoration of aquatic system. In this paper, the development and application of the ecological assessment system of watershed health by the U.S. environmental regulators, especially the U.S. Environmental Protection Agency (US EPA), were overviewed from the aspects of related laws and regulations, ecosystem function analysis, ecological health indicators, comprehensive assessment system, and monitoring and data management systems, and the health assessment systems for the rivers, lakes, estuaries, coasts, and wetlands adopted by the National$t1-1-1 Aquatic Resource Surveys (NARS) were introduced. Some suggestions for the future development of the scientific ecological assessment system of watershed health in China were put forward based on the understanding of the protection and remediation practices of our water environment.

INVESTIGATIONS INTO THE EFFECTS OF SEASON AND WATER QUALITY ON OYSTERS (CRASSOSTREA VIRGINICA) AND ASSOCIATED FISH ASSEMBLAGES IN THE CALOOSAHATCHEE RIVER ESTUARY, FLORIDA: IMPLICATIONS OF ALTERED FRESHWATER INFLOW

EPA Science Inventory

A suite of biological and ecological responses of a Valued Ecosystem Component species, Crassostrea virginica, was used to investigate ecosystem-wide health effects of watershed alterations in the Caloosahatchee River estuary, Florida. The influence of water quality and season on...

Occurrence of pesticides in surface water and sediments from three central California coastal watersheds, 2008-2009

USGS Publications Warehouse

Smalling, Kelly L.; Orlando, James L.

2011-01-01

Water and sediment (bed and suspended) were collected from January 2008 through October 2009 from 12 sites in 3 of the largest watersheds along California's Central Coast (Pajaro, Salinas, and Santa Maria Rivers) and analyzed for a suite of pesticides by the U.S. Geological Survey. Water samples were collected in each watershed from the estuaries and major tributaries during 4 storm events and 11 dry season sampling events in 2008 and 2009. Bed sediments were collected from depositional zones at the tributary sampling sites three times over the course of the study. Suspended sediment samples were collected from the major tributaries during the four storm events and in the tributaries and estuaries during three dry season sampling events in 2009. Water samples were analyzed for 68 pesticides using gas chromatography/mass spectrometry. A total of 38 pesticides were detected in 144 water samples, and 13 pesticides were detected in more than half the samples collected over the course of the study. Dissolved pesticide concentrations ranged from below their method detection limits to 36,000 nanograms per liter (boscalid). The most frequently detected pesticides in water from all the watersheds were azoxystrobin, boscalid, chlorpyrifos, DCPA, diazinon, oxyfluorfen, prometryn, and propyzamide, which were found in more than 80 percent of the samples. On average, detection frequencies and concentrations were higher in samples collected during winter storm events compared to the summer dry season. With the exception of the fungicide, myclobutanil, the Santa Maria estuary watershed exhibited higher pesticide detection frequencies than the Pajaro and Salinas watersheds. Bed and suspended sediment samples were analyzed for 55 pesticides using accelerated solvent extraction, gel permeation chromatography for sulfur removal, and carbon/alumina stacked solid-phase extraction cartridges to remove interfering sediment matrices. In bed sediment samples, 17 pesticides were detected

Hydrologic description of the Braden River watershed, west-central Florida

USGS Publications Warehouse

DelCharco, M.J.; Lewelling, B.R.

1997-01-01

The Braden River watershed drains an 83-square mile area in west-central Florida and is the largest tributary to the Manatee River. The hydrology of the Braden River was altered in 1936 when the city of Bradenton created Ward Lake, a reservoir with an 838-foot broad-crested weir 6 miles upstream from the mouth. In 1985 the reservoir, which is the sole source of drinking water for the city of Bradenton, was expanded and supplies an annual average of 5.7 million gallons of water per day. The Braden River can be hydrologically divided into three distinct sections that include an 8.6-mile reach of naturally incised, free-flowing channel; a 6.4-mile reach of impounded river created by the Ward Lake reservoir and weir; and a 6-mile reach of tidal estuary. Ten first-order and two second-order tributaries that flow into the Braden River were examined in this report. The Braden River watershed is dominated by low topographic relief. The two physiographic zones that contain the Braden River watershed, the Gulf Coast Lowlands and De Soto Plain, are both poorly drained and have numerous depressional features. The climate is subtropical with an annual average rainfall of 56 inches, annual average temperatures of 72 degrees Fahrenheit, and estimated annual lake evaporation of 52 inches. The soil series in the watershed are predominantly Myakka-Cassia and the EauGallie-Floridana; these series are characterized as nearly level and poorly drained soils. Land use within the watershed is the fastest changing characteristic that affects the hydrology of the system. The western half of the watershed is typically urban and includes parts of the city of Bradenton. Land use in the eastern half of the watershed is predominantly agricultural, but the explosive population growth of the area is driving the development of medium to high-density residential communities. The three major aquifers underlying the Braden River watershed are the surficial, intermediate, and Floridan aquifer systems

Neogene Seismic Stratigraphic Framework and Fill History of the Northeastern Albemarle Embayment, North Carolina

NASA Astrophysics Data System (ADS)

Mallinson, D. J.; Riggs, S. R.; Thieler, R.; Culver, S. J.; Corbett, D. R.; Hoffman, C. W.; Wehmiller, J.; Foster, D. S.

2002-12-01

Seismic and chirp sonar surveys were conducted in the eastern Albemarle Sound and adjacent tributaries and the inner continental shelf to define the geologic framework and evolution of the North Carolina coastal system. Surveys were utilized to target paleofluvial channels for drilling and core recovery for the assessment of sea level and climate change during the Quaternary. Lithostratigraphic and chronostratigraphic data are derived from eight drill sites on the Outer Banks, and the Mobil #1 well in the eastern Albemarle Sound. Within the study area, parallel-bedded, gently dipping Miocene beds occur at 100 to >180 mbsl, and are overlain by a southward-thickening Pliocene unit characterized by steeply inclined southward-prograding beds. The Quaternary section unconformably overlies the Pliocene unit, and consists of at least five depositional sequences exhibiting numerous incised channel-fill facies. The Quaternary section is 55 to 60 meters thick. Shallow stratigraphy (0-50 mbsl) is dominated by complex fill-stratigraphy within the incised paleo-Roanoke River valley. Radiocarbon and amino acid racemization (AAR) dates indicate that the valley-fill is late Pleistocene to Holocene in age. At least 6 distinct valley-fill units are identified in the seismic data based upon reflection geometry. Cores reveal a 3 to 6 meter thick basal fluvial channel lag that is overlain by a 15-meter thick unit of interbedded freshwater muds and sands. Organic materials within the freshwater deposits have ages of 13-11 cal. ka, and are overlain by several units comprised of shallow marine sediments. Shallow marine sediments within the valley are silty, fine- to medium-grained sands containing abundant neritic forams, suggesting that this area was an open embayment during much of the Holocene. Seismic data reveal that initial infilling occurred from the north and west during the late Pleistocene and early Holocene. Later infilling occurred from the east and is characterized by a large

An ecological assessment of land use impacts in small watersheds of the Chesapeake Bay

Treesearch

Andrew Leight; John Jacobs; Lonnie Gonsalves; Gretchen Messick; Shawn McLaughlin; Jay Lewis; Juliana Brush; Eric Daniels; Matthew Rhodes; Lewis Collier; Robert Wood

2016-01-01

The Chesapeake Bay, the nation’s largest estuary, remains in relatively poor condition despite intensive public and scientific attention. In order to better understand the stressors and impacts occurring in the Bay as a result of land management decisions we conducted an assessment of both habitat condition and organismal response in three small watersheds of the upper...

Pathways of Methylmercury Transfer to the Water Column Across Multiple Estuaries

NASA Astrophysics Data System (ADS)

Schartup, A. T.; Balcom, P. H.; Mason, R. P.; Chen, C.

2014-12-01

uniformly elevated above water dissolved MeHg in the other estuaries studied. Several estuaries had higher MeHg at low tide suggesting input as water was delivered from the watersheds. We conclude that the relative importance of sources is dependent on the physical (water residence time, water depth) and chemical characteristics (sediment organic carbon content) of the estuary.

Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection

EPA Science Inventory

We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

Carbon Transformations and Source - Sink Dynamics along a River, Marsh, Estuary, Ocean Continuum

NASA Astrophysics Data System (ADS)

Anderson, I. C.; Crosswell, J.; Czapla, K.; Van Dam, B.

2017-12-01

Estuaries, the transition zone between land and the coastal ocean, are highly dynamic systems in which carbon sourced from watersheds, marshes, atmosphere, and ocean may be transformed, sequestered, or exported. The net fate of carbon in estuaries, governed by the interactions of biotic and physical drivers varying on spatial and temporal scales, is currently uncertain because of limited observational data. In this study, conducted in a temperate, microtidal, and shallow North Carolina USA estuary, carbon exchanges via river, tributary, and fringing salt marsh, air-water fluxes, sediment C accumulation, and metabolism were monitored over two-years, with sharply different amounts of rainfall. Air-water CO2 fluxes and metabolic variables were simultaneously measured in channel and shoal by conducting high-resolution surveys at dawn, dusk and the following dawn. Marsh CO2 exchanges, sediment C inputs, and lateral exports of DIC and DOC were also measured. Carbon flows between estuary regions and export to the coastal ocean were calculated by quantifying residual transport of DIC and TOC down-estuary as flows were modified by sources, sinks and internal transformations. Variation in metabolic rates, CO2, TOC and DIC exchanges were large when determined for short time and limited spatial scales. However, when scaled to annual and whole estuarine scales, variation tended to decrease because of counteracting metabolic rates and fluxes between channel and shoal or between seasons. Although overall salt marshes accumulated OC, they were a negligible source of DIC and DOC to the estuary, and net inputs of C to the marsh were mainly derived from sediment OC. These results, as observed in other observational studies of estuaries, show that riverine input, light, temperature and metabolism are major controls on carbon cycling. Comparison of our results with other types of estuaries varying in depth, latitude, and nutrification demonstrates large discrepancies underscoring the

Simulated groundwater flow paths, travel time, and advective transport of nitrogen in the Kirkwood-Cohansey aquifer system, Barnegat Bay–Little Egg Harbor Watershed, New Jersey

USGS Publications Warehouse

Voronin, Lois M.; Cauller, Stephen J.

2017-07-31

Elevated concentrations of nitrogen in groundwater that discharges to surface-water bodies can degrade surface-water quality and habitats in the New Jersey Coastal Plain. An analysis of groundwater flow in the Kirkwood-Cohansey aquifer system and deeper confined aquifers that underlie the Barnegat Bay–Little Egg Harbor (BB-LEH) watershed and estuary was conducted by using groundwater-flow simulation, in conjunction with a particle-tracking routine, to provide estimates of groundwater flow paths and travel times to streams and the BB-LEH estuary.Water-quality data from the Ambient Groundwater Quality Monitoring Network, a long-term monitoring network of wells distributed throughout New Jersey, were used to estimate the initial nitrogen concentration in recharge for five different land-use classes—agricultural cropland or pasture, agricultural orchard or vineyard, urban non-residential, urban residential, and undeveloped. Land use at the point of recharge within the watershed was determined using a geographic information system (GIS). Flow path starting locations were plotted on land-use maps for 1930, 1973, 1986, 1997, and 2002. Information on the land use at the time and location of recharge, time of travel to the discharge location, and the point of discharge were determined for each simulated flow path. Particle-tracking analysis provided the link from the point of recharge, along the particle flow path, to the point of discharge, and the particle travel time. The travel time of each simulated particle established the recharge year. Land use during the year of recharge was used to define the nitrogen concentration associated with each flow path. The recharge-weighted average nitrogen concentration for all flow paths that discharge to the Toms River upstream from streamflow-gaging station 01408500 or to the BB-LEH estuary was calculated.Groundwater input into the Barnegat Bay–Little Egg Harbor estuary from two main sources— indirect discharge from base

Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection

EPA Science Inventory

We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

Late Neogene and Quaternary evolution of the northern Albemarle Embayment (mid-Atlantic continental margin, USA)

USGS Publications Warehouse

Mallinson, D.; Riggs, S.; Thieler, E.R.; Culver, S.; Farrell, K.; Foster, D.S.; Corbett, D.R.; Horton, B.; Wehmiller, J.F.

2005-01-01

Seismic surveys in the eastern Albemarle Sound, adjacent tributaries and the inner continental shelf define the regional geologic framework and provide insight into the sedimentary evolution of the northern North Carolina coastal system. Litho- and chronostratigraphic data are derived from eight drill sites on the Outer Banks barrier islands, and the Mobil #1 well in eastern Albemarle Sound. Within the study area, parallel-bedded, gently dipping Miocene beds occur at 95 to > 160 m below sea level (m bsl), and are overlain by a southward-thickening Pliocene unit characterized by steeply inclined, southward-prograding beds. The lower Pliocene unit consists of three seismic sequences. The 55–60 m thick Quaternary section unconformably overlies the Pliocene unit, and consists of 18 seismic sequences exhibiting numerous incised channel-fill facies. Shallow stratigraphy (< 40 m bsl) is dominated by complex fill patterns within the incised paleo-Roanoke River valley. Radiocarbon and amino-acid racemization (AAR) ages indicate that the valley-fill is latest Pleistocene to Holocene in age. At least six distinct valley-fill units are identified in the seismic data. Cores in the valley-fill contain a 3–6 m thick basal fluvial channel deposit that is overlain by a 15 m thick unit of interlaminated muds and sands of brackish water origin that exhibit increasing marine influence upwards. Organic materials within the interlaminated deposits have ages of 13–11 cal. ka. The interlaminated deposits within the valley are overlain by several units that comprise shallow marine sediments (bay-mouth and shoreface environments) that consist of silty, fine- to medium-grained sands containing open neritic foraminifera, suggesting that this area lacked a fronting barrier island system and was an open embayment from ∼10 ka to ∼4.5 ka. Seismic data show that initial infilling of the paleo-Roanoke River valley occurred from the north and west during the late Pleistocene and early

U.S. Geological Survey Science—Improving the value of the Chesapeake Bay watershed

USGS Publications Warehouse

Phillips, Scott W.; Hyer, Kenneth; Goldbaum, Elizabeth

2017-05-05

IntroductionCongress directed the Federal Government to work with States to restore the Nation’s largest estuary.Chesapeake Bay restoration provides important economic and ecological benefits:18 million people live and work in the Bay watershed and enjoy its benefits.3,600 types of fish, wildlife, and plants underpin the economic value of the Bay ecosystem.Poor water quality and habitat loss threaten restoration and negatively impact the economy.10 Goals to meet by 2025 through the Chesapeake Bay Program, a voluntary partnership.

Nitrogen Inputs to Seventy-four Southern New England Estuaries: Application of a Watershed Nitrogen Loading Model

EPA Science Inventory

Excess nitrogen inputs to estuaries have been linked to deteriorating water quality and habitat conditions which in turn have direct and indirect impacts on both commercial and recreational fish and shellfish. This paper is the first of a two-part series that applies a previously...

Identification and Prediction of Fish Assemblages in Streams of the Albemarle-Pamlico Basin, USA

EPA Science Inventory

Set within the Ecological Services Research Program (ESRP) of USEPA’s Office of Research and Development, a multi-disciplinary research collaborative (MEERT –Multimedia Ecological Exposure Research Team) has taken on a challenge to develop a regional assessment of several ecosyst...

Dissolved oxygen in two Oregon estuaries: Importance of the ocean-estuary connection - March 2011

EPA Science Inventory

We examined the role of the ocean–estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO w...

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.

Land Conservation Plan from the New Hampshire’s Coastal Watersheds (Piscataqua Region Estuaries Partnership)

EPA Pesticide Factsheets

The overarching goal of this land conservation plan is to focus conservation on those lands and waters that are most important for conserving living resources - native plants, animals and natural communities - and water quality in the coastal watersheds.

Natural and management influences on freshwater inflows and salinity in the San Francisco Estuary at monthly to interannual scales

USGS Publications Warehouse

Knowles, Noah

2002-01-01

Understanding the processes controlling the physics, chemistry, and biology of the San Francisco Estuary and their relation to climate variability is complicated by the combined influence on freshwater inflows of natural variability and upstream management. To distinguish these influences, alterations of estuarine inflow due to major reservoirs and freshwater pumping in the watershed were inferred from available data. Effects on salinity were estimated by using reconstructed estuarine inflows corresponding to differing levels of impairment to drive a numerical salinity model. Both natural and management inflow and salinity signals show strong interannual variability. Management effects raise salinities during the wet season, with maximum influence in spring. While year‐to‐year variations in all signals are very large, natural interannual variability can greatly exceed the range of management effects on salinity in the estuary.

Modelling Watershed and Estuarine Controls on Salt Marsh Distributions

NASA Astrophysics Data System (ADS)

Yousefi Lalimi, F.; Marani, M.; Murray, A. B.; D'Alpaos, A.

2017-12-01

The formation and evolution of tidal platforms have been extensively studied through observations and models, describing landform dynamics as a result of the local interactions and feedbacks among hydrodynamics, vegetation, and sediment transport. However, existing work mainly focuses on individual marsh platforms and, possibly, their immediate surrounding, such that the influence and controls on marsh dynamics of inland areas (through fluvial inputs) and of exchanges with the ocean have not been comprehensively and simultaneously accounted for. Here, we develop and use a process-based model to evaluate the relative role of watershed, estuarine, and ocean controls on salt marsh accretionary and depositional/erosional dynamics and define how these factors interact to determine salt marsh resilience to environmental change at the whole-estuary scale. Our results, in line with previous work, show that no stable equilibrium exists for the erosional dynamics of the marsh/tidal flat boundary. In addition, we find that under some circumstances, vertical accretion/erosion dynamics can lead to transitions between salt marsh and tidal flat equilibrium states that occur much more rapidly than marsh/tidal flat boundary erosion or accretion could. We further define, in the multidimensional space of estuarine-scale morphodynamic forcings, the basins of attractions leading to marsh-dominated and tidal-flat-dominated estuaries. The relatively slow dynamics asymptotically leading to marsh- or tidal-flat- dominance in many cases suggest that estuaries are likely to be found, at any given time, in a transition state dictated by temporal variations in environmental forcings.

Collection and analysis of remotely sensed data from the Rhode River Estuary Watershed

NASA Technical Reports Server (NTRS)

Jenkins, D. W.; Williamson, F. S. L.

1973-01-01

The remote sensing study to survey the Rhode River watershed for spray irrigation with secondarily treated sewage is reported. The standardization of Autumn coloration changes with Munsell color chips is described along with the mapping of old field vegetation for the spray irrigation project. The interpretation and verification of salt marsh vegetation by remote sensing of the water shed is discussed.

Climate Ready Estuaries

EPA Pesticide Factsheets

Information on climate change impacts to different estuary regions, tools and resources to monitor changes, and information to help managers develop adaptation plans for risk management of estuaries and coastal communities.

75 FR 34975 - Notice of Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-21

... Estuary Habitat Restoration Council's Intent to Revise its Estuary Habitat Restoration Strategy; Request... interagency Estuary Habitat Restoration Council, is providing notice of the Council's intent to revise the ''Estuary Habitat Restoration Strategy'' and requesting public comments to guide its revision. DATES...

Inter and intra-estuary variability in ingress, condition and settlement of the American eel Anguilla rostrata: implications for estimating and understanding recruitment.

PubMed

Sullivan, M C; Wuenschel, M J; Able, K W

2009-06-01

The objective of this study was to quantify spatial and temporal variability of anguillid glass eel ingress within and between adjacent watersheds in order to help illuminate the mechanisms moderating annual recruitment. Because single fixed locations are often used to assess annual recruitment, the intra-annual dynamics of ingress across multiple sites often remains unresolved. To address this question, plankton nets and eel collectors were deployed weekly to synoptically quantify early stage Anguilla rostrata abundance at 12 sites across two New Jersey estuaries over an ingress season. Numbers of early-stage glass eels collected at the inlet mouths were moderately variable within and between estuaries over time and showed evidence for weak lunar phase and water temperature correlations. The relative condition of glass eels, although highly variable, declined significantly over the ingress season and indicated a tendency for lower condition A. rostrata to colonize sites in the lower estuary. Accumulations of glass eels and early-stage elvers retrieved from collectors (one to >1500 A. rostrata per collector) at lower estuary sites were highly variable over time, producing only weak correlations between estuaries. By way of contrast, development into late-stage elvers, coupled with the large-scale colonization of up-river sites, was highly synchronized between and within estuaries and contingent on water temperatures reaching c. 10-12 degrees C. Averaged over the ingress season, abundance estimates were remarkably consistent between paired sites across estuaries, indicating a low degree of interestuary variability. Within an estuary, however, abundance estimates varied considerably depending on location. These results and methodology have important implications for the planning and interpretation of early-stage anguillid eel surveys as well as the understanding of the dynamic nature of ingress and the spatial scales over which recruitment varies.

Seasonal variability of the inorganic carbon system in a large coastal plain estuary

NASA Astrophysics Data System (ADS)

Joesoef, Andrew; Kirchman, David L.; Sommerfield, Christopher K.; Cai, Wei-Jun

2017-11-01

Carbonate geochemistry research in large estuarine systems is limited. More work is needed to understand how changes in land-use activity influence watershed export of organic and inorganic carbon, acids, and nutrients to the coastal ocean. To investigate the seasonal variation of the inorganic carbon system in the Delaware Estuary, one of the largest estuaries along the US east coast, dissolved inorganic carbon (DIC), total alkalinity (TA), and pH were measured along the estuary from June 2013 to April 2015. In addition, DIC, TA, and pH were periodically measured from March to October 2015 in the nontidal freshwater Delaware, Schuylkill, and Christina rivers over a range of discharge conditions. There were strong negative relationships between river TA and discharge, suggesting that changes in HCO3- concentrations reflect dilution of weathering products in the drainage basin. The ratio of DIC to TA, an understudied but important property, was high (1.11) during high discharge and low (0.94) during low discharge, reflecting additional DIC input in the form of carbon dioxide (CO2), most likely from terrestrial organic matter decomposition, rather than bicarbonate (HCO3-) inputs due to drainage basin weathering processes. This is also a result of CO2 loss to the atmosphere due to rapid water transit during the wet season. Our data further show that elevated DIC in the Schuylkill River is substantially different than that in the Delaware River. Thus, tributary contributions must be considered when attributing estuarine DIC sources to the internal carbon cycle versus external processes such as drainage basin mineralogy, weathering intensity, and discharge patterns. Long-term records in the Delaware and Schuylkill rivers indicate shifts toward higher alkalinity in estuarine waters over time, as has been found in other estuaries worldwide. Annual DIC input flux to the estuary and export flux to the coastal ocean are estimated to be 15.7 ± 8.2 × 109 mol C yr-1 and 16

DEVELOP Chesapeake Bay Watershed Hydrology - UAV Sensor Web

NASA Astrophysics Data System (ADS)

Holley, S. D.; Baruah, A.

2008-12-01

The Chesapeake Bay is the largest estuary in the United States, with a watershed extending through six states and the nation's capital. Urbanization and agriculture practices have led to an excess runoff of nutrients and sediment into the bay. Nutrients and sediment loading stimulate the growth of algal blooms associated with various problems including localized dissolved oxygen deficiencies, toxic algal blooms and death of marine life. The Chesapeake Bay Program, among other stakeholder organizations, contributes greatly to the restoration efforts of the Chesapeake Bay. These stakeholders contribute in many ways such as monitoring the water quality, leading clean-up projects, and actively restoring native habitats. The first stage of the DEVELOP Chesapeake Bay Coastal Management project, relating to water quality, contributed to the restoration efforts by introducing NASA satellite-based water quality data products to the stakeholders as a complement to their current monitoring methods. The second stage, to be initiated in the fall 2008 internship term, will focus on the impacts of land cover variability within the Chesapeake Bay Watershed. Multiple student led discussions with members of the Land Cover team at the Chesapeake Bay Program Office in the DEVELOP GSFC 2008 summer term uncovered the need for remote sensing data for hydrological mapping in the watershed. The Chesapeake Bay Program expressed in repeated discussions on Land Cover mapping that significant portions of upper river areas, streams, and the land directly interfacing those waters are not accurately depicted in the watershed model. Without such hydrological mapping correlated with land cover data the model will not be useful in depicting source areas of nutrient loading which has an ecological and economic impact in and around the Chesapeake Bay. The fall 2008 DEVELOP team will examine the use of UAV flown sensors in connection with in-situ and Earth Observation satellite data. To maximize the

Dissolved oxygen in two Oregon estuaries: The importance of the ocean-estuary connection - May 16, 2011

EPA Science Inventory

We examined the role of the ocean –estuary connection in influencing periodic reductions in dissolved oxygen (DO) levels in Yaquina and Yachats estuaries, Oregon, USA. In the Yaquina Estuary, there is close coupling between the coastal ocean and the estuary. As a result, low DO ...

Introduction to Estuaries

EPA Science Inventory

Estuaries, although minor geographical features at the global scale, have major importance for society and the world’s economies. This chapter introduces estuaries by presenting an overview of definitions, origins, physical, chemical and ecological attributes, and the interaction...

Seasonal Changes in Estuarine Dissolved Organic Matter Due to Variations in Discharge, Flushing Times and Wind-driven Mixing Events

NASA Astrophysics Data System (ADS)

Dixon, Jennifer Louise

isotopes (Bauer, 2002) and lignin (e.g., Benner and Opsahl, 2001; Harvey and Mannino, 2001). Marine DOM derived from phytoplankton typically has carbon stable isotope (delta13C) values that range from --20 to --22‰, while terrestrial DOM derived from C3 land plants typically have delta13C values that range from --26 to --28‰ (Bauer, 2002). Lignin is an important component of vascular plants, thus making it a unique geochemical biomarker, which can be used to trace the fate of terrestrial DOM in coastal seawater (e.g., Hernes and Benner, 2003; Walker et al. 2009; Osburn and Stedmon, 2011). Further, the ratios of the different phenolic compounds derived from the oxidation of lignin can be used to distinguish between plant sources (e.g. angiosperm vs. gymnosperm, or woody vs. non-woody tissue) and the extent of exposure to degradation (Hedges et al. 1988). The highly productive, eutrophic waters of the Neuse River Estuary (NRE), in eastern North Carolina, USA, serve as a transition zone for terrigenous DOM between the head of the Neuse River and Pamlico Sound. Previous studies have determined that the NRE is dominated by inputs from riverine discharge, yet very clear shifts in DOM quality are apparent as discharge varied (Paerl et al. 1998; Osburn et al. 2012). Furthermore, flushing times within the NRE will aid in determining whether DOM is primarily autochthonous or allochthonous and if it is processed internally or transported downstream to the Pamlico Sound (Paerl et al. 1998; Mari et al. 2007, Peierls et al. 2012). Therefore, the main sources of DOM and its composition can change throughout an estuary depending on the hydrodynamic conditions. For example, increases in flushing time may allow for the accumulation of autochthonous DOM because of (1) planktonic communities within the water column having more time to utilize nutrients within the system, resulting in phytoplankton blooms and (2) lower inputs of allochthonous OM from the NRE's watershed (Dixon et al

Significant alteration of Critical Zone processes in urban watersheds: shifting from a transport-limited to a weathering-limited regime

NASA Astrophysics Data System (ADS)

Moore, J.; Bird, D. L.; Dobbis, S. K.; Woodward, G.

2016-12-01

Urban areas and associated impervious surface cover (ISC) are among the fastest growing land use types. Rapid growth of urban lands has significant implications for geochemical cycling and solute sources to streams, estuaries, and coastal waters. However, little work has been done to investigate the impacts of urbanization on Critical Processes, including on the export of solutes from urban watersheds. Despite observed elevated solute concentrations in urban streams in some previous studies, neither solute sources nor total solute fluxes have been quantified due to mixed bedrock geology, lack of a forested reference watershed, or the presence of point sources that confounded separation of anthropologic and natural sources. We investigated the geochemical signal of the urban built environment (e.g., roads, parking lots, buildings) in a set of five USGS-gaged watersheds across a rural (forested) to urban gradient in the Maryland Piedmont. These watersheds have ISC ranging from 0 to 25%, no point sources, and similar felsic bedrock chemistry. Weathering from the urban built environment and ISC produces dramatically higher solute concentrations in urban watersheds than in the forested watershed. Higher solute concentrations result in chemical weathering fluxes from urban watersheds that are 11-13 times higher than the forested watershed and are similar to fluxes from mountainous, weathering-limited watersheds rather than fluxes from transport-limited, dilute streams like the forested watershed. Weathering of concrete in urban watersheds produces geochemistry similar to weathering-limited watersheds with high concentrations of Ca2+, Mg2+, and DIC, which is similar to stream chemistry due to carbonate weathering. Road salt dissolution results in high Na+ and Cl- concentrations similar to evaporite weathering. Quantifying processes causing elevated solute fluxes from urban areas is essential to understanding cycling of Ca2+, Mg2+, and DIC in urban streams and in

Suspended sediment transport in the freshwater reach of the Hudson river estuary in eastern New York

USGS Publications Warehouse

Wall, G.R.; Nystrom, E.A.; Litten, S.

2008-01-01

Deposition of Hudson River sediment into New York Harbor interferes with navigation lanes and requires continuous dredging. Sediment dynamics at the Hudson estuary turbidity maximum (ETM) have received considerable study, but delivery of sediment to the ETM through the freshwater reach of the estuary has received relatively little attention and few direct measurements. An acoustic Doppler current profiler was positioned at the approximate limit of continuous freshwater to develop a 4-year time series of water velocity, discharge, suspended sediment concentration, and suspended sediment discharge. This data set was compared with suspended sediment discharge data collected during the same period at two sites just above the Hudson head-of-tide (the Federal Dam at Troy) that together represent the single largest source of sediment entering the estuary. The mean annual suspended sediment-discharge from the freshwater reach of the estuary was 737,000 metric tons. Unexpectedly, the total suspended sediment discharge at the study site in November and December slightly exceeded that observed during March and April, the months during which rain and snowmelt typically result in the largest sediment discharge to the estuary. Suspended sediment discharge at the study site exceeded that from the Federal Dam, even though the intervening reach appears to store significant amounts of sediment, suggesting that 30-40% of sediment discharge observed at the study site is derived from tributaries to the estuary between the Federal Dam and study site. A simple model of sediment entering and passing through the freshwater reach on a timescale of weeks appears reasonable during normal hydrologic conditions in adjoining watersheds; however, this simple model may dramatically overestimate sediment delivery during extreme tributary high flows, especially those at the end of, or after, the "flushing season" (October through April). Previous estimates of annual or seasonal sediment delivery

Determining Water Quality Trends in the Sacramento-San Joaquin Delta Watershed in the Face of Climate Change

NASA Astrophysics Data System (ADS)

Kynett, K.; Azimi-Gaylon, S.; Doidic, C.

2014-12-01

The Sacramento-San Joaquin Delta and Suisun Marsh (Delta) is the largest estuary on the West Coast of the Americas and is a resource of local, State, and national significance. The Delta is simultaneously the most critical component of California's water supply, a primary focus of the state's ecological conservation measures, and a vital resource deeply imperiled by degraded water quality. Delta waterbodies are identified as impaired by salinity, excess nutrients, low dissolved oxygen, pathogens, pesticides, heavy metals, and other contaminants. Climate change is expected to exacerbate the impacts of existing stressors in the Delta and magnify the challenges of managing this natural resource. A clear understanding of the current state of the watershed is needed to better inform scientists, decision makers, and the public about potential impacts from climate change. The Delta Watershed Initiative Network (Delta WIN) leverages the ecological benefits of healthy watersheds, and enhances, expands and creates opportunities for greater watershed health by coordinating with agencies, established programs, and local organizations. At this critical junction, Delta WIN is coordinating data integration and analysis to develop better understanding of the existing and emerging water quality concerns. As first steps, Delta WIN is integrating existing water quality data, analyzing trends, and monitoring to fill data gaps and to evaluate indicators of climate change impacts. Available data will be used for trend analysis; Delta WIN will continue to monitor where data is incomplete and new questions arise. Understanding how climate change conditions may affect water quality will be used to inform efforts to build resilience and maintain water quality levels which sustain aquatic life and human needs. Assessments of historical and new data will aid in recognition of potential climate change impacts and in initiating implementation of best management practices in collaboration with

Learning Lessons from Estuaries

ERIC Educational Resources Information Center

Schnittka, Christine

2006-01-01

There is something that draws all people to the sea and especially to the fertile estuaries that nuzzle up to its shores. An estuary serves as both a nursery and a grave for sea creatures. If life evolved from some primordial sea, it may well have been an estuary--a place where ocean and rivers meet and fresh and salty waters mingle in the…

Biogeochemical transport in the Loxahatchee River estuary, Florida: The role of submarine groundwater discharge

USGS Publications Warehouse

Swarzenski, P.W.; Orem, W.H.; McPherson, B.F.; Baskaran, M.; Wan, Y.

2006-01-01

The distributions of dissolved organic carbon (DOC), Ba, U, and a suite of naturally occurring radionuclides in the U/Th decay series (222Rn, 223,224,226,228Ra) were studied during high- and low-discharge conditions in the Loxahatchee River estuary, Florida to examine the role of submarine groundwater discharge in estuarine transport. The fresh water endmember of this still relatively pristine estuary may reflect not only river-borne constituents, but also those advected during active groundwater/surface water (hyporheic) exchange. During both discharge conditions, Ba concentrations indicated slight non-conservative mixing. Such Ba excesses could be attributed either to submarine groundwater discharge or particle desorption processes. Estuarine dissolved organic carbon concentrations were highest at salinities closest to zero. Uranium distributions were lowest in the fresh water sites and mixed mostly conservatively with an increase in salinity. Suspended particulate matter (SPM) concentrations were generally lowest ( 28??dpm L- 1) at the freshwater endmember of the estuary and appear to identify regions of the river most influenced by the discharge of fresh groundwater. Activities of four naturally occurring isotopes of Ra (223,224,226,228Ra) in this estuary and select adjacent shallow groundwater wells yield mean estuarine water-mass transit times of less than 1 day; these values are in close agreement to those calculated by tidal prism and tidal frequency. Submarine groundwater discharge rates to the Loxahatchee River estuary were calculated using a tidal prism approach, an excess 226Ra mass balance, and an electromagnetic seepage meter. Average SGD rates ranged from 1.0 to 3.8 ?? 105??m3 d- 1 (20-74??L m- 2 d- 1), depending on river-discharge stage. Such calculated SGD estimates, which must include both a recirculated as well as fresh water component, are in close agreement with results obtained from a first-order watershed mass balance. Average submarine

Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

NASA Technical Reports Server (NTRS)

Al-Hamdan, Mohammad Z.; Estes, Maurice G., Jr.; Judd, Chaeli; Thom, Ron; Woodruff, Dana; Ellis, Jean T.; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

2012-01-01

Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

NASA Astrophysics Data System (ADS)

Al-Hamdan, M. Z.; Estes, M. G.; Judd, C.; Thom, R.; Woodruff, D.; Ellis, J. T.; Quattrochi, D.; Watson, B.; Rodriguez, H.; Johnson, H.

2012-12-01

Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA's EcoWatch and Gulf of Mexico Data Atlas online systems for

Spatial and temporal variation in seagrass coverage in Southwest Florida: assessing the relative effects of anthropogenic nutrient load reductions and rainfall in four contiguous estuaries.

PubMed

Tomasko, D A; Corbett, C A; Greening, H S; Raulerson, G E

2005-08-01

The estuaries of Tampa Bay, Sarasota Bay, Lemon Bay, and Upper Charlotte Harbor are contiguous waterbodies located within the subtropical environment of Southwest Florida. Based on an examination of rainfall data over the period of record (1916-2001) within the watersheds of these estuaries, there is no evidence for spatial differences (at the watershed level) or monotonic trends in annual rainfall. During the 1980s, nitrogen loads into Tampa Bay and Sarasota Bay (generated primarily by domestic wastewater treatment facilities) were reduced by 57% and 46%, respectively. In response, both Tampa Bay and Sarasota Bay have lower phytoplankton concentrations, greater water clarity and more extensive seagrass coverage in 2002 than in the early 1980s. As there is no evidence of a concurrent trend in rainfall during the period of 1982-2001, it is unlikely that variation in rainfall can account for the observed increase in seagrass coverage in these two bays. In contrast, seagrass coverage has remained relatively constant since the mid 1980s in Lemon Bay and Charlotte Harbor. Domestic wastewater treatment facilities are minor sources of nitrogen to Lemon Bay, and water clarity in Charlotte Harbor varies mostly as a function of dissolved organic matter and non-chlorophyll associated turbidity, not phytoplankton levels. Even in estuaries that share boundaries and are within 100 km of each other, varied responses to anthropogenic changes and natural phenomena were observed in water quality and associated seagrass extent. Resource management strategies must take into account system-specific factors-not all strategies will result in similar results in different systems.

EVALUATING THE INTEGRITY OF SALT MARSHES IN NARRAGANSETT BAY SUB-ESTUARIES USING A WATERSHED APPROACH

EPA Science Inventory

A watershed approach to examine measures of structure and function in salt marshes of similar geomorphology and hydrology in Narragansett Bay is being used to develop a reference system for evaluating salt marsh integrity. We describe integrity as the capability of a salt marsh t...

Spatial dynamics of large-scale, multistage crab (Callinectes sapidus) dispersal: Determinants and consequences for recruitment

USGS Publications Warehouse

Etherington, L.L.; Eggleston, D.B.

2003-01-01

We assessed determinants and consequences of multistage dispersal on spatial recruitment of the blue crab, Callinectes sapidus, within the Croatan, Albemarle, Pamlico Estuarine System (CAPES), North Carolina, U.S.A. Large-scale sampling of early juvenile crabs over 4 years indicated that spatial abundance patterns were size-dependent and resulted from primary post-larval dispersal (pre-settlement) and secondary juvenile dispersal (early post-settlement). In general, primary dispersal led to high abundances within more seaward habitats, whereas secondary dispersal (which was relatively consistent) expanded the distribution of juveniles, potentially increasing the estuarine nursery capacity. There were strong relationships between juvenile crab density and specific wind characteristics; however, these patterns were spatially explicit. Various physical processes (e.g., seasonal wind events, timing and magnitude of tropical cyclones) interacted to influence dispersal during multiple stages and determined crab recruitment patterns. Our results suggest that the nursery value of different habitats is highly dependent on the dispersal potential (primary and secondary dispersal) to and from these areas, which is largely determined by the relative position of habitats within the estuarine landscape.

Contributions of atmospheric nitrogen deposition to U.S. estuaries: Summary and conclusions: Chapter 8

USGS Publications Warehouse

Stacey, Paul E.; Greening, Holly; Kremer, James N.; Peterson, David; Tomasko, David A.; Valigura, Richard A.; Alexander, Richard B.; Castro, Mark S.; Meyers, Tilden P.; Paerl, Hans W.; Stacey, Paul E.; Turner, R. Eugene

2001-01-01

A NOAA project was initiated in 1998, with support from the U.S. EPA, to develop state-of-the-art estimates of atmospheric N deposition to estuarine watersheds and water surfaces and its delivery to the estuaries. Work groups were formed to address N deposition rates, indirect (from the watershed) yields from atmospheric and other anthropogenic sources, and direct deposition on the estuarine waterbodies, and to evaluate the levels of uncertainty within the estimates. Watershed N yields were estimated using both a land-use based process approach and a national (SPARROW) model, compared to each other, and compared to estimates of N yield from the literature. The total N yields predicted by the national model were similar to values found in the literature and the land-use derived estimates were consistently higher. Atmospheric N yield estimates were within a similar range for the two approaches, but tended to be higher in the land-use based estimates and were not wellcorrelated. Median atmospheric N yields were around 15% of the total N yield for both groups, but ranged as high as 60% when both direct and indirect deposition were considered. Although not the dominant source of anthropogenic N, atmospheric N is, and will undoubtedly continue to be, an important factor in culturally eutrophied estuarine systems, warranting additional research and management attention.

Linking the watershed to the schoolshed: teaching sustainable development in K-12 with the Chester RIver Watershed Observatory

NASA Astrophysics Data System (ADS)

Trembanis, A. C.; Levin, D.; Seidel, J.

2012-12-01

(developed by Levin) engage students in the building and testing of buoys to monitor the environment. Additional hands on science activities include the Levin developed ROVs-in-a-bucket project that Trembanis has incorporated into the University of Delaware high school summer science camp TIDE (Teaching an Interest in Delaware's Estuary) http://www.ceoe.udel.edu/tide/ in which 12-15 high school students annually participate in groups working to design, build, and operate a simple remotely operated vehicle in a series of real work simulation activities such as responding to an oil spill. The new CRW network will be the focus for formal and informal learning partnerships between schools in the watershed. Professional development opportunities for Chester River watershed teachers focus on the use of sensors, utilization of GIS in the classroom, and other resources that become available as shared teaching resources. Federal, state, regional, and local users in government, private industry, and educational venues from grades k-16 will be able to observe the trends and learn together the most prudent ways to sustain and conserve natural resources.

Geochemistry of the Amazon Estuary

USGS Publications Warehouse

Smoak, Joseph M.; Krest, James M.; Swarzenski, Peter W

2006-01-01

The Amazon River supplies more freshwater to the ocean than any other river in the world. This enormous volume of freshwater forces the estuarine mixing out of the river channel and onto the continental shelf. On the continental shelf, the estuarine mixing occurs in a very dynamic environment unlike that of a typical estuary. The tides, the wind, and the boundary current that sweeps the continental shelf have a pronounced influence on the chemical and biological processes occurring within the estuary. The dynamic environment, along with the enormous supply of water, solutes and particles makes the Amazon estuary unique. This chapter describes the unique features of the Amazon estuary and how these features influence the processes occurring within the estuary. Examined are the supply and cycling of major and minor elements, and the use of naturally occurring radionuclides to trace processes including water movement, scavenging, sediment-water interaction, and sediment accumulation rates. The biogeochemical cycling of carbon, nitrogen, and phosphorus, and the significances of the Amazon estuary in the global mass balance of these elements are examined.

Hydro-sedimentary processes of a shallow tropical estuary under Amazon influence. The Mahury Estuary, French Guiana

NASA Astrophysics Data System (ADS)

Orseau, Sylvain; Lesourd, Sandric; Huybrechts, Nicolas; Gardel, Antoine

2017-04-01

Along the Guianas coast, coastal dynamic is characterized by the migration of mud banks originating from the Amazon. This singular feature affects the dynamic and the morphology of local estuaries and can induce rapid bathymetric evolution in lower estuaries. Since 2012, the navigation channel of the Mahury Estuary (French Guiana) is enduring a severe siltation whose origin comes from a mud bank crossing the estuary mouth. This study aims to determine how the migration of a mud bank through an estuary mouth could influence the transport and fluxes in the estuary. Field measurements were performed over a year with the monitoring of the salt intrusion length, mooring surveys during spring-neap cycles and shipboard profiling surveys during semi-diurnal cycles. Salt intrusion lengths underline a significant seasonal variation characterized by the transition from a steady-state length during high river discharge and a wide range of lengths with the tidal range during low to moderate river discharge. During the rainy season, measurements indicate a fluvial-dominated condition with low suspended-sediment concentrations most of the semi-diurnal cycle. Residual sediment fluxes are usually seaward excepted when river discharge is below seasonal average. During the dry season, maximum suspended-sediment concentrations are higher in the middle part of the estuary. Residual sediment fluxes are landward along the estuary and stronger during neap tides in the estuary mouth and few kilometers upstream. In this area, a persistent density stratification traps sediments in the bottom layer and generates a gravitational circulation during neap tides, which enhances landward transports up to 2.56 t m-1 over a semi-diurnal cycle. In the middle estuary, landward fluxes are most significant during the dry season and also during the rainy season when the river discharge is below the seasonal average. Although this study includes temporal and spatial limitations, it underlines significant

Water budget and water quality of Ward Lake, flow and water-quality characteristics of the Braden River estuary, and the effects of Ward Lake on the hydrologic system, west-central Florida

USGS Publications Warehouse

Trommer, J.T.; DelCharco, M.J.; Lewelling, B.R.

1999-01-01

The Braden River is the largest tributary to the Manatee River. The river was dammed in 1936 to provide the city of Bradenton a source of freshwater supply. The resulting impoundment was called Ward Lake and had a storage capacity of about 585 million gallons. Reconstruction in 1985 increased the size of the reservoir to about 1,400 million gallons. The lake has been renamed the Bill Evers Reservoir and drains about 59 square miles. The Braden River watershed can be subdivided into three hydrologic reaches. The upper reach consists of a naturally incised free-flowing channel. The middle reach consists of a meandering channel affected by backwater as a result of the dam. The lower reach is a tidal estuary. Water budgets were calculated for the 1993 through 1997 water years. Mean surface-water inflow to Ward Lake for the 5-year period was 1,645 inches per year (equivalent depth over the surface of the lake), or about 81.8 percent of total inflow. Mean ground-water inflow was 311 inches per year, or about 15.5 percent. A mean of 55 inches of rain fell directly on the lake and accounted for only 2.7 percent. Mean surface-water outflow was 1,736 inches, or about 86.4 percent of total water leaving the lake. There was no net ground-water outflow from the lake. Mean surface-water withdrawal for public supply was 229 inches per year, or about 11.4 percent. Mean evaporation was 45 inches and accounted for only 2.2 percent of the mean outflow. Change in lake storage on the budget was negligible. Most chemical constituents contained in water flowing to Ward Lake meet the standards specified by the Florida Department of Environmental Protection and the U.S. Environmental Protection Agency. Phosphorus is the exception, exceeding the U.S. Environmental Protection Agency limits of 0.10 milligram per liter in most samples. However, the source of the phosphorus is naturally occurring phosphate deposits underlying the watershed. Organic nitrogen and orthophosphate are the dominant

Evaluating Local and Regional Sources of Trace Element Contamination in a Rural Sub Estuary of the Upper Chesapeake Bay

NASA Astrophysics Data System (ADS)

Krahforst, C.; Hartman, S.; Sherman, L.; Kehm, K.

2014-12-01

The distribution of trace elements (V, Cr, Co, Ni, Cu, Zn, As, Ag, Cd, Sn, Ba, W, Pb and U) along with Al and Fe and other sediment characteristics in surface sediment and sediment cores from the Chester River - a sub estuary of the Chesapeake Bay located in a predominantly agricultural watershed of Maryland's upper Eastern Shore, USA - have been determined in order to add to the understanding of contaminant transport and fate and inform management strategies designed to maintain or improve the ecological condition of estuaries. These analyses coupled with the comparison of elemental analysis of 210Pb - dated sediment cores, main stem water quality surveys, and a review of recent EPA National Coastal Condition Assessment sediment data from Chesapeake Bay provide added information about the roles of local and region scale processes on ecosystem condition. The high amount of suspended sediment in the Chester River (5-20 mg L-1) is an important factor controlling water quality conditions of the Chester River and a prime focus for environmental management of this system. Sources of suspended matter include local runoff, atmospheric deposition, local resuspension, and exchange with the Chesapeake Bay. In principle, each of these sources could be distinguished on the basis of chemical composition of surface sediment. Preliminary results from multivariate analytic models indicate that many of the elements investigated display significant covariance with Al (and other predominantly crustal signatures) which may indicate limited exogenic sources of contamination for sediments of this watershed. For example total Pb concentrations are mostly below the NOAA's low toxic effects level and lower than the median value of NCCA data for the upper Chesapeake suggesting that sediments have significant sources from within the watershed. Further, significant higher concentrations of Sn and Cu coincide with sediment collected in or near marinas and point to localized anthropogenic

Causes and consequences of ecosystem service regionalization in a coastal suburban watershed

USGS Publications Warehouse

Wollheim, Wilfred M.; Mark B. Green,; Pellerin, Brian A.; Morse, Nathaniel B.; Hopkinson, Charles S.

2015-01-01

The demand for ecosystem services and the ability of natural ecosystems to provide those services evolve over time as population, land use, and management practices change. Regionalization of ecosystem service activity, or the expansion of the area providing ecosystem services to a population, is a common response in densely populated coastal regions, with important consequences for watershed water and nitrogen (N) fluxes to the coastal zone. We link biophysical and historical information to explore the causes and consequences of change in ecosystem service activity—focusing on water provisioning and N regulation—from 1850 to 2010 in a coastal suburban watershed, the Ipswich River watershed in northeastern Massachusetts, USA. Net interbasin water transfers started in the late 1800s due to regionalization of water supply for use by larger populations living outside the Ipswich watershed boundaries, reaching a peak in the mid-1980s. Over much of the twentieth century, about 20 % of river runoff was diverted from reaching the estuary, with greater proportions during drought years. Ongoing regionalization of water supply has contributed to recent declines in diversions, influenced by socioecological feedbacks resulting from the river drying and fish kills. Similarly, the N budget has been greatly perturbed since the suburban era began in the 1950s due to food and lawn fertilizer imports and human waste release. However, natural ecosystems are able to remove most of this anthropogenic N, mitigating impacts on the coastal zone. We propose a conceptual model whereby the amount and type of ecosystem services provided by coastal watersheds in urban regions expand and contract over time as regional population expands and ecosystem services are regionalized. We hypothesize that suburban watersheds can be hotspots of ecosystem service sources because they retain sufficient ecosystem function to still produce services that meet increasing demand from the local population

Goddard DEVELOP Students: Using NASA Remote Sensing Technology to Study the Chesapeake Bay Watershed

NASA Technical Reports Server (NTRS)

Moore, Rachel

2011-01-01

The DEVELOP National Program is an Earth Science research internship, operating under NASA s Applied Sciences Program. Each spring, summer, and fall, DEVELOP interns form teams to investigate Earth Science related issues. Since the Fall of 2003, Goddard Space Flight Center (GSFC) has been home to one of 10 national DEVELOP teams. In past terms, students completed a variety of projects related to the Applied Sciences Applications of National Priority, such as Public Health, Natural Disasters, Water Resources, and Ecological Forecasting. These projects have focused on areas all over the world, including the United States, Africa, and Asia. Recently, Goddard DEVELOP students have turned their attention to a local environment, the Chesapeake Bay Watershed. The Chesapeake Bay Watershed is a complex and diverse ecosystem, spanning approximately 64,000 square miles. The watershed encompasses parts of six states: Delaware, Maryland, New York, Pennsylvania, Virginia, and West Virginia, as well as the District of Columbia. The Bay itself is the biggest estuary in the United States, with over 100,000 tributaries feeding into it. The ratio of fresh water to salt water varies throughout the Bay, allowing for a variety of habitats. The Bay s wetlands, marshes, forests, reefs, and rivers support more than 3,600 plant and animal species, including birds, mammals, reptiles, amphibians, fish, and crabs. The Bay is also commercially significant. It is ranked third in the nation in fishery catch, and supplies approximately 500 million pounds of seafood annually. In addition to its abundant flora and fauna, the Chesapeake Bay watershed is home to approximately 16.6 million people, who live and work throughout the watershed, and who use its diverse resources for recreational purposes. Over the past several decades, the population throughout the watershed has increased rapidly, resulting in land use changes, and ultimately decreasing the health of the Chesapeake Bay Watershed. Over the

pyLIDEM: A Python-Based Tool to Delineate Coastal Watersheds Using LIDAR Data

NASA Astrophysics Data System (ADS)

O'Banion, R.; Alameddine, I.; Gronewold, A.; Reckhow, K.

2008-12-01

-resolution Light Detection and Ranging (LIDAR) data, generates fine scale DEMs, and delineates watershed boundaries for a given pour point. Because LIDAR data are typically distributed in large sets of predefined tiles, our tool is capable of combining only the minimum number of bare earth LIDAR tiles required to delineate a watershed of interest. Our tool then processes the LIDAR data into Triangulated Irregular Networks, generates DEMs at user- specified cell sizes, and creates the required files needed to delineate watersheds within ArcGIS. To make pyLIDEM more accessible to the modeling community, we have bundled it within an ArcGIS toolbox, which also allows users to run it directly from an ArcGIS platform. We assess pyLIDEM functionality and accuracy by delineating several impaired small coastal watersheds in the Newport River Estuary in Eastern North Carolina using LIDAR data collected for the North Carolina Flood Mapping Program. We then compare the pyLIDAR-based watershed boundaries with those generated manually and with those generated using the 30-meter DEMs, and find that the pyLIDAR-based boundaries are more accurate than the 30-meter DEMs, and provide a significant time savings compared to manual delineation, particularly in cases where multiple watersheds need to be delineated for a single project.

The role of extreme floods in estuary-coastal behaviour: contrasts between river- and tide-dominated microtidal estuaries

NASA Astrophysics Data System (ADS)

Cooper, J. A. G.

2002-06-01

Contrasting modes of sedimentation and facies arrangement in tide- and river-dominated microtidal estuaries arise from the degree to which river or tidal discharge and sediment supply influences an estuary. A distinct facies gradation exists in tide-dominated systems from sandy, barrier/tidal delta-associated environments at the coast through deep mud-dominated middle reaches to fluvial sediment in the upper reaches. In river-dominated systems, fluvial sediment extends to the barrier and flood-tidal deltas are poorly developed or absent from the estuary. A number of independent observations during extreme floods on the South African coast indicate that these types of estuary respond differently to extreme river floods and that the mode of response corresponds to estuary type. Tide-dominated systems exhibit preferential erosion of noncohesive barrier and tidal delta sediments during river floods while the middle reaches remain little modified. River-dominated systems experience consistent erosion throughout their channel length during extreme floods. The increased cohesion of riverine sediments and stabilisation of bars by vegetation in river-dominated channels means that higher magnitude floods are necessary to effect significant morphological change. Barrier erosion, including the tidal delta, results in deposition of an ephemeral delta composed almost entirely of sands from these deposits in tide-dominated estuaries. In river-dominated systems, eroded channel sediments and material from the river catchment may augment barrier sediments in the ephemeral delta deposit. Post-flood, wave-reworking of ephemeral delta sediments acts to restore barriers to pre-flood morphology within a few years; however, in river-dominated systems, the additional sediment volume may produce significant coastal progradation that requires several years or decades to redistribute. These different modes of flood response mediated by the nature of the estuary have implications for coastal

Effects of watershed land use on nitrogen concentrations and δ15 nitrogen in groundwater

USGS Publications Warehouse

Cole, Marci L.; Kroeger, Kevin D.; McClelland, J.W.; Valiela, I.

2006-01-01

Eutrophication is a major agent of change affecting freshwater, estuarine, and marine systems. It is largely driven by transportation of nitrogen from natural and anthropogenic sources. Research is needed to quantify this nitrogen delivery and to link the delivery to specific land-derived sources. In this study we measured nitrogen concentrations and δ 15N values in seepage water entering three freshwater ponds and six estuaries on Cape Cod, Massachusetts and assessed how they varied with different types of land use. Nitrate concentrations and δ 15N values in groundwater reflected land use in developed and pristine watersheds. In particular, watersheds with larger populations delivered larger nitrate loads with higher δ 15N values to receiving waters. The enriched δ 15N values confirmed nitrogen loading model results identifying wastewater contributions from septic tanks as the major N source. Furthermore, it was apparent that N coastal sources had a relatively larger impact on the N loads and isotopic signatures than did inland N sources further upstream in the watersheds. This finding suggests that management priorities could focus on coastal sources as a first course of action. This would require management constraints on a much smaller population.

ESTABLISHING MINIMUM FLOWS AND LEVELS OF FRESHWATER IN THE CALOOSAHATCHEE RIVER, FLORIDA, USING RESPONSES OF OYSTERS.

EPA Science Inventory

Alterations in freshwater inflow resulting from watershed development and water management practices have impacted salinity and water quality and led to declines in oyster populations within southwest Florida estuaries. In the Caloosahatchee Estuary, Florida watershed management ...

A comparison of CO2 dynamics and air-water fluxes in a river-dominated estuary and a mangrove-dominated marine estuary

NASA Astrophysics Data System (ADS)

Akhand, Anirban; Chanda, Abhra; Manna, Sudip; Das, Sourav; Hazra, Sugata; Roy, Rajdeep; Choudhury, S. B.; Rao, K. H.; Dadhwal, V. K.; Chakraborty, Kunal; Mostofa, K. M. G.; Tokoro, T.; Kuwae, Tomohiro; Wanninkhof, Rik

2016-11-01

The fugacity of CO2 (fCO2 (water)) and air-water CO2 flux were compared between a river-dominated anthropogenically disturbed open estuary, the Hugli, and a comparatively pristine mangrove-dominated semiclosed marine estuary, the Matla, on the east coast of India. Annual mean salinity of the Hugli Estuary (≈7.1) was much less compared to the Matla Estuary (≈20.0). All the stations of the Hugli Estuary were highly supersaturated with CO2 (annual mean 2200 µatm), whereas the Matla was marginally oversaturated (annual mean 530 µatm). During the postmonsoon season, the outer station of the Matla Estuary was under saturated with respect to CO2 and acted as a sink. The annual mean CO2 emission from the Hugli Estuary (32.4 mol C m-2 yr-1) was 14 times higher than the Matla Estuary (2.3 mol C m-2 yr-1). CO2 efflux rate from the Hugli Estuary has increased drastically in the last decade, which is attributed to increased runoff from the river-dominated estuary.

Discover a Watershed: The Watershed Manager Educators Guide

ERIC Educational Resources Information Center

Project WET Foundation, 2002

2002-01-01

This guide contains 19 science-based, multidisciplinary activities that teach what a watershed is, how it works and why we must all consider ourselves watershed managers. An extensive background section introduces readers to fundamental watershed concepts. Each activity adapts to local watersheds, contains e-links for further Internet research and…

Policy development and the estuary environment: a Severn Estuary case study.

PubMed

Ballinger, R; Stojanovic, T

2010-01-01

The paper reviews the development of key policy relating to estuary management, highlighting the trends and drivers in policy development which have shaped the management and protection of the estuary environment. Focusing on policy developments over the last three decades, the paper draws attention to the significant influence of European policy and new approaches to environmental governance in stimulating wider and more integrated approaches to the environmental management of the estuary, as well as highlighting considerable environmental improvements associated with increased environmental regulation. The paper discusses how 'fit for purpose' the policy framework is to address current challenges, including those identified by recent stakeholder consultations. Significant issues include limited understanding and information related to the cause-effect relationships between policy and environmental quality as well as ongoing institutional and policy fragmentation associated with devolutionary processes. Such fragmentation, alongside under-investment in integrated estuary planning, is likely to prove a particular challenge to balanced and informed decision-making. Whilst the paper focuses on the Severn experience, the approach adopted will be of interest to all assessing policy-environment linkages. (c) 2009 Elsevier Ltd. All rights reserved.

Carbon dioxide emissions from Indian monsoonal estuaries

NASA Astrophysics Data System (ADS)

Sarma Vedula, VSS

2012-07-01

The oceans act as a net sink for atmospheric CO2, however, the role of coastal bodies on global CO2 fluxes remains unclear due to lack of data. The estimated absorption of CO2 from the continental shelves, with limited data, is 0.22 to 1.0 PgC/y, and of CO2 emission by estuaries to the atmosphere is 0.27 PgC/y. The estimates from the estuaries suffer from large uncertainties due to large variability and lack of systematic data collection. It is especially true for Southeast Asian estuaries as the biogeochemical cycling of material are different due to high atmospheric temperature, seasonality driven by monsoons, seasonal discharge etc. In order to quantify CO2 emissions from the Indian estuaries, samples were collected at 27 estuaries all along the Indian coast during discharge wet and dry periods. The emissions of CO2 to the atmosphere from Indian estuaries were 4-5 times higher during wet than dry period. The pCO2 ranged between ~300 and 18492 microatm which were within the range of world estuaries. The mean pCO2 and particulate organic carbon (POC) showed positive relation with rate of discharge suggesting availability of high quantities of organic matter that led to enhanced microbial decomposition. The annual CO2 fluxes from the Indian estuaries, together with dry period data available in the literature, amounts to 1.92 TgC which is >10 times less than that from the European estuaries. The low CO2 fluxes from the Indian estuaries are attributed to low flushing rates and less human settlements along the banks of the Indian estuaries.

Sources and fate of bioavailable dissolved organic nitrogen in the Neuse River Estuary, North Carolina

NASA Astrophysics Data System (ADS)

Paerl, H. W.; Peierls, B. L.; Hounshell, A.; Osburn, C. L.

2015-12-01

Eutrophication is a widespread problem affecting the structure and function of estuaries and is often linked to anthropogenic nitrogen (N) enrichment, since N is the primary nutrient limiting algal production. Watershed management actions typically have ignored dissolved organic nitrogen (DON) loading because of its perceived refractory nature and instead focused on inorganic N as targets for loading reductions. A fluorescence-based model indicated that anthropogenic sources of DON near the head of the microtidal Neuse River Estuary (NRE), NC were dominated by septic systems and poultry waste. A series of bioassays were used to determine the bioavailability of river DON and DON-rich sources to primary producers and whether those additions promoted the growth of certain phytoplankton taxa, particularly harmful species. Overall, at time scales up to two to three weeks, estuarine phytoplankton and bacteria only showed limited responses to additions of high molecular weight (HMW, >1 kDa) river DON. When increases in productivity and biomass did occur, they were quite small compared with the response to inorganic N. Low molecular weight (LMW) river DON, waste water treatment plant effluent, and poultry litter extract did have a positive effect on phytoplankton and bacterial production, indicating a bioavailable fraction. High variability of bulk DON concentration suggested that bioavailable compounds added in the experimental treatments were low in concentration and turned over quite rapidly. Some phytoplankton taxa, as measured by diagnostic photopigments, appeared to be selectively enhanced by the HMW and specific source DON additions, although the taxa could not be positively identified as harmful species. Preliminary tests show that labile autochthonous organic matter may act as a primer for the mineralization of the HMW DON. These and other, longer-term bioavailability studies will be needed to adequately address the fate of watershed DON in estuarine ecosystems.

An adaptive watershed management assessment based on watershed investigation data.

PubMed

Kang, Min Goo; Park, Seung Woo

2015-05-01

The aim of this study was to assess the states of watersheds in South Korea and to formulate new measures to improve identified inadequacies. The study focused on the watersheds of the Han River basin and adopted an adaptive watershed management framework. Using data collected during watershed investigation projects, we analyzed the management context of the study basin and identified weaknesses in water use management, flood management, and environmental and ecosystems management in the watersheds. In addition, we conducted an interview survey to obtain experts' opinions on the possible management of watersheds in the future. The results of the assessment show that effective management of the Han River basin requires adaptive watershed management, which includes stakeholders' participation and social learning. Urbanization was the key variable in watershed management of the study basin. The results provide strong guidance for future watershed management and suggest that nonstructural measures are preferred to improve the states of the watersheds and that consistent implementation of the measures can lead to successful watershed management. The results also reveal that governance is essential for adaptive watershed management in the study basin. A special ordinance is necessary to establish governance and aid social learning. Based on the findings, a management process is proposed to support new watershed management practices. The results will be of use to policy makers and practitioners who can implement the measures recommended here in the early stages of adaptive watershed management in the Han River basin. The measures can also be applied to other river basins.

Differences in the structure of copepod assemblages in four tropical estuaries: Importance of pollution and the estuary hydrodynamics.

PubMed

Araujo, Adriana V; Dias, Cristina O; Bonecker, Sérgio L C

2017-02-15

We examined the relationship between pollution and structure of copepod assemblages in estuaries, using sampling standardization of salinity range to reduce the effects of "Estuarine Quality Paradox". Copepod assemblages were analyzed in four Southeast Brazilian estuaries with different water quality levels and different hydrodynamic characteristics. The pollution negatively impacted the descriptors of the assemblage structure. The distribution of structure of copepod assemblages also showed a main separation trend between the most polluted estuaries and those less polluted. Temperature was the main factor affecting the assemblage structuring in the four estuaries. This factor acted in synergism with the effects of pollution impact and physical characteristics of the estuaries on the structure of copepod assemblages, supporting the potential vulnerability of coastal environments due to nutrient enrichment associated with climate change. Our study demonstrated the importance of sampling standardization of the salinity range in estuaries for reliable analysis of pollution effects on biota. Copyright © 2016 Elsevier Ltd. All rights reserved.

Insights into microbial communities involved in mercury methylation in the San Francisco Bay estuary

NASA Astrophysics Data System (ADS)

Machak, C.; Francis, C. A.

2013-12-01

San Francisco Bay (SFB) estuary is the largest estuary on the western coast of the United States, draining a watershed covering more than one third of the state of California. Mercury (Hg) contamination in SFB, as a result of gold and mercury mining in the Coast Range and Sierra Nevada region, has been observed for at least 150 years. Additional sources of Hg contamination to SFB come from active oil refineries, manufacturing, and wastewater treatment plants in the area. Concentrations of methylmercury in the sediment at the time of sample collection for the present study ranged from 0.011-3.88 μg/kg (dry weight). At some sites, the concentration exceeds wetland toxicity limits, posing a threat to the health of the ecosystem and potentially endangering humans that use the estuary for food and recreation. This study attempts to understand the factors that control the transformation of Hg to methylmercury by microorganisms in aquatic sediments, where the majority of Hg methylation is known to occur. Under anoxic conditions, some sulfate- and iron-reducing bacteria have the capacity to transform Hg into methylmercury. To better understand the microbial communities involved in Hg methylation, an extensive library of 16S rRNA sequences was generated (via Illumina sequencing) from sediment samples at 20 sites throughout the SFB estuary. In addition to genomic data, we have access to a massive database of geochemical measurements made by the SFB Regional Monitoring Program at the sampling locations. These measurements show that our sediment samples have varying methylmercury concentrations and span gradients in porewater sulfate and Fe(III), which are the two known alternative electron acceptors for mercury-methylating anaerobic bacteria. The sampling sites also span gradients in other geochemical factors known to influence microbial community composition (and potentially Hg mercury methylation), such as available organic carbon, pH, and salinity. We will present the

KNOW YOUR ESTUARY: THE WATER THROUGH TIME

EPA Science Inventory

This presentation will focus on historical changes in water quality in the Yaquina Estuary, Oregon, and factors which influence water quality within this estuary. Topics presented will include the importance of ocean conditions on water quality in the estuary; historical changes...

A History of Vegetation, Sediment and Nutrient Dynamics at Tivoli North Bay, Hudson Estuary, New York

NASA Technical Reports Server (NTRS)

Sritrairat, Sanpisa; Peteet, Dorothy M.; Kenna, Timothy C.; Sambrotto, Ray; Kurdyla, Dorothy; Guilderson, Tom

2012-01-01

We conduct a stratigraphic paleoecological investigation at a Hudson River National Estuarine Research Reserve (HRNERR) site, Tivoli Bays, spanning the past 1100 years. Marsh sediment cores were analyzed for ecosystem changes using multiple proxies, including pollen, spores, macrofossils, charcoal, sediment bulk chemistry, and stable carbon and nitrogen isotopes. The results reveal climatic shifts such as the warm and dry Medieval Warm Period (MWP) followed by the cooler Little Ice Age (LIA), along with significant anthropogenic influence on the watershed ecosystem. A five-fold expansion of invasive species, including Typha angustifolia and Phragmites australis, is documented along with marked changes in sediment composition and nutrient input. During the last century, a ten-fold sedimentation rate increase due to land-use changes is observed. The large magnitude of shifts in vegetation, sedimentation, and nutrients during the last few centuries suggest that human activities have made the greatest impact to the marshes of the Hudson Estuary during the last millennium. Climate variability and ecosystem changes similar to those observed at other marshes in northeastern and mid-Atlantic estuaries, attest to the widespread regional signature recorded at Tivoli Bays.

Climate Ready Estuaries Progress Reports

EPA Pesticide Factsheets

Climate Ready Estuaries has supported adaptation activities in National Estuary Programs since 2008. In 2012, the program partnered with 23 NEPs, completed a pilot project with water utilities, and held workshops. Download annual reports from 2009-2012.

Estuarial fingerprinting through multidimensional fluorescence and multivariate analysis.

PubMed

Hall, Gregory J; Clow, Kerin E; Kenny, Jonathan E

2005-10-01

As part of a strategy for preventing the introduction of aquatic nuisance species (ANS) to U.S. estuaries, ballast water exchange (BWE) regulations have been imposed. Enforcing these regulations requires a reliable method for determining the port of origin of water in the ballast tanks of ships entering U.S. waters. This study shows that a three-dimensional fluorescence fingerprinting technique, excitation emission matrix (EEM) spectroscopy, holds great promise as a ballast water analysis tool. In our technique, EEMs are analyzed by multivariate classification and curve resolution methods, such as N-way partial least squares Regression-discriminant analysis (NPLS-DA) and parallel factor analysis (PARAFAC). We demonstrate that classification techniques can be used to discriminate among sampling sites less than 10 miles apart, encompassing Boston Harbor and two tributaries in the Mystic River Watershed. To our knowledge, this work is the first to use multivariate analysis to classify water as to location of origin. Furthermore, it is shown that curve resolution can show seasonal features within the multidimensional fluorescence data sets, which correlate with difficulty in classification.

Characterization of turbidity in Florida's Lake Okeechobee and Caloosahatchee and St. Lucie estuaries using MODIS-Aqua measurements.

PubMed

Wang, Menghua; Nim, Carl J; Son, Seunghyun; Shi, Wei

2012-10-15

This paper describes the use of ocean color remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard the Aqua satellite to characterize turbidity in Lake Okeechobee and its primary drainage basins, the Caloosahatchee and St. Lucie estuaries from 2002 to 2010. Drainage modification and agricultural development in southern Florida transport sediments and nutrients from watershed agricultural areas to Lake Okeechobee. As a result of development around Lake Okeechobee and the estuaries that are connected to Lake Okeechobee, estuarine conditions have also been adversely impacted, resulting in salinity and nutrient fluctuations. The measurement of water turbidity in lacustrine and estuarine ecosystems allows researchers to understand important factors such as light limitation and the potential release of nutrients from re-suspended sediments. Based on a strong correlation between water turbidity and normalized water-leaving radiance at the near-infrared (NIR) band (nL(w)(869)), a new satellite water turbidity algorithm has been developed for Lake Okeechobee. This study has shown important applications with satellite-measured nL(w)(869) data for water quality monitoring and measurements for turbid inland lakes. MODIS-Aqua-measured water property data are derived using the shortwave infrared (SWIR)-based atmospheric correction algorithm in order to remotely obtain synoptic turbidity data in Lake Okeechobee and normalized water-leaving radiance using the red band (nL(w)(645)) in the Caloosahatchee and St. Lucie estuaries. We found varied, but distinct seasonal, spatial, and event driven turbidity trends in Lake Okeechobee and the Caloosahatchee and St. Lucie estuary regions. Wind waves and hurricanes have the largest influence on turbidity trends in Lake Okeechobee, while tides, currents, wind waves, and hurricanes influence the Caloosahatchee and St. Lucie estuarine areas. Published by Elsevier Ltd.

Watershed analysis

Treesearch

Alan Gallegos

2002-01-01

Watershed analyses and assessments for the Kings River Sustainable Forest Ecosystems Project were done on about 33,000 acres of the 45,500-acre Big Creek watershed and 32,000 acres of the 85,100-acre Dinkey Creek watershed. Following procedures developed for analysis of cumulative watershed effects (CWE) in the Pacific Northwest Region of the USDA Forest Service, the...

WATERSHED INFORMATION - SURF YOUR WATERSHED

EPA Science Inventory

Surf Your Watershed is both a database of urls to world wide web pages associated with the watershed approach of environmental management and also data sets of relevant environmental information that can be queried. It is designed for citizens and decision makers across the count...

Tide- and rainfall-induced variations of physical and chemical parameters in a mangrove-depleted estuary of East Hainan (South China Sea).

PubMed

Krumme, Uwe; Herbeck, Lucia S; Wang, Tianci

2012-12-01

The estuarine dynamics favoring the coexistence of mangroves, seagrass and corals at small river mouths are often poorly understood. We characterize the tidal, day/night and rainfall-induced short-term dynamics in salinity, pH, dissolved oxygen (DO), chlorophyll a (chl a), total suspended matter (TSM), water transparency, surface currents and dissolved nutrients (NO(x)(-), NH(4)(+), PO(4)(3)(-), Si(OH)(4)) of the Wenchang/Wenjiao Estuary (East Hainan, tropical China). Samples were taken at three fixed sites along the estuary during 24 h spring tide cycles in different seasons. Salinity, DO, water transparency and pH generally increased seawards while nutrients decreased. All parameters varied with the tidal cycle, partially in interaction with the diel cycle. Nutrients, chl a and TSM usually fluctuated inversely with water level. Stratification was strong. Inflowing bottom water was of higher salinity, DO and pH and lower temperature and nutrient concentrations than the surface water. Tidal mixing provided regular ventilation of the estuary and limited eutrophication effects of nutrients from aquaculture, agriculture and urban effluents. Under dry weather conditions, the brackish-water lagoon functioned as a sink of nutrients due to efficient uptake by phytoplankton. Presently, the runoff from common intense rains in the watershed affects the estuary with little time delay due to terrestrial deforestation, channelization and loss of mangrove area. The frequency, strength and duration of intermittent estuarization of the back-reef areas have likely increased in the past and deteriorate present seagrass and coral health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Watershed Central: A New Gateway to Watershed Information

EPA Science Inventory

Many communities across the country struggle to find the right approaches, tools and data to in their watershed plans. EPA recently posted a new Web site called "Watershed Central, a “onestop" tool, to help watershed organizations and others find key resources to protect their ...

Biogeochemistry of the Penobscot River watershed, Maine, USA: nutrient export patterns for carbon, nitrogen, and phosphorus.

PubMed

Cronan, Christopher S

2012-07-01

Watershed exports of carbon, nitrogen, phosphorus, major solutes, and suspended sediments were examined during five water years in the Penobscot River basin, which forms part of the Gulf of Maine watershed. Mean annual exports of dissolved organic carbon (DOC) in the Penobscot River were 58 kg C ha(-1) year(-1), whereas cumulative yearly watershed flux of DOC during the study period ranged from 8.6 to 16.1 × 10(10) g C year(-1) and averaged 11.7 × 10(10) g C year(-1). Watershed exports of total soluble N (TN) and total soluble P in the Penobscot River averaged 1.9 and 0.02 kg ha(-1) year(-1), respectively. Companion studies in two other major Maine rivers indicated that mean annual exports of DOC and TN in the Androscoggin River were 40 kg C ha(-1) year(-1) and 2.0 kg N ha(-1) year(-1), whereas exports in the Kennebec River were 43 kg C ha(-1) year(-1) and 2.2 kg N ha(-1) year(-1). Extrapolation of results from this investigation and a previous complementary study indicates that estuaries and coastal waters in the Gulf of Maine receive at least 1.0 × 10(10) g N year(-1) and 2.5 × 10(11) g C year(-1) in combined runoff from the four largest Maine river basins. Soluble exports of Ca + Mg + Na minus wet deposition inputs of cations in the Penobscot system were approximately 1,840 mol(c) ha(-1) year(-1), which represents a minimum estimate of cation denudation from the watershed. Based on its low N and P export rates, the Penobscot River watershed represents an example of reference conditions for use as a benchmark in ecological assessments of river water quality restoration or impairment. In addition, the biogeochemical metrics from this study provide an historical baseline for analysis of future trends in nutrient exports from the Penobscot watershed as a function of changing climatic and land use patterns.

Understanding Urban Watersheds through Digital Interactive Maps, San Francisco Bay Area, California

NASA Astrophysics Data System (ADS)

Sowers, J. M.; Ticci, M. G.; Mulvey, P.

2014-12-01

Dense urbanization has resulted in the "disappearance" of many local creeks in urbanized areas surrounding the San Francisco Bay. Long reaches of creeks now flow in underground pipes. Municipalities and water agencies trying to reduce non-point-source pollution are faced with a public that cannot see and therefore does not understand the interconnected nature of the drainage system or its ultimate discharge to the bay. Since 1993, we have collaborated with the Oakland Museum, the San Francisco Estuary Institute, public agencies, and municipalities to create creek and watershed maps to address the need for public understanding of watershed concepts. Fifteen paper maps are now published (www.museumca.org/creeks), which have become a standard reference for educators and anyone working on local creek-related issues. We now present digital interactive creek and watershed maps in Google Earth. Four maps are completed covering urbanized areas of Santa Clara and Alameda Counties. The maps provide a 3D visualization of the watersheds, with cartography draped over the landscape in transparent colors. Each mapped area includes both Present and Past (circa 1800s) layers which can be clicked on or off by the user. The Present layers include the modern drainage network, watershed boundaries, and reservoirs. The Past layers include the 1800s-era creek systems, tidal marshes, lagoons, and other habitats. All data are developed in ArcGIS software and converted to Google Earth format. To ensure the maps are interesting and engaging, clickable icons pop-up provide information on places to visit, restoration projects, history, plants, and animals. Maps of Santa Clara Valley are available at http://www.valleywater.org/WOW.aspx. Maps of western Alameda County will soon be available at http://acfloodcontrol.org/. Digital interactive maps provide several advantages over paper maps. They are seamless within each map area, and the user can zoom in or out, and tilt, and fly over to explore

Characterizing seston in the Penobscot River Estuary.

PubMed

Meseck, Shannon L; Li, Yaqin; Sunila, Inke; Dixon, Mark; Clark, Paul; Lipsky, Christine; Stevens, Justin R; Music, Paul; Wikfors, Gary H

2017-10-01

The Penobscot River Estuary is an important system for diadromous fish in the Northeast United States of American (USA), in part because it is home to the largest remnant population of Atlantic salmon, Salmo salar, in the country. Little is known about the chemical and biological characteristics of seston in the Penobscot River Estuary. This study used estuarine transects to characterize the seston during the spring when river discharge is high and diadromous fish migration peaks in the Penobscot River Estuary. To characterize the seston, samples were taken in spring 2015 for phytoplankton identification, total suspended matter (TSM), percent organic TSM, chlorophyll a, particle size (2 μm-180 μm), particulate carbon and nitrogen concentrations, and stable carbon and nitrogen isotopes. The estuarine profiles indicate that TSM behaved non-conservatively with a net gain in the estuary. As phytoplankton constituted only 1/1000 of the particles, the non-conservative behavior of TSM observed in the estuary was most likely not attributable to phytoplankton. Particulate carbon and nitrogen ratios and stable isotope signals indicate a strong terrestrial, allochthonous signal. The seston in the Penobscot River Estuary was dominated by non-detrital particles. During a short, two-week time period, Heterosigma akashiwo, a phytoplankton species toxic to finfish, also was detected in the estuary. A limited number of fish samples, taken after the 2015 Penobscot River Estuary bloom of H. akashiwo, indicated frequent pathological gill damage. The composition of seston, along with ichthyotoxic algae, suggest the need for further research into possible effects upon resident and migratory fish in the Penobscot River Estuary. Published by Elsevier Ltd.

Fish track wastewater pollution to estuaries.

PubMed

Schlacher, Thomas A; Liddell, Ben; Gaston, Troy F; Schlacher-Hoenlinger, Monika

2005-08-01

Excess nitrogen is a forceful agent of ecological change in coastal waters, and wastewater is a prominent source of nitrogen. In catchments where multiple sources of nitrogen pollution co-exist, biological indicators are needed to gauge the degree to which wastewater-N can propagate through the receiving food webs. The purpose of this study was to test whether estuarine fish are suitable as indicators of sewage-N pollution. Fish were analysed from three estuaries within a 100-km strip on the Australian East Coast. The estuaries differ substantially in wastewater loading: (1) the Maroochy Estuary receives a large fraction of the local shire's treated sewage, (2) the Mooloolah Estuary has no licensed treated wastewater outfalls but marinas/harbours and storm-water may contribute nitrogen, and (3) the Noosa Estuary which neither receives licensed discharges nor has suspected wastewater loads. Sampling for fish included both high rainfall ('wet' season) and low rainfall ('dry' season) periods. Muscle-delta15N was the variable predicted to respond to treated wastewater loading, reflecting the relative enrichment in 15N resulting from the treatment process and distinguishing it from alternative N sources such as fertiliser and natural nitrogen inputs (both 15N-depleted). Of the 19 fish species occurring in all three estuaries, those from the Maroochy Estuary had significantly elevated delta15N values (up to 9.9 per thousand), and inter-estuarine differences in fish-delta15N were consistent across seasons. Furthermore, not only did all fish from the estuary receiving treated wastewater carry a very distinctive sewage-N tissue signal, but enriched muscle-delta15N was also evident in all species sampled from the one estuary in which sewage contamination was previously only suspected (i.e. the Mooloolah Estuary: 0.2-4.8 per thousand enrichment over fish from reference system). Thus, fish-delta15N is a suitable indicator of wastewater-N not only in systems that receive large

Methylmercury bioaccumulation in an urban estuary: Delaware River USA.

PubMed

Buckman, Kate; Taylor, Vivien; Broadley, Hannah; Hocking, Daniel; Balcom, Prentiss; Mason, Rob; Nislow, Keith; Chen, Celia

2017-09-01

Spatial variation in mercury (Hg) and methylmercury (MeHg) bioaccumulation in urban coastal watersheds reflects complex interactions between Hg sources, land use, and environmental gradients. We examined MeHg concentrations in fauna from the Delaware River estuary, and related these measurements to environmental parameters and human impacts on the waterway. The sampling sites followed a north to south gradient of increasing salinity, decreasing urban influence, and increasing marsh cover. Although mean total Hg in surface sediments (top 4cm) peaked in the urban estuarine turbidity maximum and generally decreased downstream, surface sediment MeHg concentrations showed no spatial patterns consistent with the examined environmental gradients, indicating urban influence on Hg loading to the sediment but not subsequent methylation. Surface water particulate MeHg concentration showed a positive correlation with marsh cover whereas dissolved MeHg concentrations were slightly elevated in the estuarine turbidity maximum region. Spatial patterns of MeHg bioaccumulation in resident fauna varied across taxa. Small fish showed increased MeHg concentrations in the more urban/industrial sites upstream, with concentrations generally decreasing farther downstream. Invertebrates either showed no clear spatial patterns in MeHg concentrations (blue crabs, fiddler crabs) or increasing concentrations further downstream (grass shrimp). Best-supported linear mixed models relating tissue concentration to environmental variables reflected these complex patterns, with species specific model results dominated by random site effects with a combination of particulate MeHg and landscape variables influencing bioaccumulation in some species. The data strengthen accumulating evidence that bioaccumulation in estuaries can be decoupled from sediment MeHg concentration, and that drivers of MeHg production and fate may vary within a small region.

Arizona watershed framework in the Verde River watershed

Treesearch

Ren Northrup

2000-01-01

The Arizona Department of Environmental Quality, Water Quality Division drafted a six-step approach to guide its staff and local participants in developing and implementing watershed management plans. From January 1999 through June 2000, the draft Arizona Statewide Watershed Framework will be tested in Arizona's Verde River watershed. This concept proofing...

Evaluating cumulative effects of anthropogenic inputs in Prince Edward Island estuaries using the mummichog (Fundulus heteroclitus).

PubMed

Finley, Megan A; Courtenay, Simon C; Teather, Kevin L; Hewitt, L Mark; Holdway, D A; Hogan, Natacha S; van den Heuvel, Michael R

2013-07-01

Estuarine eutrophication as a result of agricultural land use, including the use of chemical fertilizers, is increasing worldwide. Prince Edward Island (PEI), Canada has very high agricultural intensity by international standards with approximately 44% of the land area under production, and some watersheds in excess of 75% agricultural land-use. The type of agriculture is also intensive with primarily row crops that have high chemical fertilizer and pesticide usage. In light of these stressors, the hypothesis of this study was that mummichog (Fundulus heteroclitus) population parameters would change with point and nonpoint source pollution, and that multivariate statistics could be used to draw associations with specific stressors. Fish were sampled on a monthly basis from May through August at 7 estuaries spanning a range of land use, nutrient, and contaminant loadings. A suite of environmental variables were simplified into 3 principal components: PC1 representing agricultural land use, N loading, and plant habitat, PC2 being dominated by sediment sand and silt distribution, and PC3 largely reflecting P loading and sediment organic matter. There were significant differences in abundance of both adult and young-of-the-year mummichog, and these changes associated most strongly with PC1, the largely N-driven agricultural influences. In contrast, somatic variables such as liver and gonad size did not show strong association with the environmental quality principal component scores. The sand and silt PC2 appeared to have the opposite association with the biological data, with siltier environments correlating to older, larger, less dense populations of mummichog. Although pesticide residues were detected in estuarine sediment, there was no clear relationship between these and watershed agricultural intensity or biochemical indicators. There was, however, a strong relationship between agricultural environmental variables (PC1) and in vitro steroid production that is

Winter nutrient behaviours in the Pearl River estuary

NASA Astrophysics Data System (ADS)

Wang, G.; Jin, S.; Du, M.

2017-12-01

Nutrient (nitrate, nitrite, ammonium, phosphate, and silicate) mapping and time-series investigation were carried out in winter in the Pearl River estuary, China. These nutrients behaved non-conservatively in the upper estuary. In the middle and lower estuary, however, nitrate and silicate seemed to be controled by physical mixing, while additions of nitrite, ammonium, and phosphate were found in the middle estuary. Nitrate was the dominant disslved inorganic nitrogen, with a fraction of more than 2/3. From the upper to the lower estuary the N:P ratio decreased from more than 200 to near the Redfield ratio of 16. Nutrients near the surface behaved almost the same as near the bottom in the water column at both the uppper and lower estuary. During a tidal cycle these nutrients seemed to be regulated more by physical mixing than by other processes.

About the Climate Ready Estuaries Program

EPA Pesticide Factsheets

The Climate Ready Estuaries program is a partnership between EPA and the National Estuary Programs to address climate change in coastal areas. It has helped coastal communities prepare for climate change since 2008.

Restore McComas Watershed; Meadow Creek Watershed, 2002-2003 Annual Report.

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

McRoberts, Heidi

2004-01-01

The Nez Perce Tribe Department of Fisheries Resource Management, Watershed Division approaches watershed restoration with a ridge-top to ridge-top approach. Watershed restoration projects within the Meadow Creek watershed are coordinated with the Nez Perce National Forest. The Nez Perce Tribe began watershed restoration projects within the Meadow Creek watershed of the South Fork Clearwater River in 1996. Progress has been made in restoring the watershed by excluding cattle from critical riparian areas through fencing. During years 2000-2003, trees were planted in riparian areas within the meadow and its tributaries. Culverts have been prioritized for replacement to accommodate fish passage throughoutmore » the watershed. Designs for replacement are being coordinated with the Nez Perce National Forest. Twenty miles of road were contracted for decommissioning. Tribal crews completed maintenance to the previously built fence.« less

Ambient and potential denitrification rates in marsh soils of Northeast Creek and Bass Harbor Marsh watersheds, Mount Desert Island, Maine

USGS Publications Warehouse

Huntington, Thomas G.; Culbertson, Charles W.; Duff, John H.

2012-01-01

Nutrient enrichment from atmospheric deposition, agricultural activities, wildlife, and domestic sources is a concern at Acadia National Park on Mount Desert Island, Maine, because of the potential problems of degradation of water quality and eutrophication in estuaries. Degradation of water quality has been observed at Bass Harbor Marsh estuary in the park but only minimally in Northeast Creek estuary. Previous studies at Acadia National Park have estimated nutrient inputs to estuaries from atmospheric deposition and surface-water runoff, and have identified shallow groundwater as an additional potential source of nutrients. Previous studies at Acadia National Park have assumed that a certain fraction of the nitrogen input was removed through microbial denitrification, but rates of denitrification (natural or maximum potential) in marsh soils have not been determined. The U.S. Geological Survey, in cooperation with Acadia National Park, measured in-place denitrification rates in marsh soils in Northeast Creek and in Bass Harbor Marsh watersheds during summer 2008 and summer 2009. Denitrification was measured under ambient conditions as well as after additions of inorganic nitrogen and glucose. In-place denitrification rates under ambient conditions were similar to those reported for other coastal wetlands, although they were generally lower than those reported for salt marshes having high ambient concentrations of nitrate (NO3). Denitrification rates generally increased by at least an order of magnitude following NO3 additions, with or without glucose (as the carbohydrate) additions, compared with the ambient treatments that received no nutrient additions. The treatment that added both glucose and NO3 resulted in a variety of denitrification responses when compared with the addition of NO3 alone. In most cases, the addition of glucose to a given rate of NO3 addition resulted in higher rates of denitrification. These variable responses indicate that the amount of

Watershed Central: Dynamic Collaboration for Improving Watershed Management (Philadelphia)

EPA Science Inventory

The Watershed Central web and wiki pages will be presented and demonstrated real-time as part of the overview of Web 2.0 collaboration tools for watershed management. The presentation portion will discuss how EPA worked with watershed practitioners and within the Agency to deter...

Water quality dynamics in an urbanizing subtropical estuary(Oso Bay, Texas).

PubMed

Wetz, Michael S; Hayes, Kenneth C; Fisher, Kelsey V B; Price, Lynn; Sterba-Boatwright, Blair

2016-03-15

Results are presented from a study of water quality dynamics in a shallow subtropical estuary, Oso Bay, Texas, which has a watershed that has undergone extensive urbanization in recent decades. High inorganic nutrient, dissolved organic matter and chlorophyll concentrations, as well as low pH (<8), were observed in a region of Oso Bay that receives wastewater effluent. Despite being shallow (<1 m) and subjected to strong winds on a regular basis, this region also exhibited episodic hypoxia/anoxia. The low oxygen and pH conditions are likely to impose significant stress on benthic organisms and nekton in the affected area. Signatures of eutrophied water were occasionally observed at the mouth of Oso Bay, suggesting that it may be exported to adjacent Corpus Christi Bay and contribute to seasonal hypoxia development in that system as well. These results argue for wastewater nutrient input reductions in order to alleviate the symptoms of eutrophication. Copyright © 2016 Elsevier Ltd. All rights reserved.

Establishing nursery estuary otolith geochemical tags for Sea Bass (Dicentrarchus labrax): Is temporal stability estuary dependent?

NASA Astrophysics Data System (ADS)

Ryan, Diarmuid; Wögerbauer, Ciara; Roche, William

2016-12-01

The ability to determine connectivity between juveniles in nursery estuaries and adult populations is an important tool for fisheries management. Otoliths of juvenile fish contain geochemical tags, which reflect the variation in estuarine elemental chemistry, and allow discrimination of their natal and/or nursery estuaries. These tags can be used to investigate connectivity patterns between juveniles and adults. However, inter-annual variability of geochemical tags may limit the accuracy of nursery origin determinations. Otolith elemental composition was used to assign a single cohort of 0-group sea bass Dicentrarchus labrax to their nursery estuary thus establishing an initial baseline for stocks in waters around Ireland. Using a standard LDFA model, high classification accuracies to nursery sites (80-88%) were obtained. Temporal stability of otolith geochemical tags was also investigated to assess if annual sampling is required for connectivity studies. Geochemical tag stability was found to be strongly estuary dependent.

Social-ecological network analysis of scale mismatches in estuary watershed restoration.

PubMed

Sayles, Jesse S; Baggio, Jacopo A

2017-03-07

Resource management boundaries seldom align with environmental systems, which can lead to social and ecological problems. Mapping and analyzing how resource management organizations in different areas collaborate can provide vital information to help overcome such misalignment. Few quantitative approaches exist, however, to analyze social collaborations alongside environmental patterns, especially among local and regional organizations (i.e., in multilevel governance settings). This paper develops and applies such an approach using social-ecological network analysis (SENA), which considers relationships among and between social and ecological units. The framework and methods are shown using an estuary restoration case from Puget Sound, United States. Collaboration patterns and quality are analyzed among local and regional organizations working in hydrologically connected areas. These patterns are correlated with restoration practitioners' assessments of the productivity of their collaborations to inform network theories for natural resource governance. The SENA is also combined with existing ecological data to jointly consider social and ecological restoration concerns. Results show potentially problematic areas in nearshore environments, where collaboration networks measured by density (percentage of possible network connections) and productivity are weakest. Many areas also have high centralization (a few nodes hold the network together), making network cohesion dependent on key organizations. Although centralization and productivity are inversely related, no clear relationship between density and productivity is observed. This research can help practitioners to identify where governance capacity needs strengthening and jointly consider social and ecological concerns. It advances SENA by developing a multilevel approach to assess social-ecological (or social-environmental) misalignments, also known as scale mismatches.

Social–ecological network analysis of scale mismatches in estuary watershed restoration

PubMed Central

Sayles, Jesse S.

2017-01-01

Resource management boundaries seldom align with environmental systems, which can lead to social and ecological problems. Mapping and analyzing how resource management organizations in different areas collaborate can provide vital information to help overcome such misalignment. Few quantitative approaches exist, however, to analyze social collaborations alongside environmental patterns, especially among local and regional organizations (i.e., in multilevel governance settings). This paper develops and applies such an approach using social–ecological network analysis (SENA), which considers relationships among and between social and ecological units. The framework and methods are shown using an estuary restoration case from Puget Sound, United States. Collaboration patterns and quality are analyzed among local and regional organizations working in hydrologically connected areas. These patterns are correlated with restoration practitioners’ assessments of the productivity of their collaborations to inform network theories for natural resource governance. The SENA is also combined with existing ecological data to jointly consider social and ecological restoration concerns. Results show potentially problematic areas in nearshore environments, where collaboration networks measured by density (percentage of possible network connections) and productivity are weakest. Many areas also have high centralization (a few nodes hold the network together), making network cohesion dependent on key organizations. Although centralization and productivity are inversely related, no clear relationship between density and productivity is observed. This research can help practitioners to identify where governance capacity needs strengthening and jointly consider social and ecological concerns. It advances SENA by developing a multilevel approach to assess social–ecological (or social–environmental) misalignments, also known as scale mismatches. PMID:28223529

Conditions for tidal bore formation in convergent alluvial estuaries

NASA Astrophysics Data System (ADS)

Bonneton, Philippe; Filippini, Andrea Gilberto; Arpaia, Luca; Bonneton, Natalie; Ricchiuto, Mario

2016-04-01

Over the last decade there has been an increasing interest in tidal bore dynamics. However most studies have been focused on small-scale bore processes. The present paper describes the first quantitative study, at the estuary scale, of the conditions for tidal bore formation in convergent alluvial estuaries. When freshwater discharge and large-scale spatial variations of the estuary water depth can be neglected, tide propagation in such estuaries is controlled by three main dimensionless parameters: the nonlinearity parameter ε0 , the convergence ratio δ0 and the friction parameter ϕ0. In this paper we explore this dimensionless parameter space, in terms of tidal bore occurrence, from a database of 21 estuaries (8 tidal-bore estuaries and 13 non tidal-bore estuaries). The field data point out that tidal bores occur for convergence ratios close to the critical convergence δc. A new proposed definition of the friction parameter highlights a clear separation on the parameter plane (ϕ0,ε0) between tidal-bore estuaries and non tidal-bore estuaries. More specifically, we have established that tidal bores occur in convergent estuaries when the nonlinearity parameter is greater than a critical value, εc , which is an increasing function of the friction parameter ϕ0. This result has been confirmed by numerical simulations of the two-dimensional Saint Venant equations. The real-estuary observations and the numerical simulations also show that, contrary to what is generally assumed, tide amplification is not a necessary condition for tidal bore formation. The effect of freshwater discharge on tidal bore occurrence has been analyzed from the database acquired during three long-term campaigns carried out on the Gironde/Garonne estuary. We have shown that in the upper estuary the tidal bore intensity is mainly governed by the local dimensionless tide amplitude ε. The bore intensity is an increasing function of ε and this relationship does not depend on freshwater

High-resolution remote sensing of water quality in the San Francisco Bay-Delta Estuary

USGS Publications Warehouse

Fichot, Cédric G.; Downing, Bryan D.; Bergamaschi, Brian; Windham-Myers, Lisamarie; Marvin-DiPasquale, Mark C.; Thompson, David R.; Gierach, Michelle M.

2015-01-01

The San Francisco Bay–Delta Estuary watershed is a major source of freshwater for California and a profoundly human-impacted environment. The water quality monitoring that is critical to the management of this important water resource and ecosystem relies primarily on a system of fixed water-quality monitoring stations, but the limited spatial coverage often hinders understanding. Here, we show how the latest technology in visible/near-infrared imaging spectroscopy can facilitate water quality monitoring in this highly dynamic and heterogeneous system by enabling simultaneous depictions of several water quality indicators at very high spatial resolution. The airborne portable remote imaging spectrometer (PRISM) was used to derive high-spatial-resolution (2.6 × 2.6 m) distributions of turbidity, and dissolved organic carbon (DOC) and chlorophyll-a concentrations in a wetland-influenced region of this estuary. A filter-passing methylmercury vs DOC relationship was also developed using in situ samples and enabled the high-spatial-resolution depiction of surface methylmercury concentrations in this area. The results illustrate how high-resolution imaging spectroscopy can inform management and policy development in important inland and estuarine water bodies by facilitating the detection of point- and nonpoint-source pollution, and by providing data to help assess the complex impacts of wetland restoration and climate change on water quality and ecosystem productivity.

Watershed analysis of the Salmon River watershed, Washington : hydrology

USGS Publications Warehouse

Bidlake, William R.

2003-01-01

The U.S. Geological Survey analyzed selected hydrologic conditions as part of a watershed analysis of the Salmon River watershed, Washington, conducted by the Quinault Indian Nation. The selected hydrologic conditions were analyzed according to a framework of hydrologic key questions that were identified for the watershed. The key questions were posed to better understand the natural, physical, and biological features of the watershed that control hydrologic responses; to better understand current streamflow characteristics, including peak and low flows; to describe any evidence that forest harvesting and road construction have altered frequency and magnitude of peak and low flows within the watershed; to describe what is currently known about the distribution and extent of wetlands and any impacts of land management activities on wetlands; and to describe how hydrologic monitoring within the watershed might help to detect future hydrologic change, to preserve critical ecosystem functions, and to protect public and private property.

EXHIBIT OF EMPACT ESTUARY MONITORING HANDBOOKS

EPA Science Inventory

Related EMPACT documents were displayed at the National Estuary Day Celebration held in Washington, DC, September 30-Octuber 4, 2002. The estuary monitoring technology transfer handbooks displayed were prepared based on information and monitoring technologies developed from selec...

Using Remotely Sensed Data and Watershed and Hydrodynamic Models to Evaluate the Effects of Land Cover Land Use Change on Aquatic Ecosystems in Mobile Bay, AL

NASA Technical Reports Server (NTRS)

Al-Hamdan, Mohammad; Estes, Maurice G., Jr.; Judd, Chaeli; Woodruff, Dana; Ellis, Jean; Quattrochi, Dale; Watson, Brian; Rodriquez, Hugo; Johnson, Hoyt

2012-01-01

Alabama coastal systems have been subjected to increasing pressure from a variety of activities including urban and rural development, shoreline modifications, industrial activities, and dredging of shipping and navigation channels. The impacts on coastal ecosystems are often observed through the use of indicator species. One such indicator species for aquatic ecosystem health is submerged aquatic vegetation (SAV). Watershed and hydrodynamic modeling has been performed to evaluate the impact of land cover land use (LCLU) change in the two counties surrounding Mobile Bay (Mobile and Baldwin) on SAV stressors and controlling factors (temperature, salinity, and sediment) in the Mobile Bay estuary. Watershed modeling using the Loading Simulation Package in C++ (LSPC) was performed for all watersheds contiguous to Mobile Bay for LCLU scenarios in 1948, 1992, 2001, and 2030. Remotely sensed Landsat-derived National Land Cover Data (NLCD) were used in the 1992 and 2001 simulations after having been reclassified to a common classification scheme. The Prescott Spatial Growth Model was used to project the 2030 LCLU scenario based on current trends. The LSPC model simulations provided output on changes in flow, temperature, and sediment for 22 discharge points into the estuary. These results were inputted in the Environmental Fluid Dynamics Computer Code (EFDC) hydrodynamic model to generate data on changes in temperature, salinity, and sediment on a grid throughout Mobile Bay and adjacent estuaries. The changes in the aquatic ecosystem were used to perform an ecological analysis to evaluate the impact on SAV habitat suitability. This is the key product benefiting the Mobile Bay coastal environmental managers that integrates the influences of temperature, salinity, and sediment due to LCLU driven flow changes with the restoration potential of SAVs. Data products and results are being integrated into NOAA s EcoWatch and Gulf of Mexico Data Atlas online systems for

Application of WATERSHED ECOLOGICAL RISK ASSESSMENT Methods to Watershed Management

EPA Science Inventory

Watersheds are frequently used to study and manage environmental resources because hydrologic boundaries define the flow of contaminants and other stressors. Ecological assessments of watersheds are complex because watersheds typically overlap multiple jurisdictional boundaries,...

Application of Watershed Ecological Risk Assessment Methods to Watershed Management

EPA Science Inventory

Watersheds are frequently used to study and manage environmental resources because hydrologic boundaries define the flow of contaminants and other stressors. Ecological assessments of watersheds are complex because watersheds typically overlap multiple jurisdictional boundaries,...

Catchment land use predicts benthic vegetation in small estuaries

PubMed Central

Warry, Fiona Y.; Reich, Paul; Mac Nally, Ralph; Woodland, Ryan J.

2018-01-01

Many estuaries are becoming increasingly eutrophic from human activities within their catchments. Nutrient loads often are used to assess risk of eutrophication to estuaries, but such data are expensive and time consuming to obtain. We compared the percent of fertilized land within a catchment, dissolved inorganic nitrogen loads, catchment to estuary area ratio and flushing time as predictors of the proportion of macroalgae to total vegetation within 14 estuaries in south-eastern Australia. The percent of fertilized land within the catchment was the best predictor of the proportion of macroalgae within the estuaries studied. There was a transition to a dominance of macroalgae once the proportion of fertilized land in the catchment exceeded 24%, highlighting the sensitivity of estuaries to catchment land use. PMID:29473004

Bar dimensions and bar shapes in estuaries

NASA Astrophysics Data System (ADS)

Leuven, Jasper; Kleinhans, Maarten; Weisscher, Steven; van der Vegt, Maarten

2016-04-01

Estuaries cause fascinating patterns of dynamic channels and shoals. Intertidal sandbars are valuable habitats, whilst channels provide access to harbors. We still lack a full explanation and classification scheme for the shapes and dimensions of bar patterns in natural estuaries, in contrast with bars in rivers. Analytical physics-based models suggest that bar length in estuaries increases with flow velocity, tidal excursion length or estuary width, depending on which model. However, these hypotheses were never validated for lack of data and experiments. We present a large dataset and determine the controls on bar shape and dimensions in estuaries, spanning bar lengths from centimeters (experiments) to 10s of kilometers length. First, we visually identified and classified 190 bars, measured their dimensions (width, length, height) and local braiding index. Data on estuarine geometry and tidal characteristics were obtained from governmental databases and literature on case studies. We found that many complex bars can be seen as simple elongated bars partly cut by mutually evasive ebb- and flood-dominated channels. Data analysis shows that bar dimensions scale with estuary dimensions, in particular estuary width. Breaking up the complex bars in simple bars greatly reduced scatter. Analytical bar theory overpredicts bar dimensions by an order of magnitude in case of small estuarine systems. Likewise, braiding index depends on local width-to-depth ratio, as was previously found for river systems. Our results suggest that estuary dimensions determine the order of magnitude of bar dimensions, while tidal characteristics modify this. We will continue to model bars numerically and experimentally. Our dataset on tidal bars enables future studies on the sedimentary architecture of geologically complex tidal deposits and enables studying effects of man-induced perturbations such as dredging and dumping on bar and channel patterns and habitats.

Watershed Seasons

ERIC Educational Resources Information Center

Endreny, Anna

2007-01-01

All schools are located in "watersheds," land that drains into bodies of water. Some watersheds, like the one which encompasses the school discussed in this article, include bodies of water that are walking distance from the school. The watershed cited in this article has a brook and wetland within a several-block walk from the school. This…

AFS Estuaries Section - A Successful Partnership

EPA Science Inventory

The Estuaries Section of the American Fisheries Society offers travel awards to students in support of their attendance and presentations at the AFS meeting. Since 2007, the Southern Association of Marine Laboratories has partnered with the Estuaries Section to sponsor two stude...

Evolution of mid-Atlantic coastal and back-barrier estuary environments in response to a hurricane: Implications for barrier-estuary connectivity

USGS Publications Warehouse

Miselis, Jennifer L.; Andrews, Brian D.; Nicholson, Robert S.; Defne, Zafer; Ganju, Neil K.; Navoy, Anthony S.

2016-01-01

Assessments of coupled barrier island-estuary storm response are rare. Hurricane Sandy made landfall during an investigation in Barnegat Bay-Little Egg Harbor estuary that included water quality monitoring, geomorphologic characterization, and numerical modeling; this provided an opportunity to characterize the storm response of the barrier island-estuary system. Barrier island morphologic response was characterized by significant changes in shoreline position, dune elevation, and beach volume; morphologic changes within the estuary were less dramatic with a net gain of only 200,000 m3 of sediment. When observed, estuarine deposition was adjacent to the back-barrier shoreline or collocated with maximum estuary depths. Estuarine sedimentologic changes correlated well with bed shear stresses derived from numerically simulated storm conditions, suggesting that change is linked to winnowing from elevated storm-related wave-current interactions rather than deposition. Rapid storm-related changes in estuarine water level, turbidity, and salinity were coincident with minima in island and estuarine widths, which may have influenced the location of two barrier island breaches. Barrier-estuary connectivity, or the transport of sediment from barrier island to estuary, was influenced by barrier island land use and width. Coupled assessments like this one provide critical information about storm-related coastal and estuarine sediment transport that may not be evident from investigations that consider only one component of the coastal system.

Geographic signatures of North American West Coast estuaries

USGS Publications Warehouse

Emmett, Robert; Llansó, Roberto; Newton, Jan; Thom, Ron; Hornberger, Michelle; Morgan, Cheryl; Levings, Colin; Copping, Andrea; Fishman, Paul

2000-01-01

West Coast estuaries are geologically young and composed of a variety of geomorphological types. These estuaries range from large fjords to shallow lagoons; from large to low freshwater flows. Natural hazards include E1 Niños, strong Pacific storms, and active tectonic activity. West Coast estuaries support a wide range of living resources: five salmon species, harvestable shellfish, waterfowl and marine birds, marine mammals, and a variety of algae and plants. Although populations of many of these living resources have declined (salmonids), others have increased (marine mammals). West Coast estuaries are also centers of commerce and increasingly large shipping traffic. The West Coast human population is rising faster than most other areas of the U.S. and Canada, and is distributed heavily in southern California, the San Francisco Bay area, around Puget Sound, and the Fraser River estuary. While water pollution is a problem in many of the urbanized estuaries, most estuaries do not suffer from poor water quality. Primary estuarine problems include habitat alterations, degradation, and loss; diverted freshwater flows; marine sediment contamination; and exotic species introductions. The growing West Coast economy and population are in part related to the quality of life, which is dependent on the use and enjoyment of abundant coastal natural resources.

The Estuary Guide. Level 3: High School. Draft.

ERIC Educational Resources Information Center

Alexander, Glen; And Others

Estuaries are marine systems that serve as nurseries for animals, links in the migratory pathways, and habitat for a complex community of organisms. This curriculum guide intended for use at the high school level seeks to teach what estuaries are; provide opportunities to practice decision-making that affects estuaries; and encourage students to…

Meaningful Watershed Experiences for Middle and High School Students

NASA Astrophysics Data System (ADS)

Landry, Melinda; Smith, Cynthia; Greene, Joy

2014-05-01

Prince William County Public Schools and George Mason University in Virginia, USA, partnered to provide Meaningful Watershed Educational Experiences (MWEEs) for over 25,000 middle and high school students (11-18 year olds) across 34 schools. This school district, situated in a rapidly growing region 55 km southwest of Washington DC, has over 82,000 K-12 students. As native forest cover has been replaced with farming and urbanization, water quality has significantly degraded in the 166,534 km2 Chesapeake Bay watershed. This project was designed to increase student awareness of their impact on the land and waters of the largest estuary in the United States. MWEE is a long-term comprehensive project that incorporates a classroom preparation phase, a hands-on outdoor field investigation, and a reflection and data-sharing component. Training and technical assistance enhances the capacity of teachers of 6th grade, high school Earth Science and Environmental Science to deliver MWEEs which includes schoolyard stewardship, inquiry driven field study, use of hand-held technology and computer based mapping and analysis, project sharing and outreach. George Mason University researchers worked closely with K-12 science educators to create a comprehensive watershed-focused curriculum. Graduate and undergraduate students with strong interests in environmental science and education were trained to deliver the field investigation component of the MWEE. Representative teachers from each school were provided 3 days of professional development and were responsible for the training of their school's science education team. A comprehensive curriculum provided teachers with activities and tools designed to enhance students' mastery of state science objectives. Watershed concepts were used as the unifying theme to support student understanding of curriculum and STEM objectives including: scientific investigation, data collection and communication, chemistry, energy, erosion, human

SENSITIVITY OF NITROGEN CONCENTRATIONS IN ESTUARIES TO LOADING AND WATER RESIDENCE TIME: APPLICATION TO THE POTOMAC ESTUARY

EPA Science Inventory

We use a simple nitrogen budget model to analyze concentrations of total nitrogen (TN) in estuaries for which both nitrogen inputs and water residence time are correlated with freshwater inflow rates. While the nitrogen concentration of an estuary varies linearly with TN loading ...

AN APPROACH TO DEVELOPING NUTRIENT CRITERIA FOR PACIFIC NORTHWEST ESTUARIES: A CASE STUDY OF YAQUINA ESTUARY, OREGON

EPA Science Inventory

NHEERL scientists have developed an approach that could be used by the State of Oregon for development of nutrient and other water quality criteria for the Yaquina Estuary, Oregon. The principle objective in setting protective criteria is to prevent future degradation of estuari...

PECONIC ESTUARY: AN INVENTORY OF SUBMERGED AQUATIC VEGETATION AND HARDENED SHORELINES FOR THE PECONIC ESTUARY, NEW YORK

EPA Science Inventory

Executive Summary The Peconic Estuary Program (PEP) is interested in the extent of eelgrass and other submerged aquatic vegetation and in documenting changes in the shorelines of the Peconic Estuary. The Suffolk County Department of Health Services' Office of Ecology provided fun...

Environmental flow assessments for transformed estuaries

NASA Astrophysics Data System (ADS)

Sun, Tao; Zhang, Heyue; Yang, Zhifeng; Yang, Wei

2015-01-01

Here, we propose an approach to environmental flow assessment that considers spatial pattern variations in potential habitats affected by river discharges and tidal currents in estuaries. The approach comprises four steps: identifying and simulating the distributions of critical environmental factors for habitats of typical species in an estuary; mapping of suitable habitats based on spatial distributions of the Habitat Suitability Index (HSI) and adopting the habitat aggregation index to understand fragmentation of potential suitable habitats; defining variations in water requirements for a certain species using trade-off analysis for different protection objectives; and recommending environmental flows in the estuary considering the compatibility and conflict of freshwater requirements for different species. This approach was tested using a case study in the Yellow River Estuary. Recommended environmental flows were determined by incorporating the requirements of four types of species into the assessments. Greater variability in freshwater inflows could be incorporated into the recommended environmental flows considering the adaptation of potential suitable habitats with variations in the flow regime. Environmental flow allocations should be conducted in conjunction with land use conflict management in estuaries. Based on the results presented here, the proposed approach offers flexible assessment of environmental flow for aquatic ecosystems that may be subject to future change.

Impact of urban effluents on summer hypoxia in the highly turbid Gironde Estuary, applying a 3D model coupling hydrodynamics, sediment transport and biogeochemical processes

NASA Astrophysics Data System (ADS)

Lajaunie-Salla, Katixa; Wild-Allen, Karen; Sottolichio, Aldo; Thouvenin, Bénédicte; Litrico, Xavier; Abril, Gwenaël

2017-10-01

Estuaries are increasingly degraded due to coastal urban development and are prone to hypoxia problems. The macro-tidal Gironde Estuary is characterized by a highly concentrated turbidity maximum zone (TMZ). Field observations show that hypoxia occurs in summer in the TMZ at low river flow and a few days after the spring tide peak. In situ data highlight lower dissolved oxygen (DO) concentrations around the city of Bordeaux, located in the upper estuary. Interactions between multiple factors limit the understanding of the processes controlling the dynamics of hypoxia. A 3D biogeochemical model was developed, coupled with hydrodynamics and a sediment transport model, to assess the contribution of the TMZ and the impact of urban effluents through wastewater treatment plants (WWTPs) and sewage overflows (SOs) on hypoxia. Our model describes the transport of solutes and suspended material and the biogeochemical mechanisms impacting oxygen: primary production, degradation of all organic matter (i.e. including phytoplankton respiration, degradation of river and urban watershed matter), nitrification and gas exchange. The composition and the degradation rates of each variable were characterized by in situ measurements and experimental data from the study area. The DO model was validated against observations in Bordeaux City. The simulated DO concentrations show good agreement with field observations and satisfactorily reproduce the seasonal and neap-spring time scale variations around the city of Bordeaux. Simulations show a spatial and temporal correlation between the formation of summer hypoxia and the location of the TMZ, with minimum DO centered in the vicinity of Bordeaux. To understand the contribution of the urban watershed forcing, different simulations with the presence or absence of urban effluents were compared. Our results show that in summer, a reduction of POC from SO would increase the DO minimum in the vicinity of Bordeaux by 3% of saturation. Omitting

Modeling ecosystem processes with variable freshwater inflow to the Caloosahatchee River Estuary, southwest Florida. I. Model development

NASA Astrophysics Data System (ADS)

Buzzelli, Christopher; Doering, Peter H.; Wan, Yongshan; Sun, Detong; Fugate, David

2014-12-01

Variations in freshwater inflow have ecological consequences for estuaries ranging among eutrophication, flushing and transport, and high and low salinity impacts on biota. Predicting the potential effects of the magnitude and composition of inflow on estuaries over a range of spatial and temporal scales requires reliable mathematical models. The goal of this study was to develop and test a model of ecosystem processes with variable freshwater inflow to the sub-tropical Caloosahatchee River Estuary (CRE) in southwest Florida from 2002 to 2009. The modeling framework combined empirically derived inputs of freshwater and materials from the watershed, daily predictions of salinity, a box model for physical transport, and simulation models of biogeochemical and seagrass dynamics. The CRE was split into 3 segments to estimate advective and dispersive transport of water column constituents. Each segment contained a sub-model to simulate changes in the concentrations of organic nitrogen and phosphorus (ON and OP), ammonium (NH4+), nitrate-nitrite (NOx-), ortho-phosphate (PO4-3), phytoplankton chlorophyll a (CHL), and sediment microalgae (SM). The seaward segment also had sub-models for seagrasses (Halodule wrightii and Thalassia testudinum). The model provided realistic predictions of ON in the upper estuary during wet conditions since organic nitrogen is associated with freshwater inflow and low salinity. Although simulated CHL concentrations were variable, the model proved to be a reliable predictor in time and space. While predicted NOx- concentrations were proportional to freshwater inflow, NH4+ was less predictable due to the complexity of internal cycling during times of reduced freshwater inflow. Overall, the model provided a representation of seagrass biomass changes despite the absence of epiphytes, nutrient effects, or sophisticated translocation in the formulation. The model is being used to investigate the relative importance of colored dissolved organic

Hydro-morphological modelling of small, wave-dominated estuaries

NASA Astrophysics Data System (ADS)

Slinger, Jill H.

2017-11-01

Small, intermittently open or closed estuaries are characteristic of the coasts of South Africa, Australia, California, Mexico and many other areas of the world. However, modelling attention has tended to focus on big estuaries that drain large catchments and serve a wide diversity of interests e.g. agriculture, urban settlement, recreation, commercial fishing. In this study, the development of a simple, parametric, system dynamics model to simulate the opening and closure of the mouths of small, wave-dominated estuaries is reported. In the model, the estuary is conceived as a basin with a specific water volume to water level relationship, connected to the sea by a channel of fixed width, but variable sill height. Changes in the form of the basin are not treated in the model, while the dynamics of the mouth channel are central to the model. The magnitude and direction of the flow through the mouth determines whether erosion or deposition of sediment occurs in the mouth channel, influencing the sill height. The model is implemented on the Great Brak Estuary in South Africa and simulations reveal that the raised low water levels in the estuary during spring tide relative to neap tide, are occasioned by the constriction of the tidal flow through the shallow mouth. Freshwater inflows to the estuary are shown to be significant in determining the behaviour of the inlet mouth, a factor often ignored in studies on tidal inlets. Further it is the balance between freshwater inflows and wave events that determines the opening or closure of the mouth of a particular estuary.

The Estuary Book: A Guide to Promoting Understanding and Regional Management of Maine's Estuaries and Embayments.

ERIC Educational Resources Information Center

Ruffing, Jenny

The objective of this document is to provide information about estuaries, the impact of uses on the environmental health of an estuary, and what communities and concerned individuals can do to manage and protect their local estuarine resources successfully. Much of the information presented here pertains to other embayments along the Maine coast…

Microplastic in three urban estuaries, China.

PubMed

Zhao, Shiye; Zhu, Lixin; Li, Daoji

2015-11-01

Estuarine Microplastics (MPs) are limited to know globally. By filtering subsurface water through 330 μm nets, MPs in Jiaojiang, Oujiang Estuaries were quantified, as well as that in Minjiang Estuary responding to Typhoon Soulik. Polymer matrix was analyzed by Raman spectroscopy. MP (<5 mm) comprised more than 90% of total number plastics. The highest MPs density was found in Minjiang, following Jiaojiang and Oujiang. Fibers and granules were the primary shapes, with no pellets found. Colored MPs were the majority. The concentrations of suspended microplastics determine their bioavailability to low trophic organisms, and then possibly promoting the transfer of microplastic to higher trophic levels. Polypropylene and polyethylene were the prevalent types of MPs analyzed. Economic structures in urban estuaries influenced on MPs contamination levels. Typhoon didn't influence the suspended MP densities significantly. Our results provide basic information for better understanding suspended microplastics within urban estuaries and for managerial actions. Copyright © 2015. Published by Elsevier Ltd.

MAPPING BATHYMETRY AND BOTTOM TYPE IN A SHALLOW ESTUARY

EPA Science Inventory

Bathymetry and bottom type are important in characterizing estuaries and their ecology but hard to map, especially in shallow estuaries. Acoustic backscattering was used to remotely sense these properties in the shallow Slocums River Estuary of Massachusetts. Acoustic pulses were...

Suspended-Sediment Export From Four Small Montane Humid-Tropical Watersheds With Varying Land use and Lithology, Puerto Rico

NASA Astrophysics Data System (ADS)

Larsen, M. C.

2003-12-01

Intensive land-use conversion of forested landscapes to agricultural use accelerated in most of the global tropics during the 20th century and has resulted in large increases in soil erosion and suspended-sediment export. Fluvial sediment is one of the most abundant freshwater contaminants on earth. Stormflows episodically transport sediment to reservoirs, estuaries and in coastal waters where coral reefs are located. The sediment and associated contaminants such as pesticides, herbicides, and fertilizers, degrade water quality and are harmful to aquatic organisms in these areas. Improved understanding of the processes and rates of fluvial sediment transport in natural and anthropogenically disturbed settings enhances management of natural resources and aids in the establishment of standards for acceptable sediment concentrations. Four USGS WEBB (Water, Energy, and Biogeochemical Budgets) study watersheds in Puerto Rico (18° latitude) were paired to compare and contrast the effects of land use and bedrock geology on suspended-sediment yield. Sediment concentration, calculated as sediment yield normalized to runoff, was more than three times greater in two watersheds in secondary forest and pasture compared to sediment concentration in watersheds in primary forest. The influence of lithology was comparable: sediment concentration in intrusive-bedrock (quartz diorite and granodiorite) watersheds was more than three times higher than sediment concentration in volcaniclastic-bedrock (volcanic sandstone, mudstone, and breccia) watersheds. These contrasts highlight the well-known effect of land use on sediment concentration and yield but also demonstrate the strong control of bedrock geology. Most importantly, the high sediment yields in the watersheds that were converted to pasture and secondary forest, even after 60 years of forest reestablishment, provide a glimpse into the future of tropical watersheds elsewhere that are now undergoing deforestation. Erosion rates

A Climate Ready Estuaries Vulnerability Assessment

EPA Science Inventory

The purpose of the the Climate Ready Estuaries program is to build capacity in the National Estuary Programs (NEPs) for local leadership and expertise to adapt to the effects of climate change through a joint effort with the NEPs and EPA.

Background

Sedimentary fabrics of the macrotidal, mud-dominated, inner estuary to fluvio-tidal transition zone, Petitcodiac River estuary, New Brunswick, Canada

NASA Astrophysics Data System (ADS)

Shchepetkina, Alina; Gingras, Murray K.; Zonneveld, John-Paul; Pemberton, S. George

2016-03-01

The study provides a detailed description of mud-dominated sedimentary fabrics and their application for the rock record within the inner estuary to the fluvial zone of the Petitcodiac River estuary, New Brunswick, Canada. Sedimentological characteristics and facies distributions of the clay- and silt-rich deposits are reported. The inner estuary is characterized by thick accumulations of interbedded silt and silty clay on intertidal banks that flank the tidally influenced channel. The most common sedimentary structures observed are parallel and wavy lamination, small-scale soft-sediment deformation with microfaults, and clay and silt current ripples. The tidal channel contains sandy silt and clayey silt with planar lamination, massive and convolute bedding. The fluvio-tidal transition zone is represented by interbedded trough cross-stratified sand and gravel beds with planar laminated to massive silty mud. The riverine, non-tidal reach of the estuary is characterized by massive, planar tabular and trough cross-stratified gravel-bed deposits. The absence of bioturbation within the inner estuary to the fluvio-tidal transition zone can be explained by the following factors: low water salinities (0-5 ppt), amplified tide and current speeds, and high concentrations of flocculated material in the water body. Notably, downstream in the middle and outer estuary, bioturbation is seasonally pervasive: in those locales the sedimentary conditions are similar, but salinity is higher. In this study, the sedimentological (i.e., grain size, bedding characters, sedimentary structures) differences between the tidal estuary and the fluvial setting are substantial, and those changes occur over only a few hundred meters. This suggests that the widely used concept of an extensive fluvio-tidal transition zone and its depositional character may not be a geographically significant component of fluvial or estuary deposits, which can go unnoticed in the study of the ancient rocks.

Modeling and sediment study in the watershed Medjerda, Tunisia

NASA Astrophysics Data System (ADS)

Kotti, Fatma; Mahé, Gil; Habaieb, Hamadi; Dieulin, Claudine; Hermassi, Taoufik

2015-04-01

series than should be about one century. The cores' analysis results show a succession of sedimentary layers that likely correspond to different flood deposits that succeeded on this site, and especially the datation of the cores shows that the selected area is a very important deposition area. This sedimentary study will help estimate the sediment dynamics to major estuaries, which is poorly known for most of the rivers of Maghreb. The reduction of the sediment supply to the sea is tipped as a major factor to be taken into account for a better understanding of the dynamics of coastal areas in the context of global climate change and sea level rise. Keywords: sediment core, Medjerda watershed, dam, hydrology, modeling, Tunisia

The Suwannee River Hydrologic Observatory: A Subtropical Coastal Plain Watershed in Transition

NASA Astrophysics Data System (ADS)

Graham, W. D.

2004-12-01

. In addition, population growth is fueling increased groundwater withdrawals from the Floridan aquifer for local consumption affecting water supply. Inter-basin transfers from the lower Suwannee River to south Florida have been suggested as one solution to south Florida's growing water crisis. Three Distinct Hydrologic Regimes - The Suwannee River watershed comprises three distinct but linked hydrologic landscape units. The upper Suwannee River interacts with the surficial aquifer but is largely separated from the Floridan aquifer by a confining unit. The middle Suwannee River interacts with both surficial aquifers and the unconfined karstic Floridan aquifer. The lower Suwannee River discharges to a deltaic estuary as surface water along with diffuse submarine groundwater discharge. Extensive Existing Data Infrastructure - Some discharge data exists from the turn of the 19th century to the present. More recently, the USDA Agricultural Research Service through the Southeast Watershed Research Laboratory (SEWRL) has monitored the Little River watershed in Georgia at the headwaters of the Suwannee River since 1965, and the Suwannee River Water Management District (SRWMD) has monitored the Suwannee River watershed in Florida since 1972. Other groups (USGS, Suwannee River Partnership, and individual university investigators) have long worked on specific, local geological, hydrological, and biological problems within the watershed. Contributing Organizations: University of Florida, Florida State University, University of South Florida, University of Central Florida, University of Georgia, USGS, USDA, and SRWMD

SAN FRANCISCO ESTUARY PROJECT COMPREHENSIVE CONSERVATION AND MANAGEMENT PLAN

EPA Science Inventory

The Estuary, a significant natural resource, San Francisco Bay and the Delta combine to form the West Coast's largest estuary. The Estuary conveys the waters of the Sacramento and San Joaquin Rivers to the Pacific Ocean. It encompasses roughly 1,600 square miles, drains over 40 p...

DELAWARE ESTUARY A MANAGEMENT PLAN FOR THE DELAWARE ESTUARY

EPA Science Inventory

Wise conservation and management of the Delaware Estuary is arguably the most important cooperative environmental initiative ever jointly undertaken by the States of New Jersey, Pennsylvania, and Delaware. While much has been accomplished over the past few decades to improve wate...

Silicon dynamics in the Oder estuary, Baltic Sea

NASA Astrophysics Data System (ADS)

Pastuszak, Marianna; Conley, Daniel J.; Humborg, Christoph; Witek, Zbigniew; Sitek, Stanisław

2008-10-01

Studies on dissolved silicate (DSi) and biogenic silica (BSi) dynamics were carried out in the Oder estuary, Baltic Sea in 2000-2005. The Oder estuary proved to be an important component of the Oder River-Baltic Sea continuum where very intensive seasonal DSi uptake during spring and autumn, but also BSi regeneration during summer take place. Owing to the regeneration process annual DSi patterns in the river and the estuary distinctly differed; the annual patterns of DSi in the estuary showed two maxima and two minima in contrast to one maximum- and one minimum-pattern in the Oder River. DSi concentrations in the river and in the estuary were highest in winter (200-250 μmol dm - 3 ) and lowest (often less than 1 μmol dm - 3 ) in spring, concomitant with diatom growth; such low values are known to be limiting for new diatom growth. Secondary DSi summer peaks at the estuary exit exceeded 100 μmol dm - 3 , and these maxima were followed by autumn minima coinciding with the autumn diatom bloom. Seasonal peaks in BSi concentrations (ca. 100 μmol dm - 3 ) occurred during the spring diatom bloom in the Oder River. Mass balance calculations of DSi and BSi showed that DSi + BSi import to the estuary over a two year period was 103.2 kt and that can be compared with the DSi export of 98.5 kt. The difference between these numbers gives room for ca. 2.5 kt BSi to be annually exported to the Baltic Sea. Sediment cores studies point to BSi annual accumulation on the level of 2.5 kt BSi. BSi import to the estuary is on the level of ca. 10.5 kt, thus ca. 5 kt of BSi is annually converted into the DSi, increasing the pool of DSi that leaves the system. BSi concentrations being ca. 2 times higher at the estuary entrance than at its exit remain in a good agreement with the DSi and BSi budgeting presented in the paper.

Local Estuary Programs

EPA Pesticide Factsheets

This page provides information about Local Individual Estuary Programs including links to their NEP homepages, social media, Comprehensive Conservation and Management Plans, and state of the bay reports.

Milwaukee Estuary AOC

EPA Pesticide Factsheets

The rivers in the Milwaukee estuary in Wisconsin drain into Lake Michigan. Wastewater treatment plants and combined sewer overflows contribute pollution which affects fish and wildlife and recreation.

Teaching Practical Watershed Science to non-Watershed Science Majors

NASA Astrophysics Data System (ADS)

Fassnacht, S. R.; Laituri, M.; Layden, P.; Coleman, R.

2008-12-01

The Warner College of Natural Resources (WCNR) at Colorado State University (CSU) has had a long tradition of integrating field measurements into the classroom, dating back to the first forestry summer camp held in 1917 at the CSU Pingree Park mountain campus. In the early 1960s, the Cooperative Watershed Management Unit coordinated efforts to understand and analyse the basic resources of the area, with an emphasis on the geology, hydrology, and climate. Much of this understand is now used as the Abiotic (Geology and Watershed) component of a five-credit, four-week course offered twice each summer at Pingree Park. With the exception of Geology students who have their own field course, this Natural Resources Ecology and Measurements course (NR 220) is required for all WCNR undergraduate students. These majors include Watershed Science, Forestry, Rangeland Ecology, Fisheries, Wildlife Biology, Conservation Biology, and Recreation and Tourism. Since most of these are students are much better trained in biological and/or social sciences rather than physical sciences, a challenge for the Watershed professor is to teaching practical Watershed Science to non-Watershed Science majors. This presentation describes how this challenge is met and how this course helps broaden the knowledge base of Natural Resources students.

Evaluation of the effects of sewering on nitrogen loads to the Niantic River, southeastern Connecticut, 2005-2011

USGS Publications Warehouse

Mullaney, John R.

2015-01-01

Nitrogen loads from groundwater discharge to the Niantic River Estuary from the lower part of the Niantic River watershed, including Pine Grove, were estimated to be 18,800 pounds (lb) in 2011. This compares with an additional 51,000 lb from the surface-water tributaries to the estuary and an unknown quantity of nitrogen load from stormwater runoff in the lower Niantic watershed.

Distribution and assessment of sediment toxicity in Tamaki Estuary, Auckland, New Zealand

NASA Astrophysics Data System (ADS)

Abrahim, G. M. S.; Parker, R. J.; Nichol, S. L.

2007-07-01

Heavy metal levels in surface sediments from Tamaki Estuary demonstrate significant up estuary increases in Cu, Pb, Zn, Cd and mud concentrations. Increased metal levels towards the head of the estuary are linked to local catchment sources reflecting the historical development, industrialisation and urbanisation of catchment areas surrounding the upper estuary. The relatively narrow constriction in the middle estuary (Panmure area), makes it susceptible to accumulation of upper estuary pollutants, since the constriction reduces circulation and extends the time required for fine waterborne sediments in the upper estuary to exchange with fresh coastal water. As a result fine fraction sediments trapped in the upper estuary facilitate capture and retention of pollutants at the head of the estuary. The increase in sandy mud poor sediments towards the mouth of the estuary is associated with generally low metal concentrations. The estuary’s geomorphic shape with a mid estuary constriction, sediment texture and mineralogy and catchment history are significant factors in understanding the overall spatial distribution of contaminants in the estuary. Bulk concentration values for Cu, Pb, Zn, and Cd in all the studied surface samples occur below ANZECC ISQG-H toxicity values. Cd and Cu concentrations are also below the ISQG-L toxicity levels for these elements. However, Pb and Zn concentrations do exceed the ISQG-L values in some of the surface bulk samples in the upper estuary proximal to long established sources of catchment pollution.

Urban Watershed Forestry Manual Part 1: Methods for Increasing Forest Cover in a Watershed

Treesearch

Karen Cappiella; Tom Schueler; Tiffany Wright

2005-01-01

This manual is one in a three-part series on using trees to protect and restore urban watersheds. A brief description of each part follows. Part 1: Methods for Increasing Forest Cover in a Watershed introduces the emerging topic of urban watershed forestry. This part also presents new methods for the watershed planner or forester to systematically measure watershed...

Monitoring Phenology as Indicator for Timing of Nutrient Inputs in Northern Gulf Watersheds

NASA Technical Reports Server (NTRS)

Ross, Kenton W.; Spiering, Bruce A.; Kalcic, Maria T.

2009-01-01

Nutrient over-enrichment defined by the U.S. Environmental Protection Agency as the anthropogenic addition of nutrients, in addition to any natural processes, causing adverse effects or impairments to the beneficial uses of a water body has been identified as one of the most significant environmental problems facing sensitive estuaries and coastal waters. Understanding the timing of nutrient inputs into those waters through remote sensing observables helps define monitoring and mitigation strategies. Remotely sensed data products can trace both forcings and effects of the nutrient system from landscape to estuary. This project is focused on extracting nutrient information from the landscape. The timing of nutrients entering coastal waters from the land boundary is greatly influenced by hydrologic processes, but can also be affected by the timing of nutrient additions across the landscape through natural or anthropogenic means. Non-point source nutrient additions to watersheds are often associated with specific seasonal cycles, such as decomposition of organic materials in fall and winter or addition of fertilizers to crop lands in the spring. These seasonal cycles or phenology may in turn be observed through the use of satellite sensors. Characterization of the phenology of various land cover types may be of particular interest in Gulf of Mexico estuarine systems with relatively short pathways between intensively managed systems and the land/estuarine boundary. The objective of this study is to demonstrate the capability of monitoring phenology of specific classes of land, such as agriculture and managed timberlands, at a refined watershed level. The extraction of phenological information from the Moderate Resolution Imaging Spectroradiometer (MODIS) data record is accomplished using analytical tools developed for NASA at Stennis Space Center: the Time Series Product Tool and the Phenological Parameters Estimation Tool. MODIS reflectance data (product MOD09) were

Comparison of Nutrient Drivers and Response Metrics in Oregon Estuaries

EPA Science Inventory

With the goal of assessing sensitivity to nutrient enrichment, we present a cross-estuary comparison of nutrient sources, levels, and biological responses (phytoplankton and macroalgae) for thirteen Oregon estuaries. Nitrogen levels in the upstream portions of the estuaries are ...

Estuaries of the northeastern United States: Habitat and land use signatures

USGS Publications Warehouse

Roman, C.T.; Jaworski, N.; Short, F.T.; Findlay, S.; Warren, R.S.

2000-01-01

Geographic signatures are physical, chemical, biotic, and human-induced characteristics or processes that help define similar or unique features of estuaries along latitudinal or geographic gradients. Geomorphologically, estuaries of the northeastern U.S., from the Hudson River estuary and northward along the Gulf of Maine shoreline, are highly diverse because of a complex bedrock geology and glacial history. Back-barrier estuaries and lagoons occur within the northeast region, but the dominant type is the drowned-river valley, often with rocky shores. Tidal range and mean depth of northeast estuaries are generally greater when compared to estuaries of the more southern U.S. Atlantic coast and Gulf of Mexico. Because of small estuarine drainage basins, low riverine flows, a bedrock substrate, and dense forest cover, sediment loads in northeast estuaries are generally quite low and water clarity is high. Tidal marshes, seagrass meadows, intertidal mudflats, and rocky shores represent major habitat types that fringe northeast estuaries, supporting commercially-important fauna, forage nekton and benthos, and coastal bird communities, while also serving as links between deeper estuarine waters and habitats through detritus-based pathways. Regarding land use and water quality trends, portions of the northeast have a history of over a century of intense urbanization as reflected in increased total nitrogen and total phosphorus loadings to estuaries, with wastewater treatment facilities and atmospheric deposition being major sources. Agricultural inputs are relatively minor throughout the northeast, with relative importance increasing for coastal plain estuaries. Identifying geographic signatures provides an objective means for comparing the structure function, and processes of estuaries along latitudinal gradients.

Watershed assessment-watershed analysis: What are the limits and what must be considered

Treesearch

Robert R. Ziemer

2000-01-01

Watershed assessment or watershed analysis describes processes and interactions that influence ecosystems and resources in a watershed. Objectives and methods differ because issues and opportunities differ.

Volunteer Watershed Health Monitoring by Local Stakeholders: New Mexico Watershed Watch

ERIC Educational Resources Information Center

Fleming, William

2003-01-01

Volunteers monitor watershed health in more than 700 programs in the US, involving over 400,000 local stakeholders. New Mexico Watershed Watch is a student-based watershed monitoring program sponsored by the state's Department of Game and Fish which provides high school teachers and students with instruction on methods for water quality…

Application of Watershed Scale Models to Predict Nitrogen Loading From Coastal Plain Watersheds

Treesearch

George M. Chescheir; Glenn P Fernandez; R. Wayne Skaggs; Devendra M. Amatya

2004-01-01

DRAINMOD-based watershed models have been developed and tested using data collected from an intensively instrumented research site on Kendricks Creek watershed near Plymouth. NC. These models were applied to simulate the hydrology and nitrate nitrogen (NO3-N) loading from two other watersheds in the Coastal Plain of North Carolina, the 11600 ha Chicod Creek watershed...

Building Regional Threat-Based Networks for Estuaries in the Western United States

PubMed Central

Merrifield, Matthew S.; Hines, Ellen; Liu, Xiaohang; Beck, Michael W.

2011-01-01

Estuaries are ecologically and economically valuable and have been highly degraded from both land and sea. Estuarine habitats in the coastal zone are under pressure from a range of human activities. In the United States and elsewhere, very few conservation plans focused on estuaries are regional in scope; fewer still address threats to estuary long term viability.We have compiled basic information about the spatial extent of threats to identify commonalities. To do this we classify estuaries into hierarchical networks that share similar threat characteristics using a spatial database (geodatabase) of threats to estuaries from land and sea in the western U.S.Our results show that very few estuaries in this region (16%) have no or minimal stresses from anthropogenic activity. Additionally, one quarter (25%) of all estuaries in this study have moderate levels of all threats. The small number of un-threatened estuaries is likely not representative of the ecological variability in the region and will require working to abate threats at others. We think the identification of these estuary groups can foster sharing best practices and coordination of conservation activities amongst estuaries in any geography. PMID:21387006

Application of the Geophysical Scale Multi-Block Transport Modeling System to Hydrodynamic Forcing of Dredged Material Placement Sediment Transport within the James River Estuary

NASA Astrophysics Data System (ADS)

Kim, S. C.; Hayter, E. J.; Pruhs, R.; Luong, P.; Lackey, T. C.

2016-12-01

The geophysical scale circulation of the Mid Atlantic Bight and hydrologic inputs from adjacent Chesapeake Bay watersheds and tributaries influences the hydrodynamics and transport of the James River estuary. Both barotropic and baroclinic transport govern the hydrodynamics of this partially stratified estuary. Modeling the placement of dredged sediment requires accommodating this wide spectrum of atmospheric and hydrodynamic scales. The Geophysical Scale Multi-Block (GSMB) Transport Modeling System is a collection of multiple well established and USACE approved process models. Taking advantage of the parallel computing capability of multi-block modeling, we performed one year three-dimensional modeling of hydrodynamics in supporting simulation of dredged sediment placements transport and morphology changes. Model forcing includes spatially and temporally varying meteorological conditions and hydrological inputs from the watershed. Surface heat flux estimates were derived from the National Solar Radiation Database (NSRDB). The open water boundary condition for water level was obtained from an ADCIRC model application of the U. S. East Coast. Temperature-salinity boundary conditions were obtained from the Environmental Protection Agency (EPA) Chesapeake Bay Program (CBP) long-term monitoring stations database. Simulated water levels were calibrated and verified by comparison with National Oceanic and Atmospheric Administration (NOAA) tide gage locations. A harmonic analysis of the modeled tides was performed and compared with NOAA tide prediction data. In addition, project specific circulation was verified using US Army Corps of Engineers (USACE) drogue data. Salinity and temperature transport was verified at seven CBP long term monitoring stations along the navigation channel. Simulation and analysis of model results suggest that GSMB is capable of resolving the long duration, multi-scale processes inherent to practical engineering problems such as dredged material

Scavenging Rate Ecoassay: A Potential Indicator of Estuary Condition

PubMed Central

Porter, Augustine G.; Scanes, Peter R.

2015-01-01

Monitoring of estuary condition is essential due to the highly productive and often intensely impacted nature of these ecosystems. Assessment of the physico-chemical condition of estuaries is expensive and difficult due to naturally fluctuating water quality and biota. Assessing the vigour of ecosystem processes is an alternative method with potential to overcome much of the variability associated with physico-chemical measures. Indicators of estuary condition should have small spatial and temporal variability, have a predictable response to perturbation and be ecologically relevant. Here, we present tests of the first criterion, the spatio-temporal variability of a potential ecoassay measuring the rate of scavenging in estuaries. We hypothesised that the proposed scavenging ecoassay would not vary significantly among A) sites in an estuary, B) trips separated by weeks, or C) days in a trip. Because not all habitats are present in all estuaries, this test was undertaken in two habitats. When conducted over bare substrate there were occasional significant differences, but no discernible patterns, within levels of the experiment. When conducted over vegetated substrate, days within a trip did not vary significantly, but later trips experienced greater scavenging. This scavenging ecoassay shows potential as a tool for assessing the condition of estuarine ecosystems, and further exploration of this protocol is warranted by implementation in estuaries across a gradient of anthropogenic stress. PMID:26024225

Scavenging rate ecoassay: a potential indicator of estuary condition.

PubMed

Porter, Augustine G; Scanes, Peter R

2015-01-01

Monitoring of estuary condition is essential due to the highly productive and often intensely impacted nature of these ecosystems. Assessment of the physico-chemical condition of estuaries is expensive and difficult due to naturally fluctuating water quality and biota. Assessing the vigour of ecosystem processes is an alternative method with potential to overcome much of the variability associated with physico-chemical measures. Indicators of estuary condition should have small spatial and temporal variability, have a predictable response to perturbation and be ecologically relevant. Here, we present tests of the first criterion, the spatio-temporal variability of a potential ecoassay measuring the rate of scavenging in estuaries. We hypothesised that the proposed scavenging ecoassay would not vary significantly among A) sites in an estuary, B) trips separated by weeks, or C) days in a trip. Because not all habitats are present in all estuaries, this test was undertaken in two habitats. When conducted over bare substrate there were occasional significant differences, but no discernible patterns, within levels of the experiment. When conducted over vegetated substrate, days within a trip did not vary significantly, but later trips experienced greater scavenging. This scavenging ecoassay shows potential as a tool for assessing the condition of estuarine ecosystems, and further exploration of this protocol is warranted by implementation in estuaries across a gradient of anthropogenic stress.

Dissolved Oxygen Data for Coos Estuary (Oregon)

EPA Science Inventory

The purpose of this product is the transmittal of dissolved oxygen data collected in the Coos Estuary, Oregon to Ms. Molly O'Neill (University of Oregon), for use in her studies on the factors influencing spatial and temporal patterns in dissolved oxygen in this estuary. These d...

Influence of Exceptionally High Salinities, Marked Variations in Freshwater Discharge and Opening of Estuary Mouth on the Characteristics of the Ichthyofauna of a Normally-Closed Estuary

NASA Astrophysics Data System (ADS)

Young, G. C.; Potter, I. C.

2002-08-01

This study aimed to determine how the characteristics of the ichthyofauna of the normally-closed Wellstead Estuary on the south coast of Western Australia are influenced by the exceptionally high salinities attained during protracted periods of landlocking and, at other times, by atypically heavy freshwater discharge and consequently the opening of the estuary mouth. After 47 months of continuous closure, this estuary became open to the sea for 30 days in September/October 1997 and then closed again for a further six months. Nearshore, shallow and offshore, deeper waters of the lower, middle and upper regions of this estuary were sampled using seine and gill nets, respectively, in alternate months between July 1996 and May 1998. Mean monthly salinities in each region were >40 on all sampling occasions, except immediately preceding and following the opening of the estuary mouth and, in the lower estuary, they rose to a maximum of 112 in March 1997, before declining to a minimum of 14 in September 1997. The fish fauna of Wellstead Estuary was highly depauperate (20 species), presumably due mainly to the very limited opportunities for the immigration of marine species. However, appreciable numbers of two marine species ( Mugil cephalus and Aldrichetta forsteri) entered from the sea when the estuary was open in the period prior to October 1993 and were able to survive in the highly variable salinities found in this estuary when it was landlocked for the following 47 months. There was strong evidence that, as salinities rose to very high levels in 1997, all of the Leptatherina wallacei and Amoya bifrenatus found in the estuary died and some other species moved from the lower to upper reaches of the estuary where salinities did not rise to such high levels. The atherinid Atherinosoma elongata was the only species caught in March 1997 at the site in the lower estuary where the salinity reached 122. Subsequently, the number of species and overall density of fish in the

Impact of the Clean Water Act on the levels of toxic metals in urban estuaries: The Hudson River estuary revisited

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

Sanudo-Wilhelmy, S.A.; Gill, G.A.

1999-10-15

To establish the impact of the Clean Water Act on the water quality of urban estuaries, dissolved trace metals and phosphate concentrations were determined in surface waters collected along the Hudson River estuary between 1995 and 1997 and compared with samples collected in the mid-1970s by Klinkhammer and Bender. The median concentrations along the estuary have apparently declined 36--56% for Cu, 55--89% for Cd, 53--85% for Ni, and 53--90% for Zn over a period of 23 years. These reductions appear to reflect improvements in controlling discharges from municipal and industrial wastewater treatment plants since the Clean Water Act was enactedmore » in 1972. In contrast, levels of dissolved nutrients (PO{sub 4}) have remained relatively constant during the same period of time, suggesting that wastewater treatment plant improvements in the New York/New Jersey Metropolitan area have not been as effective at reducing nutrient levels within the estuary. While more advanced wastewater treatment could potentially reduce the levels of Ag and PO{sub 4} along the estuary, these improvements would have a more limited effect on the levels of other trace metals.« less

Modeling pesticide fate in a small tidal estuary

USGS Publications Warehouse

McCarthy, A.M.; Bales, J.D.; Cope, W.G.; Shea, D.

2007-01-01

The exposure analysis modeling system (EXAMS), a pesticide fate model developed by the U.S. Environmental Protection Agency, was modified to model the fate of the herbicides atrazine and metolachlor in a small tidally dominated estuary (Bath Creek) in North Carolina, USA where freshwater inflow accounts for only 3% of the total flow. The modifications simulated the changes that occur during the tidal cycle in the estuary, scenarios that are not possible with the original EXAMS model. Two models were created within EXAMS, a steady-state model and a time-variant tidally driven model. The steady-state model accounted for tidal flushing by simply altering freshwater input to yield an estuary residence time equal to that measured in Bath Creek. The tidal EXAMS model explicitly incorporated tidal flushing by modifying the EXAMS code to allow for temporal changes in estuary physical attributes (e.g., volume). The models were validated with empirical measurements of atrazine and metolachlor concentrations in the estuary shortly after herbicide application in nearby fields and immediately following a rain event. Both models provided excellent agreement with measured concentrations. The steady-state EXAMS model accurately predicted atrazine concentrations in the middle of the estuary over the first 3 days and under-predicted metolachlor by a factor of 2-3. The time-variant, tidally driven EXAMS model accurately predicted the rise and plateau of both herbicides over the 6-day measurement period. We have demonstrated the ability of these modified EXAMS models to be useful in predicting pesticide fate and exposure in small tidal estuaries. This is a significant improvement and expansion of the application of EXAMS, and given the wide use of EXAMS for surface water quality modeling by both researchers and regulators and the ability of EXAMS to interface with terrestrial models (e.g., pesticide root zone model) and bioaccumulation models, we now have an easily-accessible and

Engaging Watershed Stakeholders for Cost-Effective Environmental Management Planning with "Watershed Manager"

ERIC Educational Resources Information Center

Williams, Jeffery R.; Smith, Craig M.; Roe, Josh D.; Leatherman, John C.; Wilson, Robert M.

2012-01-01

"Watershed Manager" is a spreadsheet-based model that is used in extension education programs for learning about and selecting cost-effective watershed management practices to reduce soil, nitrogen, and phosphorus losses from cropland. It can facilitate Watershed Restoration and Protection Strategy (WRAPS) stakeholder groups' development…

Wind Wave Behavior in Fetch and Depth Limited Estuaries

NASA Astrophysics Data System (ADS)

Karimpour, Arash; Chen, Qin; Twilley, Robert R.

2017-01-01

Wetland dominated estuaries serve as one of the most productive natural ecosystems through their ecological, economic and cultural services, such as nursery grounds for fisheries, nutrient sequestration, and ecotourism. The ongoing deterioration of wetland ecosystems in many shallow estuaries raises concerns about the contributing erosive processes and their roles in restraining coastal restoration efforts. Given the combination of wetlands and shallow bays as landscape components that determine the function of estuaries, successful restoration strategies require knowledge of wind wave behavior in fetch and depth limited water as a critical design feature. We experimentally evaluate physics of wind wave growth in fetch and depth limited estuaries. We demonstrate that wave growth rate in shallow estuaries is a function of wind fetch to water depth ratio, which helps to develop a new set of parametric wave growth equations. We find that the final stage of wave growth in shallow estuaries can be presented by a product of water depth and wave number, whereby their product approaches 1.363 as either depth or wave energy increases. Suggested wave growth equations and their asymptotic constraints establish the magnitude of wave forces acting on wetland erosion that must be included in ecosystem restoration design.

Wind Wave Behavior in Fetch and Depth Limited Estuaries.

PubMed

Karimpour, Arash; Chen, Qin; Twilley, Robert R

2017-01-18

Wetland dominated estuaries serve as one of the most productive natural ecosystems through their ecological, economic and cultural services, such as nursery grounds for fisheries, nutrient sequestration, and ecotourism. The ongoing deterioration of wetland ecosystems in many shallow estuaries raises concerns about the contributing erosive processes and their roles in restraining coastal restoration efforts. Given the combination of wetlands and shallow bays as landscape components that determine the function of estuaries, successful restoration strategies require knowledge of wind wave behavior in fetch and depth limited water as a critical design feature. We experimentally evaluate physics of wind wave growth in fetch and depth limited estuaries. We demonstrate that wave growth rate in shallow estuaries is a function of wind fetch to water depth ratio, which helps to develop a new set of parametric wave growth equations. We find that the final stage of wave growth in shallow estuaries can be presented by a product of water depth and wave number, whereby their product approaches 1.363 as either depth or wave energy increases. Suggested wave growth equations and their asymptotic constraints establish the magnitude of wave forces acting on wetland erosion that must be included in ecosystem restoration design.

Trophic flow structure of a neotropical estuary in northeastern Brazil and the comparison of ecosystem model indicators of estuaries

NASA Astrophysics Data System (ADS)

Lira, Alex; Angelini, Ronaldo; Le Loc'h, François; Ménard, Frédéric; Lacerda, Carlos; Frédou, Thierry; Lucena Frédou, Flávia

2018-06-01

We developed an Ecopath model for the Estuary of Sirinhaém River (SIR), a small-sized system surrounded by mangroves, subject to high impact, mainly by the sugar cane and other farming industries in order to describe the food web structure and trophic interactions. In addition, we compared our findings with those of 20 available Ecopath estuarine models for tropical, subtropical and temperate regions, aiming to synthesize the knowledge on trophic dynamics and provide a comprehensive analysis of the structures and functioning of estuaries. Our model consisted of 25 compartments and its indicators were within the expected range for estuarine areas around the world. The average trophic transfer efficiency for the entire system was 11.8%, similar to the theoretical value of 10%. The Keystone Index and MTI (Mixed Trophic Impact) analysis indicated that the snook (Centropomus undecimalis and Centropomus parallelus) and jack (Caranx latus and Caranx hippos) are considered as key resources in the system, revealing their high impact in the food web. Both groups have a high ecological and commercial relevance, despite the unregulated fisheries. As result of the comparison of ecosystem model indicators in estuaries, differences in the ecosystem structure from the low latitude zones (tropical estuaries) to the high latitude zones (temperate system) were noticed. The structure of temperate and sub-tropical estuaries is based on high flows of detritus and export, while tropical systems have high biomass, respiration and consumption rates. Higher values of System Omnivory Index (SOI) and Overhead (SO) were observed in the tropical and subtropical estuaries, denoting a more complex food chain. Globally, none of the estuarine models were classified as fully mature ecosystems, although the tropical ecosystems were considered more mature than the subtropical and temperate ecosystems. This study is an important contribution to the trophic modeling of estuaries, which may also help

Tidal exchange between a freshwater tidal marsh and an impacted estuary: the Scheldt estuary, Belgium

NASA Astrophysics Data System (ADS)

Van Damme, Stefan; Frank, Dehairs; Micky, Tackx; Olivier, Beauchard; Eric, Struyf; Britta, Gribsholt; Oswald, Van Cleemput; Patrick, Meire

2009-11-01

Tidal marsh exchange studies are relatively simple tools to investigate the interaction between tidal marshes and estuaries. They have mostly been confined to only a few elements and to saltwater or brackish systems. This study presents mass-balance results of an integrated one year campaign in a freshwater tidal marsh along the Scheldt estuary (Belgium), covering oxygen, nutrients (N, P and Si), carbon, chlorophyll, suspended matter, chloride and sulfate. The role of seepage from the marsh was also investigated. A ranking between the parameters revealed that oxygenation was the strongest effect of the marsh on the estuarine water. Particulate parameters showed overall import. Export of dissolved silica (DSi) was more important than exchange of any other nutrient form. Export of DSi and import of total dissolved nitrogen (DIN) nevertheless contributed about equally to the increase of the Si:N ratio in the seepage water. The marsh had a counteracting effect on the long term trend of nutrient ratios in the estuary.

Introduction to the Watershed Central Web Site and Watershed Wiki Mini-Workshop

EPA Science Inventory

Many communities across the country struggle to find the right approaches, tools and data to include in their watershed plans. EPA recently posted a new web site called "Watershed Central,” a “one-stop" tool, to help watershed organizations and others find key resources to protec...

Bar dynamics and channel junctions in scale-experiments of estuaries

NASA Astrophysics Data System (ADS)

Leuven, J.; Braat, L.; van Dijk, W. M.; Haas, T. D.; Kleinhans, M. G.

2017-12-01

The evolution of channels and bars in estuaries has high socio-economic relevance, with strong implications for navigation, dredging and ecology. However, the spatial and temporal evolution of channels and bars in estuaries is poorly understood. Here, we study feedbacks of bar morphodynamics on widening and narrowing of estuaries. Therefore, we conducted an experiment in a 20 m long and 3 m wide tilting flume (the 'Metronome'), in which we monitored the evolution of a self-formed estuary that developed from an intial straight channel into an irregular planform with multiple channels, braided bars and a meandering ebb channel. At locations where the estuary width is confined, major channel junctions occur, while the zones between the junctions are characterised by high braiding indices, periodically migrating channels and a relatively large estuary width. The junction locations were forced by the in- and outflow locations on the sides of the ebb-tidal delta and at the location where the channel pattern transitions from multiple channels into a single channel. In the middle of the estuary, self-confinement occurred by sedimentation on the sides of the estuary, which caused another major junction. The channel orientation at the junctions steers the morphodynamics of channels and bars immediately landward and seaward, because the orientation of inflow from the ebb-tidal delta and landward river perpetually varies. In natural systems major junction locations are mostly forced by inherited geology or human engineering. However, this study concludes that even without external forcing, the estuary planform will not converge to an ideal shape but will self-confine at major junctions and widens in the adjacent zones, resulting in an irregular planform shape.

Watershed-based survey designs

USGS Publications Warehouse

Detenbeck, N.E.; Cincotta, D.; Denver, J.M.; Greenlee, S.K.; Olsen, A.R.; Pitchford, A.M.

2005-01-01

Watershed-based sampling design and assessment tools help serve the multiple goals for water quality monitoring required under the Clean Water Act, including assessment of regional conditions to meet Section 305(b), identification of impaired water bodies or watersheds to meet Section 303(d), and development of empirical relationships between causes or sources of impairment and biological responses. Creation of GIS databases for hydrography, hydrologically corrected digital elevation models, and hydrologic derivatives such as watershed boundaries and upstream–downstream topology of subcatchments would provide a consistent seamless nationwide framework for these designs. The elements of a watershed-based sample framework can be represented either as a continuous infinite set defined by points along a linear stream network, or as a discrete set of watershed polygons. Watershed-based designs can be developed with existing probabilistic survey methods, including the use of unequal probability weighting, stratification, and two-stage frames for sampling. Case studies for monitoring of Atlantic Coastal Plain streams, West Virginia wadeable streams, and coastal Oregon streams illustrate three different approaches for selecting sites for watershed-based survey designs.

Watersheds: where we live

USGS Publications Warehouse

Vandas, Stephen; Farrar, Frank

1996-01-01

We all live in a watershed. Animals and plants all live there with us. Everyone affects what happens in a watershed by how we treat the natural resources. So what is a watershed? It is the land area that drains water to a stream, river, lake, or ocean. Water travels over the Earth's surface across forest land, farm fields, pastures, suburban lawns, and city streets, or it seeps into the soil and makes its way to a stream as local ground water. Watersheds come in many different shapes and sizes. Some contain mountains and hills, and others are nearly flat. A watershed can be affected by many different activities and events. Construction of cities and towns, farming, logging, and the application and disposal of many garden and household chemicals can affect the quantity and quality of water flowing from a watershed.

Improving estuary models by reducing uncertainties associated with river flows

NASA Astrophysics Data System (ADS)

Robins, Peter E.; Lewis, Matt J.; Freer, Jim; Cooper, David M.; Skinner, Christopher J.; Coulthard, Tom J.

2018-07-01

To mitigate against future changes to estuaries such as water quality, catchment and estuary models can be coupled to simulate the transport of harmful pathogenic viruses, pollutants and nutrients from their terrestrial sources, through the estuary and to the coast. To predict future changes to estuaries, daily mean river flow projections are typically used. We show that this approach cannot resolve higher frequency discharge events that have large impacts to estuarine dilution, contamination and recovery for two contrasting estuaries. We therefore characterise sub-daily scale flow variability and propagate this through an estuary model to provide robust estimates of impacts for the future. River flow data (35-year records at 15-min sampling) were used to characterise variabilities in storm hydrograph shapes and simulate the estuarine response. In particular, we modelled a fast-responding catchment-estuary system (Conwy, UK), where the natural variability in hydrograph shapes generated large variability in estuarine circulation that was not captured when using daily-averaged river forcing. In the extreme, the freshwater plume from a 'flash' flood (lasting <12 h) was underestimated by up to 100% - and the response to nutrient loading was underestimated further still. A model of a slower-responding system (Humber, UK), where hydrographs typically last 2-4 days, showed less variability in estuarine circulation and good approximation with daily-averaged flow forcing. Our result has implications for entire system impact modelling; when we determine future changes to estuaries, some systems will need higher resolution future river flow estimates.

33 CFR 334.410 - Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... bombs which contain only small explosive charges for producing smoke puffs to mark points of impact. All... operations. Dummy ammunition, waterfilled or smoke bombs and inert rockets will be used, except during wartime when live ammunition, bombs and rockets may be used. The area will be open to navigation except...

33 CFR 334.410 - Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... bombs which contain only small explosive charges for producing smoke puffs to mark points of impact. All... operations. Dummy ammunition, waterfilled or smoke bombs and inert rockets will be used, except during wartime when live ammunition, bombs and rockets may be used. The area will be open to navigation except...

33 CFR 334.410 - Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... bombs which contain only small explosive charges for producing smoke puffs to mark points of impact. All... operations. Dummy ammunition, waterfilled or smoke bombs and inert rockets will be used, except during wartime when live ammunition, bombs and rockets may be used. The area will be open to navigation except...

33 CFR 334.410 - Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... bombs which contain only small explosive charges for producing smoke puffs to mark points of impact. All... operations. Dummy ammunition, waterfilled or smoke bombs and inert rockets will be used, except during wartime when live ammunition, bombs and rockets may be used. The area will be open to navigation except...

33 CFR 334.410 - Albemarle Sound, Pamlico Sound, and adjacent waters, NC; danger zones for naval aircraft operations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... paragraph (b) of the section the placing of nets, traps, buoys, pots, fishponds, stakes, or other equipment... agency. The regulations in this section shall be enforced by the Commander, Naval Air Force, U.S...

Sierra Leone Estuary

NASA Image and Video Library

2014-02-05

This image acquired by NASA Terra spacecraft is of the Sierra Leone estuary, which became a focal point for trade and interaction between Africans and Europeans because of its exceptional harbor, starting in the mid-15th century.

Watershed Central: Harnessing a social media tool to organize local technical knowledge and find the right watershed resources for your watershed

EPA Science Inventory

Watershed Central was developed to be a bridge between sharing and searching for information relating to watershed issues. This is dependent upon active user support through additions and updates to the Watershed Central Wiki. Since the wiki is user driven, the content and applic...

Tidal fluctuations influence E. coli concentrations in urban estuaries.

PubMed

Jovanovic, Dusan; Coleman, Rhys; Deletic, Ana; McCarthy, David T

2017-06-15

This study investigated the influence of water level and velocity on Escherichia coli levels over multiple tidal cycles in an urban microtidal estuary in Melbourne, Australia. Over 3,500 E. coli samples and high resolution water level and velocity measurements from two locations within the estuary were used for the analysis. E. coli negatively correlated with water level in the upper estuary which was proposed to be linked to increased resuspension of estuarine sediments during low tide. No relationship was found in the lower estuary, likely due to wet weather inputs dwarfing subtler tidal-related processes. Removal of wet weather data enabled significant relationships to emerge in the lower estuary: 1) positive with water level (when a 9-h shift applied corresponding to the phase shift between water levels and velocities) and; 2) positive with velocity (no shift applied). This supports a link between increased E. coli levels and tidal-related resuspension. Copyright © 2017 Elsevier Ltd. All rights reserved.

Physical characteristics of the Bahia Blanca estuary (Argentina)

NASA Astrophysics Data System (ADS)

Piccolo, Maria Cintia; Perillo, Gerardo M. E.

1990-09-01

Based on temperature, salinity and current velocity and direction data, the physical characteristics of the Bahia Blanca estuary are described. Data were gathered in vertical profiles made in longitudinal as well as in hourly surveys. Freshwater runoff averages 2 m 3 s -1; however, peak floods may reach 10-50 m 3 s -1. The temperature distribution is quite homogeneous in the estuary. Based on the salinity distribution, the estuary can be divided into two sectors: an inner one showing partially mixed characteristics with a strong tendency to become sectionally homogeneous during runoff conditions similar to the historical averages, and an outer sector which is sectionally homogeneous. Salinity values in the inner sector may be larger than those observed in the inner continental shelf. This is initiated by the restricted circulation in the inner estuary and added to by the tidal washing of back-estuary salt flats and by evaporation processes. Analysis of the residual circulation shows a marked difference in the direction of mass transport. In the deeper regions of the sections (northern flank) the flow reverses with depth, being headward near the bottom. However, net transport is landward in the shallower parts.

Restoration of the Golden Horn Estuary (Halic).

PubMed

Coleman, Heather M; Kanat, Gurdal; Aydinol Turkdogan, F Ilter

2009-12-01

Restoration of the iconic Golden Horn Estuary in Istanbul, Turkey was a substantial political, logistical, ecological, and social challenge. Forty years of uncontrolled industrial and urban growth resulted in thick layers of anoxic sediment, toxic bacteria, strong hydrogen sulfide odor, and ecologically unlivable conditions. The major components of restoration, spanning two decades, have included (1) demolition and relocation of industries and homes along the shore, (2) creation of wastewater infrastructure, (3) removal of anoxic sludge from the estuary, (4) removal of a floating bridge that impeded circulation, and (5) creation of cultural and social facilities. Although Turkey is not known as an environmental leader in pollution control, the sum of these efforts was largely successful in revitalizing the area through dramatic water quality improvement. Consequently, the estuary is once again inhabitable for aquatic life as well as amenable to local resource users and foreign visitors, and Istanbul has regained a lost sense of cultural identity. This paper focuses on literature review and personal interviews to discuss the causes of degradation, solutions employed to rehabilitate the estuary, and subsequent physicochemical, ecological, and social changes.

Sources, Ages, and Alteration of Organic Matter in Estuaries.

PubMed

Canuel, Elizabeth A; Hardison, Amber K

2016-01-01

Understanding the processes influencing the sources and fate of organic matter (OM) in estuaries is important for quantifying the contributions of carbon from land and rivers to the global carbon budget of the coastal ocean. Estuaries are sites of high OM production and processing, and understanding biogeochemical processes within these regions is key to quantifying organic carbon (Corg) budgets at the land-ocean margin. These regions provide vital ecological services, including nutrient filtration and protection from floods and storm surge, and provide habitat and nursery areas for numerous commercially important species. Human activities have modified estuarine systems over time, resulting in changes in the production, respiration, burial, and export of Corg. Corg in estuaries is derived from aquatic, terrigenous, and anthropogenic sources, with each source exhibiting a spectrum of ages and lability. The complex source and age characteristics of Corg in estuaries complicate our ability to trace OM along the river-estuary-coastal ocean continuum. This review focuses on the application of organic biomarkers and compound-specific isotope analyses to estuarine environments and on how these tools have enhanced our ability to discern natural sources of OM, trace their incorporation into food webs, and enhance understanding of the fate of Corg within estuaries and their adjacent waters.

Wind Wave Behavior in Fetch and Depth Limited Estuaries

PubMed Central

Karimpour, Arash; Chen, Qin; Twilley, Robert R.

2017-01-01

Wetland dominated estuaries serve as one of the most productive natural ecosystems through their ecological, economic and cultural services, such as nursery grounds for fisheries, nutrient sequestration, and ecotourism. The ongoing deterioration of wetland ecosystems in many shallow estuaries raises concerns about the contributing erosive processes and their roles in restraining coastal restoration efforts. Given the combination of wetlands and shallow bays as landscape components that determine the function of estuaries, successful restoration strategies require knowledge of wind wave behavior in fetch and depth limited water as a critical design feature. We experimentally evaluate physics of wind wave growth in fetch and depth limited estuaries. We demonstrate that wave growth rate in shallow estuaries is a function of wind fetch to water depth ratio, which helps to develop a new set of parametric wave growth equations. We find that the final stage of wave growth in shallow estuaries can be presented by a product of water depth and wave number, whereby their product approaches 1.363 as either depth or wave energy increases. Suggested wave growth equations and their asymptotic constraints establish the magnitude of wave forces acting on wetland erosion that must be included in ecosystem restoration design. PMID:28098236

WATER QUALITY MODELING IN THE RIO CHONE ESTUARY

EPA Science Inventory

Water quality in the Rio Chone Estuary, a seasonally inverse, tropical estuary, in Ecuador was characterized by modeling the distribution of biochemical oxygen demand (BOD) and dissolved inorganic nitrogen (DIN) within the water column. These two variables are modeled using modif...

Sediment balance of intertidal mudflats in a macrotidal estuary

NASA Astrophysics Data System (ADS)

lafite, R.; Deloffre, J.; Lemoine, M.

2012-12-01

Intertidal area contributes widely to fine-grained sediment balance in estuarine environments. Their sedimentary dynamics is controlled by several forcing parameters including tidal range, river flow and swell, affected by human activities such as dredging, construction or vessels traffic leading to modify sediment transport pattern. Although the estuarine hydrodynamics is well documented, the link between forcing parameters and these sedimentary processes is weakly understood. One of the main reasons is the difficulty to integrate spatial (from the fluvial to the estuary mouth) and temporal (from swell in seconds to pluriannual river flow variability) patterns. This study achieved on intertidal mudflats distributed along the macrotidal Seine estuary (France) aims (i) to quantify the impact of forcing parameters on each intertidal area respect to its longitudinal position in the estuarine system and (ii) to assess the fine-grained sediment budget at estuarine scale. The Seine estuary is a macrotidal estuary developed over 160 km up the upstream limit of tidal wave penetration. With an average river flow of 450m3.s-1, 80% of the Suspended Particles Matter (SPM) annual flux is discharged during the flood period. In the downstream part, the Seine estuary Turbidity Maximum (TM) is the SPM stock located near the mouth. During their transfer toward the sea, the fine particles can be trapped in (i) the intertidal mudflats; preferential areas characterized by low hydrodynamics and generally sheltered of the tidal dominant flow, the main tidal current the Seine River and (ii) the TM. The Seine estuary is an anthropic estuary in order to secure navigation: one consequence of these developments is the tidal bore disappearance. Along the macrotidal Seine estuary hydrodynamics features and sedimentary fluxes were followed during at least 1 year using respectively Acoustic Doppler Velocimeter, Optical BackScatter and altimeter. Results in the fluvial estuary enhance the role of

Linking behavior, physiology, and survival of Atlantic Salmon smolts during estuary migration

USGS Publications Warehouse

Stich, Daniel S.; Zydlewski, Gayle B.; Kocik, John F.; Zydlewski, Joseph D.

2015-01-01

Decreased marine survival is identified as a component driver of continued declines of Atlantic Salmon Salmo salar. However, estimates of marine mortality often incorporate loss incurred during estuary migration that may be mechanistically distinct from factors affecting marine mortality. We examined movements and survival of 941 smolts (141 wild and 800 hatchery-reared fish) released in freshwater during passage through the Penobscot River estuary, Maine, from 2005 to 2013. We related trends in estuary arrival date, movement rate, and survival to fish characteristics, migratory history, and environmental conditions in the estuary. Fish that experienced the warmest thermal history arrived in the estuary 8 d earlier than those experiencing the coolest thermal history during development. Estuary arrival date was 10 d later for fish experiencing high flow than for fish experiencing low flow. Fish released furthest upstream arrived in the estuary 3 d later than those stocked further downstream but moved 0.5 km/h faster through the estuary. Temporally, movement rate and survival in the estuary both peaked in mid-May. Spatially, movement rate and survival both decreased from freshwater to the ocean. Wild smolts arrived in the estuary later than hatchery fish, but we observed no change in movement rate or survival attributable to rearing history. Fish with the highest gill Na+, K+-ATPase activity incurred 25% lower mortality through the estuary than fish with the lowest gill Na+, K+-ATPase activity. Smolt survival decreased (by up to 40%) with the increasing number of dams passed (ranging from two to nine) during freshwater migration. These results underscore the importance of physiological preparedness on performance and the delayed, indirect effects of dams on survival of Atlantic Salmon smolts during estuary migration, ultimately affecting marine survival estimates.

Subtidal sea level variability in a shallow Mississippi River deltaic estuary, Louisiana

USGS Publications Warehouse

Snedden, G.A.; Cable, J.E.; Wiseman, W.J.

2007-01-01

The relative roles of river, atmospheric, and tidal forcings on estuarine sea level variability are examined in Breton Sound, a shallow (0.7 m) deltaic estuary situated in an interdistributary basin on the Mississippi River deltaic plain. The deltaic landscape contains vegetated marshes, tidal flats, circuitous channels, and other features that frictionally dissipate waves propagating through the system. Direct forcing by local wind stress over the surface of the estuary is minimal, owing to the lack of significant fetch due to landscape features of the estuary. Atmospheric forcing occurs almost entirely through remote forcing, where alongshore winds facilitate estuary-shelf exchange through coastal Ekman convergence. The highly frictional nature of the deltaic landscape causes the estuary to act as a low-pass filter to remote atmospheric forcing, where high-frequency, coastally-induced fluctuations are significantly damped, and the damping increases with distance from the estuary mouth. During spring, when substantial quantities of controlled Mississippi River inputs (q?? = 62 m3 s-1) are discharged into the estuary, upper estuary subtidal sea levels are forced by a combination of river and remote atmospheric forcings, while river effects are less clear downestuary. During autumn (q?? = 7 m3 s-1) sea level variability throughout the estuary is governed entirely by coastal variations at the marine boundary. A frequency-dependent analytical model, previously used to describe sea level dynamics forced by local wind stress and coastal forcing in deeper, less frictional systems, is applied in the shallow Breton Sound estuary. In contrast to deeper systems where coastally-induced fluctuations exhibit little or no frictional attenuation inside the estuary, these fluctuations in the shallow Breton Sound estuary show strong frequency-dependent amplitude reductions that extend well into the subtidal frequency spectrum. ?? 2007 Estuarine Research Federation.

An Investigation of Estuary Gate Effect on Freshwater Fish Biotope and a Study on Ecological Scheduling

NASA Astrophysics Data System (ADS)

Zhang, H. W.; Hu, P.; Ni, G.; Jia, Y. W.; Ge, J. J.

2017-12-01

The presence of an estuary gate changes the existing hydrologic regime and produces a far-reaching and accumulated impact on river biotopes and fish stocks. This work investigates the estuary gate effect in the Yong River valley on the species Elopichthys bambusa (E. bambusa). By combininge hydrodynamic results from the MIKE FLOOD model with observations of the E. bambusa habitat indicators. After the establishment of the gate, the hydrological conditions required for spawning, egg hatching and oviposition stimulation, were analysed, and the corresponding strategies for ecological water demand were proposed. This study finds that satisfactory fish egg hatching hydrodynamic conditions are created when the Fenghua River flow reaches 120 m3/s in the spawning season. With Fenghua River, Yao River gate, and Yong River gate discharges at 120 m3/s, 90 m3/s, and 210 m3/s respectively, an average flow speed increase above 0.2 m/s/day may be generated for E. bambusa spawning sites and migration passages. This hydraulic condition stimulates spawning in natural streams. At the most suitable spawning season temperature, an ecological scheduling scheme that maintains a pulse flow for 5-7 days provides E. bambusa with the hydrodynamic conditions required for the whole process of reproduction, thereby maintaining healthy stream ecology. The flow rate scheduling rules, as provided in this paper, may serve as references in watershed ecological scheduling after gate installation.

Patterns and watershed controls of dissolved nitrogen in temperate rainforest streams, southeast Alaska

NASA Astrophysics Data System (ADS)

Kreitinger, E.; D'Amore, D. V.; Walter, M. T.

2016-12-01

The Alaskan perhumid coastal temperate rainforest (PCTR) is part of the largest expanse of temperate rainforest in the world. Steep topography in this region characterizes thousands of small watersheds, from which more than 760 km3 y-1 of freshwater is exported from terrestrial systems to the nearshore estuary. This hydrologic flux carries large amounts of carbon and nutrients, which are believed to drive important bottom-up controls on ecosystem productivity. In recent years, carbon has been the focus of biogeochemical research in the PCTR, while nitrogen (N) dynamics remain relatively unstudied. We analyzed water chemistry from streams at the outflow points of discrete coastal watersheds in the region and developed predictive models for N flux across varying physiographic features. Predictive variables tested for this nutrient model were derived from regional geographic data to improve scalability. These include topography, wetland extent, forest type, harvest history and other variables related to ecosystem state-factor controls. Results indicate distinct patterns of nitrogen loss across the landscape. Dissolved organic nitrogen (DON) was the dominant form of N in nearly all samples across seasons (range 34.01-351.90 ppb, mean 154.30 ppb). The mean ratio of dissolved inorganic nitrogen as nitrate (NO3) and ammonium (NH4+) to total dissolved nitrogen (DIN:TDN) was .30 in spring and .13 in fall (SE ± .03 at both times). Overall trends in stream N concentrations are such that DON>>NO3>NH3. Results from this research improve our ability to predict dissolved N concentrations using landscape patterns in unsampled watersheds, where accessibility and cost pose hurdles to sampling. The model provides a basis for developing regional nitrogen budgets, which are fundamental to our understanding of aquatic and terrestrial ecosystems' response to management practices and climate change.

Watershed Stewardship Education Program--A Multidisciplinary Extension Education Program for Oregon's Watershed Councils.

ERIC Educational Resources Information Center

Conway, Flaxen D. L.; Godwin, Derek; Cloughesy, Mike; Nierenberg, Tara

2003-01-01

The Watershed Stewardship Education Program (WSEP) is a multidisciplinary Oregon Extension designed to help watershed councils, landowners, and others work effectively together on water management. Components include practical, easy-to-use educational materials, training in effective collaboration, a Master Watershed Stewards program, and advanced…

The ecology of Tijuana Estuary, California: An estuarine profile

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

Zedler, J.B.; Nordby, C.S.

1986-06-01

This is the first attempt to synthesize and interpret a rapidly growing data base on the estuary's diverse biota - its vegetation, algae, birds, fishes, and invertebrates. Because so many changes have occurred in response to recent catastrophic events, we describe how each aspect of the estuary appeared before 1980 and how it has responded to several perturbations. The experimental tests of these cause-effect relationships have not been completed, and there is little reason to expect that environmental conditions have stabilized or that new types of disturbances won't occur. Thus, this profile should be viewed as a stage in themore » process of understanding Tijuana Estuary. Like the estuary itself, our knowledge is continuously evolving.« less

Analysis of climate change impact on runoff and sediment delivery in a Great Lake watershed using SWAT

NASA Astrophysics Data System (ADS)

Verma, S.; Bhattarai, R.; Cooke, R.

2011-12-01

The green house gas loading of the atmosphere has been increasing since the mid 19th century which threatens to dramatically change the earth's climate in the 21st Century. Scientific evidences show that earth's global average surface temperature has risen some 0.75°C (1.3°F) since 1850. Third Assessment Report (TAR) from the Intergovernmental Panel on Climate Change (IPCC) concluded that human activities have increased the atmospheric concentration of greenhouse gases (GHGs), which will result in a warming world and other changes in the climate. TAR has projected an increase in globally average surface temperature of 1.4 to 5.8 °C and an increase in precipitation of 5 to 20 % over the period of 1990 to 2100. Assuming a global temperature increase of between 2.8 and 5.2 °C, it was estimated a 7-15% increase in global evaporation and precipitation rates. Global warming and subsequent climate change could raise sea level by several tens of centimeters in the next fifty years. Such a rise may erode beaches, worsen coastal flooding and threaten water quality in estuaries and aquifers. With the climate already changing and further change in climate highly likely to happen, study of impact of climate and the adaptation is a necessary component of any response to climate change. The objective of this study is to analyze the impact of climate change on runoff and sediment delivery in a Great Lake watershed located in Northern Ohio. Maumee River watershed is predominantly an agricultural watershed with an area of 6330 sq mile and drains to Lake Erie. Agricultural area covers about 89.9% of the watershed while wooded area covers 7.3%, 1.2% is urban area and other land uses account for 1.6%. Water Quality Laboratory, Heidelberg College has monitored the watershed for last 25 years. The Soil and Water Assessment Tool (SWAT) model is used for both water quantity and water quality simulations for past and future scenarios. SWAT is a continuous, long-term watershed scale

Modeling ecosystem processes with variable freshwater inflow to the Caloosahatchee River Estuary, southwest Florida. II. Nutrient loading, submarine light, and seagrasses

NASA Astrophysics Data System (ADS)

Buzzelli, Christopher; Doering, Peter; Wan, Yongshan; Sun, Detong

2014-12-01

Short- and long-term changes in estuarine biogeochemical and biological attributes are consequences of variations in both the magnitude and composition of freshwater inputs. A common conceptualization of estuaries depicts nutrient loading from coastal watersheds as the stressor that promotes algal biomass, decreases submarine light penetration, and degrades seagrass habitats. Freshwater inflow depresses salinity while simultaneously introducing colored dissolved organic matter (color or CDOM) which greatly reduces estuarine light penetration. This is especially true for sub-tropical estuaries. This study applied a model of the Caloosahatchee River Estuary (CRE) in southwest Florida to explore the relationships between freshwater inflow, nutrient loading, submarine light, and seagrass survival. In two independent model series, the loading of dissolved inorganic nitrogen and phosphorus (DIN and DIP) was reduced by 10%, 20%, 30%, and 50% relative to the base model case from 2002 to 2009 (2922 days). While external nutrient loads were reduced by lowering inflow (Q0) in the first series (Q0 series), reductions were accomplished by decreasing the incoming concentrations of DIN and DIP in the second series (NP Series). The model also was used to explore the partitioning of submarine light extinction due to chlorophyll a, CDOM, and turbidity. Results suggested that attempting to control nutrient loading by decreasing freshwater inflow could have minor effects on water column concentrations but greatly influence submarine light and seagrass biomass. This is because of the relative importance of Q0 to salinity and submarine light. In general, light penetration and seagrass biomass decreased with increased inflow and CDOM. Increased chlorophyll a did account for more submarine light extinction in the lower estuary. The model output was used to help identify desirable levels of inflow, nutrient loading, water quality, salinity, and submarine light for seagrass in the lower CRE

A Simple Model of Nitrogen Concentration, Throughput, and Denitrification in Estuaries

EPA Science Inventory

The Estuary Nitrogen Model (ENM) is a mass balance model that includes calculation of nitrogen losses within bays and estuaries using system flushing time. The model has been used to demonstrate the dependence of throughput and denitrification of nitrogen in bays and estuaries on...

Performance of National Maps of Watershed Integrity at Watershed Scales

EPA Science Inventory

Watershed integrity, the capacity of a watershed to support and maintain ecological processes essential to the sustainability of services provided to society, can be influenced by a range of landscape and in-stream factors. Ecological response data from four intensively monitored...

The Modification of an Estuary

NASA Astrophysics Data System (ADS)

Nichols, Frederic H.; Cloern, James E.; Luoma, Samuel N.; Peterson, David H.

1986-02-01

The San Francisco Bay estuary has been rapidly modified by human activity. Diking and filling of most of its wetlands have eliminated habitats for fish and waterfowl; the introduction of exotic species has transformed the composition of its aquatic communities; reduction of freshwater inflow by more than half has changed the dynamics of its plant and animal communities; and wastes have contaminated its sediments and organisms. Continued disposal of toxic wastes, the probable further reduction in freshwater inflow, and the possible synergy between the two provide the potential for further alteration of the estuary's water quality and biotic communities.

The modification of an estuary

USGS Publications Warehouse

Nichols, F.H.; Cloern, J.E.; Luoma, S.N.; Peterson, D.H.

1986-01-01

The San Francisco Bay estuary has been rapidly modified by human activity. Diking and filling of most of its wetlands have eliminated habitats for fish and waterfowl; the introduction of exotic species has transformed the composition of its aquatic communities; reduction of freshwater inflow by more than half has changed the dynamics of its plant and animal communities; and wastes have contaminated its sediments and organisms. Continued disposal of toxic wastes, the probable further reduction in freshwater inflow, and the possible synergy between the two provide the potential for further alteration of the estuary's water quality and biotic communities.

Nitrogen Flux in Watersheds: The Role of Soil Distributions and Climate in Nitrogen Flux to the Coastal Ecosystems

NASA Astrophysics Data System (ADS)

Showers, W. J.; Reyes, M. M.; Genna, B. J.

2009-12-01

Quantifying the flux of nitrate from different landscape sources in watersheds is important to understand the increased flux of nitrogen to coastal ecosystems. Recent technological advances in chemical sensor networks has demonstrated that chemical variability in aquatic environments are chronically under-sampled, and that many nutrient monitoring programs with monthly or daily sampling rates are inadequate to characterize the dominate seasonal, daily or semi-diurnal fluxes in watersheds. The RiverNet program has measured the nitrate flux in the Neuse River Basin, NC on a 15 minute interval over the past eight years. Significant diurnal variation has been observed in nitrate concentrations during high and low flow periods associated with waste water treatment plants in urban watersheds that are not present in agricultural watersheds. Discharge and N flux in the basin also has significant inter-annual variations associated with El Nino oscillations modified by the North Atlantic oscillation. Positive JMA and NAO indexes are associated with increased groundwater levels, nutrient fluxes, and estuary fish kills. To understand how climate oscillation affect discharge and nutrient fluxes, we have monitored runoff/drainages and groundwater inputs adjacent to a large waste application field over the past 4 years, and used the nitrate inputs as a tracer. Surface water run off is well correlated to precipitation patterns and is the largest nutrient flux into the river. Groundwater inputs are variable spatially and temporally, and are controlled by geology and groundwater levels. Hydric soil spatial distributions are an excellent predictor of nutrient transport across landscapes, and is related to the distribution of biogeochemical “hotspots” The isotopic composition of oxygen and nitrogen in dissolved nitrate indicate that sources change with discharge state, and that atmospherically deposited nitrogen is only important to river fluxes in forested and urban watersheds

Geochemistry of tin in rivers and estuaries

NASA Astrophysics Data System (ADS)

Byrd, James T.; Andreae, Meinrat O.

1986-05-01

On the basis of measurements from a large number of rivers from pristine and polluted regions, we estimate the riverine fluxes of tin to the oceans to be 0.76 × 10 6molyr-1 for the dissolved fraction and 300-600 × 10 6 mol yr -1 for the paniculate fraction. The paniculate flux agrees with the flux calculated from denudation rates. Estuaries were found not to have a large effect upon the transport of tin to the oceans. Evidence for the remobilization of tin was found in an estuary that is highly polluted with tin from mining and smelting activities. Monobutyltin was found to be present in polluted estuaries and is presumed to be a degradation product of tributyltin additives to antifouling paint.

Watersheds in disordered media

NASA Astrophysics Data System (ADS)

Andrade, Joséi, Jr.; Araújo, Nuno; Herrmann, Hans; Schrenk, Julian

2015-02-01

What is the best way to divide a rugged landscape? Since ancient times, watersheds separating adjacent water systems that flow, for example, toward different seas, have been used to delimit boundaries. Interestingly, serious and even tense border disputes between countries have relied on the subtle geometrical properties of these tortuous lines. For instance, slight and even anthropogenic modifications of landscapes can produce large changes in a watershed, and the effects can be highly nonlocal. Although the watershed concept arises naturally in geomorphology, where it plays a fundamental role in water management, landslide, and flood prevention, it also has important applications in seemingly unrelated fields such as image processing and medicine. Despite the far-reaching consequences of the scaling properties on watershed-related hydrological and political issues, it was only recently that a more profound and revealing connection has been disclosed between the concept of watershed and statistical physics of disordered systems. This review initially surveys the origin and definition of a watershed line in a geomorphological framework to subsequently introduce its basic geometrical and physical properties. Results on statistical properties of watersheds obtained from artificial model landscapes generated with long-range correlations are presented and shown to be in good qualitative and quantitative agreement with real landscapes.

Global patterns and predictors of fish species richness in estuaries.

PubMed

Vasconcelos, Rita P; Henriques, Sofia; França, Susana; Pasquaud, Stéphanie; Cardoso, Inês; Laborde, Marina; Cabral, Henrique N

2015-09-01

1. Knowledge of global patterns of biodiversity and regulating variables is indispensable to develop predictive models. 2. The present study used predictive modelling approaches to investigate hypotheses that explain the variation in fish species richness between estuaries over a worldwide spatial extent. Ultimately, such models will allow assessment of future changes in ecosystem structure and function as a result of environmental changes. 3. A comprehensive worldwide data base was compiled of the fish assemblage composition and environmental characteristics of estuaries. Generalized Linear Models were used to quantify how variation in species richness among estuaries is related to historical events, energy dynamics and ecosystem characteristics, while controlling for sampling effects. 4. At the global extent, species richness differed among marine biogeographic realms and continents and increased with mean sea surface temperature, terrestrial net primary productivity and the stability of connectivity with a marine ecosystem (open vs. temporarily open estuaries). At a smaller extent (within a marine biogeographic realm or continent), other characteristics were also important in predicting variation in species richness, with species richness increasing with estuary area and continental shelf width. 5. The results suggest that species richness in an estuary is defined by predictors that are spatially hierarchical. Over the largest spatial extents, species richness is influenced by the broader distributions and habitat use patterns of marine and freshwater species that can colonize estuaries, which are in turn governed by history contingency, energy dynamics and productivity variables. Species richness is also influenced by more regional and local parameters that can further affect the process of community colonization in an estuary including the connectivity of the estuary with the adjacent marine habitat, and, over smaller spatial extents, the size of these

Biological effects of anthropogenic contaminants in the San Francisco Estuary

USGS Publications Warehouse

Thompson, B.; Adelsbach, T.; Brown, C.; Hunt, J.; Kuwabara, J.; Neale, J.; Ohlendorf, H.; Schwarzbach, S.; Spies, R.; Taberski, K.

2007-01-01

Concentrations of many anthropogenic contaminants in the San Francisco Estuary exist at levels that have been associated with biological effects elsewhere, so there is a potential for them to cause biological effects in the Estuary. The purpose of this paper is to summarize information about biological effects on the Estuary's plankton, benthos, fish, birds, and mammals, gathered since the early 1990s, focusing on key accomplishments. These studies have been conducted at all levels of biological organization (sub-cellular through communities), but have included only a small fraction of the organisms and contaminants of concern in the region. The studies summarized provide a body of evidence that some contaminants are causing biological impacts in some biological resources in the Estuary. However, no general patterns of effects were apparent in space and time, and no single contaminant was consistently related to effects among the biota considered. These conclusions reflect the difficulty in demonstrating biological effects due specifically to contamination because there is a wide range of sensitivity to contaminants among the Estuary's many organisms. Additionally, the spatial and temporal distribution of contamination in the Estuary is highly variable, and levels of contamination covary with other environmental factors, such as freshwater inflow or sediment-type. Federal and State regulatory agencies desire to develop biological criteria to protect the Estuary's biological resources. Future studies of biological effects in San Francisco Estuary should focus on the development of meaningful indicators of biological effects, and on key organism and contaminants of concern in long-term, multifaceted studies that include laboratory and field experiments to determine cause and effect to adequately inform management and regulatory decisions. ?? 2006 Elsevier Inc. All rights reserved.

Winds and the orientation of a coastal plane estuary plume

NASA Astrophysics Data System (ADS)

Xia, Meng; Xie, Lian; Pietrafesa, Leonard J.

2010-10-01

Based on a calibrated coastal plane estuary plume model, ideal model hindcasts of estuary plumes are used to describe the evolution of the plume pattern in response to river discharge and local wind forcing by selecting a typical partially mixed estuary (the Cape Fear River Estuary or CFRE). With the help of an existing calibrated plume model, as described by Xia et al. (2007), simulations were conducted using different parameters to evaluate the plume behavior type and its change associated with the variation of wind forcing and river discharge. The simulations indicate that relatively moderate winds can mechanically reverse the flow direction of the plume. Downwelling favorably wind will pin the plume to the coasts while the upwelling plume could induce plume from the left side to right side in the application to CFRE. It was found that six major types of plumes may occur in the estuary and in the corresponding coastal ocean. To better understand these plumes in the CFRE and other similar river estuary systems, we also investigated how the plumes transition from one type to another. Results showed that wind direction, wind speed, and sometimes river discharge contribute to plume transitions.

Tracking Nonpoint Source Nitrogen and Carbon in Watersheds of Chesapeake Bay

NASA Astrophysics Data System (ADS)

Kaushal, S.; Pennino, M. J.; Duan, S.; Blomquist, J.

2012-12-01

Humans have altered nitrogen and carbon cycles in rivers regionally with important impacts on coastal ecosystems. Nonpoint source nitrogen pollution is a leading contributor to coastal eutrophication and hypoxia. Shifts in sources of carbon impact downstream ecosystem metabolism and fate and transport of contaminants in coastal zones. We used a combination of stable isotopes and optical tracers to investigate fate and transport of nitrogen and carbon sources in tributaries of the largest estuary in the U.S., the Chesapeake Bay. We analyzed isotopic composition of water samples from major tributaries including the Potomac River, Susquehanna River, Patuxent River, and Choptank River during routine and storm event sampling over multiple years. A positive correlation between δ15N-NO3- and δ18O-NO3- in the Potomac River above Washington D.C. suggested denitrification or biological uptake in the watershed was removing agriculturally-derived N during summer months. In contrast, the Patuxent River in Maryland showed elevated δ15N-NO3- (5 - 12 per mil) with no relationship to δ18O-NO3- suggesting the importance of wastewater sources. From the perspective of carbon sources, there were distinct isotopic values of the δ13C-POM of particulate organic matter and fluorescence excitation emission matrices (EEMS) for rivers influenced by their dominant watershed land use. EEMS showed that there were increases in the humic and fulvic fractions of dissolved organic matter during spring floods, particularly in the Potomac River. Stable isotopic values of δ13C-POM also showed rapid depletion suggesting terrestrial carbon "pulses" in the Potomac River each spring. The δ15N-POM peaked to 10 - 15 per mil each spring suggested a potential manure source or result of biological processing within the watershed. Overall, there were considerable changes in sources and transformations of nitrogen and carbon that varied across rivers and that contribute to nitrogen and carbon loads

The role of interior watershed processes in improving parameter estimation and performance of watershed models.

PubMed

Yen, Haw; Bailey, Ryan T; Arabi, Mazdak; Ahmadi, Mehdi; White, Michael J; Arnold, Jeffrey G

2014-09-01

Watershed models typically are evaluated solely through comparison of in-stream water and nutrient fluxes with measured data using established performance criteria, whereas processes and responses within the interior of the watershed that govern these global fluxes often are neglected. Due to the large number of parameters at the disposal of these models, circumstances may arise in which excellent global results are achieved using inaccurate magnitudes of these "intra-watershed" responses. When used for scenario analysis, a given model hence may inaccurately predict the global, in-stream effect of implementing land-use practices at the interior of the watershed. In this study, data regarding internal watershed behavior are used to constrain parameter estimation to maintain realistic intra-watershed responses while also matching available in-stream monitoring data. The methodology is demonstrated for the Eagle Creek Watershed in central Indiana. Streamflow and nitrate (NO) loading are used as global in-stream comparisons, with two process responses, the annual mass of denitrification and the ratio of NO losses from subsurface and surface flow, used to constrain parameter estimation. Results show that imposing these constraints not only yields realistic internal watershed behavior but also provides good in-stream comparisons. Results further demonstrate that in the absence of incorporating intra-watershed constraints, evaluation of nutrient abatement strategies could be misleading, even though typical performance criteria are satisfied. Incorporating intra-watershed responses yields a watershed model that more accurately represents the observed behavior of the system and hence a tool that can be used with confidence in scenario evaluation. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Modelling extreme climatic events in Guadalquivir Estuary ( Spain)

NASA Astrophysics Data System (ADS)

Delgado, Juan; Moreno-Navas, Juan; Pulido, Antoine; García-Lafuente, Juan; Calero Quesada, Maria C.; García, Rodrigo

2017-04-01

Extreme climatic events, such as heat waves and severe storms are predicted to increase in frequency and magnitude as a consequence of global warming but their socio-ecological effects are poorly understood, particularly in estuarine ecosystems. The Guadalquivir Estuary has been anthropologically modified several times, the original salt marshes have been transformed to grow rice and cotton and approximately one-fourth of the total surface of the estuary is now part of two protected areas, one of them is a UNESCO, MAB Biosphere Reserve. The climatic events are most likely to affect Europe in forthcoming decades and a further understanding how these climatic disturbances drive abrupt changes in the Guadalquivir estuary is needed. A barotropic model has been developed to study how severe storm events affects the estuary by conducting paired control and climate-events simulations. The changes in the local wind and atmospheric pressure conditions in the estuary have been studied in detail and several scenarios are obtained by running the model under control and real storm conditions. The model output has been validated with in situ water elevation and good agreement between modelled and real measurements have been obtained. Our preliminary results show that the model demonstrated the capability describe of the tide-surge levels in the estuary, opening the possibility to study the interaction between climatic events and the port operations and food production activities. The barotropic hydrodynamic model provide spatially explicit information on the key variables governing the tide dynamics of estuarine areas under severe climatic scenarios . The numerical model will be a powerful tool in future climate change mitigation and adaptation programs in a complex socio-ecological system.

Selected pharmaceuticals entering an estuary: Concentrations, temporal trends, partitioning, and fluxes.

PubMed

Cantwell, Mark G; Katz, David R; Sullivan, Julia C; Ho, Kay; Burgess, Robert M; Cashman, Michaela

2016-11-01

In many coastal watersheds and ecosystems, rivers discharging to estuaries receive waters from domestic wastewater-treatment plants resulting in the release and distribution of pharmaceuticals to the marine environment. In the present study, 15 active pharmaceutical ingredients were measured regularly over 1 yr in the dissolved and particulate phases as they entered Narragansett Bay from the Pawtuxet River in Cranston (Rhode Island, USA). Of the active pharmaceutical ingredients measured, 14 were consistently present in the dissolved phase, with concentrations ranging from below detection to >310 ng/L, whereas 8 were present in the particulate phase (0.2-18 ng/g). Partition coefficients (K d s and K OC s) were determined, and organic carbon normalization reduced variability associated with K d s for the active pharmaceutical ingredients evaluated. Flux estimates based on river flow were calculated for both dissolved and particulate-phase active pharmaceutical ingredients, with particulate fluxes being low (1-12 g/yr) and dissolved fluxes of active pharmaceutical ingredients being 155 g/yr to 11 600 g/yr. Results indicate that the pharmaceuticals measured in the present study reside primarily in the dissolved phase and thus are likely bioavailable on entering the estuarine waters of Narragansett Bay. This long-term temporal study provides important information on seasonal and annual dynamics of pharmaceuticals in an urban estuarine watershed. Environ Toxicol Chem 2016;35:2665-2673. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.

Island Watershed Activity.

ERIC Educational Resources Information Center

Benson, Rod

2003-01-01

Describes a 90-minute "Island Watershed" activity to help earth science students understand the concept of the water cycle. Introduces a surface waters unit appropriate for students in grades 7-10. Includes watershed project guidelines. (Author/KHR)

Polycyclic Aromatic Hydrocarbon (pah) In The Bulk Precipitation of The Seine Estuary, France

NASA Astrophysics Data System (ADS)

Motelay-Massei, A.; Ollivon, D.; Garban, B.; Chevreuil, M.

The evolution of industry and the rising of population have resulted in deep changes in the quality of the environment. Nowadays much more often the attention of analysts is focused on the presence of organic pollutants in precipitation, such as polycyclic aromatic hydrocarbons or pesticides. Atmospheric inputs play a significant role in semivolatile chemicals cycling and alter so the hydrological cycle. PAHs are semi- volatile organic contaminants of great environmental concern because of their car- cinogenic properties. PAHs are produced primarily during incomplete combustion of fossil fuels and wood. Major sources of PAHs to urban atmosphere include au- tomobile traffic, home heating, municipal incinerators and industrial emissions. De- spite their production in urban and industrial sites, PAHs occur at high concentra- tions in rural areas due to their persistence and ability to be transported over long distances. The aim of this investigation was to obtain information about occurrence of organic trace components in precipitation in the Seine Estuary. It was also of in- terest to investigate the spatial and temporal variability of PAHs in the bulk (wet and dry) deposition occurring in the estuary region and to estimate PAH deposition flux on watershed (urban, industrial or rural). Precipitation samples were collected at four locations in the Seine Estuary: the first is an industrial site (Le Havre), two are urban sites (Rouen, representative of urban area influenced by heavy traffic and Notre-Dame de Gravenchon, near from an industrial center) and the last one is ru- ral (Evreux). Each of the sites is located close to a meteorological station. Sam- pling is performed weekly since March 2001. In our analytical conditions, "total PAH" includes 15 compounds: naphthalene (NAP), acenaphtene (ACE), phenanthrene (PHE), anthracene (ANT), fluoranthene (FTH), pyrene (PYR), benzo(a)anthracene (BaA), chrysene (CHR), benzo(b)fluoranthene (BbF), benzo(k)fluoranthene (Bk

Effect of effluent from a nitrogen fertilizer factory and a pulp mill on the distribution and abundance of Aeromonas hydrophila in Albemarle Sound, North Carolina.

PubMed Central

Hazen, T C; Esch, G W

1983-01-01

The density of Aeromonas hydrophila, standard count bacteria, fecal coliform bacteria, and 18 physical and chemical parameters were measured simultaneously at six sites for 12 months in Albemarle Sound, N.C. One site was above and two sites were below the discharge plume of a Kraft pulping process paper mill. The fourth site was above and the remaining two sites were below the discharge point of a nitrogen fertilizer factory. The impact of the pulp mill on water quality was acute, whereas that of the nitrogen fertilizer factory was chronic and much more subtle. Diffusion chamber studies indicated that A. hydrophila survival is increased by pulp mill effluent and decreased by nitrogen fertilizer factory effluent. From correlation and regression analysis, A. hydrophila was found to be directly affected by phytoplankton density and, thus, indirectly by concentrations of phosphate, nitrate, and total organic carbon. These two point sources are suspect as indirect causes of red-sore disease epizootics, a disease of fish caused by A. hydrophila. PMID:6297393

East Fork Watershed Cooperative: Toward better system-scale watershed management

EPA Science Inventory

The East Fork Watershed Cooperative is a group intent on understanding how to best manage water quality in a large mixed-use Midwestern watershed system. The system contains a reservoir that serves as a source of drinking water and is popular for water recreation. The reservoir i...

Continuous resistivity profiling data from the Corsica River Estuary, Maryland

USGS Publications Warehouse

Cross, V.A.; Bratton, J.F.; Worley, C.R.; Crusius, John; Kroeger, K.D.

2011-01-01

Submarine groundwater discharge (SGD) into Maryland's Corsica River Estuary was investigated as part of a larger study to determine its importance in nutrient delivery to the Chesapeake Bay. The Corsica River Estuary represents a coastal lowland setting typical of much of the eastern bay. An interdisciplinary U.S. Geological Survey (USGS) science team conducted field operations in the lower estuary in April and May 2007. Resource managers are concerned about nutrients that are entering the estuary via SGD that may be contributing to eutrophication, harmful algal blooms, and fish kills. Techniques employed in the study included continuous resistivity profiling (CRP), piezometer sampling of submarine groundwater, and collection of a time series of radon tracer activity in surface water. A CRP system measures electrical resistivity of saturated subestuarine sediments to distinguish those bearing fresh water (high resistivity) from those with saline or brackish pore water (low resistivity). This report describes the collection and processing of CRP data and summarizes the results. Based on a grid of 67.6 kilometers of CRP data, low-salinity (high-resistivity) groundwater extended approximately 50-400 meters offshore from estuary shorelines at depths of 5 to >12 meters below the sediment surface, likely beneath a confining unit. A band of low-resistivity sediment detected along the axis of the estuary indicated the presence of a filled paleochannel containing brackish groundwater. The meandering paleochannel likely incised through the confining unit during periods of lower sea level, allowing the low-salinity groundwater plumes originating from land to mix with brackish subestuarine groundwater along the channel margins and to discharge. A better understanding of the spatial variability and geological controls of submarine groundwater flow beneath the Corsica River Estuary could lead to improved models and mitigation strategies for nutrient over-enrichment in the

The status of fish conservation in South African estuaries.

PubMed

Whitfield, A K; Cowley, P D

2010-06-01

Estuary-dependent fish species are defined as those taxa whose populations would be adversely affected by the loss of estuarine habitats. Of the 155 species regularly recorded in South African estuaries, only 32 (21%) are completely dependent on these systems, but this figure increases to 103 species (66%) if partially dependent taxa are included in the analysis. The conservation of fishes in estuaries on the subcontinent is threatened by a number of factors, including habitat degradation, disruption of essential ecological processes, hydrological manipulations, environmental pollution, overexploitation due to fishing activities and, more recently, climate change and the effects of introduced aquatic animals. Although major threats to fishes are usually linked to environmental degradation, there is increasing evidence that the stocks of certain fish species are overexploited or collapsed. Fish conservation and fisheries management does not depend on the implementation of a single action, but rather the co-ordination of a detailed plan, often in a multidisciplinary context. Some examples of innovative means of contributing to estuarine fish conservation in a South African context include the determination and implementation of the ecological freshwater requirements for estuaries, the zoning of estuaries for different uses and the recognition that the maintenance of ecological processes are vital to aquatic ecosystem health. Apart from the designation of protected areas, the main direct means of conserving fish species and stocks include habitat conservation, controls over fishing methods, effort, efficiency and seasonality, pollution control and the prevention of artificial manipulation of estuary mouths. Since becoming a democracy in 1994, environmental legislation, policy and institutional arrangements in South Africa have undergone some major changes, which, if fully implemented, will be very positive for fish conservation in estuaries on the subcontinent.

Estuary-dependence of larval fishes in a non-estuary associated South African surf zone: evidence for continuity of surf assemblages

NASA Astrophysics Data System (ADS)

Strydom, Nadine A.; d'Hotman, Bruce D.

2005-04-01

Larval fishes were collected in the Cape Padrone surf zone on the southeast coast of South Africa, using a modified small-mesh seine net. The aim of the study was to assess the composition of fish larvae, with respect to their association with estuaries, in a surf zone that was not in close proximity to an estuary (>5 km). Sampling took place bimonthly during diurnal spring low tides between March and July 2003. In total, 544 fish were caught in the surf zone, comprising 14 families represented by 19 positively identified species, as well as an additional two species that were differentiated but remain unidentified. The families Mugilidae (65%) and Sparidae (26%) dominated the larval catch. The majority of larval fishes caught were in the postflexion stage of development, although some early juveniles were also caught. Body lengths of fish larvae ranged between 2 and 28 mm, with the majority of larvae at the recruitment size for the species. A high proportion of the fish species caught were estuary-dependent. Estuary-dependent marine fish larvae (categories I, II and IV) comprised 68% of total catch by species and 98% by number of individuals. Exclusively marine species (category III) were encountered in low numbers in the surf. The present study provides evidence for continuity in temperate South African surf zones in terms of domination by estuary-dependent larvae and reasons for this pattern are discussed.

78 FR 9887 - Proposed Information Collection; Comment Request; National Estuaries Restoration Inventory

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... Collection; Comment Request; National Estuaries Restoration Inventory AGENCY: National Oceanic and... for a revision and extension of a currently approved information collection. Collection of estuary... information) will be undertaken in order to populate a restoration project database mandated by the Estuary...

An historical perspective on eutrophication in the Pensacola Bay Estuary, FL, USA

EPA Science Inventory

In this chapter, we provide a brief description of the Pensacola Bay estuary, examining the available historical data for evidence of trends in eutrophication within the estuary. Common to many industrialized estuaries, Pensacola Bay has been subjected to unregulated point source...

Small watershed response to porous rock check dams in a semiarid watershed

NASA Astrophysics Data System (ADS)

Nichols, Mary; Polyakov, Viktor; Nearing, Mark

2016-04-01

Rock check dams are used throughout the world as technique for mitigating erosion problems on degraded lands. Increasingly, they are being used in restoration efforts on rangelands in the southwestern US, however, their impact on watershed response and channel morphology is not well quantified. In 2008, 37 porous rock structures were built on two small (4.0 and 3.1 ha) instrumented watersheds on an alluvial fan at the base of the Santa Rita Mountains in southern Arizona, USA. 35 years of historical rainfall and runoff, and sediment data are available to compare with 7 years of data collected after check dam construction. In addition, post construction measurements of channel geometry and longitudinal channel profiles were compared with pre-construction measurements to characterize the impact of check dams on sediment retention and channel morphology. The primary impact of the check dams is was retention of channel sediment and reduction in channel gradient; however response varied between the proximal watersheds with 80% of the check dams on one of the watersheds filled to 100% of their capacity after 7 runoff seasons. In addition, initial impact on precipitation runoff ratios is was not persistent. The contrasting watershed experiences lower sediment yields and only 20% of the check dams on this watershed are were filled to capacity and continue to influence runoff during small events. Within the watersheds the mean gradient of the channel reach immediately upstream of the structures has been reduced by 35% (from 0.061 to 0.039) and 34% on (from 0.071 to 0.047).

Pairing high-frequency data with a link-node model to manage dissolved oxygen impairment in a dredged estuary.

PubMed

Camarillo, Mary Kay; Weissmann, Gregory A; Gulati, Shelly; Herr, Joel; Sheeder, Scott; Stringfellow, William T

2016-08-01

High-frequency data and a link-node model were used to investigate the relative importance of mass loads of oxygen-demanding substances and channel geometry on recurrent low dissolved oxygen (DO) in the San Joaquin River Estuary in California. The model was calibrated using 6 years of data. The calibrated model was then used to determine the significance of the following factors on low DO: excavation of the river to allow navigation of large vessels, non-point source pollution from the agricultural watershed, effluent from a wastewater treatment plant, and non-point source pollution from an urban area. An alternative metric for low DO, excess net oxygen demand (ENOD), was applied to better characterize DO impairment. Model results indicate that the dredged ship channel had the most significant effect on DO (62 % fewer predicted hourly DO violations), followed by mass load inputs from the watershed (52 % fewer predicted hourly DO violations). Model results suggest that elimination of any one factor will not completely resolve DO impairment and that continued use of supplemental aeration is warranted. Calculation of ENOD proved more informative than the sole use of DO. Application of the simple model allowed for interpretation of the extensive data collected. The current monitoring program could be enhanced by additional monitoring stations that would provide better volumetric estimates of low DO.

Changing ecosystem response to nitrogen load into Buzzards Bay, MA

NASA Astrophysics Data System (ADS)

Williamson, S.; Rheuban, J. E.; Costa, J. E.; Glover, D. M.; Doney, S. C.

2016-02-01

Nitrogen (N) and chlorophyll-a (Chla) concentration in estuarine systems often correlate positively with increased N inputs. Evaluation of a long-term water quality data set (1992 -2013) for Buzzards Bay, MA, however reveals that ecosystem response to N inputs may be changing over time, as represented by increased yield of Chla per unit total nitrogen (TN) from 1992-2013. To determine if this change is caused by changes in nitrogen sources, we estimate nitrogen input from 28 watersheds. Combining parcel specific waste water disposal, land use, and atmospheric deposition data, we estimated N loads into Buzzards Bay from 1985-2013 using a previously verified Nitrogen Loading Model. Of the 28 watersheds analyzed, the six largest watersheds released the largest absolute N loads into receiving estuaries ranging from approximately 50,000-220,000 kg N yr-1. Normalizing N loads by watershed and estuarine areas revealed that smaller watersheds release some of the greatest relative loads into estuaries making these watersheds more vulnerable to increases in N load. A linear regression analysis of N load through time revealed decreasing N loads for most watersheds on the western side of Buzzards Bay which we believe is reflecting decreased atmospheric N from 1985-2013. Out of the ten sub-watersheds on the eastern side, increases in human waste, driven primarily by increased parcels on septic have resulted in overall N load increases for 9 watersheds. Comparison of in situ TN and Chla concentrations with N load estimates for several watersheds and adjoining estuaries suggest that varied ecosystem responses to N load may be reflecting differences in physical stressors such as estuarine morphology, residence time, and climate change. Results of this study also reveal the importance of watershed specific mitigation efforts to best accommodate dominant N sources which may be influenced regionally (atmospheric N) and locally (fertilizer and human waste).

Integrated Watershed Management using the Watershed Management Optimization Support Tool (WMOST)

EPA Science Inventory

Integrated watershed management is an effective planning strategy to balance tradeoffs between competing water uses within a watershed. WMOST is an Excel-based decision tool to aid planners in making cost effective decisions that meet water quantity and quality regulations. WMOST...

Understanding nutrients in the Chesapeake Bay watershed and implications for management and restoration: the Eastern Shore

USGS Publications Warehouse

Ator, Scott W.; Denver, Judith M.

2015-03-12

The Eastern Shore includes only a small part of the Chesapeake Bay watershed, but contributes disproportionately large loads of the excess nitrogen and phosphorus that have contributed to ecological and economic degradation of the bay in recent decades. Chesapeake Bay is the largest estuary in the United States and a vital ecological and economic resource. The bay and its tributaries have been degraded in recent decades by excessive nitrogen and phosphorus in the water column, however, which cause harmful algal blooms and decreased water clarity, submerged aquatic vegetation, and dissolved oxygen. The disproportionately large nitrogen and phosphorus yields from the Eastern Shore to Chesapeake Bay are attributable to human land-use practices as well as natural hydrogeologic and soil conditions. Applications of nitrogen and phosphorus compounds to the Eastern Shore from human activities are intensive. More than 90 percent of nitrogen and phosphorus reaching the land in the Eastern Shore is applied as part of inorganic fertilizers or manure, or (for nitrogen) fixed directly from the atmosphere in cropland. Also, hydrogeologic and soil conditions promote the movement of these compounds from application areas on the landscape to groundwater and (or) surface waters, and the proximity of much of the Eastern Shore to tidal waters limits opportunities for natural removal of these compounds in the landscape. The Eastern Shore only includes 7 percent of the Chesapeake Bay watershed, but receives nearly twice as much nitrogen and phosphorus applications (per area) as the remainder of the watershed and yields greater nitrogen and phosphorus, on average, to the bay. Nitrogen and phosphorus commonly occur in streams at concentrations that may adversely affect aquatic ecosystems and have increased in recent decades.

Ecological Engineering Practices for the Reduction of Excess Nitrogen in Human-Influenced Landscapes: A Guide for Watershed Managers

NASA Astrophysics Data System (ADS)

Passeport, Elodie; Vidon, Philippe; Forshay, Kenneth J.; Harris, Lora; Kaushal, Sujay S.; Kellogg, Dorothy Q.; Lazar, Julia; Mayer, Paul; Stander, Emilie K.

2013-02-01

Excess nitrogen (N) in freshwater systems, estuaries, and coastal areas has well-documented deleterious effects on ecosystems. Ecological engineering practices (EEPs) may be effective at decreasing nonpoint source N leaching to surface and groundwater. However, few studies have synthesized current knowledge about the functioning principles, performance, and cost of common EEPs used to mitigate N pollution at the watershed scale. Our review describes seven EEPs known to decrease N to help watershed managers select the most effective techniques from among the following approaches: advanced-treatment septic systems, low-impact development (LID) structures, permeable reactive barriers, treatment wetlands, riparian buffers, artificial lakes and reservoirs, and stream restoration. Our results show a broad range of N-removal effectiveness but suggest that all techniques could be optimized for N removal by promoting and sustaining conditions conducive to biological transformations (e.g., denitrification). Generally, N-removal efficiency is particularly affected by hydraulic residence time, organic carbon availability, and establishment of anaerobic conditions. There remains a critical need for systematic empirical studies documenting N-removal efficiency among EEPs and potential environmental and economic tradeoffs associated with the widespread use of these techniques. Under current trajectories of N inputs, land use, and climate change, ecological engineering alone may be insufficient to manage N in many watersheds, suggesting that N-pollution source prevention remains a critical need. Improved understanding of N-removal effectiveness and modeling efforts will be critical in building decision support tools to help guide the selection and application of best EEPs for N management.

PEER REVIEW OF PECONIC ESTUARY PROGRAM HYDRODYNAMIC AND WATER QUALITY (EUTROPHICATION) MODEL

EPA Science Inventory

The Peconic Estuary is located on the eastern end of Long Island, New York. Under the Federal Clean Water Act, the Peconic Estuary was named an "Estuary of National Significance" in 1992. Because of its high concentration of rare, threatened and endangered species and habitats,...

Benthic macrofaunal dynamics and environmental stress across a salt wedge Mediterranean estuary.

PubMed

Nebra, Alfonso; Alcaraz, Carles; Caiola, Nuno; Muñoz-Camarillo, Gloria; Ibáñez, Carles

2016-06-01

The spatial distribution of benthic macroinvertebrate community in relation to environmental factors was studied along the Ebro Estuary (NE Iberian Peninsula), a salt wedge Mediterranean estuary. Both ordination methods and generalized additive models were performed to identify the different benthic assemblages and their relationship to abiotic factors. Our results showed a strong relationship between macrofaunal assemblages and the predominant environmental gradients (e.g. salinity); thus revealing spatial differences in their structure and composition. Two different stretches were identified, namely the upper (UE) and the lower Ebro Estuary (LE). UE showed riverine characteristics and hence was colonized by a freshwater community; whereas LE was influenced by marine intrusion and sustained a complex marine-origin community. However, within each stretch, water and sediment characteristics played an important role in explaining species composition differences among sampling stations. Moreover, outcomes suggested a total species replacement pattern, instead of the nestedness pattern usually associated with well-mixed temperate estuaries. The sharp species turnover together with the estuarine stratification point out that the Ebro Estuary is working, in terms of ecological boundaries, under an ecotone model. Finally, despite obvious differences with well mixed estuaries (i.e. lack of tidal influence, stratification and species turnover), the Ebro Estuary shares important ecological attributes with well-mixed temperate estuaries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Watershed councils: it takes a community to restore a watershed

Treesearch

Marie Oliver; Rebecca Flitcroft

2011-01-01

Regulation alone cannot solve complex ecological problems on private lands that are managed for diverse uses. Executing coordinated restoration projects at the watershed scale is only possible with the cooperation and commitment of all stakeholders. Locally organized, nonregulatory watershed councils have proven to be a powerful method of engaging citizens from all...

MANAGING URBAN WATERSHED PATHOGEN CONTAMINATION

EPA Science Inventory

This document is written as a resource for state and local watershed managers who have the responsibility of managing pathogen contamination in urban watersheds. In addition it can be an information source for members of the public interested in watershed mitigation efforts aime...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Petersburg watershed. 251.35... Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Petersburg watershed. 251.35... Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 36 Parks, Forests, and Public Property 2 2014-07-01 2014-07-01 false Petersburg watershed. 251.35... Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 36 Parks, Forests, and Public Property 2 2011-07-01 2011-07-01 false Petersburg watershed. 251.35... Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest, as...

36 CFR 251.35 - Petersburg watershed.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 36 Parks, Forests, and Public Property 2 2012-07-01 2012-07-01 false Petersburg watershed. 251.35... Miscellaneous Land Uses Petersburg Watershed § 251.35 Petersburg watershed. (a) Except as authorized in paragraphs (b) and (c), access to lands within the Petersburg watershed, Tongass National Forest, as...

Distribution of heavy metals and environmental assessment of surface sediment of typical estuaries in eastern China.

PubMed

Bi, Shipu; Yang, Yuan; Xu, Chengfen; Zhang, Yong; Zhang, Xiaobo; Zhang, Xianrong

2017-08-15

Estuary sediment is a major pollutant enrichment medium and is an important biological habitat. This sediment has attracted the attention of the marine environmental scientists because it is a more stable and effective medium than water for monitoring regional environmental quality conditions and trends. Based on a large amount of measurement data, we analyzed the concentrations, distribution, and sources of seven heavy metals (As, Cd, Cr, Cu, Hg, Pb, and Zn) in the surface sediment of typical estuaries that empty into the sea in eastern China: the Liaohe River Estuary, Yellow River Estuary, Yangtze River Estuary, Minjiang River Estuary, and Pearl River Estuary. The heavy metal concentrations in the sediments vary considerably from one estuary to the next. The Liaohe River Estuary sediment contains elevated levels of Cd, Hg, and Zn. The Yellow River Estuary sediment contains elevated levels of As. The sediments in the Yangtze River and Minjiang River estuaries contain elevated levels of Cd and Cu and of Pb and Zn, respectively. The sediment in the Pearl River Estuary contains elevated levels of all seven heavy metals. We used the Nemerow index method to assess the environment quality. The heavy metal pollution in the Liaohe River and Pearl River estuaries is more severe than that in the other estuaries. Additional work indicates that the heavy metal pollution in the Liaohe River and Pearl River estuaries is caused mainly by human activity. Copyright © 2017. Published by Elsevier Ltd.

The relationship between CDOM and salinity in estuaries: An analytical and graphical solution

NASA Astrophysics Data System (ADS)

Bowers, D. G.; Brett, H. L.

2008-09-01

The relationship between coloured dissolved organic matter (CDOM) and salinity in an estuary is explored using a simple box model in which the river discharge and concentration of CDOM in the river are allowed to vary with time. The results are presented as analytical and graphical solutions. The behaviour of the estuary depends upon the ratio, β, of the flushing time of the estuary to the timescale of the source variation. For small values of β, the variation in CDOM concentration in the estuary tracks that in the source, producing a linear relationship on a CDOM-salinity plot. As β increases, the estuary struggles to keep up with the changes in the source; and a curved CDOM-salinity plot results. For very large values of β, however, corresponding to estuaries with a long flushing time, the CDOM concentration in the estuary settles down to a mean value which again lies on a straight line on a CDOM-salinity plot (and extrapolates to the time-mean concentration in the source). The results are discussed in terms of the mapping of surface salinity in estuaries through the visible band remote sensing of CDOM.

Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed.

PubMed

Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

2017-03-03

In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world.

Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed

PubMed Central

Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

2017-01-01

In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world. PMID:28273834

Predicting fish community properties within estuaries: Influence of habitat type and other environmental features

NASA Astrophysics Data System (ADS)

França, Susana; Vasconcelos, Rita P.; Fonseca, Vanessa F.; Tanner, Susanne E.; Reis-Santos, Patrick; Costa, Maria José; Cabral, Henrique N.

2012-07-01

Statistical models predicting species distributions are essential not only to increase knowledge on species but for their application in conservation and ecologically-based management. The variation of fish species richness and abundance in the most representative habitats (saltmarsh, mudflat and subtidal) in five estuaries along the Portuguese coast was analysed through seasonal sampling surveys in 2009. Generalized additive models (GAM) were developed to describe the variation of species richness and abundances with a set of geomorphologic, hydrologic and environmental characteristics from the sampled estuaries and habitats. GAM were chosen as the complex interactions dominating these ecosystems and species distribution are non-linear. Final models built for each estuary and for all estuaries together performed well during the calibration phase and also during the validation phase, where an unused data sub-set from each estuary was used. There was not a similar combination of variables retained by the models for the studied estuaries but factors such as the area of the habitat, the distance to estuary mouth, percentage of mud in the sediment and depth were commonly retained. The partial effect of these predictor variables on the variation of species richness and abundance in the estuaries varied markedly and the importance of preserving the heterogeneity of habitats within estuaries was highlighted. Models for each individual estuary performed better than models for estuaries combined. Predictive models could be useful as a preliminary tool to prepare long-term conservation plans at different scales.

Watershed Effects on Streamflow Quantity and Quality in Six Watersheds of Gwinnett County, Georgia

USGS Publications Warehouse

Landers, Mark N.; Ankcorn, Paul D.; McFadden, Keith W.

2007-01-01

Watershed management is critical for the protection and enhancement of streams that provide multiple benefits for Gwinnett County, Georgia, and downstream communities. Successful watershed management requires an understanding of how stream quality is affected by watershed characteristics. The influence of watershed characteristics on stream quality is complex, particularly for the nonpoint sources of pollutants that affect urban watersheds. The U.S. Geological Survey (USGS), in cooperation with Gwinnett County Department of Water Resources (formerly known as Public Utilities), established a water-quality monitoring program during late 1996 to collect comprehensive, consistent, high-quality data for use by watershed managers. Between 1996 and 2003, more than 10,000 analyses were made for more than 430 water-quality samples. Continuous-flow and water-quality data have been collected since 1998. Loads have been computed for selected constituents from 1998 to 2003. Changing stream hydrology is a primary driver for many other water-quality and aquatic habitat effects. Primary factors affecting stream hydrology (after watershed size and climate) within Gwinnett County are watershed slope and land uses. For the six study watersheds in Gwinnett County, watershedwide imperviousness up to 12 percent does not have a well-defined influence on stream hydrology, whereas two watersheds with 21- and 35-percent impervious area are clearly impacted. In the stream corridor, however, imperviousness from 1.6 to 4.4 percent appears to affect baseflow and stormflow for all six watersheds. Relations of concentrations to discharge are used to develop regression models to compute constituent loads using the USGS LOAD ESTimator model. A unique method developed in this study is used to calibrate the model using separate baseflow and stormflow sample datasets. The method reduced model error and provided estimates of the load associated with the baseflow and stormflow parts of the hydrograph

The behavior of dissolved inorganic selenium in the Changjiang Estuary

NASA Astrophysics Data System (ADS)

Chang, Yan; Zhang, Jing; Qu, Jianguo; Zhang, Guosen; Zhang, Anyu; Zhang, Ruifeng

2016-02-01

To investigate the behavior of inorganic selenium species in the Changjiang Estuary, samples were taken during summer (July 2011) and winter (March 2012). Dissolved inorganic selenium (DISe) concentrations averaged 1.79 nmol/L in summer and 1.24 nmol/L in winter; the average selenite [Se(IV)] to selenate [Se(VI)] ratio [Se(IV)/Se(VI)] was 0.42 in summer and 0.61 in winter. The data show that Se(IV) and Se(VI) concentrations in the estuary behaved strictly conservatively during winter but non-conservatively during summer due to adsorption by suspended particulate matter (SPM) and assimilation by phytoplankton. In addition, the Se concentration distributions in the Changjiang Estuary were controlled by three water masses, each with a specific Se(IV)/Se(VI) ratio "signature": the Changjiang Water input, the Taiwan Warm Current, and the Yellow Sea Coastal Current. The Se(IV) concentrations were related to the nitrate, silicate, and phosphate concentrations in the estuary. The DISe and Se(IV) concentrations were comparable to those found in other coastal regions and estuaries, which were considered to be natural levels.

Plastic pollution in five urban estuaries of KwaZulu-Natal, South Africa.

PubMed

Naidoo, Trishan; Glassom, David; Smit, Albertus J

2015-12-15

Monitoring plastic concentrations in estuaries is vital in assessing the magnitude of terrestrial inputs to oceanic environments. Data on plastics ≤ 5 mm in estuaries are scant. This study determined microplastic levels within five estuaries along the Durban coastline and on intervening beaches. Plastics were isolated from estuarine sediment, beach sediment and the surface water of each estuary and characterised. Sediment at the Bayhead area of Durban harbour had the highest average plastic concentrations (745.4 ± 129.7 particles per 500 ml) and an attenuating concentration trend away from the city centre was found. Prevailing south to north longshore drift was hypothesised to result in plastic accumulation on the northern shores of beaches with estuarine effluents, however, this was not found. Fragments composed the largest percent of plastics (59%) found in Bayhead, whereas fibres dominated other estuaries with proportions ranging from 38% of total plastics in the uMgeni estuary to 66% in the Mdloti. Copyright © 2015 Elsevier Ltd. All rights reserved.

ASSESSING THE ECOLOGICAL CONDITION OF SOUTHEAST U. S. ESTUARIES

EPA Science Inventory

As a means to assess ecological condition, 151 stations located in southeastern estuaries from Cape Henry, Virginia to Biscayne Bay, Florida were sampled by state agencies during the summer of 2000 using a probabilistic design. The design used 8 size classes of estuaries ranging ...

Text only version of the National Estuary Program Story Map

EPA Pesticide Factsheets

Since 1987, the EPA National Estuary Program (NEP) has made a unique and lasting contribution to protecting and restoring our nation's estuaries, delivering environmental and public health benefits to the American people.

Watershed Restoration Project

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

Julie Thompson; Betsy Macfarlan

2007-09-27

In 2003, the U.S. Department of Energy issued the Eastern Nevada Landscape Coalition (ENLC) funding to implement ecological restoration in Gleason Creek and Smith Valley Watersheds. This project was made possible by congressionally directed funding that was provided through the US Department of Energy, Energy Efficiency and Renewable Energy, Office of the Biomass Program. The Ely District Bureau of Land Management (Ely BLM) manages these watersheds and considers them priority areas within the Ely BLM district. These three entities collaborated to address the issues and concerns of Gleason Creek and Smith Valley and prepared a restoration plan to improve themore » watersheds’ ecological health and resiliency. The restoration process began with watershed-scale vegetation assessments and state and transition models to focus on restoration sites. Design and implementation of restoration treatments ensued and were completed in January 2007. This report describes the restoration process ENLC undertook from planning to implementation of two watersheds in semi-arid Eastern Nevada.« less

Late Holocene Environmental History of the Los Osos Watershed, Morro Bay, CA

NASA Astrophysics Data System (ADS)

Broadman, E.; Reidy, L. M.; Wahl, D.

2014-12-01

A comprehensive understanding of past changes in wetland ecosystems is integral for creating policies for modern land use practices. The Morro Bay salt marsh is home to a large wetland that has experienced significant environmental impacts in the last few centuries. In this study, sediment cores from the Morro Bay salt marsh were analyzed to discern changes in environment since the time of European contact, which occurred in 1772. The marsh is fed by two creeks (Chorro and Los Osos) and their associated watersheds. Sediment cores taken from a portion of the marsh fed by Los Osos creek were analyzed and the results compared to those from previous studies on cores taken from the Chorro and Los Osos portions of the marsh. Magnetic susceptibility, loss on ignition, pollen, radiocarbon, and X-ray fluorescence (XRF) analyses were conducted. An age-depth model was established for the Los Osos cores using two radiocarbon dates, as well as Erodium cicutarium as a chronological marker. Preliminary pollen analysis from Chorro marsh cores indicates vegetation shifts at the time of contact, when the salt marsh formed. Magnetic susceptibility and XRF data indicate dramatically increased rates of erosion from the time of contact consistently until the present. Influx of non-carbonate inorganic material also indicates a rapid increase in sedimentation in the marsh starting at the time of contact. Comparison of sedimentation rates between the two creeks suggests that differences in watershed geomorphology and land use practices have had pronounced impacts on erosional processes. Over the last decade, the Morro Bay National Estuary Program (MBNEP) has taken more measures to reduce erosion and sedimentation rates in the Chorro watershed, as is reflected by reduced sedimentation rates in MBNEP data collected within the last few years. Our study helps to elucidate the impacts of anthropogenic land use change on wetland systems, and provides much needed data to policy makers seeking to

Assessing the impact of nutrient enrichment in estuaries: susceptibility to eutrophication.

PubMed

Painting, S J; Devlin, M J; Malcolm, S J; Parker, E R; Mills, D K; Mills, C; Tett, P; Wither, A; Burt, J; Jones, R; Winpenny, K

2007-01-01

The main aim of this study was to develop a generic tool for assessing risks and impacts of nutrient enrichment in estuaries. A simple model was developed to predict the magnitude of primary production by phytoplankton in different estuaries from nutrient input (total available nitrogen and/or phosphorus) and to determine likely trophic status. In the model, primary production is strongly influenced by water residence times and relative light regimes. The model indicates that estuaries with low and moderate light levels are the least likely to show a biological response to nutrient inputs. Estuaries with a good light regime are likely to be sensitive to nutrient enrichment, and to show similar responses, mediated only by site-specific geomorphological features. Nixon's scale was used to describe the relative trophic status of estuaries, and to set nutrient and chlorophyll thresholds for assessing trophic status. Estuaries identified as being eutrophic may not show any signs of eutrophication. Additional attributes need to be considered to assess negative impacts. Here, likely detriment to the oxygen regime was considered, but is most applicable to areas of restricted exchange. Factors which limit phytoplankton growth under high nutrient conditions (water residence times and/or light availability) may favour the growth of other primary producers, such as macrophytes, which may have a negative impact on other biological communities. The assessment tool was developed for estuaries in England and Wales, based on a simple 3-category typology determined by geomorphology and relative light levels. Nixon's scale needs to be validated for estuaries in England and Wales, once more data are available on light levels and primary production.

Hydro-ecological degradation due to human impacts in the Twin Streams Watershed, Auckland, New Zealand

NASA Astrophysics Data System (ADS)

Torrecillas Nunez, C.; Miguel-rodriguez, A.

2012-12-01

wide range of impacts due to human actions which will exacerbated by future development as the population in the watershed is forecast to increase by at least 65% and the likely impacts of global warming. The rural watershed generates sediment which smothers the streams and harbor, while the urban watershed is the source of point and diffuse contamination with heavy metals which damage ecosystems. Evidence of impacts is given by the extent of flooding, reduced ecological flows and sampling results showing that more than 50% of the sites do not comply with environmental guidelines for: water clarity, turbidity, suspended solids, nitrogen, phosphorus, copper, zinc, conductivity, Dieldrin, DDT, Dissolved Oxygen, E.Coli, macroinvertebrates ,etc. , with water quality deteriorating progressively downstream where there is greater urbanization. But perhaps the most stunning evidence of the impacts was established by comparing aerial photographs of the 1940s and 2006 and seeing the build-up of sediments in the estuaries, the change in vegetation cover and discolored water. It is highly likely that the tipping point was reached before urbanization started but there is no doubt that urban development has accelerated the impacts, which has been corroborated by studies in other watersheds in Auckland.

WATERSHED INFORMATION NETWORK

EPA Science Inventory

Resource Purpose:The Watershed Information Network is a set of about 30 web pages that are organized by topic. These pages access existing databases like the American Heritage Rivers Services database and Surf Your Watershed. WIN in itself has no data or data sets.
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