Human mediated transport determines the non-native distribution of a dispersal limited estuarine invertebrate

EPA Science Inventory

Sessile invertebrates are common invaders of estuarine ecosystems. To expand their non-native ranges, these invasive taxa must contend with the geographically and ecologically discontinuous nature of estuarine habitats, in many cases without the benefit of highly dispersed larval...

An assessment of landscape characteristics affecting estuarine nitrogen loading in an urban watershed.

PubMed

Yang, Xiaojun

2012-02-01

Exploring the quantitative association between landscape characteristics and the ecological conditions of receiving waters has recently become an emerging area for eco-environmental research. While the landscape-water relationship research has largely targeted on inland aquatic systems, there has been an increasing need to develop methods and techniques that can better work with coastal and estuarine ecosystems. In this paper, we present a geospatial approach to examine the quantitative relationship between landscape characteristics and estuarine nitrogen loading in an urban watershed. The case study site is in the Pensacola estuarine drainage area, home of the city of Pensacola, Florida, USA, where vigorous urban sprawling has prompted growing concerns on the estuarine ecological health. Central to this research is a remote sensor image that has been used to extract land use/cover information and derive landscape metrics. Several significant landscape metrics are selected and spatially linked with the nitrogen loading data for the Pensacola bay area. Landscape metrics and nitrogen loading are summarized by equal overland flow-length rings, and their association is examined by using multivariate statistical analysis. And a stepwise model-building protocol is used for regression designs to help identify significant variables that can explain much of the variance in the nitrogen loading dataset. It is found that using landscape composition or spatial configuration alone can explain most of the nitrogen loading variability. Of all the regression models using metrics derived from a single land use/cover class as the independent variables, the one from the low density urban gives the highest adjusted R-square score, suggesting the impact of the watershed-wide urban sprawl upon this sensitive estuarine ecosystem. Measures towards the reduction of non-point source pollution from urban development are necessary in the area to protect the Pensacola bay ecosystem and its

Triclosan alterations of estuarine phytoplankton community structure.

PubMed

Pinckney, James L; Thompson, Laura; Hylton, Sarah

2017-06-15

Antimicrobial additives in pharmaceutical and personal care products are a major environmental concern due to their potential ecological impacts on aquatic ecosystems. Triclosan (TCS) has been used as an antiseptic, disinfectant, and preservative in various media. The sublethal and lethal effects of TCS on estuarine phytoplankton community composition were investigated using bioassays of natural phytoplankton communities to measure phytoplankton responses to different concentrations of TCS ranging from 1 to 200μgl -1 . The EC 50 (the concentration of an inhibitor where the growth is reduced by half) for phytoplankton groups (diatoms, chlorophytes, cryptophytes) examined in this ranged from 10.7 to 113.8μg TCS l -1 . Exposures resulted in major shifts in phytoplankton community composition at concentrations as low as 1.0μg TCS l -1 . This study demonstrates estuarine ecosystem sensitivity to TCS exposure and highlights potential alterations in phytoplankton community composition at what are typically environmental concentrations of TCS in urbanized estuaries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Columbia River Estuary ecosystem classification—Concept and application

USGS Publications Warehouse

Simenstad, Charles A.; Burke, Jennifer L.; O'Connor, Jim E.; Cannon, Charles; Heatwole, Danelle W.; Ramirez, Mary F.; Waite, Ian R.; Counihan, Timothy D.; Jones, Krista L.

2011-01-01

This document describes the concept, organization, and application of a hierarchical ecosystem classification that integrates saline and tidal freshwater reaches of estuaries in order to characterize the ecosystems of large flood plain rivers that are strongly influenced by riverine and estuarine hydrology. We illustrate the classification by applying it to the Columbia River estuary (Oregon-Washington, USA), a system that extends about 233 river kilometers (rkm) inland from the Pacific Ocean. More than three-quarters of this length is tidal freshwater. The Columbia River Estuary Ecosystem Classification ("Classification") is based on six hierarchical levels, progressing from the coarsest, regional scale to the finest, localized scale: (1) Ecosystem Province; (2) Ecoregion; (3) Hydrogeomorphic Reach; (4) Ecosystem Complex; (5) Geomorphic Catena; and (6) Primary Cover Class. We define and map Levels 1-3 for the entire Columbia River estuary with existing geospatial datasets, and provide examples of Levels 4-6 for one hydrogeomorphic reach. In particular, three levels of the Classification capture the scales and categories of ecosystem structure and processes that are most tractable to estuarine research, monitoring, and management. These three levels are the (1) eight hydrogeomorphic reaches that embody the formative geologic and tectonic processes that created the existing estuarine landscape and encompass the influence of the resulting physiography on interactions between fluvial and tidal hydrology and geomorphology across 230 kilometers (km) of estuary, (2) more than 15 ecosystem complexes composed of broad landforms created predominantly by geologic processes during the Holocene, and (3) more than 25 geomorphic catenae embedded within ecosystem complexes that represent distinct geomorphic landforms, structures, ecosystems, and habitats, and components of the estuarine landscape most likely to change over short time periods.

SPATIAL AND TEMPORAL VARIABILITY AND DRIVERS OF NET ECOSYSTEM METABOLISM IN WESTERN GULF OF MEXICO ESTUARIES

EPA Science Inventory

Net ecosystem metabolism (NEM) is becoming a commonly used ecological indicator of estuarine ecosystem metabolic rates. Estuarine ecosystem processes are spatially and temporally variable, but the corresponding variability in NEM has not been properly assessed. Spatial and temp...

Functional trait responses to sediment deposition reduce macrofauna-mediated ecosystem functioning in an estuarine mudflat

NASA Astrophysics Data System (ADS)

Mestdagh, Sebastiaan; Bagaço, Leila; Braeckman, Ulrike; Ysebaert, Tom; De Smet, Bart; Moens, Tom; Van Colen, Carl

2018-05-01

Human activities, among which dredging and land use change in river basins, are altering estuarine ecosystems. These activities may result in changes in sedimentary processes, affecting biodiversity of sediment macrofauna. As macrofauna controls sediment chemistry and fluxes of energy and matter between water column and sediment, changes in the structure of macrobenthic communities could affect the functioning of an entire ecosystem. We assessed the impact of sediment deposition on intertidal macrobenthic communities and on rates of an important ecosystem function, i.e. sediment community oxygen consumption (SCOC). An experiment was performed with undisturbed sediment samples from the Scheldt river estuary (SW Netherlands). The samples were subjected to four sedimentation regimes: one control and three with a deposited sediment layer of 1, 2 or 5 cm. Oxygen consumption was measured during incubation at ambient temperature. Luminophores applied at the surface, and a seawater-bromide mixture, served as tracers for bioturbation and bio-irrigation, respectively. After incubation, the macrofauna was extracted, identified, and counted and then classified into functional groups based on motility and sediment reworking capacity. Total macrofaunal densities dropped already under the thinnest deposits. The most affected fauna were surficial and low-motility animals, occurring at high densities in the control. Their mortality resulted in a drop in SCOC, which decreased steadily with increasing deposit thickness, while bio-irrigation and bioturbation activity showed increases in the lower sediment deposition regimes but decreases in the more extreme treatments. The initial increased activity likely counteracted the effects of the drop in low-motility, surficial fauna densities, resulting in a steady rather than sudden fall in oxygen consumption. We conclude that the functional identity in terms of motility and sediment reworking can be crucial in our understanding of the

Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

USGS Publications Warehouse

Cloern, J.E.; Jassby, A.D.

2012-01-01

Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion; human modification of sediment supply; introduction of non-native species; sewage input; environmental policy; and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion; decreasing turbidity; restructuring of plankton communities; nutrient enrichment; elimination of hypoxia and reduced metal contamination of biota; and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The wide range of variability time scales and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs. But the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

Drivers of change in estuarine-coastal ecosystems: Discoveries from four decades of study in San Francisco Bay

NASA Astrophysics Data System (ADS)

Cloern, James E.; Jassby, Alan D.

2012-12-01

Poised at the interface of rivers, ocean, atmosphere and dense human settlement, estuaries are driven by a large array of natural and anthropogenic forces. San Francisco Bay exemplifies the fast-paced change occurring in many of the world's estuaries, bays, and inland seas in response to these diverse forces. We use observations from this particularly well-studied estuary to illustrate responses to six drivers that are common agents of change where land and sea meet: water consumption and diversion, human modification of sediment supply, introduction of nonnative species, sewage input, environmental policy, and climate shifts. In San Francisco Bay, responses to these drivers include, respectively, shifts in the timing and extent of freshwater inflow and salinity intrusion, decreasing turbidity, restructuring of plankton communities, nutrient enrichment, elimination of hypoxia and reduced metal contamination of biota, and food web changes that decrease resistance of the estuary to nutrient pollution. Detection of these changes and discovery of their causes through environmental monitoring have been essential for establishing and measuring outcomes of environmental policies that aim to maintain high water quality and sustain services provided by estuarine-coastal ecosystems. The many time scales of variability and the multiplicity of interacting drivers place heavy demands on estuarine monitoring programs, but the San Francisco Bay case study illustrates why the imperative for monitoring has never been greater.

DOES TERRESTRIAL CARBON SUBSIDIZE PRODUCTION OF ESTUARINE FISH LARVAE?

EPA Science Inventory

The research presented demonstrates the important role that terrestrial ecosystems can play in coastal food webs. We show that terrestrial carbon subsidizes the tidal freshwater and oligohaline portions of an estuarine food web, but that this exogenous carbon source is not impor...

Fish community-based measures of estuarine ecological quality and pressure-impact relationships

NASA Astrophysics Data System (ADS)

Fonseca, Vanessa F.; Vasconcelos, Rita P.; Gamito, Rita; Pasquaud, Stéphanie; Gonçalves, Catarina I.; Costa, José L.; Costa, Maria J.; Cabral, Henrique N.

2013-12-01

Community-based responses of fish fauna to anthropogenic pressures have been extensively used to assess the ecological quality of estuarine ecosystems. Several methodologies have been developed recently combining metrics reflecting community structure and function. A fish community facing significant environmental disturbances will be characterized by a simplified structure, with lower diversity and complexity. However, estuaries are naturally dynamic ecosystems exposed to numerous human pressures, making it difficult to distinguish between natural and anthropogenic-induced changes to the biological community. In the present work, the variability of several fish metrics was assessed in relation to different pressures in estuarine sites. The response of a multimetric index (Estuarine Fish Assessment Index) was also analysed. Overall, fish metrics and the multimetric index signalled anthropogenic stress, particularly environmental chemical pollution. The fish assemblage associated with this type of pressure was characterized by lower species diversity, lower number of functional guilds, lower abundance of marine migrants and of piscivorous individuals, and higher abundance of estuarine resident species. A decreased ecological quality status, based on the EFAI, was also determined for sites associated with this pressure group. Ultimately, the definition of each pressure groups favoured a stressor-specific analysis, evidencing pressure patterns and accounting for multiple factors in a highly dynamic environment.

Progress and challenges in coupled hydrodynamic-ecological estuarine modeling.

PubMed

Ganju, Neil K; Brush, Mark J; Rashleigh, Brenda; Aretxabaleta, Alfredo L; Del Barrio, Pilar; Grear, Jason S; Harris, Lora A; Lake, Samuel J; McCardell, Grant; O'Donnell, James; Ralston, David K; Signell, Richard P; Testa, Jeremy M; Vaudrey, Jamie M P

2016-03-01

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear, because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a "theory of everything" for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.

Progress and challenges in coupled hydrodynamic-ecological estuarine modeling

USGS Publications Warehouse

Ganju, Neil K.; Brush, Mark J.; Rashleigh, Brenda; Aretxabaleta, Alfredo L.; del Barrio, Pilar; Grear, Jason S.; Harris, Lora A.; Lake, Samuel J.; McCardell, Grant; O'Donnell, James; Ralston, David K.; Signell, Richard P.; Testa, Jeremy; Vaudrey, Jamie M. P.

2016-01-01

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.

Progress and challenges in coupled hydrodynamic-ecological estuarine modeling

PubMed Central

Ganju, Neil K.; Brush, Mark J.; Rashleigh, Brenda; Aretxabaleta, Alfredo L.; del Barrio, Pilar; Grear, Jason S.; Harris, Lora A.; Lake, Samuel J.; McCardell, Grant; O’Donnell, James; Ralston, David K.; Signell, Richard P.; Testa, Jeremy M.; Vaudrey, Jamie M.P.

2016-01-01

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear, because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a “theory of everything” for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy. PMID:27721675

Impacts of Suspended Sediment and Estuarine - Shelf Exchange Pathways on Shelf Ecosystem Dynamics in the Northern Gulf of Mexico

NASA Astrophysics Data System (ADS)

Wiggert, J. D.; Pan, C.; Dinniman, M. S.; Lau, Y.; Fitzpatrick, P. J.; O'Brien, S. J.; Bouchard, C.; Quas, L. M.; Miles, T. N.; Cambazoglu, M. K.; Dykstra, S. L.; Dzwonkowski, B.; Jacobs, G. A.; Church, I.; Hofmann, E. E.

2017-12-01

A circulation model based on the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System, with coupled biogeochemical and sediment transport modules, has been implemented for Mississippi Sound and the adjacent continental shelf region. The model has 400-m horizontal resolution, 24 vertical layers, and includes wetting/drying capability to resolve shallow inshore regions. The circulation model was spun-up using oceanographic initial and lateral boundary conditions provided by a 1-km resolution regional implementation of the Navy Coastal Ocean Model (NCOM) in the Gulf of Mexico. The biogeochemical module includes multiple size classes of phytoplankton, zooplankton and detritus, a fish larvae compartment, and explicitly tracks dissolved oxygen with benthic cycling interaction. The sediment transport model is implemented based on benthic mapping data that provides bottom sediment type distributions and spatio-temporal validation. A regionally specific atmospheric forcing product that provides improved spatial and temporal resolution, including diurnal sea breeze impacts, has been developed and applied. Model experiments focus on periods when comprehensive ship-based sampling was deployed by the CONCORDE (Consortium for Coastal River-Dominated Ecosystems) research program, which was established to investigate the complex fine-scale biological, chemical and physical interactions in a marine system controlled by pulsed-river plume dynamics. Biophysical interactions and biogeochemical variability associated with estuarine - shelf exchanges between nearshore lagoonal estuarine waters and the continental shelf revealed by the model provide new insight into how seasonal variation of hydrological forcing conditions influence ecological and biogeochemical processes in the highly productive Northern Gulf region. Application of the COAWST-based model system with and without inclusion of the sediment transport module demonstrates how suspended sediment in the

Principal processes within the estuarine salinity gradient: a review.

PubMed

Telesh, Irena V; Khlebovich, Vladislav V

2010-01-01

The salinity gradient is one of the main features characteristic of any estuarine ecosystem. Within this gradient in a critical salinity range of 5-8 PSU the major biotic and abiotic processes demonstrate non-linear dynamics of change in rates and directions. In estuaries, this salinity range acts as both external ecological factor and physiological characteristics of internal environment of aquatic organisms; it divides living conditions appropriate for freshwater and marine faunas, separates invertebrate communities with different osmotic regulation types, and defines the distribution range of high taxa. In this paper, the non-linearity of biotic processes within the estuarine salinity gradient is illustrated by the data on zooplankton from the Baltic estuaries. The non-tidal Baltic Sea provides a good demonstration of the above phenomena due to gradual changes of environmental factors and relatively stable isohalines. The non-linearity concept coupled with the ecosystem approach served the basis for a new definition of an estuary proposed by the authors. Copyright 2010 Elsevier Ltd. All rights reserved.

A CONCEPTUAL MODEL FOR MULTI-SCALAR ASSESSMENTS OF ESTUARINE ECOLOGICAL INTEGRITY

EPA Science Inventory

A conceptual model was developed that relates an estuarine system's anthropogenic inputs to it's ecological integrity. Ecological integrity is operationally defined as an emergent property of an ecosystem that exists when the structural components are complete and the functional ...

Ecoengineering with Ecohydrology: Successes and failures in estuarine restoration

NASA Astrophysics Data System (ADS)

Elliott, Michael; Mander, Lucas; Mazik, Krysia; Simenstad, Charles; Valesini, Fiona; Whitfield, Alan; Wolanski, Eric

2016-07-01

Ecological Engineering (or Ecoengineering) is increasingly used in estuaries to re-create and restore ecosystems degraded by human activities, including reduced water flow or land poldered for agricultural use. Here we focus on ecosystem recolonization by the biota and their functioning and we separate Type A Ecoengineering where the physico-chemical structure is modified on the basis that ecological structure and functioning will then follow, and Type B Ecoengineering where the biota are engineered directly such as through restocking or replanting. Modifying the physical system to create and restore natural processes and habitats relies on successfully applying Ecohydrology, where suitable physical conditions, especially hydrography and sedimentology, are created to recover estuarine ecology by natural or human-mediated colonisation of primary producers and consumers, or habitat creation. This successional process then allows wading birds and fish to reoccupy the rehabilitated areas, thus restoring the natural food web and recreating nursery areas for aquatic biota. We describe Ecohydrology principles applied during Ecoengineering restoration projects in Europe, Australia, Asia, South Africa and North America. These show some successful and sustainable approaches but also others that were less than successful and not sustainable despite the best of intentions (and which may even have harmed the ecology). Some schemes may be 'good for the ecologists', as conservationists consider it successful that at least some habitat was created, albeit in the short-term, but arguably did little for the overall ecology of the area in space or time. We indicate the trade-offs between the short- and long-term value of restored and created ecosystems, the success at developing natural structure and functioning in disturbed estuaries, the role of this in estuarine and wetland management, and the costs and benefits of Ecoengineering to the socio-ecological system. These global case

Combined proteomic and metallomic analyses in Scrobicularia plana clams to assess environmental pollution of estuarine ecosystems.

PubMed

González-Domínguez, Raúl; Santos, Hugo Miguel; Bebianno, Maria João; García-Barrera, Tamara; Gómez-Ariza, José Luis; Capelo, José Luis

2016-12-15

Estuaries are very important ecosystems with great ecological and economic value, but usually highly impacted by anthropogenic pressure. Thus, the assessment of pollution levels in these habitats is critical in order to evaluate their environmental quality. In this work, we combined complementary metallomic and proteomic approaches with the aim to monitor the effects of environmental pollution on Scrobicularia plana clams captured in three estuarine systems from the south coast of Portugal; Arade estuary, Ria Formosa and Guadiana estuary. Multi-elemental profiling of digestive glands was carried out to evaluate the differential pollution levels in the three study areas. Then, proteomic analysis by means of two-dimensional gel electrophoresis and mass spectrometry revealed twenty-one differential proteins, which could be associated with multiple toxicological mechanisms induced in environmentally stressed organisms. Accordingly, it could be concluded that the combination of different omic approaches presents a great potential in environmental research. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ecosystem Services Transcend Boundaries: Estuaries Provide Resource Subsidies and Influence Functional Diversity in Coastal Benthic Communities

PubMed Central

Savage, Candida; Thrush, Simon F.; Lohrer, Andrew M.; Hewitt, Judi E.

2012-01-01

Background Estuaries are highly productive ecosystems that can export organic matter to coastal seas (the ‘outwelling hypothesis’). However the role of this food resource subsidy on coastal ecosystem functioning has not been examined. Methodology/Principal Findings We investigated the influence of estuarine primary production as a resource subsidy and the influence of estuaries on biodiversity and ecosystem functioning in coastal mollusk-dominated sediment communities. Stable isotope values (δ13C, δ15N) demonstrated that estuarine primary production was exported to the adjacent coast and contributed to secondary production up to 4 km from the estuary mouth. Further, isotope signatures of suspension feeding bivalves on the adjacent coast (Dosinia subrosea) closely mirrored the isotope values of the dominant bivalves inside the estuaries (Austrovenus stutchburyi), indicating utilization of similar organic matter sources. However, the food subsidies varied between estuaries; with estuarine suspended particulate organic matter (SPOM) dominant at Tairua estuary, while seagrass and fringing vegetation detritus was proportionately more important at Whangapoua estuary, with lesser contributions of estuarine SPOM. Distance from the estuary mouth and the size and density of large bivalves (Dosinia spp.) had a significant influence on the composition of biological traits in the coastal macrobenthic communities, signaling the potential influence of these spatial subsidies on ecosystem functioning. Conclusions/Significance Our study demonstrated that the locations where ecosystem services like productivity are generated are not necessarily where the services are utilized. Further, we identified indirect positive effects of the nutrient subsidies on biodiversity (the estuarine subsidies influenced the bivalves, which in turn affected the diversity and functional trait composition of the coastal sediment macrofaunal communities). These findings highlight the importance of

SCOR Working Group 137: "Global Patterns of Phytoplankton Dynamics in Coastal Ecosystems": An introduction to the special issue of Estuarine, Coastal and Shelf Science

NASA Astrophysics Data System (ADS)

Paerl, Hans W.; Yin, Kedong; O'Brien, Todd D.

2015-09-01

Phytoplankton form the base of most aquatic food webs and play a central role in assimilation and processing of carbon and nutrients, including nitrogen, phosphorus, silicon, iron and a wide range of trace elements (Reynolds, 2006). In the marine environment, estuarine and coastal ecosystems (jointly termed coastal here) are among the most productive, resourceful and dynamic habitats on Earth (Malone et al., 1999; Day et al., 2012). These ecosystems constitute only ∼10% of the global oceans' surface, but account for over 30% of its primary production (Day et al., 2012). They process vast amounts of nutrients, sediments, carbonaceous, and xenobiotic compounds generated in coastal watersheds, in which approximately 70% of the world's human population resides (Nixon, 1995; Vitousek et al., 1997; NOAA, 2013). Estuarine and coastal ecosystems are also strongly influenced by localized nutrient enrichment from coastal upwelling, with major impacts on the structure and function of phytoplankton communities and the food webs they support (Legendre and Rassoulzadegan, 2012; Paerl and Justić, 2012). In addition, introductions and invasions of exotic plant and animal species have led to significant "top down" mediated changes in phytoplankton community structure and function (Carlton, 1999; Thompson, 2005). Lastly, the coastal zone is the "front line" of climatically-induced environmental change, including warming, altered rainfall patterns, intensities and magnitudes (Trenberth, 2005; IPCC, 2012), which jointly impact phytoplankton community structure and function (Cloern and Jassby, 2012; Hall et al., 2013). The combined effects of these pressures translate into a myriad of changes in phytoplankton production and community structure along geomorphological and geographic gradients (Fig. 1), with cascading quantitative and qualitative impacts on biogeochemical cycling, food web structure and function, water quality and overall resourcefulness and sustainability of these

ASSESSMENT OF RISK REDUCTION STRATEGIES FOR THE MANAGEMENT OF AGRICULTURAL NONPOINT SOURCE PESTICIDE RUNOFF IN ESTUARINE ECOSYSTEMS

EPA Science Inventory

Agricultural nonpoint source (NPS) runoff may result in significant discharges of pesticides, suspended sediments, and fertilizers into estuarine habitats adjacent to agricultural areas or downstream from agricultural watersheds. Exposure of estuarine fin fish and shellfish to to...

DIAGNOSING CAUSES OF IMPAIRMENT IN COASTAL ECOSYSTEMS

EPA Science Inventory

Engle, Virginia D. and Stephen J. Jordan. In press. Diagnosing Causes of Impairment in Coastal Ecosystems (Abstract). To be presented at the SETAC Fourth World Congress, 14-18 November 2004, Portland, OR. 1 p. (ERL,GB R1008).

Estuarine and coastal ecosystems are challenge...

Challenging paradigms in estuarine ecology and management

NASA Astrophysics Data System (ADS)

Elliott, M.; Whitfield, A. K.

2011-10-01

For many years, estuarine science has been the 'poor relation' in aquatic research - freshwater scientists ignored estuaries as they tended to get confused by salt and tides, and marine scientists were more preoccupied by large open systems. Estuaries were merely regarded by each group as either river mouths or sea inlets respectively. For the past four decades, however, estuaries (and other transitional waters) have been regarded as being ecosystems in their own right. Although often not termed as such, this has led to paradigms being generated to summarise estuarine structure and functioning and which relate to both the natural science and management of these systems. This paper defines, details and affirms these paradigms that can be grouped into those covering firstly the science (definitions, scales, linkages, productivity, tolerances and variability) and secondly the management (pressures, valuation, health and services) of estuaries. The more 'science' orientated paradigms incorporate the development and types of ecotones, the nature of stressed and variable systems (with specific reference to resilience and redundancy), the relationship between generalists and specialists produced by environmental tolerance, the relevance of scale in relation to functioning and connectivity, the sources of production and degree of productivity, the biodiversity-ecosystem functioning and the stress-subsidy debates. The more 'management' targeted paradigms include the development and effects of exogenic unmanaged pressures and endogenic managed pressures, the perception of health and the ability to manage estuaries (related to internal and external influences), and the influence of all of these on the production of ecosystem services and societal benefits.

Size, sex and individual-level behaviour drive intrapopulation variation in cross-ecosystem foraging of a top-predator.

PubMed

Nifong, James C; Layman, Craig A; Silliman, Brian R

2015-01-01

Large-bodied, top-predators are often highly mobile, with the potential to provide important linkages between spatially distinct food webs. What biological factors contribute to variation in cross-ecosystem movements, however, have rarely been examined. Here, we investigated how ontogeny (body size), sex and individual-level behaviour impacts intrapopulation variation in cross-ecosystem foraging (i.e. between freshwater and marine systems), by the top-predator Alligator mississippiensis. Field surveys revealed A. mississippiensis uses marine ecosystems regularly and are abundant in estuarine tidal creeks (from 0·3 to 6·3 individuals per km of creek, n = 45 surveys). Alligator mississippiensis captured in marine/estuarine habitats were significantly larger than individuals captured in freshwater and intermediate habitats. Stomach content analysis (SCA) showed that small juveniles consumed marine/estuarine prey less frequently (6·7% of individuals) than did large juveniles (57·8%), subadult (73%), and adult (78%) size classes. Isotopic mixing model analysis (SIAR) also suggests substantial variation in use of marine/estuarine prey resources with differences among and within size classes between sexes and individuals (range of median estimates for marine/estuarine diet contribution = 0·05-0·76). These results demonstrate the importance of intrapopulation characteristics (body size, sex and individual specialization) as key determinants of the strength of predator-driven ecosystem connectivity resulting from cross-ecosystem foraging behaviours. Understanding the factors, which contribute to variation in cross-ecosystem foraging behaviours, will improve our predictive understanding of the effects of top-predators on community structure and ecosystem function. © 2014 The Authors. Journal of Animal Ecology © 2014 British Ecological Society.

Tidal effects on net ecosystem exchange of carbon in an estuarine wetland

Treesearch

H. Guo; A. Noormets; B. Zhao; J. Chen; G. Sun; Y. Gu; B. Li; J. Chen

2009-01-01

One year of continuous data from two eddy-flux towers established along an elevation gradient incoastal Shanghai was analyzed to evaluate the tidal effect on carbon flux (Fc) over an estuarine wetland.The measured wavelet spectra and cospectra of Fc and other environmental factors demonstrated thatthe...

Incorporating Ecosystem Services into Community-level ...

EPA Pesticide Factsheets

EPA’s Office of Research and Development’s Sustainable and Healthy Communities Research Program is developing tools and approaches to incorporate ecosystem goods and services concepts into community-level decision-making. The San Juan Community Study is one of a series of coordinated community studies, which also include Mobile Bay, AL, Great Lakes Areas of Concern, and the Pacific Northwest. Common elements across the community studies include a focus on watershed management and national estuary programs (National Estuary Program, National Estuarine Research Reserve System). San Juan, Puerto Rico, is unique from the other community studies in that it is located in a highly urbanized watershed integrated with a number of freshwater and coastal ecosystems. The San Juan Community Study will explore linkages between watershed management decisions (e.g., dredging canals, restoration of mangrove buffers, sewage discharge interventions, climate adaptive strategies) targeting priority stressors (e.g., nutrients, contaminants, and pathogens; aquatic debris; habitat loss; modified hydrology and water circulation; sea level rise; storm intensity and frequency) effecting the condition of ecosystems (e.g., estuarine habitats and fish, as well as the connected terrestrial and coastal ecosystems), associated ecosystem goods and services (e.g., tourism and recreation, fishing, nutrient & sediment retention, contaminant processing, carbon sequestration, flood protection),

Foraging ecology of sanderlings Calidris alba wintering in estuarine and non-estuarine intertidal areas

NASA Astrophysics Data System (ADS)

Lourenço, Pedro M.; Alves, José A.; Catry, Teresa; Granadeiro, José P.

2015-10-01

Outside the breeding season, most shorebirds use either estuarine or non-estuarine intertidal areas as foraging grounds. The sanderling Calidris alba is mostly associated with coastal sandy beaches, a habitat which is currently at risk worldwide due to increasing coastal erosion, but may also use estuarine sites as alternative foraging areas. We aimed to compare the trophic conditions for sanderlings wintering in estuarine and non-estuarine sites within and around the Tejo estuary, Portugal, where these two alternative wintering options are available within a relatively small spatial scale. To achieve this, we analysed sanderling diet, prey availability, foraging behaviour, and time and energy budgets in the different substrates available in estuarine and non-estuarine sites. In terms of biomass, the most important sanderling prey in the estuarine sites were siphons of the bivalve Scrobicularia plana, polychaetes, staphylinids and the gastropod Hydrobia ulvae. In non-estuarine sites the main prey were polychaetes, the bivalve Donax trunculus and chironomid larvae. Both food availability and energetic intake rates were higher on estuarine sites, and sanderlings spent a higher proportion of time foraging on non-estuarine sites. In the estuary, sanderlings foraged in muddy-sand substrate whenever it was available, achieving higher intake rates than in sandy substrates. In the non-estuarine sites they used both sandy and rocky substrates throughout the tidal cycle but had higher intakes rates in sandy substrate. Estuarine sites seem to offer better foraging conditions for wintering sanderlings than non-estuarine sites. However, sanderlings only use muddy-sand and sandy substrates, which represent a small proportion of the intertidal area of the estuary. The extent of these substrates and the current sanderling density in the estuary suggest it is unlikely that the estuary could provide alternative wintering habitat for sanderlings if they face habitat loss and

ECOLOGICAL RESPONSES TO POLLUTION ABATEMENT: A FRAMEWORK FOR MEASUREMENT AND ASSESSMENT FOR COASTAL ECOSYSTEMS

EPA Science Inventory

Ecological Responses to Pollution Abatement: A Framework for Measurement and Assessment for Coastal Ecosystems (Abstract). To be presented at the 16th Biennial Conference of the Estuarine Research Foundation, ERF 2001: An Estuarine Odyssey, 4-8 November 2001, St. Pete Beach, FL. ...

Freshwater Detention by Oyster Reefs: Quantifying a Keystone Ecosystem Service.

PubMed

Kaplan, David A; Olabarrieta, Maitane; Frederick, Peter; Valle-Levinson, Arnoldo

2016-01-01

Oyster reefs provide myriad ecosystem services, including water quality improvement, fisheries and other faunal support, shoreline protection from erosion and storm surge, and economic productivity. However, their role in directing flow during non-storm conditions has been largely neglected. In regions where oyster reefs form near the mouth of estuarine rivers, they likely alter ocean-estuary exchange by acting as fresh water "dams". We hypothesize that these reefs have the potential to detain fresh water and influence salinity over extensive areas, thus providing a "keystone" ecosystem service by supporting estuarine functions that rely on the maintenance of estuarine (i.e., brackish) conditions in the near-shore environment. In this work, we investigated the effects of shore-parallel reefs on estuarine salinity using field data and hydrodynamic modeling in a degraded reef complex in the northeastern Gulf of Mexico. Results suggested that freshwater detention by long linear chains of oyster reefs plays an important role in modulating salinities, not only in the oysters' local environment, but over extensive estuarine areas (tens of square kilometers). Field data confirmed the presence of salinity differences between landward and seaward sides of the reef, with long-term mean salinity differences of >30% between sides. Modeled results expanded experimental findings by illustrating how oyster reefs affect the lateral and offshore extent of freshwater influence. In general, the effects of simulated reefs were most pronounced when they were highest in elevation, without gaps, and when riverine discharge was low. Taken together, these results describe a poorly documented ecosystem service provided by oyster reefs; provide an estimate of the magnitude and spatial extent of this service; and offer quantitative information to help guide future oyster reef restoration.

Small estuarine fishes feed on large trematode cercariae: Lab and field investigations

USGS Publications Warehouse

Kaplan, A.T.; Rebhal, S.; Lafferty, K.D.; Kuris, A.M.

2009-01-01

In aquatic ecosystems, dense populations of snails can shed millions of digenean trematode cercariae every day. These short-lived, free-living larvae are rich in energy and present a potential resource for consumers. We investigated whether estuarine fishes eat cercariae shed by trematodes of the estuarine snail Cerithidea californica. In aquaria we presented cercariae from 10 native trematode species to 6 species of native estuarine fishes. Many of these fishes readily engorged on cercariae. To determine if fishes ate cercariae in the field, we collected the most common fish species, Fundulus parvipinnis (California killifish), from shallow water on rising tides when snails shed cercariae. Of 61 killifish, 3 had recognizable cercariae in their gut. Because cercariae are common in this estuary, they could be frequent sources of energy for small fishes. In turn, predation on cercariae by fishes (and other predators) could also reduce the transmission success of trematodes. ?? 2009 American Society of Parasitologists.

Mapping estuarine distributions of the non-indigenous Japanese Eelgrass Zostera japonica using Color Infrared Aerial Photography

EPA Science Inventory

This presentation describes a technique for mapping distributions of the nonindigenous Japanese eelgrass Zostera japonica in estuarine ecosystems of the Pacific Northwest. The relatively broad distribution of this intertidal plant, often on very soft substrate, makes classical g...

The use of mechanistic descriptions of algal growth and zooplankton grazing in an estuarine eutrophication model

NASA Astrophysics Data System (ADS)

Baird, M. E.; Walker, S. J.; Wallace, B. B.; Webster, I. T.; Parslow, J. S.

2003-03-01

A simple model of estuarine eutrophication is built on biomechanical (or mechanistic) descriptions of a number of the key ecological processes in estuaries. Mechanistically described processes include the nutrient uptake and light capture of planktonic and benthic autotrophs, and the encounter rates of planktonic predators and prey. Other more complex processes, such as sediment biogeochemistry, detrital processes and phosphate dynamics, are modelled using empirical descriptions from the Port Phillip Bay Environmental Study (PPBES) ecological model. A comparison is made between the mechanistically determined rates of ecological processes and the analogous empirically determined rates in the PPBES ecological model. The rates generally agree, with a few significant exceptions. Model simulations were run at a range of estuarine depths and nutrient loads, with outputs presented as the annually averaged biomass of autotrophs. The simulations followed a simple conceptual model of eutrophication, suggesting a simple biomechanical understanding of estuarine processes can provide a predictive tool for ecological processes in a wide range of estuarine ecosystems.

NEP-ORD Collaborations on Quantifying the Ecosystem Goods and Services of Estuaries

EPA Science Inventory

Nature’s goods and services provided by estuarine ecosystems are integral to the economies and well-being of coastal communities. However, many valuable ecosystem goods and services (EGS), including their benefits to surrounding communities, are not explicitly considered i...

INDICATORS OF ECOSYSTEM INTEGRITY FOR ESTUARIES

EPA Science Inventory

Jordan, Stephen J. and Lisa M. Smith. In press. Indicators of Ecosystem Integrity for Estuaries. In: Proceedings of the Estuarine Indicators Workshop, 29-31 October 2003, Sanibel Island, FL. Sanibel-Captiva Conservation Foundation, Sanibel, FL. 23 p. (ERL,GB 1194).

Ideal ...

Freshwater Detention by Oyster Reefs: Quantifying a Keystone Ecosystem Service

PubMed Central

Olabarrieta, Maitane; Frederick, Peter; Valle-Levinson, Arnoldo

2016-01-01

Oyster reefs provide myriad ecosystem services, including water quality improvement, fisheries and other faunal support, shoreline protection from erosion and storm surge, and economic productivity. However, their role in directing flow during non-storm conditions has been largely neglected. In regions where oyster reefs form near the mouth of estuarine rivers, they likely alter ocean-estuary exchange by acting as fresh water “dams”. We hypothesize that these reefs have the potential to detain fresh water and influence salinity over extensive areas, thus providing a “keystone” ecosystem service by supporting estuarine functions that rely on the maintenance of estuarine (i.e., brackish) conditions in the near-shore environment. In this work, we investigated the effects of shore-parallel reefs on estuarine salinity using field data and hydrodynamic modeling in a degraded reef complex in the northeastern Gulf of Mexico. Results suggested that freshwater detention by long linear chains of oyster reefs plays an important role in modulating salinities, not only in the oysters’ local environment, but over extensive estuarine areas (tens of square kilometers). Field data confirmed the presence of salinity differences between landward and seaward sides of the reef, with long-term mean salinity differences of >30% between sides. Modeled results expanded experimental findings by illustrating how oyster reefs affect the lateral and offshore extent of freshwater influence. In general, the effects of simulated reefs were most pronounced when they were highest in elevation, without gaps, and when riverine discharge was low. Taken together, these results describe a poorly documented ecosystem service provided by oyster reefs; provide an estimate of the magnitude and spatial extent of this service; and offer quantitative information to help guide future oyster reef restoration. PMID:27936184

Estuarine Salinity Mapping From Airborne Radiometry

NASA Astrophysics Data System (ADS)

Walker, J. P.; Gao, Y.; Cook, P. L. M.; Ye, N.

2016-12-01

Estuaries are critical ecosystems providing both ecological habitat and human amenity including boating and recreational fishing. Salinity gradients, caused by the mixing of fresh and salt water, exert an overwhelming control on estuarine ecology and biogeochemistry as well as being a key tracer for model calibration. At present, salinity monitoring within estuaries typically uses point measurements or underway boat-based methods, which makes sensing of localised phenomena such as upwelling of saline bottom water difficult. This study has pioneered the use of airborne radiometry (passive microwave) sensing as a new method to remotely quantify estuarine salinity, allowing rapid production of high resolution surface salinity maps. The airborne radiometry mapping was conducted for the Gippsland Lakes, the largest estuary in Australia, in February, July, October and November of 2015, using the Polarimetric L-band Microwave Radiometer (PLMR). Salinity was retrieved from the brightness temperature collected by PLMR with results validated against boat sampling conducted concurrently with each flight. Results showed that the retrieval accuracy of the radiative transfer model was better than 5 ppt for most flights. The spatial, temporal and seasonal variations of salinity observed in this study are also analysed and discussed.

Halogen Radicals Promote the Photodegradation of Microcystins in Estuarine Systems.

PubMed

Parker, Kimberly M; Reichwaldt, Elke S; Ghadouani, Anas; Mitch, William A

2016-08-16

The transport of microcystin, a hepatotoxin produced by cyanobacteria (e.g., Microcystis aeruginosa), to estuaries can adversely affect estuarine and coastal ecosystems. We evaluated whether halogen radicals (i.e., reactive halogen species (RHS)) could significantly contribute to microcystin photodegradation during transport within estuaries. Experiments in synthetic and natural water samples demonstrated that the presence of seawater halides increased quantum yields for microcystin indirect photodegradation by factors of 3-6. Additional experiments indicated that photoproduced RHS were responsible for this effect. Despite the fact that dissolved organic matter (DOM) concentrations decreased in more saline waters, the calculated photochemical half-life of microcystin decreased 6-fold with increasing salinity along a freshwater-estuarine transect due to the halide-associated increase in quantum yield. Modeling of microcystin photodegradation along this transect indicated that the time scale for RHS-mediated microcystin photodegradation is comparable to the time scale of transport. Microcystin concentrations decline by ∼98% along the transect when considering photodegradation by RHS, but only by ∼54% if this pathway were ignored. These results suggest the importance of considering RHS-mediated photodegradation in future models of microcystin fate in freshwater-estuarine systems.

Methylmercury production in estuarine sediments: role of organic matter

PubMed Central

Schartup, Amina T.; Mason, Robert P.; Balcom, Prentiss H.; Hollweg, Terill A.; Chen, Celia Y.

2013-01-01

Methylmercury (MeHg) affects wildlife and human health mainly through marine fish consumption. In marine systems, MeHg is formed from inorganic mercury (HgII) species primarily in sediments then accumulates and biomagnifies in the food web. Most of the fish consumed in the US are from estuarine and marine systems highlighting the importance of understanding MeHg formation in these productive regions. Sediment organic matter has been shown to limit mercury methylation in estuarine ecosystems, as a result it is often described as the primary control over MeHg production. In this paper, we explore the role of organic matter by looking at the effects of its changing sediment concentrations on the methylation rates across multiple estuaries. We measured sedimentary MeHg production at eleven estuarine sites that were selected for their contrasting biogeochemical characteristics, mercury (Hg) content, and location in the Northeastern US (ME, NH, CT, NY, and NJ). Sedimentary total Hg concentrations ranged across five orders of magnitude, increasing in concentration from the pristine, sandy sediments of Wells (ME), to industrially contaminated areas like Portsmouth (NH) and Hackensack (NJ). We find that methylation rates are the highest at locations with high Hg content (relative to carbon), and that organic matter does not hinder mercury methylation in estuaries. PMID:23194318

Nitrogen distribution in a tropical urbanized estuarine system in northeastern Brazil.

PubMed

Dos Santos, Celimarcos Bezerra; Silva, Maria Aparecida Macêdo; de Souza, Marcelo F Landim; da Silva, Daniela Mariano Lopes

2018-01-08

Nitrogen enters estuaries mostly through fluvial discharge and tide, although anthropogenic sources are known to influence the amount of this element in these aquatic ecosystems. Thus, the objective of this work was to verify which river (Cachoeira, Fundão, and/or Santana) exerts greater influence on the distribution of dissolved N forms (Dissolved Organic Nitrogen and Dissolved Inorganic Nitrogen = NH 3 /NH 4 + , NO 2 - , and NO 3 - ) along a tropical urbanized estuarine system in northeastern Brazil. The studies estuarine system lies with in urban municipality, and the upper portion of the Cachoeira river estuary receives the treated effluent from this municipality through a sewage treatment station and untreated effluents from nearby villages. The selected sampling stations were located near the outfall of the rivers in the estuaries to the treatment plant and the villages. Of all the nitrogen forms, dissolved organic nitrogen (DON) prevailed in the estuarine system, followed by nitrate (NO 3 - ) as the main inorganic form. The highest concentrations were recorded in the fluvial portion and upper estuary of Cachoeira river in the dry season. Based on the N concentrations found in the estuarine system, Cachoeira river has the greatest anthropogenic influence due to the amount of untreated effluents from the villages and treated effluents from the sewage treatment plant (STP) in the upper portion of the estuary.

15 CFR 921.3 - National Estuarine Research Reserve System biogeographic classification scheme and estuarine...

Code of Federal Regulations, 2012 CFR

2012-01-01

... System biogeographic classification scheme and estuarine typologies. 921.3 Section 921.3 Commerce and... biogeographic classification scheme and estuarine typologies. (a) National Estuarine Research Reserves are... classification scheme based on regional variations in the nation's coastal zone has been developed. The...

15 CFR 921.3 - National Estuarine Research Reserve System biogeographic classification scheme and estuarine...

Code of Federal Regulations, 2013 CFR

2013-01-01

... System biogeographic classification scheme and estuarine typologies. 921.3 Section 921.3 Commerce and... biogeographic classification scheme and estuarine typologies. (a) National Estuarine Research Reserves are... classification scheme based on regional variations in the nation's coastal zone has been developed. The...

15 CFR 921.3 - National Estuarine Research Reserve System biogeographic classification scheme and estuarine...

Code of Federal Regulations, 2010 CFR

2010-01-01

... System biogeographic classification scheme and estuarine typologies. 921.3 Section 921.3 Commerce and... biogeographic classification scheme and estuarine typologies. (a) National Estuarine Research Reserves are... classification scheme based on regional variations in the nation's coastal zone has been developed. The...

15 CFR 921.3 - National Estuarine Research Reserve System biogeographic classification scheme and estuarine...

Code of Federal Regulations, 2014 CFR

2014-01-01

... System biogeographic classification scheme and estuarine typologies. 921.3 Section 921.3 Commerce and... biogeographic classification scheme and estuarine typologies. (a) National Estuarine Research Reserves are... classification scheme based on regional variations in the nation's coastal zone has been developed. The...

15 CFR 921.3 - National Estuarine Research Reserve System biogeographic classification scheme and estuarine...

Code of Federal Regulations, 2011 CFR

2011-01-01

... System biogeographic classification scheme and estuarine typologies. 921.3 Section 921.3 Commerce and... biogeographic classification scheme and estuarine typologies. (a) National Estuarine Research Reserves are... classification scheme based on regional variations in the nation's coastal zone has been developed. The...

Spatial analysis of the trophic interactions between two juvenile fish species and their preys along a coastal-estuarine gradient

NASA Astrophysics Data System (ADS)

Kopp, Dorothée; Le Bris, Hervé; Grimaud, Lucille; Nérot, Caroline; Brind'Amour, Anik

2013-08-01

Coastal and estuarine systems provide nursery grounds for many marine fish species. Their productivity has been correlated with terrigeneous inputs entering the coastal-estuarine benthic food web, thereby favouring the establishment of fish juveniles. Studies in these ecosystems often describe the nursery as a single large habitat without verifying nor considering the presence of contiguous habitats. Our study aimed at identifying different habitats based on macrozoobenthic communities and morpho-sedimentary characteristics and assessing the trophic interactions between fish juveniles and their benthic preys within these habitats. It included 43 sampling sites covering 5 habitats in which we described taxonomically and quantitatively the invertebrates and fish communities with stable isotopes and gut contents. It suggested that the benthic common sole Solea solea displayed feeding plasticity at the population level, separating the juveniles (G0) from the older fish (G1) into different "feeding sub-populations". Size-based feeding plasticity was also observable in the spatial occupancy of that species in the studied bay. The demersal pouting, Trisopterus luscus, equally used the different habitats but displayed low feeding plasticity across and inside each habitat. Stable isotopes proved to be powerful tools to study the spatial distribution of trophic interactions in complex ecosystems like the bay of Vilaine and to define optimal habitats for fish that use the coastal-estuarine ecosystem as nursery grounds.

ESTUARINE HABITAT RESTORATION

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

Thom, Ronald M.; Borde, Amy B.

2015-09-01

Restoring estuarine habitats generally means repairing damages caused by humans and natural forces. Because of the extensive human occupation, development, and use of coastal areas for centuries, the extensive estuarine habitats have been either destroyed or significantly impaired.

Nutrient dynamics in tropical rivers, estuarine-lagoons, and coastal ecosystems along the eastern Hainan Island

NASA Astrophysics Data System (ADS)

Li, R. H.; Liu, S. M.; Li, Y. W.; Zhang, G. L.; Ren, J. L.; Zhang, J.

2013-06-01

Nutrient dynamics were studied along the eastern Hainan Island based on field observations during 2006-2009, to understand nutrient biogeochemical processes and to have an overview of human perturbations on coastal ecosystems in this tropical region. The concentrations of nutrients in the rivers had seasonal variations enriched with dissolved inorganic nitrogen (DIN). High riverine concentrations of nitrate were mainly originated from agricultural fertilizer input. The ratios of DIN : PO43- ranged from 37 to 1063, suggesting preferential PO43- relative to nitrogen in the rivers. The areal yields of dissolved silicate (DSi) varied from 76 to 448 × 103 mol km-2 yr-1 due to erosion over the drainage area, inducing high levels of DSi among worldwide tropical systems. Aquaculture ponds contained high concentrations of NH4+ (up to 157 μM) and DON (up to 130 μM). Particulate phosphorus concentrations (0.5 ∼1.4 μM) were in lower level comparied with estuaries around the world. Particulate silicate levels in rivers and lagoons were lower than global average level. Nutrient biogeochemistry in coastal areas were affected by human activities (e.g. aquaculture, agriculture), as well as natural events such as typhoon. Nutrient concentrations were low because open sea water dispersed land-derived nutrients. Nutrient budgets were built based on a steady-state box model, which showed that riverine fluxes would be magnified by estuarine processes (e.g. regeneration, desorption) in the Wenchanghe/Wenjiaohe Estuary, Wanquan River estuary, and the Laoyehai Lagoon except in the Xiaohai Lagoon. Riverine and groundwater input were the major sources of nutrients to the Xiaohai Lagoon and the Laiyehai Lagoon, respectively. Riverine input and aquaculture effluent were the major sources of nutrients to the eastern coastal of Hainan Island. Nutrient inputs to the coastal ecosystem can be increased by typhoon-induced runoff of rainwater, and phytoplankton bloom in the sea would be

Assessment of the impact of increased solar ultraviolet radiation upon marine ecosystems

NASA Technical Reports Server (NTRS)

Worrest, R. C.; Vandyke, H.

1978-01-01

Reduction of the earth's ozone layer, with a resultant increase in transmission of solar ultraviolet radiation in the 290 to 320nm waveband (UV-B), via space shuttle operations through the stratosphere is considered. It is shown that simulated solar ultraviolet radiation can, under experimental conditions, detrimentally affect the marine organisms that form the base of the food web of oceanic and estuarine ecosystems. Whether a small increase in biologically harmful ultraviolet radiation might overwhelm these mechanisms and produce changes that will have damaging consequences to the biosphere is discussed. The potential for irreversible damage to the productivity, structure and/or functioning of a model estuarine ecosystem by increased UV-B radiation and whether these ecosystems are highly stable or amenable to adaptive change is studied. Data are provided to assess the potential impact upon marine ecosystems if space shuttle operations contribute to a reduction of the stratospheric ozone layer and the sensitivity of key community components to increased UV-B radiation is examined.

Effects of Bottom-up and Top-down Controls and Climate Change on Estuarine Macrophyte Communities and the Ecosystem Services they Provide

EPA Science Inventory

Macrophytes provide important estuarine benthic habitats and support a significant portion of estuarine productivity. The composition and characteristics of these benthic communities are regulated bottom-up by resource availability and from the top-down by herbivory and predation...

Impact of estuarine pollution on birds

USGS Publications Warehouse

Blus, L.J.; Wiemeyer, Stanley N.; Kerwin, J.A.; Stendell, R.C.; Ohlendorf, H.M.; Stickel, L.F.

1977-01-01

Pollution of estuaries affects bird populations indirectly through changes in habitat and food supply. The multi-factor pollution of Chesapeake Bay has resulted in diminution of submerged aquatic plants and consequent change in food habits of the canvasback duck. Although dredge-spoil operations can improve wildlife habitat, they often result in its demise. Pollution of estuaries also affects birds directly, through chemical toxication, which may result in outright mortality or in reproductive impairment. Lead from industrial sources and roadways enters the estuaries and is accumulated in tissues of birds. Lead pellets deposited in estuaries as a result of hunting are consumed by ducks with sufficient frequency .to result m large annual die-offs from lead poisoning. Fish in certain areas, usually near industrial sources, may contain levels of mercury high enough to be hazardous to birds that consume them. Other heavy metals are present in estuarine birds, but their significance is poorly known. Oil exerts lethal or sublethal effects on birds by oiling their feathers, oiling eggs and young by contaminated parents, and by ingestion of oil-contaminated food. Organochlorine chemicals, of both agricultural and industrial origin, travel through the food chains and reach harmful levels in susceptible species of birds in certain estuarine ecosystems. Both outright mortality and reproductive impairment have occurred.

Assessing estuarine quality: A cost-effective in situ assay with amphipods.

PubMed

Martinez-Haro, Monica; Acevedo, Pelayo; Pais-Costa, Antónia Juliana; Taggart, Mark A; Martins, Irene; Ribeiro, Rui; Marques, João Carlos

2016-05-01

In situ assays based on feeding depression can be powerful ecotoxicological tools that can link physiological organism-level responses to population and/or community-level effects. Amphipods are traditional target species for toxicity tests due to their high sensitivity to contaminants, availability in the field and ease of handling. However, cost-effective in situ assays based on feeding depression are not yet available for amphipods that inhabit estuarine ecosystems. The aim of this work was to assess a short-term in situ assay based on postexposure feeding rates on easily quantifiable food items with an estuarine amphipod. Experiments were carried out under laboratory conditions using juvenile Echinogammarus marinus as the target individual. When 60 Artemia franciscana nauplii (as prey) were provided per individual for a period of 30 min in dark conditions, feeding rates could be easily quantified. As an endpoint, postexposure feeding inhibition in E. marinus was more sensitive to cadmium contamination than mortality. Assay calibration under field conditions demonstrated the relevance of sediment particle size in explaining individual feeding rates in uncontaminated water bodies. An evaluation of the 48-h in situ bioassay based on postexposure feeding rates indicated that it is able to discriminate between unpolluted and polluted estuarine sites. Using the harmonized protocol described here, the in situ postexposure feeding assay with E. marinus was found to be a potentially useful, cost-effective tool for assessing estuarine sediment and water quality. Copyright © 2016 Elsevier Ltd. All rights reserved.

An evaluation of contaminated estuarine sites using sediment quality guidelines and ecological assessment methodologies.

PubMed

Fulton, M; Key, P; Wirth, E; Leight, A K; Daugomah, J; Bearden, D; Sivertsen, S; Scott, G

2006-10-01

Toxic contaminants may enter estuarine ecosystems through a variety of pathways. When sediment contaminant levels become sufficiently high, they may impact resident biota. One approach to predict sediment-associated toxicity in estuarine ecosystems involves the use of sediment quality guidelines (ERMs, ERLs) and site-specific contaminant chemistry while a second approach utilizes site-specific ecological sampling to assess impacts at the population or community level. The goal of this study was to utilize an integrated approach including chemical contaminant analysis, sediment quality guidelines and grass shrimp population monitoring to evaluate the impact of contaminants from industrial sources. Three impacted sites and one reference site were selected for study. Grass shrimp populations were sampled using a push-netting approach. Sediment samples were collected at each site and analyzed for metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides. Contaminant levels were then compared to sediment quality guidelines. In general, grass shrimp population densities at the sites decreased as the ERM quotients increased. Grass shrimp densities were significantly reduced at the impacted site that had an ERM exceedance for chromium and the highest Mean ERM quotient. Regression analysis indicated that sediment chromium concentrations were negatively correlated with grass shrimp density. Grass shrimp size was reduced at two sites with intermediate levels of contamination. These findings support the use of both sediment quality guidelines and site-specific population monitoring to evaluate the impacts of sediment-associated contaminants in estuarine systems.

EMERGY ANALYSIS OF THE COBSCOOK BAY ECOSYSTEM

EPA Science Inventory

A naturally eutrophic, estuarine ecosystem has developed in Cobscook Bay over the past three to four thousand years under the influence of six meter tides and rich flows of nitrogen from the deep waters of the Gulf of Maine. In this paper, measurements of primary production and...

Trophic Dynamics of Filter Feeding Bivalves in the Yangtze Estuarine Intertidal Marsh: Stable Isotope and Fatty Acid Analyses

PubMed Central

Wang, Sikai; Jin, Binsong; Qin, Haiming; Sheng, Qiang; Wu, Jihua

2015-01-01

Benthic bivalves are important links between primary production and consumers, and are essential intermediates in the flow of energy through estuarine systems. However, information on the diet of filter feeding bivalves in estuarine ecosystems is uncertain, as estuarine waters contain particulate matter from a range of sources and as bivalves are opportunistic feeders. We surveyed bivalves at different distances from the creek mouth at the Yangtze estuarine marsh in winter and summer, and analyzed trophic dynamics using stable isotope (SI) and fatty acid (FA) techniques. Different bivalve species had different spatial distributions in the estuary. Glauconome chinensis mainly occurred in marshes near the creek mouth, while Sinonovacula constricta preferred the creek. Differences were found in the diets of different species. S. constricta consumed more diatoms and bacteria than G. chinensis, while G. chinensis assimilated more macrophyte material. FA markers showed that plants contributed the most (38.86 ± 4.25%) to particular organic matter (POM) in summer, while diatoms contributed the most (12.68 ± 1.17%) during winter. Diatoms made the largest contribution to the diet of S. constricta in both summer (24.73 ± 0.44%) and winter (25.51 ± 0.59%), and plants contributed no more than 4%. This inconsistency indicates seasonal changes in food availability and the active feeding habits of the bivalve. Similar FA profiles for S. constricta indicated that the bivalve had a similar diet composition at different sites, while different δ13C results suggested the diet was derived from different carbon sources (C4 plant Spartina alterniflora and C3 plant Phragmites australis and Scirpus mariqueter) at different sites. Species-specific and temporal and/or spatial variability in bivalve feeding may affect their ecological functions in intertidal marshes, which should be considered in the study of food webs and material flows in estuarine ecosystems. PMID:26261984

Environmental and Microbial Features Affecting Denitrification and Anammox Hotspots in an Estuarine Ecosystem

NASA Astrophysics Data System (ADS)

Lisa, J.; Song, B.; Lefcheck, J. S.; Tobias, C. R.

2016-02-01

Biogeochemical hotspots are characterized as a few sites that exhibit extremely high reaction rates relative to surrounding area, and often account for a high percentage of the overall reaction rates in an ecosystem. Criteria for quantitatively identifying these sites have not been well established. Further, the underlying mechanisms of hotspots have been described in terms of environmental conditions, with little attention paid to the microbial community. The objectives of this study were to establish quantitative criteria to identify denitrification and anammox hotspots, and determine the underlying microbial and environmental factors responsible for elevated N2 production. We used 15N isotope pairing incubation experiments to measure denitrification and anammox rates in the New River Estuary, NC. Quantitative PCR assays of nitrous oxide reductase (nosZ Clades I and II) and hydrazine oxidoreductase (hzo) genes were conducted to estimate denitrifier and anammox abundance. Structural Equation Modeling (SEM) was used to elucidate complex causal relationships between environmental and biological variables. Denitrification hotspots, quantitatively defined as statistical outliers, accounted for 35.6% total denitrification while comprising only 7.3% of the sites. Anammox hotspots,10.6% of the sites, accounted for 60.9% of total anammox. SEM revealed increased sediment organics at lower salinities supported higher functional gene abundance, which in turn resulted in higher N2 production. Surprisingly, denitrification rates were significantly and positively correlated with nosZ Clade II gene abundance, after accounting for the non-significant contributions of the naturally more abundant nosZ Clade I, and other environmental covariates. This is the first time that a quantitative definition of biogeochemical hotspots was put forth and used to determine the importance of anammox and denitrification hotspots in estuarine nitrogen removal capacity. Despite the low area

Coevolution of hydraulic, soil and vegetation processes in estuarine wetlands

NASA Astrophysics Data System (ADS)

Trivisonno, Franco; Rodriguez, Jose F.; Riccardi, Gerardo; Saco, Patricia; Stenta, Hernan

2014-05-01

Estuarine wetlands of south eastern Australia, typically display a vegetation zonation with a sequence mudflats - mangrove forest - saltmarsh plains from the seaward margin and up the topographic gradient. Estuarine wetlands are among the most productive ecosystems in the world, providing unique habitats for fish and many terrestrial species. They also have a carbon sequestration capacity that surpasess terrestrial forest. Estuarine wetlands respond to sea-level rise by vertical accretion and horizontal landward migration, in order to maintain their position in the tidal frame. In situations in which buffer areas for landward migration are not available, saltmarsh can be lost due to mangrove encroachment. As a result of mangrove invasion associated in part with raising estuary water levels and urbanisation, coastal saltmarsh in parts of south-eastern Australia has been declared an endangered ecological community. Predicting estuarine wetlands response to sea-level rise requires modelling the coevolving dynamics of water flow, soil and vegetation. This paper presents preliminary results of our recently developed numerical model for wetland dynamics in wetlands of the Hunter estuary of NSW. The model simulates continuous tidal inflow into the wetland, and accounts for the effect of varying vegetation types on flow resistance. Coevolution effects appear as vegetation types are updated based on their preference to prevailing hydrodynamic conditions. The model also considers that accretion values vary with vegetation type. Simulations are driven using local information collected over several years, which includes estuary water levels, accretion rates, soil carbon content, flow resistance and vegetation preference to hydraulic conditions. Model results predict further saltmarsh loss under current conditions of moderate increase of estuary water levels.

15 CFR 921.51 - Estuarine research guidelines.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Estuarine research guidelines. 921.51... MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Special Research Projects § 921.51 Estuarine research guidelines. (a) Research within the National Estuarine Research Reserve System shall be...

15 CFR 921.51 - Estuarine research guidelines.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 15 Commerce and Foreign Trade 3 2013-01-01 2013-01-01 false Estuarine research guidelines. 921.51... MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Special Research Projects § 921.51 Estuarine research guidelines. (a) Research within the National Estuarine Research Reserve System shall be...

15 CFR 921.51 - Estuarine research guidelines.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 15 Commerce and Foreign Trade 3 2012-01-01 2012-01-01 false Estuarine research guidelines. 921.51... MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Special Research Projects § 921.51 Estuarine research guidelines. (a) Research within the National Estuarine Research Reserve System shall be...

15 CFR 921.51 - Estuarine research guidelines.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Estuarine research guidelines. 921.51... MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Special Research Projects § 921.51 Estuarine research guidelines. (a) Research within the National Estuarine Research Reserve System shall be...

Ecosystem services provided by pacific NW Estuaries: State of knowledge

EPA Science Inventory

Coastal regions in the United States are rapidly developing areas, with increasing urbanization and growing populations. Estuarine and nearshore coastal marine waters provide valuable ecosystem services to resident and transient human communities. In the Pacific Northwest (PNW)...

Composition, sources, and bioavailability of nitrogen in a longitudinal gradient from freshwater to estuarine waters.

PubMed

Jani, Jariani; Toor, Gurpal S

2018-06-15

Nitrogen (N) transport from land to water is a dominant contributor of N in estuarine waters leading to eutrophication, harmful algal blooms, and hypoxia. Our objectives were to (1) investigate the composition of inorganic and organic N forms, (2) distinguish the sources and biogeochemical mechanisms of nitrate-N (NO 3 -N) transport using stable isotopes of NO 3 - and Bayesian mixing model, and (3) determine the dissolved organic N (DON) bioavailability using bioassays in a longitudinal gradient from freshwater to estuarine ecosystem located in the Tampa Bay, Florida, United States. We found that DON was the most dominant N form (mean: 64%, range: 46-83%) followed by particulate organic N (PON, mean: 22%, range: 14-37%), whereas inorganic N forms (NO x -N: 7%, NH 4 -N: 7%) were 14% of total N in freshwater and estuarine waters. Stable isotope data of NO 3 - revealed that nitrification was the main contributor (36.4%), followed by soil and organic N sources (25.5%), NO 3 - fertilizers (22.4%), and NH 4 + fertilizers (15.7%). Bioassays showed that 14 to 65% of DON concentrations decreased after 5-days of incubation indicating utilization of DON by microbes in freshwater and estuarine waters. These results suggest that despite low proportion of inorganic N forms, the higher concentrations and bioavailability of DON can be a potential source of N for algae and bacteria leading to water quality degradation in the estuarine waters. Copyright © 2018 Elsevier Ltd. All rights reserved.

Habitat restoration from an ecosystem goods and services perspective: Application of a spatially explicit individual-based model

EPA Science Inventory

Estuarine ecosystems provide many services to humans, but these ecosystems are also under pressure from human development, which has led to large investments in habitat protection and restoration. Restoration in estuaries is typically focused on emergent and submerged vegetation ...

Detecting Subtle Shifts in Ecosystem Functioning in a Dynamic Estuarine Environment

PubMed Central

Pratt, Daniel R.; Lohrer, Andrew M.; Thrush, Simon F.; Hewitt, Judi E.; Townsend, Michael; Cartner, Katie; Pilditch, Conrad A.; Harris, Rachel J.; van Colen, Carl; Rodil, Iván F.

2015-01-01

Identifying the effects of stressors before they impact ecosystem functioning can be challenging in dynamic, heterogeneous ‘real-world’ ecosystems. In aquatic systems, for example, reductions in water clarity can limit the light available for photosynthesis, with knock-on consequences for secondary consumers, though in naturally turbid wave-swept estuaries, detecting the effects of elevated turbidity can be difficult. The objective of this study was to investigate the effects of shading on ecosystem functions mediated by sandflat primary producers (microphytobenthos) and deep-dwelling surface-feeding macrofauna (Macomona liliana; Bivalvia, Veneroida, Tellinidae). Shade cloths (which reduced incident light intensity by ~80%) were deployed on an exposed, intertidal sandflat to experimentally stress the microphytobenthic community associated with the sediment surface. After 13 weeks, sediment properties, macrofauna and fluxes of oxygen and inorganic nutrients across the sediment-water interface were measured. A multivariate metric of ecosystem function (MF) was generated by combining flux-based response variables, and distance-based linear models were used to determine shifts in the drivers of ecosystem function between non-shaded and shaded plots. No significant differences in MF or in the constituent ecosystem function variables were detected between the shaded and non-shaded plots. However, shading reduced the total explained variation in MF (from 64% in non-shaded plots to 15% in shaded plots) and affected the relative influence of M. liliana and other explanatory variables on MF. This suggests that although shade stress may shift the drivers of ecosystem functioning (consistent with earlier investigations of shading effects on sandflat interaction networks), ecosystem functions appear to have a degree of resilience to those changes. PMID:26214854

Toxic pressure of herbicides on microalgae in Dutch estuarine and coastal waters

NASA Astrophysics Data System (ADS)

Booij, Petra; Sjollema, Sascha B.; van der Geest, Harm G.; Leonards, Pim E. G.; Lamoree, Marja H.; de Voogt, W. Pim; Admiraal, Wim; Laane, Remi W. P. M.; Vethaak, A. Dick

2015-08-01

For several decades now, there has been an increase in the sources and types of chemicals in estuarine and coastal waters as a consequence of anthropogenic activities. This has led to considerable concern about the effects of these chemicals on the marine food chain. The fact is that estuarine and coastal waters are the most productive ecosystems with high primary production by microalgae. The toxic pressure of specific phytotoxic chemicals now poses a major threat to these ecosystems. In a previous study, six herbicides (atrazine, diuron, irgarol, isoproturon, terbutryn and terbutylazine) were identified as the main contaminants affecting photosynthesis in marine microalgae. The purpose of this study is to investigate the toxic pressure of these herbicides in the Dutch estuarine and coastal waters in relation to the effective photosystem II efficiency (ΦPSII) in microalgae. Temporal and spatial variations in the concentrations of these herbicides were analyzed based on monitoring data. Additionally, a field study was carried out in which chemical analysis of water was performed and also a toxicity assessment using the Pulse Amplitude Modulation (PAM) fluorometry assay that measures ΦPSII. The toxic pressure on ΦPSII in microalgae has decreased with 55-82% from 2003 to 2012, with the Western Scheldt estuary showing the highest toxic pressure. By combining toxicity data from the PAM assay with chemical analysis of herbicide concentrations, we have identified diuron and terbutylazine as the main contributors to the toxic pressure on microalgae. Although direct effects are not expected, the toxic pressure is close to the 10% effect level in the PAM assay. A compliance check with the current environmental legislation of the European Union revealed that the quality standards are not sufficient to protect marine microalgae.

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...

76 FR 2083 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research.... ACTION: Notice of Public Comment Period for the revised Jobos Bay National Estuarine Research Reserve... revised Jobos Bay National Estuarine Research Reserve Management Plan. The Jobos Bay National Estuarine...

EVALUATION AND EMERGY ANALYSIS OF THE COBSCOOK BAY ECOSYSTEM

EPA Science Inventory

A naturally eutrophic, estuarine ecosystem with many unique features has developed in Cobscook Bay over the past four thousand years under the influence of six meter tides and rich flows of nitrogen from the deep waters of the Gulf of Maine. In this paper measurements of primary ...

Climate Change, Precipitation and Impacts on an Estuarine Refuge from Disease

PubMed Central

Levinton, Jeffrey; Doall, Michael; Ralston, David; Starke, Adam; Allam, Bassem

2011-01-01

Background Oysters play important roles in estuarine ecosystems but have suffered recently due to overfishing, pollution, and habitat loss. A tradeoff between growth rate and disease prevalence as a function of salinity makes the estuarine salinity transition of special concern for oyster survival and restoration. Estuarine salinity varies with discharge, so increases or decreases in precipitation with climate change may shift regions of low salinity and disease refuge away from optimal oyster bottom habitat, negatively impacting reproduction and survival. Temperature is an additional factor for oyster survival, and recent temperature increases have increased vulnerability to disease in higher salinity regions. Methodology/Principal Findings We examined growth, reproduction, and survival of oysters in the New York Harbor-Hudson River region, focusing on a low-salinity refuge in the estuary. Observations were during two years when rainfall was above average and comparable to projected future increases in precipitation in the region and a past period of about 15 years with high precipitation. We found a clear tradeoff between oyster growth and vulnerability to disease. Oysters survived well when exposed to intermediate salinities during two summers (2008, 2010) with moderate discharge conditions. However, increased precipitation and discharge in 2009 reduced salinities in the region with suitable benthic habitat, greatly increasing oyster mortality. To evaluate the estuarine conditions over longer periods, we applied a numerical model of the Hudson to simulate salinities over the past century. Model results suggest that much of the region with suitable benthic habitat that historically had been a low salinity refuge region may be vulnerable to higher mortality under projected increases in precipitation and discharge. Conclusions/Significance Predicted increases in precipitation in the northeastern United States due to climate change may lower salinities past

Estuarine Food for Thought

NASA Astrophysics Data System (ADS)

M�ller-Solger, A. B.; M�ller-Navarra, D. B.

2002-12-01

Recent research in animal and human nutrition has shown the importance of long-chain polyunsaturated fatty acids (LC-PUFA) such as the n-3 LC-PUFA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These LC-PUFA are needed for healthy development and functioning of the nervous and vascular systems. De novo synthesis or elongation to LC-PUFA in animals is inefficient at best; thus sufficient amounts of these PUFA must be supplied by food sources. Algae, especially diatoms, dinoflagellates, and cryptophytes, are the quantitatively most important producers of EPA and DHA. These types of algae often dominate estuarine producer communities. The upper San Francisco Estuary is no exception, and we found its LC-PUFA-rich phytoplankton biomass, but not the quantitatively prevalent terrestrial plant detritus, to be highly predictive of zooplankton (Daphnia) growth. In contrast, in freshwater lakes dominated by relatively LC-PUFA-poor phytoplankton, EPA, not total phytoplankton biomass, best predicted Daphnia growth. The commonly high abundance of LC-PUFA-rich algae in estuaries may help explain the high trophic efficiencies in these systems and resulting high consumer production. Moreover, LC-PUFA-rich estuarine food resources may also provide essential nutrition and associated health and evolutionary benefits to land-dwelling consumers of such foods, including humans. Ensuring LC-PUFA-rich, uncontaminated estuarine production is thus an important goal for estuarine restoration and a convincing argument for estuarine conservation.

Groundwater flow, variability, and transport pathways in the Mar Negro of the Jobos Bay National Estuarine Research Reserve, Puerto Rico

USDA-ARS?s Scientific Manuscript database

The Jobos Bay National Estuarine Research Reserve (JBNERR) is a semi-enclosed ecosystem along the southeast coast of Puerto Rico. Agriculture, including vegetable, row crop, tree fruit, pasture, and poultry, is an important land use within the watershed. To better understand the potential impact of ...

Differential impact of lytic viruses on prokaryotic morphopopulations in a tropical estuarine system (Cochin estuary, India).

PubMed

Jasna, Vijayan; Pradeep Ram, Angia Sriram; Parvathi, Ammini; Sime-Ngando, Telesphore

2018-01-01

Our understanding on the importance of viral lysis in the functioning of tropical estuarine ecosystem is limited. This study examines viral infection of prokaryotes and subsequent lysis of cells belonging to different morphotypes across a salinity gradient in monsoon driven estuarine ecosystem (Cochin estuary, India). High standing stock of viruses and prokaryotes accompanied by lytic infection rates in the euryhaline/mesohaline region of the estuary suggests salinity to have an influential role in driving interactions between prokaryotes and viruses. High prokaryotic mortality rates, up to 42% of prokaryote population in the pre-monsoon season is further substantiated by a high virus to prokaryote ratio (VPR), suggesting that maintenance of a high number of viruses is dependent on the most active fraction of bacterioplankton. Although myoviruses were the dominant viral morphotype (mean = 43%) throughout the study period, there was significant variation among prokaryotic morphotypes susceptible to viral infection. Among them, the viral infected short rod prokaryote morphotype with lower burst estimates (mean = 18 viruses prokaryote-1) was dominant (35%) in the dry seasons whereas a substantial increase in cocci forms (30%) infected by viruses with high burst size (mean = 31 viruses prokaryote-1) was evident during the monsoon season. Such preferential infections of prokaryotic morphopopulations with respect to seasons can have a strong and variable impact on the carbon and energy flow in this tropical ecosystem.

Differential impact of lytic viruses on prokaryotic morphopopulations in a tropical estuarine system (Cochin estuary, India)

PubMed Central

Jasna, Vijayan; Pradeep Ram, Angia Sriram; Sime-Ngando, Telesphore

2018-01-01

Our understanding on the importance of viral lysis in the functioning of tropical estuarine ecosystem is limited. This study examines viral infection of prokaryotes and subsequent lysis of cells belonging to different morphotypes across a salinity gradient in monsoon driven estuarine ecosystem (Cochin estuary, India). High standing stock of viruses and prokaryotes accompanied by lytic infection rates in the euryhaline/mesohaline region of the estuary suggests salinity to have an influential role in driving interactions between prokaryotes and viruses. High prokaryotic mortality rates, up to 42% of prokaryote population in the pre-monsoon season is further substantiated by a high virus to prokaryote ratio (VPR), suggesting that maintenance of a high number of viruses is dependent on the most active fraction of bacterioplankton. Although myoviruses were the dominant viral morphotype (mean = 43%) throughout the study period, there was significant variation among prokaryotic morphotypes susceptible to viral infection. Among them, the viral infected short rod prokaryote morphotype with lower burst estimates (mean = 18 viruses prokaryote-1) was dominant (35%) in the dry seasons whereas a substantial increase in cocci forms (30%) infected by viruses with high burst size (mean = 31 viruses prokaryote-1) was evident during the monsoon season. Such preferential infections of prokaryotic morphopopulations with respect to seasons can have a strong and variable impact on the carbon and energy flow in this tropical ecosystem. PMID:29534102

Hydrologic influence on redox dynamics in estuarine environments

NASA Astrophysics Data System (ADS)

Michael, H. A.; Kim, K. H.; Guimond, J. A.; Heiss, J.; Ullman, W. J.; Seyfferth, A.

2017-12-01

Redox conditions in coastal aquifers control reactions that impact nutrient cycling, contaminant release, and carbon budgets, with implications for water resources and ecosystem health. Hydrologic changes can shift redox boundaries and inputs of reactants, especially in dynamic coastal systems subject to fluctuations on tidal, lunar, and longer timescales. We present two examples of redox shifts in estuarine systems in Delaware, USA: a beach aquifer and a saltmarsh. Beach aquifers are biogeochemical hot spots due to mixing between fresh groundwater and infiltrating seawater. At Cape Henlopen, DE, geochemical measurements identified reactions in the intertidal aquifer that include cycling of carbon, nitrogen, iron, and sulfur. Measurements and modeling illustrate that redox potential as well as the locations of redox reactions shift on tidal to seasonal timescales and in response to changing beach and aquifer properties, impacting overall rates of reactions such as denitrification that reduces N loads to coastal waters. In the St. Jones National Estuarine Research Reserve, tidal fluctuations in channels cause periodic groundwater-surface water exchange, water table movement, and intermittent flooding that varies spatially across the saltmarsh. These changes create shifts in redox potential that are greatest near channels and in the top 20 cm of sediments. The magnitude of redox change depends on hydrologic setting (near channels or in marsh interior), hydrologic conditions (tidal stage, seasonal shifts), as well as prevalence of macropores created by crab burrows that change seasonally with crab activity. These shifts correspond to changes in porewater chemistry that have implications for nutrient cycling and carbon export to the ocean. Understanding hydrologic influence on redox geochemistry is critical for predicting how these systems and their ecosystem services may change in the future in response to anthropogenic and climate change.

Assessment of the impact of increased solar ultraviolet radiation upon marine ecosystems

NASA Technical Reports Server (NTRS)

Vandyke, H.; Worrest, R. C.

1976-01-01

Data was provided to assess the potential impact upon marine ecosystems if space shuttle operations contribute to a reduction of the stratospheric ozone layer. The potential for irreversible damage to the productivity, structure and/or functioning of a model estuarine ecosystem by increased UV-B radiation was established. The sensitivity of key community components (the primary producers) to increased UV-B radiation was delineated.

Shifts in the community structure and activity of anaerobic ammonium oxidation bacteria along an estuarine salinity gradient

NASA Astrophysics Data System (ADS)

Zheng, Yanling; Jiang, Xiaofen; Hou, Lijun; Liu, Min; Lin, Xianbiao; Gao, Juan; Li, Xiaofei; Yin, Guoyu; Yu, Chendi; Wang, Rong

2016-06-01

Anaerobic ammonium oxidation (anammox) is a major microbial pathway for nitrogen (N) removal in estuarine and coastal environments. However, understanding of anammox bacterial dynamics and associations with anammox activity remains scarce along estuarine salinity gradient. In this study, the diversity, abundance, and activity of anammox bacteria, and their potential contributions to total N2 production in the sediments along the salinity gradient (0.1-33.8) of the Yangtze estuarine and coastal zone, were studied using 16S rRNA gene clone library, quantitative polymerase chain reaction assay, and isotope-tracing technique. Phylogenetic analysis showed a significant change in anammox bacterial community structure along the salinity gradient (P < 0.01), with the dominant genus shifting from Brocadia in the freshwater region to Scalindua in the open ocean. Anammox bacterial abundance ranged from 3.67 × 105 to 8.22 × 107 copies 16S rRNA gene g-1 and related significantly with salinity (P < 0.05). The anammox activity varied between 0.08 and 6.46 nmol N g-1 h-1 and related closely with anammox bacterial abundance (P < 0.01). Contributions of anammox activity to total N loss were highly variable along the salinity gradient, ranging from 5 to 77% and were significantly negatively correlated with salinity (P < 0.01). Sediment organic matter was also recognized as an important factor in controlling the relative role of anammox to total N2 production in the Yangtze estuarine and coastal zone. Overall, our data demonstrated a biogeographical distribution of anammox bacterial diversity, abundance, and activity along the estuarine salinity gradient and suggested that salinity is a major environmental control on anammox process in the estuarine and coastal ecosystems.

Adventures in holistic ecosystem modelling: the cumberland basin ecosystem model

NASA Astrophysics Data System (ADS)

Gordon, D. C.; Keizer, P. D.; Daborn, G. R.; Schwinghamer, P.; Silvert, W. L.

A holistic ecosystem model has been developed for the Cumberland Basin, a turbid macrotidal estuary at the head of Canada's Bay of Fundy. The model was constructed as a group exercise involving several dozen scientists. Philosophy of approach and methods were patterned after the BOEDE Ems-Dollard modelling project. The model is one-dimensional, has 3 compartments and 3 boundaries, and is composed of 3 separate submodels (physical, pelagic and benthic). The 28 biological state variables cover the complete estuarine ecosystem and represent broad functional groups of organisms based on trophic relationships. Although still under development and not yet validated, the model has been verified and has reached the stage where most state variables provide reasonable output. The modelling process has stimulated interdisciplinary discussion, identified important data gaps and produced a quantitative tool which can be used to examine ecological hypotheses and determine critical environmental processes. As a result, Canadian scientists have a much better understanding of the Cumberland Basin ecosystem and are better able to provide competent advice on environmental management.

Mechanistic models as a transferable framework for projecting effects of habitat change on production and delivery of ecosystem services

EPA Science Inventory

Drawing a link between habitat change and the production and delivery of ecosystem services is a priority in coastal estuarine ecosystems. Mechanistic modeling tools are highly functional for exploring this link because they allow for the synthesis of multiple ecological and beh...

78 FR 50038 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-16

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research.... ACTION: Notice of Public Comment Period for the Wells, Maine National Estuarine Research Reserve... National Estuarine Research [[Page 50039

Ecosystem services provided by Pacific NW estuaries: State of knowledge - March 3, 2011

EPA Science Inventory

Coastal regions in the United States are rapidly developing areas, with increasing urbanization and growing populations. Estuarine and nearshore coastal marine waters provide valuable ecosystem services to resident and transient human communities. In the Pacific Northwest (PNW) ...

Modelling the effect of hydrological change on estuarine health: An Australian Perspective. (Invited)

NASA Astrophysics Data System (ADS)

Bruce, L. C.; Adiyanti, S.; Ruibal, A. L.; Hipsey, M. R.

2013-12-01

Estuaries provide an important role in the filtering and transformation of carbon and nutrients from coastal catchments into the marine environment. Global trends including climate change, increased population, industrialization and agriculture have led to the rapid deterioration of estuarine ecosystems across the world. Within the Australian context, a particular concern is how changes to hydrological regimes, due to both water diversions and climate variability, are contributing to increased stress and consequent decline in estuarine health. In this study we report the modeling output of five Australian estuaries, each with different hydrological regimes and alternative management issues relating to altered hydrology: 1) The Yarra River estuary is a highly urbanized system, also receiving agriculturally derived nutrients, where the concern is the role of periodic hypoxia in reducing the assimilation capacity of nitrogen and thus increased risk of algal blooms forming in the coastal environment; 2) The upper Swan River estuary in Western Australia, which experiences persistent anoxia and hypoxia brought about by reduced flows has led to the commissioning of several oxygenation plants to alleviate stress on biodiversity and overall estuarine health; 3) The health of the Caboolture estuary in Queensland has deteriorated in the past decade with the aim of model development to quantify the various sources of surface and groundwater derived nutrients; 4) The construction of an additional channel to increase flushing in the Peel Harvey estuary in Western Australia was designed to control persistent harmful algal blooms; and 5) The Lower River Murray estuary experienced a prolonged drought that led to the development of acid sulfate soils and acid drainage deteriorating water quality. For these applications we applied 3-D hydrodynamic-biogeochemical models to determine underlying relationships between altered flow regimes, increased temperatures and the response of

An introduced Asian parasite threatens northeastern Pacific estuarine ecosystems

USDA-ARS?s Scientific Manuscript database

We test a prevalent assumption in marine ecology that species are native to where they are found until contrary evidence appears. The native assumption significantly biases interpretations of marine community and ecosystem dynamics if it results in oversight of critically important introduced specie...

77 FR 60107 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-02

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research... Research Reserve Management Plan Revisions. SUMMARY: Notice is hereby given that the Estuarine Reserves..., Alaska National Estuarine Research Reserve Management Plan Revisions. The revised management plans...

78 FR 53732 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-30

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research.... ACTION: Notice of approval of the Grand Bay, Mississippi and Delaware National Estuarine Research Reserve... Estuarine Research Reserve Management Plan Revisions. The revised management plans outline the...

78 FR 75548 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-12

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research...: Notice of Approval of the Wells, Maine National Estuarine Research Reserve Management Plan revision... Commerce approves the Wells, Maine National Estuarine Research Reserve Management Plan revision. The...

78 FR 26617 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2013-05-07

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research.... ACTION: Notice of Public Comment Period for the Grand Bay, Mississippi National Estuarine Research Reserve Management Plan and the Delaware National Estuarine Research Reserve Management Plan revisions...

75 FR 65613 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-26

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research... Research Reserves: North Inlet-Winyah Bay, SC and San Francisco Bay, CA. SUMMARY: Notice is hereby given... National Estuarine Research Reserve and the San Francisco Bay, CA National Estuarine Research Reserve. The...

75 FR 59696 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-28

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research... Estuarine Research Reserves: Arraigns Bay, RI and Tijuana River, CA. SUMMARY: Notice is hereby given that... the revised management plans of the Arraigns Bay, RI National Estuarine Research Reserve and the...

76 FR 16620 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-24

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research... Research Reserves: ACE Basin, SC and Old Woman Creek, OH. SUMMARY: Notice is hereby given that the... National Estuarine Research Reserve and Old Woman Creek, OH National Estuarine Research Reserve. The...

Assessment of the impact of increased solar ultraviolet radiation upon marine ecosystems

NASA Technical Reports Server (NTRS)

Vandyke, H.

1977-01-01

Specifically, the study has addressed the following: (1) potential for irreversible damage to the productivity, structure and/or functioning of a model estuarine ecosystem by increased UV-B radiation or ecosystems highly stable or amenable to adaptive change, and (2) the sensitivity of key community components (the primary producers, consumers, and decomposers) to increased UV-B radiation. Three areas of study were examined during the past year: (1) a continuation of the study utilizing the two seminatural ecosystem chambers, (2) a pilot study utilizing three flow-through ecosystem tanks enclosed in a small, outdoor greenhouse, and (3) sensitivity studies of representative primary producers and consumers.

The contribution of oyster microbiomes to denitrification and nitrous oxide emissions in estuarine and coastal ecosystems

NASA Astrophysics Data System (ADS)

Arfken, A. M.; Song, B.; Smyth, A.

2016-02-01

Oysters are important nitrogen transformers in estuaries. Studies have shown that benthic-pelagic coupling by oysters stimulates sedimentary denitrification. The microbiomes living in and on oysters may also have high denitrification activity, generating N2O and N2 as end products. In order to evaluate the importance of oyster microbiome denitrification and its contribution to N2O emission in estuaries, continuous flow experiments with 15NO3- addition were conducted with oyster reef adjacent sediments, live oysters, live oysters with biofilm removed, and oyster shells. Denitrification rates were highest in live oysters, followed by scrubbed oysters, oyster shells, and finally by sediments, with the lowest activity. N2O production followed a similar trend, but with scrubbed oysters and shells being similar. We also found a significant linear correlation between N2 and N2O production, which indicates that denitrification is the source of N2O from oyster and oyster shells. Molecular analysis of microbiomes in oyster shells, guts and gills will be conducted using next generation sequencing of 16S rRNA gene and quantitative PCR assays targeting the functional genes in denitrification. We expect that within live oysters, the anaerobic gut microbiome will have higher abundances of denitrifiers than the shell biofilms or sediments, corresponding to higher denitrification activities in live oysters. This study will demonstrate that enhanced denitrification activity in oysters, in conjunction with sedimentary denitrification stimulated by oyster biodeposits, leads to oyster reefs being nitrogen removal hotspots and potential emission sources of N2O in estuarine and coastal ecosystems. In addition, the importance of microbiome structures in relation to oyster denitrification will be revealed.

How a clogged canal impacts ecological health in a tropical urban wetland ecosystem

EPA Science Inventory

The coastal city of San Juan, Puerto Rico is a tropical urban ecosystem interwoven among a series of interconnected bays, lagoons, canals, and mangrove wetlands. As the city has expanded, infilling and urban encroachment on what was previously mangrove wetland and open estuarine ...

Effects of Salinity on Oil Spill Dispersant Toxicity in Estuarine Organisms

NASA Astrophysics Data System (ADS)

Eckmann, C. A.

2016-02-01

Chemical dispersants can be a useful tool to mitigate oil spills, but the potential risks to sensitive estuarine species should be carefully considered. To improve the decision making process, more information is needed regarding the effects of oil spill dispersants on the health of coastal ecosystems under variable environmental conditions such as salinity. The two oil dispersants used in this study were Corexit ® 9500 and Finasol ® OSR 52. Corexit ® 9500 was the primary dispersant used during the 2010 Deepwater Horizon oil spill event, while Finasol® OSR 52 is another dispersant approved for oil spill response in the U.S., yet considerably less is known regarding its toxicity to estuarine species. The grass shrimp, Palaemonetes pugio, was used as a model estuarine species. It is a euryhaline species that tolerates salinities from brackish to full strength seawater. Adult and larval life stages were tested with each dispersant at three salinities, 5ppt, 20ppt, and 30ppt. Median acute lethal toxicity thresholds were calculated. Lipid peroxidation assays were conducted on surviving shrimp to investigate sublethal effects. The toxicity of both dispersants was significantly influenced by salinity, with greatest toxicity observed at the lowest salinity tested. Larval shrimp were significantly more sensitive than adult shrimp to both dispersants, and both life stages were significantly more sensitive to Finasol than to Corexit. Furthermore, significant sublethal effects were seen at higher concentrations of both dispersants compared to the control. These data will enable environmental managers to make informed decisions regarding dispersant use in future oil spills.

Effects of Salinity on Oil Spill Dispersant Toxicity in Estuarine Organisms

NASA Astrophysics Data System (ADS)

Eckmann, C. A.

2015-12-01

Chemical dispersants can be a useful tool to mitigate oil spills, but the potential risks to sensitive estuarine species should be carefully considered. To improve the decision making process, more information is needed regarding the effects of oil spill dispersants on the health of coastal ecosystems under variable environmental conditions such as salinity. The two oil dispersants used in this study were Corexit ® 9500 and Finasol ® OSR 52. Corexit ® 9500 was the primary dispersant used during the 2010 Deepwater Horizon oil spill event, while Finasol® OSR 52 is another dispersant approved for oil spill response in the U.S., yet considerably less is known regarding its toxicity to estuarine species. The grass shrimp, Palaemonetes pugio, was used as a model estuarine species. It is a euryhaline species that tolerates salinities from brackish to full strength seawater. Adult and larval life stages were tested with each dispersant at three salinities, 5ppt, 20ppt, and 30ppt. Median acute lethal toxicity thresholds were calculated. Lipid peroxidation assays were conducted on surviving shrimp to investigate sublethal effects. The toxicity of both dispersants was significantly influenced by salinity, with greatest toxicity observed at the lowest salinity tested. Larval shrimp were significantly more sensitive than adult shrimp to both dispersants, and both life stages were significantly more sensitive to Finasol than to Corexit. Furthermore, significant sublethal effects were seen at higher concentrations of both dispersants compared to the control. These data will enable environmental managers to make informed decisions regarding dispersant use in future oil spills.

Effects of light reduction on food webs and associated ecosystem services of Yaquina Bay

EPA Science Inventory

Reduced water clarity can affect estuarine primary production but little is known of its subsequent effects to consumer guilds or ecosystem services. We investigated those effects using inverse analysis of modeled food webs of the lower (polyhaline) and upper (mesohaline) reache...

Nitrogen cycling process rates across urban ecosystems.

PubMed

Reisinger, Alexander J; Groffman, Peter M; Rosi-Marshall, Emma J

2016-09-21

Nitrogen (N) pollution of freshwater, estuarine, and marine ecosystems is widespread and has numerous environmental and economic impacts. A portion of this excess N comes from urban watersheds comprised of natural and engineered ecosystems which can alter downstream N export. Studies of urban N cycling have focused on either specific ecosystems or on watershed-scale mass balances. Comparisons of specific N transformations across ecosystems are required to contextualize rates from individual studies. Here we reviewed urban N cycling in terrestrial, aquatic, and engineered ecosystems, and compared N processing in these urban ecosystem types to native reference ecosystems. We found that net N mineralization and net nitrification rates were enhanced in urban forests and riparian zones relative to reference ecosystems. Denitrification was highly variable across urban ecosystem types, but no significant differences were found between urban and reference denitrification rates. When focusing on urban streams, ammonium uptake was more rapid than nitrate uptake in urban streams. Additionally, reduction of stormwater runoff coupled with potential decreases in N concentration suggests that green infrastructure may reduce downstream N export. Despite multiple environmental stressors in urban environments, ecosystems within urban watersheds can process and transform N at rates similar to or higher than reference ecosystems. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Top 10 principles for designing healthy coastal ecosystems

USGS Publications Warehouse

Gaydos, Joseph K.; Dierauf, Leslie; Kirby, Grant; Brosnan, Deborah; Gilardi, Kirsten; Davis, Gary E.

2008-01-01

Like other coastal zones around the world, the inland sea ecosystem of Washington (USA) and British Columbia (Canada), an area known as the Salish Sea, is changing under pressure from a growing human population, conversion of native forest and shoreline habitat to urban development, toxic contamination of sediments and species, and overharvest of resources. While billions of dollars have been spent trying to restore other coastal ecosystems around the world, there still is no successful model for restoring estuarine or marine ecosystems like the Salish Sea. Despite the lack of a guiding model, major ecological principles do exist that should be applied as people work to design the Salish Sea and other large marine ecosystems for the future. We suggest that the following 10 ecological principles serve as a foundation for educating the public and for designing a healthy Salish Sea and other coastal ecosystems for future generations: (1) Think ecosystem: political boundaries are arbitrary; (2) Account for ecosystem connectivity; (3) Understand the food web; (4) Avoid fragmentation; (5) Respect ecosystem integrity; (6) Support nature's resilience; (7) Value nature: it's money in your pocket; (8) Watch wildlife health; (9) Plan for extremes; and (10) Share the knowledge.

15 CFR 921.51 - Estuarine research guidelines.

Code of Federal Regulations, 2011 CFR

2011-01-01

... conducted in a manner consistent with Estuarine Research Guidelines developed by NOAA. (b) A summary of the... funds discussed in § 921.50(c). (c) The Estuarine Research Guidelines are reviewed annually by NOAA...

Estaurine Freshwater Entrainment By Oyster Reefs: Quantifying A Keystone Ecosystem Service

NASA Astrophysics Data System (ADS)

Kaplan, D. A.; Olabarrieta, M.; Frederick, P.; Valle-Levinson, A.; Seavey, J.

2014-12-01

Oyster reefs have been shown to provide myriad critical ecosystem services, however their role in directing flow and currents during non-storm conditions has been largely neglected. In many regions, oyster reefs form as linear structures perpendicular to the coast and across the path of streams and rivers, potentially entraining large volumes of freshwater flow and altering nearshore mixing. We hypothesize that these reefs have the potential to influence salinity over large areas, providing a "keystone" ecosystem service by supporting multiple estuarine functions. Here we present results from a field and modeling study to quantify the effects of reef extent and elevation on estuarine salinities under varying river discharge. We found salinity differences ranging from 2 to 16 g/kg between inshore and offshore sides of degraded oyster reefs in the Suwannee Sound (FL, USA), supporting the role of reefs as local-scale freshwater dams. Moreover, differences between inshore and offshore salinities were correlated with flow, with the most marked differences during periods of low flow. Hydrodynamic modeling using the 3-D Regional Ocean Modeling System (ROMS) suggests that the currently degraded reef system entrained greater volumes of freshwater in the past, buffering the landward advance of high salinities, particularly during low flow events related to droughts. Using ROMS, we also modeled a variety of hypothetical oyster bar morphology scenarios (historical, current, and "restored") to understand how changes in reef structure (elevation, extent, and completeness) impact estuarine mixing and near-shore salinities. Taken together, these results serve to: 1) elucidate a poorly documented ecosystem service of oyster reefs; 2) provide an estimate of the magnitude and sptial extent of the freshwater entrainment effect; and 3) offer quantitative information to managers and restoration specialists interested in restoring oyster habitat.

The Role of Heterotrophic Microbial Communities in Estuarine C Budgets and the Biogeochemical C Cycle with Implications for Global Warming: Research Opportunities and Challenges.

PubMed

Anderson, O Roger

2016-05-01

Estuaries are among the most productive and economically important marine ecosystems at the land-ocean interface and contribute significantly to exchange of CO2 with the atmosphere. Estuarine microbial communities are major links in the biogeochemical C cycle and flow of C in food webs from primary producers to higher consumers. Considerable attention has been given to bacteria and autotrophic eukaryotes in estuarine ecosystems, but less research has been devoted to the role of heterotrophic eukaryotic microbes. Current research is reviewed here on the role of heterotrophic eukaryotic microbes in C biogeochemistry and ecology of estuaries, with particular attention to C budgets, trophodynamics, and the metabolic fate of C in microbial communities. Some attention is given to the importance of these processes in climate change and global warming, especially in relation to sources and sinks of atmospheric CO2 , while also documenting the current paucity of research on the role of eukaryotic microbes that contribute to this larger question of C biogeochemistry and the environment. Some recommendations are made for future directions of research and opportunities of applying newer technologies and analytical approaches to a more refined analysis of the role of C in estuarine microbial community processes and the biogeochemical C cycle. © 2015 The Author Journal of Eukaryotic Microbiology © 2015 International Society of Protistologists.

How a clogged canal effects ecological and human health in a tropical urban wetland ecosystem

EPA Science Inventory

The coastal city of San Juan, Puerto Rico is a tropical urban ecosystem interwoven among a series of interconnected bays, lagoons, canals, and mangrove wetlands. As the city has expanded, infilling and urban encroachment on what was previously mangrove wetland and open estuarine ...

Influence of glacier runoff on ecosystem structure in Gulf of Alaska fjords

USGS Publications Warehouse

Arimitsu, Mayumi L.; Piatt, John F.; Mueter, Franz J.

2016-01-01

To better understand the influence of glacier runoff on fjord ecosystems, we sampled oceanographic conditions, nutrients, zooplankton, forage fish and seabirds within 4 fjords in coastal areas of the Gulf Alaska. We used generalized additive models and geostatistics to identify the range of glacier runoff influence into coastal waters within fjords of varying estuarine influence and topographic complexity. We also modeled the response of depth-integrated chlorophyll a concentration, copepod biomass, fish and seabird abundance to physical, nutrient and biotic predictor variables. The effects of glacial runoff were traced at least 10 km into coastal fjords by cold, turbid, stratified and generally nutrient-rich near-surface conditions. Glacially modified physical gradients, nutrient availability and among-fjord differences explained 67% of the variation in phytoplankton abundance, which is a driver of ecosystem structure at higher trophic levels. Copepod, euphausiid, fish and seabird distribution and abundance were related to environmental gradients that could be traced to glacial freshwater input, particularly turbidity and temperature. Seabird density was predicted by prey availability and silicate concentrations, which may be a proxy for upwelling areas where this nutrient is in excess. Similarities in ecosystem structure among fjords were attributable to an influx of cold, fresh and sediment-laden water, whereas differences were likely related to fjord topography and local differences in estuarine vs. ocean influence. We anticipate that continued changes in the timing and volume of glacial runoff will ultimately alter coastal ecosystems in the future.

Oyster Reefs Support Coastal Resilience by Altering Nearshore Salinity: An Observational and Modeling Study to Quantify a "Keystone" Ecosystem Service

NASA Astrophysics Data System (ADS)

Kaplan, D. A.; Olabarrieta, M.; Frederick, P.; Valle-Levinson, A.

2016-12-01

Oyster reefs provide myriad ecosystem services, including water quality improvement, fisheries and other faunal support, shoreline protection from erosion and storm surge, and economic productivity. However, their role in directing flow during non-storm conditions has been largely neglected. In regions where oyster reefs form near the mouth of estuarine rivers, they likely alter ocean-estuary exchange by acting as fresh water "dams". We hypothesize that these reefs have the potential to detain fresh water and influence salinity over extensive areas, thus providing a "keystone" ecosystem service by supporting estuarine functions that rely on the maintenance of estuarine (i.e., brackish) conditions in the near-shore environment. In this work, we investigated the effects of shore-parallel reefs on near-shore salinity using field data and hydrodynamic modeling in a degraded reef complex in Suwannee Sound (Florida, USA). Results suggested that freshwater detention by long linear chains of oyster reefs plays an important role in modulating salinities, not only in the oysters' local environment, but over extensive estuarine areas (tens of square kilometers). Field data confirmed the presence of salinity differences between landward and seaward sides of the reef, with long-term mean salinity differences of >30% between sides. Modeled results expanded experimental findings by illustrating how oyster reefs affect the lateral and offshore extent of freshwater influence. In general, the effects of simulated reefs were most pronounced when they were highest in elevation, without gaps, and when riverine discharge was low. Taken together, these results describe a poorly documented ecosystem service provided by oyster reefs; provide an estimate of the magnitude and spatial extent of this service; and offer quantitative information to help guide future oyster reef restoration.

Salinity stress response in estuarine fishes from the Murray Estuary and Coorong, South Australia.

PubMed

Hossain, Md Afzal; Aktar, Shefali; Qin, Jian G

2016-12-01

Estuaries are unstable ecosystems and can be changed by the environmental and anthropogenic impact. The Murray Estuary and Coorong were degraded by drought and low freshwater input in the last decade and therefore transformed into the largest hyper-saline lagoon in Australia. This study evaluates the physiological stress of two estuarine fish species (small-mouthed hardyhead Atherinosoma microstoma and Tamar goby Afurcagobius tamarensis) to the induced salinity change in captivity. The test fishes were collected from the Coorong and transported to the laboratory in the water from the Coorong. Each fish species was exposed to different levels of salinity, and a number of enzymes were assessed to measure the stress response of fish to salinity change. The activity of reactive oxygen species was significantly increased with the salinity change in both fish species compared with the fish in the control. Significant salinity effect on superoxide dismutase activity was observed on Tamar goby but not on small-mouthed hardyhead. Conversely, the impact of salinity on catalase activity was detected on small-mouthed hardyhead but not on Tamar goby. The study reveals that the induction of physical stress by salinity changes occurred in both Tamar goby and small-mouthed hardyhead despite the varying response of antioxidant enzymes between fish species. The study provides an insight into the understanding of physiological adaptation in estuarine fish to salinity change. The results could improve our knowledge on stress response and resilience of estuarine fish to hypo- and hyper-salinity stress.

Size matters: The contribution of mega-infauna to the food webs and ecosystem services of an Oregon estuary - ESA

EPA Science Inventory

Background/Questions/Methods Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because ...

Reverse Estuarine Circulation Due to Local and Remote Wind Forcing, Enhanced by the Presence of Along-Coast Estuaries

NASA Astrophysics Data System (ADS)

Giddings, S. N.; MacCready, P.

2017-12-01

have been significantly impacted, threatening their important functionality. Understanding estuarine dynamics is critical to understanding estuarine ecosystems. Hydrodynamic connectivity between estuaries and the coastal ocean is a key dynamical driver impacting critical biological and biogeochemical processes such as ocean/estuarine nutrient and phytoplankton exchange and regulation of estuarine residence time, dissolved oxygen, and acidification levels. Typically estuarine-ocean exchange brings oceanic water into the estuary at depth, mixes it upwards within the estuary, and returns an outflowing mixture of oceanic and riverine water at the surface to the ocean. This manuscript documents seasonal reversals to this typical circulation pattern and the hydrodynamic drivers of the reversals. It highlights the importance of offshore winds and connectivity with neighboring estuaries. Improved understanding of these mechanisms can help us predict how estuaries will respond to a changing climate.

Habitat and Recreational Fishing Opportunity in Tampa Bay: Linking Ecological and Ecosystem Services to Human Beneficiaries

EPA Science Inventory

Estimating value of estuarine habitat to human beneficiaries requires that we understand how habitat alteration impacts function through both production and delivery of ecosystem goods and services (EGS). Here we expand on the habitat valuation technique of Bell (1997) with an es...

15 CFR 921.52 - Promotion and coordination of estuarine research.

Code of Federal Regulations, 2010 CFR

2010-01-01

... estuarine research. 921.52 Section 921.52 Commerce and Foreign Trade Regulations Relating to Commerce and... AND COASTAL RESOURCE MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Special Research Projects § 921.52 Promotion and coordination of estuarine research. (a) NOAA will promote and...

Estuarine Food Webs

EPA Science Inventory

Estuaries provide habitat for abundant plants, animals and micro-organisms, ranging from microscopic plankton (bacteria, yeasts, algae, protozoa) to larger benthic and pelagic organisms (seagrass, clams, crabs, sea trout, pelicans and dolphins). Estuarine biota can be characteri...

Phytoplankton Diversity and Community Composition along the Estuarine Gradient of a Temperate Macrotidal Ecosystem: Combined Morphological and Molecular Approaches

PubMed Central

Bazin, Pauline; Jouenne, Fabien; Friedl, Thomas; Deton-Cabanillas, Anne-Flore; Le Roy, Bertrand; Véron, Benoît

2014-01-01

Microscopical and molecular analyses were used to investigate the diversity and spatial community structure of spring phytoplankton all along the estuarine gradient in a macrotidal ecosystem, the Baie des Veys (eastern English Channel). Taxa distribution at high tide in the water column appeared to be mainly driven by the tidal force which superimposed on the natural salinity gradient, resulting in a two-layer flow within the channel. Lowest taxa richness and abundance were found in the bay where Teleaulax-like cryptophytes dominated. A shift in species composition occurred towards the mouth of the river, with the diatom Asterionellopsis glacialis dramatically accumulating in the bottom waters of the upstream brackish reach. Small thalassiosiroid diatoms dominated the upper layer river community, where taxa richness was higher. Through the construction of partial 18S rDNA clone libraries, the microeukaryotic diversity was further explored for three samples selected along the surface salinity gradient (freshwater - brackish - marine). Clone libraries revealed a high diversity among heterotrophic and/or small-sized protists which were undetected by microscopy. Among them, a rich variety of Chrysophyceae and other lineages (e.g. novel marine stramenopiles) are reported here for the first time in this transition area. However, conventional microscopy remains more efficient in revealing the high diversity of phototrophic taxa, low in abundances but morphologically distinct, that is overlooked by the molecular approach. The differences between microscopical and molecular analyses and their limitations are discussed here, pointing out the complementarities of both approaches, for a thorough phytoplankton community description. PMID:24718653

Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater delta

USGS Publications Warehouse

Sobczak, W.V.; Cloern, J.E.; Jassby, A.D.; Cole, B.E.; Schraga, T.S.; Arnsberg, A.

2005-01-01

Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The Delta ecosystem has low primary productivity but large detrital inputs, so we hypothesized that detritus is the primary energy source fueling production in pelagic food webs. We assessed the sources, quantity, composition, and bioavailability of organic matter among a diversity of habitats (e.g., marsh sloughs, floodplains, tidal lakes, and deep river channels) over two years to test this hypothesis. Our results support the emerging principle that detritus dominates riverine and estuarine organic matter supply and supports the majority of ecosystem metabolism. Yet in contrast to prevailing ideas, we found that detritus was weakly coupled to the Delta's pelagic food web. Results from independent approaches showed that phytoplankton production was the dominant source of organic matter for the Delta's pelagic food web, even though primary production accounts for a small fraction of the Delta's organic matter supply. If these results are general, they suggest that the value of organic matter to higher trophic levels, including species targeted by programs of ecosystem restoration, is a function of phytoplankton production. ?? 2005 Estuarine Research Federation.

Sustainable exploitation and management of autogenic ecosystem engineers: application to oysters in Chesapeake Bay.

PubMed

Wilberg, Michael J; Wiedenmann, John R; Robinson, Jason M

2013-06-01

Autogenic ecosystem engineers are critically important parts of many marine and estuarine systems because of their substantial effect on ecosystem services. Oysters are of particular importance because of their capacity to modify coastal and estuarine habitats and the highly degraded status of their habitats worldwide. However, models to predict dynamics of ecosystem engineers have not previously included the effects of exploitation. We developed a linked population and habitat model for autogenic ecosystem engineers undergoing exploitation. We parameterized the model to represent eastern oyster (Crassostrea virginica) in upper Chesapeake Bay by selecting sets of parameter values that matched observed rates of change in abundance and habitat. We used the model to evaluate the effects of a range of management and restoration options including sustainability of historical fishing pressure, effectiveness of a newly enacted sanctuary program, and relative performance of two restoration approaches. In general, autogenic ecosystem engineers are expected to be substantially less resilient to fishing than an equivalent species that does not rely on itself for habitat. Historical fishing mortality rates in upper Chesapeake Bay for oysters were above the levels that would lead to extirpation. Reductions in fishing or closure of the fishery were projected to lead to long-term increases in abundance and habitat. For fisheries to become sustainable outside of sanctuaries, a substantial larval subsidy would be required from oysters within sanctuaries. Restoration efforts using high-relief reefs were predicted to allow recovery within a shorter period of time than low-relief reefs. Models such as ours, that allow for feedbacks between population and habitat dynamics, can be effective tools for guiding management and restoration of autogenic ecosystem engineers.

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

Comparative metabolomic and ionomic approach for abundant fishes in estuarine environments of Japan

PubMed Central

Yoshida, Seiji; Date, Yasuhiro; Akama, Makiko; Kikuchi, Jun

2014-01-01

Environmental metabolomics or ionomics is widely used to characterize the effects of environmental stressors on the health of aquatic organisms. However, most studies have focused on liver and muscle tissues of fish, and little is known about how the other organs are affected by environmental perturbations and effects such as metal pollutants or eutrophication. We examined the metabolic and mineral profiles of three kinds of abundant fishes in estuarine ecosystem, yellowfin goby, urohaze-goby, and juvenile Japanese seabass sampled from Tsurumi River estuary, Japan. Multivariate analyses, including nuclear magnetic resonance-based metabolomics and inductively coupled plasma optical emission spectrometry-based ionomics approaches, revealed that the profiles were clustered according to differences among body tissues rather than differences in body size, sex, and species. The metabolic and mineral profiles of the muscle and fin tissues, respectively, suggest that these tissues are most appropriate for evaluating environmental perturbations. Such analyses will be highly useful in evaluating the environmental variation and diversity in aquatic ecosystems. PMID:25387575

The Abundance and Activity of Nitrate-Reducing Microbial Populations in Estuarine Sediments

NASA Astrophysics Data System (ADS)

Cardarelli, E.; Francis, C. A.

2014-12-01

Estuaries are productive ecosystems that ameliorate nutrient and metal contaminants from surficial water supplies. At the intersection of terrestrial and aquatic environments, estuarine sediments host major microbially-mediated geochemical transformations. These include denitrification (the conversion of nitrate to nitrous oxide and/or dinitrogen) and dissimilatory nitrate reduction to ammonium (DNRA). Denitrification has historically been seen as the predominant nitrate attenuation process and functions as an effective sink for nitrate. DNRA has previously been believed to be a minor nitrate reduction process and transforms nitrate within the ecosystem to ammonium, a more biologically available N species. Recent studies have compared the two processes in coastal environments and determined fluctuating environmental conditions may suppress denitrification, supporting an increased role for DNRA in the N cycle. Nitrate availability and salinity are factors thought to influence the membership of the microbial communities present, and the nitrate reduction process that predominates. The aim of this study is to investigate how nitrate concentration and salinity alter the transcript abundances of N cycling functional gene markers for denitrification (nirK, nirS) and DNRA (nrfA) in estuarine sediments at the mouth of the hypernutrified Old Salinas River, CA. Short-term whole core incubations amended with artificial freshwater/artificial seawater (2 psu, 35 psu) and with varying NO3- concentrations (200mM, 2000mM) were conducted to assess the activity as well as the abundance of the nitrate-reducing microbial populations present. Gene expression of nirK, nirS, and nrfA at the conclusion of the incubations was quantified using reverse transcription quantitative polymerase chain reaction (RT-qPCR). High abundances of nirK, nirS, and nrfA under particular conditions coupled with the resulting geochemical data ultimately provides insight onto how the aforementioned factors

TOP DOWN CONTROL OF THE MICROBIAL LOOP IN ESTUARINE PHYTOPLANKTON

EPA Science Inventory

Top Down Control of the Microbial Loop in Estuarine Plankton (Abstract). To be presented at the 16th Biennial Conference of the Estuarine Research Foundation, ERF 2001: An Estuarine Odyssey, 4-8 November 2001, St. Pete Beach, FL. 1 p. (ERL,GB R846).

We examined the effects...

Transient controls on estuarine SPM fluxes: case study in the Dee Estuary, UK.

NASA Astrophysics Data System (ADS)

Amoudry, Laurent; Williams, Megan; Todd, David

2017-04-01

Estuaries are a critical interface between land and coastal ocean across which freshwater, suspended particulate matter (SPM), and consequently terrestrial carbon, nutrients and anthropogenic contaminants are exchanged. Suspended particulate matter is closely linked to estuarine turbidity; it affects water quality and estuarine ecology; and it contributes to overall estuarine sediment budgets. However, predicting the response of estuarine ecosystems to climate change and human interventions remains difficult partly due to a lack of comprehensive understanding of SPM concentrations and fluxes across time scales from intratidal to seasonal and interannual variability. We investigate the dynamics of suspended sediment and suspended particulate matter in a hypertidal estuary with a maximum tidal range in excess of 10 m and tidal currents reaching over 1 m/s: the Dee Estuary. This estuary is located in northwest England and outflows in Liverpool Bay, itself in the eastern Irish Sea. The Dee Estuary is a funnel-shaped, coastal plain estuary, which is about 30 km long with a maximum width of 8.5 km at the mouth, and consists of mixed sediments. We focus on field observations, collected during several campaigns in the channels of the Dee Estuary from 2004 to 2009 using acoustic and optical instrumentation, which provide intratidal measurements of flow velocity and suspended sediment, and thus sediment fluxes, over approximately a month. Measurements in February-March 2008 highlight three distinct hydrodynamic regimes: a current dominant regime at neap tides (14-21 February); a combined wave-current regime at spring tides (21-29 February); and a wave dominant regime at neap tide (1-4 March). While analysis of tidal distortion and dominance predicts weak ebb dominant channels, the observations yield flood dominant sediment transport. The net sediment flux exhibits a two-layer structure - import near the bed, export near the surface - that is consistent with the residual

Assessing the potential ecological risk of Co, Cr, Cu, Fe and Zn in the sediments of Hooghly-Matla estuarine system, India.

PubMed

Ghosh, Somdeep; Bakshi, Madhurima; Kumar, Alok; Ramanathan, A L; Biswas, Jayanta Kumar; Bhattacharyya, Subarna; Chaudhuri, Punarbasu; Shaheen, Sabry M; Rinklebe, Jörg

2018-05-09

Hooghly-Matla estuarine system along with the Sundarbans mangroves forms one of the most diverse and vulnerable ecosystems in the world. We have investigated the distribution of Co, Cr, Cu, Fe and Zn along with sediment properties at six locations [Shamshernagar (S1), Kumirmari (S2 and S3), Petuaghat (S4), Tapoban (S5) and Chemaguri (S6)] in the Hooghly estuary and reclaimed islands of the Sundarbans for assessing the degree of contamination and potential ecological risks. Enrichment factor values (0.9-21.6) show enrichment of Co, Cu and Zn in the intertidal sediments considering all sampling locations and depth profiles. Geo-accumulation index values irrespective of sampling locations and depth revealed that Co and Cu are under class II and class III level indicating a moderate contamination of sediments. The pollution load index was higher than unity (1.6-2.1), and Co and Cu were the major contributors to the sediment pollution followed by Zn, Cr and Fe with the minimum values at S1 and the maximum values at S5. The sediments of the Hooghly-Matla estuarine region (S4, S5 and S6) showed considerable ecological risks, when compared with effect range low/effect range median and threshold effect level/probable effect level values. The variation in the distribution of the studied elements may be due to variation in discharge pattern and exposure to industrial effluent and domestic sewage, storm water and agricultural run-off and fluvial dynamics of the region. The study illuminates the necessity for the proper management of vulnerable coastal estuarine ecosystem by stringent pollution control measures along with regular monitoring and checking program.

76 FR 40338 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-08

... Reserve System AGENCY: Estuarine Reserves Division, Office of Ocean and Coastal Resource Management.... SUMMARY: The Estuarine Reserves Division, Office of Ocean and Coastal Resource Management, National Ocean... support reserve operations. The objectives described in this plan address the most critical coastal issues...

75 FR 49887 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-16

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research... Research Reserves: Narragansett Bay, RI and Tijuana River, CA. SUMMARY: Notice is hereby given that the... Research Reserve and the Tijuana, CA National Estuarine Research Reserve. The Narragansett Bay, RI Reserve...

Estuarine Facies Model Revisited: Conceptual Model of Estuarine Sediment Dynamics During Non-Equilibrium Conditions

NASA Astrophysics Data System (ADS)

Elliott, E. A.; Rodriguez, A. B.; McKee, B. A.

2017-12-01

Traditional models of estuarine systems show deposition occurs primarily within the central basin. There, accommodation space is high within the deep central valley, which is below regional wave base and where current energy is presumed to reach a relative minimum, promoting direct deposition of cohesive sediment and minimizing erosion. However, these models often reflect long-term (decadal-millennial) timescales, where accumulation rates are in relative equilibrium with the rate of relative sea-level rise, and lack the resolution to capture shorter term changes in sediment deposition and erosion within the central estuary. This work presents a conceptual model for estuarine sedimentation during non-equilibrium conditions, where high-energy inputs to the system reach a relative maximum in the central basin, resulting in temporary deposition and/or remobilization over sub-annual to annual timescales. As an example, we present a case study of Core Sound, NC, a lagoonal estuarine system where the regional base-level has been reached, and sediment deposition, resuspension and bypassing is largely a result of non-equilibrium, high-energy events. Utilizing a 465 cm-long sediment core from a mini-basin located between Core Sound and the continental shelf, a 40-year sub-annual chronology was developed for the system, with sediment accumulation rates (SAR) interpolated to a monthly basis over the 40-year record. This study links erosional processes in the estuary directly with sediment flux to the continental shelf, taking advantage of the highly efficient sediment trapping capability of the mini-basin. The SAR record indicates high variation in the estuarine sediment supply, with peaks in the SAR record at a recurrence interval of 1 year (+/- 0.25). This record has been compared to historical storm influence for the area. Through this multi-decadal record, sediment flushing events occur at a much more frequent interval than previously thought (i.e. annual rather than

A Simulation Model for Studying Effects of Pollution and Freshwater Inflow on Secondary Productivity in an Ecosystem. Ph.D. Thesis - North Carolina State Univ.

NASA Technical Reports Server (NTRS)

Johnson, R. W.

1974-01-01

A mathematical model of an ecosystem is developed. Secondary productivity is evaluated in terms of man related and controllable factors. Information from an existing physical parameters model is used as well as pertinent biological measurements. Predictive information of value to estuarine management is presented. Biological, chemical, and physical parameters measured in order to develop models of ecosystems are identified.

Size matters: The contribution of mega-infauna to the food webs and ecosystem services of an Oregon estuary - 9-30-12

EPA Science Inventory

Large-bodied invertebrates (bivalves, polychaetes, burrowing shrimps) are common to infaunal communities of NE Pacific estuaries, but their contribution to estuarine community structure, function and ecosystem services is poorly understood because they are difficult to sample and...

Conservation Priority Index for Estuarine Fish (COPIEF)

NASA Astrophysics Data System (ADS)

Branco, Paulo; Costa, José Lino; Raposo de Almeida, Pedro

2008-12-01

Public awareness regarding environmental issues has increased in recent decades. The increasing number of impact assessment studies, management and conservation plans, as well as ecological monitoring studies, demand new and more efficient techniques. Indices are an important tool to aid biologists in these studies and should allow an easier comprehension of the data by managers, decision-makers and the general public. This study presents the first multi-metrical index able to establish a hierarchical ordination of the conservation priority of the estuarine fish species using 72 species from 16 estuarine systems (W and S coasts of Portugal). The index is composed of 10 metrics, comprising species life traits, distribution and population trends. The information needed to score each metric was gathered from the published literature and the index validation was done by external means. This methodology allowed the definition of those fish species most in need of conservation planning, and those less prone to extinction in Portuguese estuarine systems. The proposed index fills a gap in our knowledge and provides a useful tool to the scientific community and to the decision-makers, being a breakthrough in the field of conservation planning of estuarine fish species.

Ecotoxicology of bromoacetic acid on estuarine phytoplankton.

PubMed

Gordon, Ana R; Richardson, Tammi L; Pinckney, James L

2015-11-01

Bromoacetic acid is formed when effluent containing chlorine residuals react with humics in natural waters containing bromide. The objective of this research was to quantify the effects of bromoacetic acid on estuarine phytoplankton as a proxy for ecosystem productivity. Bioassays were used to measure the EC50 for growth in cultured species and natural marine communities. Growth inhibition was estimated by changes in chlorophyll a concentrations measured by fluorometry and HPLC. The EC50s for cultured Thalassiosira pseudonana were 194 mg L(-1), 240 mg L(-1) for Dunaliella tertiolecta and 209 mg L(-1) for Rhodomonas salina. Natural phytoplankton communities were more sensitive to contamination with an EC50 of 80 mg L(-1). Discriminant analysis suggested that bromoacetic acid additions cause an alteration of phytoplankton community structure with implications for higher trophic levels. A two-fold EC50 decrease in mixed natural phytoplankton populations affirms the importance of field confirmation for establishing water quality criteria. Copyright © 2015 Elsevier Ltd. All rights reserved.

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).

Human effects on estuarine shoreline decadal evolution

NASA Astrophysics Data System (ADS)

Rilo, A.; Freire, P.; Ceia, R.; Mendes, R. N.; Catalão, J.; Taborda, R.

2012-04-01

Due to their sheltered conditions and natural resources, estuaries were always attractive to human activities (industrial, agriculture, residential and recreation). Consequently, the complex interactions between anthropogenic and natural drivers increase estuarine shoreline vulnerability to climate changes impacts. The environmental sustainability of these systems depends on a fragile balance between societal development and natural values that can be further disturbed by climate change effects. This challenging task for scientific community, managers and stakeholders can only be accomplished with interdisplinary approaches. In this context, it seems clear that estuarine management plans should incorporate the concept of change into the planning of policy decisions since these natural dynamic areas are often under human pressure and are recognized as sensitive to climate change effects. Therefore, the knowledge about historical evolution of estuarine shoreline is important to provide new insights on the spatial and temporal dimensions of estuarine change. This paper aims to present and discuss shoreline changes due to human intervention in Tagus estuary, located on the west coast of Portugal. Detailed margins cartography, in a 550m fringe (drawn inland from the highest astronomical tide line), was performed based on 2007 orthophotos (spatial resolution of 0.5 m) analysis. Several classification categories were considered, as urbanized areas, industrial, port and airport facilities, agriculture spaces, green areas and natural zones. The estuarine bed (area bellow the highest astronomical tide line) was also mapped (including human occupation, natural habitats, morpho-sedimentary units) based on the geographic information above and LANSAT 7 TM+ images using image processing techniques. Aerial photographs dated from 1944, 1946, 1948, 1955 and 1958 were analyzed for a set of pilot zones in order to fully understand the decadal shoreline change. Estuarine bed presents

Evidence of El Niño driven desiccation cycles in a shallow estuarine lake: The evolution and fate of Africa's largest estuarine system, Lake St Lucia

NASA Astrophysics Data System (ADS)

Humphries, M. S.; Green, A. N.; Finch, J. M.

2016-12-01

Projections of an increase in drought frequency and intensity over the next century are expected to have severe implications for a number of globally important coastal ecosystems. In this paper, we present geochemical data from three sediment cores extracted from the main depositional basins of Lake St Lucia, Africa's largest estuarine system. Lake St Lucia is subject to extreme natural variations in salinity. The sedimentary record documents the evolution of the system from a relatively deep-water, open lagoon to a confined, shallow estuarine lake that today is highly sensitive to changes in freshwater supply. This is particularly evident in the northern portions of the system, where the presence of distinct halite-enriched horizons document episodes of prolonged drought. The lateral persistence of these halite layers, as revealed by seismic profiling, point to a system-wide onset of desiccation associated with a major shift in the regional hydroclimate. The most severe drought events identified, which may have lasted several years, occur at 1100 and 1750 cal year BP, and are associated with known peaks in El Niño frequency and intensity. Our analyses suggest that past cycles of desiccation and hyper-salinity have been controlled by climatic changes related to ENSO intensification. This study provides a valuable new record from a key ENSO-sensitive region of the Southern Hemisphere. Our findings have important relevance for understanding ENSO variability across the Indo-Pacific region and the influence exerted on systems sensitive to changes in moisture balance.

Detrital shadows: estuarine food web connectivity depends on fluvial influence and consumer feeding mode.

PubMed

Howe, Emily; Simenstad, Charles A; Ogston, Andrea

2017-10-01

We measured the influence of landscape setting on estuarine food web connectivity in five macrotidal Pacific Northwest estuaries across a gradient of freshwater influence. We used stable isotopes (δ 13 C, δ 15 N, δ 34 S) in combination with a Bayesian mixing model to trace primary producer contributions to suspension- and deposit-feeding bivalve consumers (Mytilus trossulus and Macoma nasuta) transplanted into three estuarine vegetation zones: emergent marsh, mudflat, and eelgrass. Eelgrass includes both Japanese eelgrass (Zostera japonica) and native eelgrass (Zostera marina). Fluvial discharge and consumer feeding mode strongly influenced the strength and spatial scale of observed food web linkages, while season played a secondary role. Mussels displayed strong cross-ecosystem connectivity in all estuaries, with decreasing marine influence in the more fluvial estuaries. Mussel diets indicated homogenization of detrital sources within the water column of each estuary. In contrast, the diets of benthic deposit-feeding clams indicated stronger compartmentalization in food web connectivity, especially in the largest river delta where clam diets were trophically disconnected from marsh sources of detritus. This suggests detritus deposition is patchy across space, and less homogenous than the suspended detritus pool. In addition to fluvial setting, other estuary-specific environmental drivers, such as marsh area or particle transport speed, influenced the degree of food web linkages across space and time, often accounting for unexpected patterns in food web connectivity. Transformations of the estuarine landscape that alter river hydrology or availability of detritus sources can thus potentially disrupt natural food web connectivity at the landscape scale, especially for sedentary organisms, which cannot track their food sources through space. © 2017 by the Ecological Society of America.

Estuarine biodiversity as an indicator of groundwater discharge

NASA Astrophysics Data System (ADS)

Silva, A. C. F.; Tavares, P.; Shapouri, M.; Stigter, T. Y.; Monteiro, J. P.; Machado, M.; Cancela da Fonseca, L.; Ribeiro, L.

2012-01-01

Communities located in the interface between marine/brackish and freshwater habitats are likely to be early responders to climatic changes as they are exposed to both saline and freshwater conditions, and thus are expected to be sensitive to any change in their environmental conditions. Climatic effects are predicted to reduce the availability of groundwater, altering the hydrological balance on estuarine-aquifer interfaces. Here, we aimed to characterise the estuarine faunal community along a gradient dependent on groundwater input, under a predicted climatic scenario of reduction in groundwater discharge into the estuary. Sediment macrofauna was sampled along a salinity gradient following both the wet and dry seasons in 2009. Results indicated that species abundance varied significantly with the salinity gradient created by the groundwater discharge into the estuarine habitat and with sampling time. The isopode Cyathura carinata (Krøyer, 1847) and the polychaetes Heteromastus filiformis (Claparède, 1864) and Hediste diversicolor O.F. Muller, 1776 were associated with the more saline locations, while oligochaeta and Spionidae were more abundant in areas of lower salinity. The polychaete Alkmaria romijni Horst, 1919 was the dominant species and ubiquitous throughout sampling stations. This study provides evidence for estuarine fauna to be considered as a potentially valuable indicator of variation in the input of groundwater into marine-freshwater interface habitats, expected from climatic pressures on aquifer levels, condition and recharge rates. For instance, a reduction in the abundance of some polychaete species, found here to be more abundant in freshwater conditions, and increasing Oligochaeta found here on higher salinities, can potentially be early warnings of a reduction in the input of groundwater into estuaries. Estuarine benthic species are often the main prey for commercially important fish predators such as in our case study, making it important to

Biochemical Mechanisms and Microorganisms Involved in Anaerobic Testosterone Metabolism in Estuarine Sediments

PubMed Central

Shih, Chao-Jen; Chen, Yi-Lung; Wang, Chia-Hsiang; Wei, Sean T.-S.; Lin, I-Ting; Ismail, Wael A.; Chiang, Yin-Ru

2017-01-01

Current knowledge on the biochemical mechanisms underlying microbial steroid metabolism in anaerobic ecosystems is extremely limited. Sulfate, nitrate, and iron [Fe (III)] are common electron acceptors for anaerobes in estuarine sediments. Here, we investigated anaerobic testosterone metabolism in anaerobic sediments collected from the estuary of Tamsui River, Taiwan. The anaerobic sediment samples were spiked with testosterone (1 mM) and individual electron acceptors (10 mM), including nitrate, Fe3+, and sulfate. The analysis of androgen metabolites indicated that testosterone biodegradation under denitrifying conditions proceeds through the 2,3-seco pathway, whereas testosterone biodegradation under iron-reducing conditions may proceed through an unidentified alternative pathway. Metagenomic analysis and PCR-based functional assays suggested that Thauera spp. were the major testosterone degraders in estuarine sediment samples incubated with testosterone and nitrate. Thauera sp. strain GDN1, a testosterone-degrading betaproteobacterium, was isolated from the denitrifying sediment sample. This strain tolerates a broad range of salinity (0–30 ppt). Although testosterone biodegradation did not occur under sulfate-reducing conditions, we observed the anaerobic biotransformation of testosterone to estrogens in some testosterone-spiked sediment samples. This is unprecedented since biotransformation of androgens to estrogens is known to occur only under oxic conditions. Our metagenomic analysis suggested that Clostridium spp. might play a role in this anaerobic biotransformation. These results expand our understanding of microbial metabolism of steroids under strictly anoxic conditions. PMID:28848528

Reconstructing early 17th century estuarine drought conditions from Jamestown oysters.

PubMed

Harding, Juliana M; Spero, Howard J; Mann, Roger; Herbert, Gregory S; Sliko, Jennifer L

2010-06-08

Oysters (Crassostrea virginica) were a central component of the Chesapeake Bay ecosystem in 1607 when European settlers established Jamestown, VA, the first permanent English settlement in North America. These estuarine bivalves were an important food resource during the early years of the James Fort (Jamestown) settlement while the colonists were struggling to survive in the face of inadequate supplies and a severe regional drought. Although oyster shells were discarded as trash after the oysters were eaten, the environmental and ecological data recorded in the bivalve geochemistry during shell deposition remain intact over centuries, thereby providing a unique window into conditions during the earliest Jamestown years. We compare oxygen isotope data from these 17th century oyster shells with modern shells to quantify and contrast estuarine salinity, season of oyster collection, and shell provenance during Jamestown colonization (1609-1616) and the 21st century. Data show that oysters were collected during an extended drought between fall 1611 and summer 1612. The drought shifted the 14 psu isohaline above Jamestown Island, facilitating individual oyster growth and extension of oyster habitat upriver toward the colony, thereby enhancing local oyster food resources. Data from distinct well layers suggest that the colonists also obtained oysters from reefs near Chesapeake Bay to augment oyster resources near Jamestown Island. The oyster shell season of harvest reconstructions suggest that these data come from either a 1611 well with a very short useful period or an undocumented older well abandoned by late 1611.

Marine biodiversity–ecosystem functions under uncertain environmental futures

PubMed Central

Bulling, Mark T.; Hicks, Natalie; Murray, Leigh; Paterson, David M.; Raffaelli, Dave; White, Piran C. L.; Solan, Martin

2010-01-01

Anthropogenic activity is currently leading to dramatic transformations of ecosystems and losses of biodiversity. The recognition that these ecosystems provide services that are essential for human well-being has led to a major interest in the forms of the biodiversity–ecosystem functioning relationship. However, there is a lack of studies examining the impact of climate change on these relationships and it remains unclear how multiple climatic drivers may affect levels of ecosystem functioning. Here, we examine the roles of two important climate change variables, temperature and concentration of atmospheric carbon dioxide, on the relationship between invertebrate species richness and nutrient release in a model benthic estuarine system. We found a positive relationship between invertebrate species richness and the levels of release of NH4-N into the water column, but no effect of species richness on the release of PO4-P. Higher temperatures and greater concentrations of atmospheric carbon dioxide had a negative impact on nutrient release. Importantly, we found significant interactions between the climate variables, indicating that reliably predicting the effects of future climate change will not be straightforward as multiple drivers are unlikely to have purely additive effects, resulting in increased levels of uncertainty. PMID:20513718

Marine biodiversity-ecosystem functions under uncertain environmental futures.

PubMed

Bulling, Mark T; Hicks, Natalie; Murray, Leigh; Paterson, David M; Raffaelli, Dave; White, Piran C L; Solan, Martin

2010-07-12

Anthropogenic activity is currently leading to dramatic transformations of ecosystems and losses of biodiversity. The recognition that these ecosystems provide services that are essential for human well-being has led to a major interest in the forms of the biodiversity-ecosystem functioning relationship. However, there is a lack of studies examining the impact of climate change on these relationships and it remains unclear how multiple climatic drivers may affect levels of ecosystem functioning. Here, we examine the roles of two important climate change variables, temperature and concentration of atmospheric carbon dioxide, on the relationship between invertebrate species richness and nutrient release in a model benthic estuarine system. We found a positive relationship between invertebrate species richness and the levels of release of NH(4)-N into the water column, but no effect of species richness on the release of PO(4)-P. Higher temperatures and greater concentrations of atmospheric carbon dioxide had a negative impact on nutrient release. Importantly, we found significant interactions between the climate variables, indicating that reliably predicting the effects of future climate change will not be straightforward as multiple drivers are unlikely to have purely additive effects, resulting in increased levels of uncertainty.

Great Lakes rivermouth ecosystems: scientific synthesis and management implications

USGS Publications Warehouse

Larson, James H.; Trebitz, Anett S.; Steinman, Alan D.; Wiley, Michael J.; Carlson Mazur, Martha; Pebbles, Victoria; Braun, Heather A.; Seelbach, Paul W.

2013-01-01

At the interface of the Great Lakes and their tributary rivers lies the rivermouths, a class of aquatic ecosystem where lake and lotic processes mix and distinct features emerge. Many rivermouths are the focal point of both human interaction with the Great Lakes and human impacts to the lakes; many cities, ports, and beaches are located in rivermouth ecosystems, and these human pressures often degrade key ecological functions that rivermouths provide. Despite their ecological uniqueness and apparent economic importance, there has been relatively little research on these ecosystems as a class relative to studies on upstream rivers or the open-lake waters. Here we present a synthesis of current knowledge about ecosystem structure and function in Great Lakes rivermouths based on studies in both Laurentian rivermouths, coastal wetlands, and marine estuarine systems. A conceptual model is presented that establishes a common semantic framework for discussing the characteristic spatial features of rivermouths. This model then is used to conceptually link ecosystem structure and function to ecological services provided by rivermouths. This synthesis helps identify the critical gaps in understanding rivermouth ecology. Specifically, additional information is needed on how rivermouths collectively influence the Great Lakes ecosystem, how human alterations influence rivermouth functions, and how ecosystem services provided by rivermouths can be managed to benefit the surrounding socioeconomic networks.

Impact assessment of non-indigenous jellyfish species on the estuarine community dynamic: A model of medusa phase

NASA Astrophysics Data System (ADS)

Muha, Teja Petra; Teodósio, Maria Alexandra; Ben-Hamadou, Radhouan

2017-03-01

Non-indigenous jellyfish species (NIJS) Blackforida virginica have recently been introduced to the Guadiana Estuary. A modelling approach was used for the assessment of the species-specific impact on the native community, during the medusa phase. The novel interactions between NIJS and the native community are assessed through biomass variation including hydrodynamic and climatic variables. Sensitivity analysis shows that both native species, as well as NIJS highly depend on the water discharge regime, nutrient contribution and the amount of detritus production. Abiotic factors such as the Northern Atlantic Oscillation, water discharge, nutrient load and detritus production are the most influential factors for the dynamics of the estuarine ecosystem demonstrated by the model. Low water discharge and low nutrient retention rate appear to be the most favourable conditions for B. virginica. The species is a non-selective predator able to integrate into the system effectively and has caused a decrease in the biomass of other organisms in the estuarine ecosystem throughout the summer after dam removal. The B. virginica significant impact can be evaluated only when the jellyfish detritus food pathway is involved. The B. virginica predatory impact potential, as well as food preference, appears to be the most influential factors for the overall biomass variation. On the contrary, winter freshwater pulses reduce the survival rate of jellyfish polyps which results in a decrease of medusa during summer. The model presents a strong ecohydrology movement where the fluctuation of organism biomass strongly depends on the hydrological conditions including the amount of nutrient load.

Comparing Measures of Estuarine Ecosystem Production in a Temperate New England Estuary

EPA Science Inventory

Anthropogenic nutrient enrichments and concerted efforts at nutrient reductions, compounded with the influences of climate change, are likely changing the net ecosystem production (NEP) of our coastal systems. To quantify these changes, scientists monitor a range of physical, che...

Diverse effects of invasive ecosystem engineers on marine biodiversity and ecosystem functions: A global review and meta-analysis.

PubMed

Guy-Haim, Tamar; Lyons, Devin A; Kotta, Jonne; Ojaveer, Henn; Queirós, Ana M; Chatzinikolaou, Eva; Arvanitidis, Christos; Como, Serena; Magni, Paolo; Blight, Andrew J; Orav-Kotta, Helen; Somerfield, Paul J; Crowe, Tasman P; Rilov, Gil

2018-03-01

Invasive ecosystem engineers (IEE) are potentially one of the most influential types of biological invaders. They are expected to have extensive ecological impacts by altering the physical-chemical structure of ecosystems, thereby changing the rules of existence for a broad range of resident biota. To test the generality of this expectation, we used a global systematic review and meta-analysis to examine IEE effects on the abundance of individual species and communities, biodiversity (using several indices) and ecosystem functions, focusing on marine and estuarine environments. We found that IEE had a significant effect (positive and negative) in most studies testing impacts on individual species, but the overall (cumulative) effect size was small and negative. Many individual studies showed strong IEE effects on community abundance and diversity, but the direction of effects was variable, leading to statistically non-significant overall effects in most categories. In contrast, there was a strong overall effect on most ecosystem functions we examined. IEE negatively affected metabolic functions and primary production, but positively affected nutrient flux, sedimentation and decomposition. We use the results to develop a conceptual model by highlighting pathways whereby IEE impact communities and ecosystem functions, and identify several sources of research bias in the IEE-related invasion literature. Only a few of the studies simultaneously quantified IEE effects on community/diversity and ecosystem functions. Therefore, understanding how IEE may alter biodiversity-ecosystem function relationships should be a primary focus of future studies of invasion biology. Moreover, the clear effects of IEE on ecosystem functions detected in our study suggest that scientists and environmental managers ought to examine how the effects of IEE might be manifested in the services that marine ecosystems provide to humans. © 2017 John Wiley & Sons Ltd.

Geographic variation in species richness, rarity, and the selection of areas for conservation: An integrative approach with Brazilian estuarine fishes

NASA Astrophysics Data System (ADS)

Vilar, Ciro C.; Joyeux, Jean-Christophe; Spach, Henry L.

2017-09-01

While the number of species is a key indicator of ecological assemblages, spatial conservation priorities solely identified from species richness are not necessarily efficient to protect other important biological assets. Hence, the results of spatial prioritization analysis would be greatly enhanced if richness were used in association to complementary biodiversity measures. In this study, geographic patterns in estuarine fish species rarity (i.e. the average range size in the study area), endemism and richness, were mapped and integrated to identify regions important for biodiversity conservation along the Brazilian coast. Furthermore, we analyzed the effectiveness of the national system of protected areas to represent these regions. Analyses were performed on presence/absence data of 412 fish species in 0.25° latitudinal bands covering the entire Brazilian biogeographical province. Species richness, rarity and endemism patterns differed and strongly reflected biogeographical limits and regions. However, among the existing 154 latitudinal bands, 48 were recognized as conservation priorities by concomitantly harboring high estuarine fish species richness and assemblages of geographically rare species. Priority areas identified for all estuarine fish species largely differed from those identified for Brazilian endemics. Moreover, there was no significant correlation between the different aspects of the fish assemblages considered (i.e. species richness, endemism or rarity), suggesting that designating reserves based on a single variable may lead to large gaps in the overall protection of biodiversity. Our results further revealed that the existing system of protected areas is insufficient for representing the priority bands we identified. This highlights the urgent need for expanding the national network of protected areas to maintain estuarine ecosystems with high conservation value.

Mapping ecosystem service indicators in a Great Lakes estuarine Area of Concern

EPA Science Inventory

Estuaries provide multiple ecosystem services from which humans benefit. Currently, thirty-six Great Lakes estuaries in the United States and Canada are designated as Areas of Concern (AOCs) due to a legacy of chemical contamination, degraded habitat, and non-point-source polluti...

How U-Th series radionuclides have come to trace estuarine processes

NASA Astrophysics Data System (ADS)

Church, T. M.

2014-12-01

Some forty years ago, the essence of estuarine processes was pioneered in terms of property-property (salinity) parameterization and end member mixing experiments. The result revealed how scavenging via "flocculation" of organic material such as humic acids affect primary nutrients and trace elements, many of pollutant interest. Defined in the Delaware are estuarine reaction zones, including one more "geochemical" in upper turbid areas and another more" biochemical" in more productive photic zones of lower areas. Since then, the natural U-Th radionuclide series have been employed to quantify estuarine transport and scavenging processes. Parent U appears negatively non-conserved during summer in estuarine and coastal waters, while that of Ra isotopes positively non-conservative dominated by a ground water end member. For both U and Ra, the biogeochemical influence of marginal salt marshes is significant. Indeed in the marsh atmospheric 210-Pb has become the metric of choice for the chronology of estuarine pollutant records. Using the more particle reactive isotopes in quantifying estuarine mixing processes (e.g. Th or Pb) proves to be fruitful in the Delaware and upper Chesapeake. While Th simply tracks that of particle abundance, both 210-Pb and 210-Po show differential scavenging with residence times of weeks to a month according to lithogenic and biogenic cycling processes, respectively.

OVERVIEW OF GIS APPLICATIONS IN ESTUARINE MONITORING AND ASSESSMENT RESEARCH

EPA Science Inventory

Geographic information systems (GIS) tools are now considered integral in estuarine monitoring and assessment research. A synopsis is presented of our estuarine applications of GIS in the Northeast region of the U.S. The applications discussed cover sample site selection, support...

Monitoring nekton as a bioindicator in shallow estuarine habitats

USGS Publications Warehouse

Raposa, K.B.; Roman, C.T.; Heltshe, J.F.

2003-01-01

Long-term monitoring of estuarine nekton has many practical and ecological benefits but efforts are hampered by a lack of standardized sampling procedures. This study provides a rationale for monitoring nekton in shallow (< 1 m), temperate, estuarine habitats and addresses some important issues that arise when developing monitoring protocols. Sampling in seagrass and salt marsh habitats is emphasized due to the susceptibility of each habitat to anthropogenic stress and to the abundant and rich nekton assemblages that each habitat supports. Extensive sampling with quantitative enclosure traps that estimate nekton density is suggested. These gears have a high capture efficiency in most habitats and are small enough (e.g., 1 m(2)) to permit sampling in specific microhabitats. Other aspects of nekton monitoring are discussed, including spatial and temporal sampling considerations, station selection, sample size estimation, and data collection and analysis. Developing and initiating long-term nekton monitoring programs will help evaluate natural and human-induced changes in estuarine nekton over time and advance our understanding of the interactions between nekton and the dynamic estuarine environment.

Impact of intertidal area characteristics on estuarine tidal hydrodynamics: A modelling study for the Scheldt Estuary

NASA Astrophysics Data System (ADS)

Stark, J.; Smolders, S.; Meire, P.; Temmerman, S.

2017-11-01

Marsh restoration projects are nowadays being implemented as ecosystem-based strategies to reduce flood risks and to restore intertidal habitat along estuaries. Changes in estuarine tidal hydrodynamics are expected along with such intertidal area changes. A validated hydrodynamic model of the Scheldt Estuary is used to gain fundamental insights in the role of intertidal area characteristics on tidal hydrodynamics and tidal asymmetry in particular through several geomorphological scenarios in which intertidal area elevation and location along the estuary is varied. Model results indicate that the location of intertidal areas and their storage volume relative to the local tidal prism determine the intensity and reach along the estuary over which tidal hydrodynamics are affected. Our model results also suggest that intertidal storage areas that are located within the main estuarine channel system, and hence are part of the flow-carrying part of the estuary, may affect tidal hydrodynamics differently than intertidal areas that are side-basins of the main estuarine channel, and hence only contribute little to the flow-carrying cross-section of the estuary. If tidal flats contribute to the channel cross-section and exert frictional effects on the tidal propagation, the elevation of intertidal flats influences the magnitude and direction of tidal asymmetry along estuarine channels. Ebb-dominance is most strongly enhanced if tidal flats are around mean sea level or slightly above. Conversely, flood-dominance is enhanced if the tidal flats are situated low in the tidal frame. For intertidal storage areas at specific locations besides the main channel, flood-dominance in the estuary channel peaks in the vicinity of those areas and generally reduces upstream and downstream compared to a reference scenario. Finally, the model results indicate an along-estuary varying impact on the tidal prism as a result of adding intertidal storage at a specific location. In addition to known

Marine and Estuarine Pollution.

ERIC Educational Resources Information Center

Reish, Donald J.

1978-01-01

Presents a literature review of the effects of various pollutants on marine and estuarine organisms, covering publications of 1976-77. This review includes: (1) effects of pesticides, dredging, dumping, sludge, and petroleum hydrocarbons; and (2) diseases and tissue abnormalities. A list of 441 references is also presented. (HM)

Non-Linear Interactions Determine the Impact of Sea-Level Rise on Estuarine Benthic Biodiversity and Ecosystem Processes

PubMed Central

Yamanaka, Tsuyuko; Raffaelli, David; White, Piran C. L.

2013-01-01

Sea-level rise induced by climate change may have significant impacts on the ecosystem functions and ecosystem services provided by intertidal sediment ecosystems. Accelerated sea-level rise is expected to lead to steeper beach slopes, coarser particle sizes and increased wave exposure, with consequent impacts on intertidal ecosystems. We examined the relationships between abundance, biomass, and community metabolism of benthic fauna with beach slope, particle size and exposure, using samples across a range of conditions from three different locations in the UK, to determine the significance of sediment particle size beach slope and wave exposure in affecting benthic fauna and ecosystem function in different ecological contexts. Our results show that abundance, biomass and oxygen consumption of intertidal macrofauna and meiofauna are affected significantly by interactions among sediment particle size, beach slope and wave exposure. For macrofauna on less sloping beaches, the effect of these physical constraints is mediated by the local context, although for meiofauna and for macrofauna on intermediate and steeper beaches, the effects of physical constraints dominate. Steeper beach slopes, coarser particle sizes and increased wave exposure generally result in decreases in abundance, biomass and oxygen consumption, but these relationships are complex and non-linear. Sea-level rise is likely to lead to changes in ecosystem structure with generally negative impacts on ecosystem functions and ecosystem services. However, the impacts of sea-level rise will also be affected by local ecological context, especially for less sloping beaches. PMID:23861863

Non-linear interactions determine the impact of sea-level rise on estuarine benthic biodiversity and ecosystem processes.

PubMed

Yamanaka, Tsuyuko; Raffaelli, David; White, Piran C L

2013-01-01

Sea-level rise induced by climate change may have significant impacts on the ecosystem functions and ecosystem services provided by intertidal sediment ecosystems. Accelerated sea-level rise is expected to lead to steeper beach slopes, coarser particle sizes and increased wave exposure, with consequent impacts on intertidal ecosystems. We examined the relationships between abundance, biomass, and community metabolism of benthic fauna with beach slope, particle size and exposure, using samples across a range of conditions from three different locations in the UK, to determine the significance of sediment particle size beach slope and wave exposure in affecting benthic fauna and ecosystem function in different ecological contexts. Our results show that abundance, biomass and oxygen consumption of intertidal macrofauna and meiofauna are affected significantly by interactions among sediment particle size, beach slope and wave exposure. For macrofauna on less sloping beaches, the effect of these physical constraints is mediated by the local context, although for meiofauna and for macrofauna on intermediate and steeper beaches, the effects of physical constraints dominate. Steeper beach slopes, coarser particle sizes and increased wave exposure generally result in decreases in abundance, biomass and oxygen consumption, but these relationships are complex and non-linear. Sea-level rise is likely to lead to changes in ecosystem structure with generally negative impacts on ecosystem functions and ecosystem services. However, the impacts of sea-level rise will also be affected by local ecological context, especially for less sloping beaches.

Seasonal succession of estuarine fish, shrimps, macrozoobenthos and plankton: Physico-chemical and trophic influence. The Gironde estuary as a case study

NASA Astrophysics Data System (ADS)

Selleslagh, Jonathan; Lobry, Jérémy; N'Zigou, Aimé Roger; Bachelet, Guy; Blanchet, Hugues; Chaalali, Aurélie; Sautour, Benoît; Boët, Philippe

2012-10-01

Characterization of the structure and seasonal variability of biotic communities is essential for a better understanding of estuarine ecosystem functioning and in order to manage these highly fluctuating and naturally stressed systems. Numerous studies have investigated the role of environmental factors in controlling temporal variations in biotic communities. However, most have concluded that the explanatory power of physico-chemical variables was significant but not sufficient to explain ecological dynamics. The present study aimed to propose the importance of trophic interactions as an additional structuring factor of species seasonal variability by examining simultaneous dynamics of all estuarine biotic communities, using the oligo-mesohaline area of the Gironde estuary (SW France) as a case study. Data on the main biological groups (fish, shrimps, macrozoobenthos and plankton) sampled during a five-year period (2004-2008) at monthly intervals using a well standardized protocol, as well as data on environmental variables, were compiled here for the first time. According to species composition, the Gironde estuary is used as a nursery, feeding, resident and migratory habitat. For almost all species, strong seasonal fluctuations occurred with a succession of species, indicating an optimization of the use of the available resources over a typical year by estuarine biological communities. Multivariate analyses discriminated four seasonal groups of species with two distinctive ecological seasons. A clear shift in July indicated a biomass transfer from a "planktonic phase" to a "bentho-demersal phase", corresponding to spring and summer-autumn periods, respectively. With regard to the temporal fluctuations of dominant species of all biological groups, this study highlighted the possible influence of trophic relationships, predation in particular, on seasonal variations in species abundance, in addition to the physico-chemical influence. This study enabled us to

Low mercury levels in marine fish from estuarine and coastal environments in southern China.

PubMed

Pan, Ke; Chan, Heidi; Tam, Yin Ki; Wang, Wen-Xiong

2014-02-01

This study is the first comprehensive evaluation of total Hg and methylmercury (MeHg) concentrations in wild marine fish from an estuarine and a coastal ecosystem in southern China. A total of 571 fish from 54 different species were examined. Our results showed that the Hg levels were generally low in the fish, and the Hg levels were below 30 ng g(-1) (wet weight) for 82% of the samples, which may be related to the reduced size of the fish and altered food web structure due to overfishing. Decreased coastal wetland coverage and different carbon sources may be responsible for the habitat-specific Hg concentrations. The degree of biomagnification was relatively low in the two systems. Copyright © 2013 Elsevier Ltd. All rights reserved.

15 CFR 921.40 - Ongoing oversight and evaluations of designated National Estuarine Research Reserves.

Code of Federal Regulations, 2010 CFR

2010-01-01

... designated National Estuarine Research Reserves. 921.40 Section 921.40 Commerce and Foreign Trade Regulations..., DEPARTMENT OF COMMERCE OCEAN AND COASTAL RESOURCE MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM... and evaluations of designated National Estuarine Research Reserves. (a) The Sanctuaries and Reserve...

15 CFR 921.52 - Promotion and coordination of estuarine research.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Research Projects § 921.52 Promotion and coordination of estuarine research. (a) NOAA will promote and coordinate the use of the National Estuarine Research Reserve System for research purposes. (b) NOAA will, in...) NOAA will consult with other Federal and state agencies to promote use of one or more research reserves...

15 CFR 921.52 - Promotion and coordination of estuarine research.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Research Projects § 921.52 Promotion and coordination of estuarine research. (a) NOAA will promote and coordinate the use of the National Estuarine Research Reserve System for research purposes. (b) NOAA will, in...) NOAA will consult with other Federal and state agencies to promote use of one or more research reserves...

15 CFR 921.52 - Promotion and coordination of estuarine research.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Research Projects § 921.52 Promotion and coordination of estuarine research. (a) NOAA will promote and coordinate the use of the National Estuarine Research Reserve System for research purposes. (b) NOAA will, in...) NOAA will consult with other Federal and state agencies to promote use of one or more research reserves...

15 CFR 921.52 - Promotion and coordination of estuarine research.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Research Projects § 921.52 Promotion and coordination of estuarine research. (a) NOAA will promote and coordinate the use of the National Estuarine Research Reserve System for research purposes. (b) NOAA will, in...) NOAA will consult with other Federal and state agencies to promote use of one or more research reserves...

Finding refuge: The estuarine distribution of the nemertean egg predator Carcinonemertes errans on the Dungeness crab, Cancer magister

NASA Astrophysics Data System (ADS)

Dunn, Paul H.; Young, Craig M.

2013-12-01

Parasites can significantly impact ecosystems by altering the distributions and population sizes of their host organisms. Some hosts are thought to find refuge from parasitism by entering habitats where their parasites cannot survive. The nemertean worm Carcinonemertes errans is an egg predator that infects the Dungeness crab, Cancer magister, throughout the host's range. To determine if C. magister experiences a refuge from C. errans within estuarine environments, we examined the distribution of C. errans on Dungeness crabs within Oregon's Coos Bay Estuary. Year-round sampling over a three-year period also allowed us to test for temporal variation in the parasite's distribution. We found that parasite prevalence, mean intensity, and parasite density of C. errans infecting C. magister varied along a clear estuarine gradient, with crabs nearest the ocean carrying the heaviest parasite loads. Larger crabs were more heavily infected with worms, and seasonal infection patterns were observed at some sites within the bay. Crabs sampled from coastal waters near the estuary carried significantly more worms than did crabs from the bay, suggesting that the estuary is acting as a spatiotemporal parasite refuge for this important fishery species.

Parameter Space of the Columbia River Estuarine Turbidity Maxima

NASA Astrophysics Data System (ADS)

McNeil, C. L.; Shcherbina, A.; Lopez, J.; Karna, T.; Baptista, A. M.; Crump, B. C.; Sanford, T. B.

2016-12-01

We present observations of estuarine turbidity maxima (ETM) in the North Channel of the Columbia River estuary (OR and WA, USA) covering different river discharge and flood tide conditions. Measurements were made using optical backscattering sensors on two REMUS-100 autonomous underwater vehicles (AUVs) during spring 2012, summer 2013, and fall 2012. Although significant short term variability in AUV measured optical backscatter was observed, some clustering of the data occurs around the estuarine regimes defined by a mixing parameter and a freshwater Froude number (Geyer & MacCready [2014]). Similar clustering is observed in long term time series of turbidity from the SATURN observatory. We will use available measurements and numerical model simulations of suspended sediment to further explore the variability of suspended sediment dynamics within a frame work of estuarine parameter space.

Estuarine-Shelf Interactions,

DTIC Science & Technology

1986-01-01

latter process occurs at the mouth of the Magothy strength of the flow rather than being specified a River, an estuary tributary to Chesapeake Bay...periods. It is also clear, Magothy in the immediate past. As the density though, that significant geographical variability front associated with the...Estuarine Coastal chemical hydrography of the Magothy River, ?tar. Sci., ’)(4), 485-496, 1977. Tech. Rep. XVIR, Ref. 59-2, Chesapeake bay Hachey, H. B

Integrated Approaches to Estuarine Use and Protection: Tampa Bay Ecosystem Services Case Study.

EPA Science Inventory

The Tampa Bay region faces projected stress from climate change, contaminants, nutrients, and of human development on a natural ecosystem that is valued (economically, aesthetically and culturally) in its present state. With fast-paced population increases, conversion and develop...

Organo-tins in sediments and mussels from the Sado estuarine system (Portugal).

PubMed

Quevauviller, P; Lavigne, R; Pinel, R; Astruc, M

1989-01-01

Analyses of methyl- and butyl-tin levels in freshwater, estuarine and marine sediments from the Sado estuarine system, and in mussels (Mytilus galloprovincialis) from its adjacent coast, have been performed in order to detect the contaminated areas. The main inputs of tributyl-tin (TBT), along with degradation products di- and monobutyl-tin (DBT and MBT), were detected in the estuarine zone, due to high discharge from shipyards located in this area. These levels are sometimes very high, ranging from 235 to 12,200 ng g(-1) total butyl-tins in sediments. Such inputs lead to higher bioconcentration values in mussels in the estuarine zone, as well as in a harbour located along the adjacent coast. The bioconcentration of organo-tins in mussel tissues could be enhanced in estuarine turbid waters, due to an ingestion of butyl-tins adsorbed onto fine particles, in comparison with non-turbid coastal waters. Debutylation processes occur in both sediments and mussel tissues; in organisms, these processes may lead to the formation of inorganic tin, which may be methylated differently according to the period of the year.

Riparian vegetation structure and the hunting behavior of adult estuarine crocodiles

PubMed Central

Davies, Andrew B.; Goossens, Benoit; Asner, Gregory P.

2017-01-01

Riparian ecosystems are amongst the most biodiverse tropical habitats. They are important, and essential, ecological corridors, linking remnant forest fragments. In this study, we hypothesised that crocodile’s actively select nocturnal resting locations based on increased macaque predation potential. We examined the importance of riparian vegetation structure in the maintenance of crocodile hunting behaviours. Using airborne Light Detection and Ranging (LiDAR) and GPS telemetry on animal movement, we identified the repeated use of nocturnal resting sites by adult estuarine crocodiles (Crocodylus porosus) throughout the fragmented Lower Kinabatangan Wildlife Sanctuary in Sabah, Malaysia. Crocodile resting locations were found to resemble, in terms of habitat characteristics, the sleeping sites of long-tailed macaque; positioned in an attempt to avoid predation by terrestrial predators. We found individual crocodiles were actively selecting overhanging vegetation and that the protrusion of trees from the tree line was key to site selection by crocodiles, as well as influencing both the presence and group size of sleeping macaques. Although these findings are correlational, they have broad management implications, with the suggestion that riparian corridor maintenance and quality can have implications beyond that of terrestrial fauna. We further place our findings in the context of the wider ecosystem and the maintenance of trophic interactions, and discuss how future habitat management has the potential to mitigate human-wildlife conflict. PMID:29020111

Riparian vegetation structure and the hunting behavior of adult estuarine crocodiles.

PubMed

Evans, Luke J; Davies, Andrew B; Goossens, Benoit; Asner, Gregory P

2017-01-01

Riparian ecosystems are amongst the most biodiverse tropical habitats. They are important, and essential, ecological corridors, linking remnant forest fragments. In this study, we hypothesised that crocodile's actively select nocturnal resting locations based on increased macaque predation potential. We examined the importance of riparian vegetation structure in the maintenance of crocodile hunting behaviours. Using airborne Light Detection and Ranging (LiDAR) and GPS telemetry on animal movement, we identified the repeated use of nocturnal resting sites by adult estuarine crocodiles (Crocodylus porosus) throughout the fragmented Lower Kinabatangan Wildlife Sanctuary in Sabah, Malaysia. Crocodile resting locations were found to resemble, in terms of habitat characteristics, the sleeping sites of long-tailed macaque; positioned in an attempt to avoid predation by terrestrial predators. We found individual crocodiles were actively selecting overhanging vegetation and that the protrusion of trees from the tree line was key to site selection by crocodiles, as well as influencing both the presence and group size of sleeping macaques. Although these findings are correlational, they have broad management implications, with the suggestion that riparian corridor maintenance and quality can have implications beyond that of terrestrial fauna. We further place our findings in the context of the wider ecosystem and the maintenance of trophic interactions, and discuss how future habitat management has the potential to mitigate human-wildlife conflict.

Estuarine science and decision-support tools to restore Puget Sound delta and estuarine ecosystems: The Skagit River Delta

NASA Astrophysics Data System (ADS)

Grossman, E. E.; Rosenbauer, R. J.; Takesue, R. K.; Gelfenbaum, G.; Reisenbichler, R.; Paulson, A.; Sexton, N. R.; Labiosa, B.; Beamer, E. M.; Hood, G.; Wyllie-Echeverria, S.

2006-12-01

Historic land use, ongoing resource extraction, and population expansion throughout Puget Sound have scientists and managers rapidly seeking effective restoration strategies to recover salmon (a cultural icon, as well as, a host of other endangered species and threatened habitats. Of principal concern is the reduction of salmon (Oncorhynchus spp.) and diminished carrying capacity of critical habitat in deltaic regions. Delta habitats, essential to salmon survival, have lost 70 to 80 % area since ~1850 and are now adjusting to a new suite of environmental changes associated with land use practices, including wetland restoration, and regional climate change. The USGS Coastal Habitats in Puget Sound Project, in collaboration with partners from the Skagit River System Cooperative, University of Washington, and other federal, state, and local agencies, is integrating geologic, biologic, hydrologic, and socioeconomic information to quantify changes in the distribution and function of deltaic-estuarine nearshore habitats and better predict "possible futures". We are combining detailed geologic and geochemical analyses of sedimentary environments, plant biomarkers (n-alkanes, PAHs, fatty-acids, and sterols), and compound-specific isotopes to estimate historic habitat coverage, eelgrass (Zostera marina) abundance and modern characteristics of nutrient cycling. Hydrologic and sediment transport processes are being measured to characterize physical processes shaping modern habitats including sediment transport and freshwater mixing that control the temporal and spatial pattern of substrate and water column conditions available as habitat. We are using geophysical, remote sensing, and modeling techniques to determine large-scale coastal morphologic and land-use change and characterize how alteration of physical, hydrologic, and biogeochemical processes influence the dynamics of freshwater mixing, and sediment and nutrient transport in the nearshore. To assist restoration

Comparison of Vibrio parahaemolyticus grown in estuarine water and rich medium.

PubMed Central

Pace, J; Chai, T J

1989-01-01

Cell envelope composition and selected physiological traits of Vibrio parahaemolyticus were studied in regard to the Kanagawa phenomenon and growth conditions. Cell envelopes were prepared from cells cultured in Proteose Peptone-beef extract (Difco Laboratories, Detroit, Mich.) medium or filtered estuarine water. Protein, phospholipid, and lipopolysaccharide contents varied with culture conditions. The phospholipids present in the cell envelopes were identified as phosphatidylethanolamine, phosphatidylglycerol, and cardiolipin. Phosphatidylethanolamine decreased and phosphatidylglycerol increased in cells grown in estuarine water. Profiles of proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis demonstrated numerous protein species, with four to six predominant proteins ranging from 26,000 to 120,000 in molecular weight. The profile of V. parahaemolyticus cell envelope proteins was unique and might be useful in the identification of the organism. Alkaline phosphatase activity was slightly higher in Kanagawa-negative strains and was higher in cells grown in estuarine water than in cells grown in rich laboratory medium. The DNA levels in estuarine water-grown cells increased, while RNA levels and cell volume decreased. Bacteriophage sensitivity typing demonstrated a close intraspecies relationship. Results indicated that Kanagawa-positive and -negative strains were closely related, but they could be grouped separately and may have undergone starvation-related physiological changes when cultured in estuarine water. Images PMID:2782869

Mapping invasive wetland plants in the Hudson River National Estuarine Research Reserve using quickbird satellite imagery

USGS Publications Warehouse

Laba, M.; Downs, R.; Smith, S.; Welsh, S.; Neider, C.; White, S.; Richmond, M.; Philpot, W.; Baveye, P.

2008-01-01

The National Estuarine Research Reserve (NERR) program is a nationally coordinated research and monitoring program that identifies and tracks changes in ecological resources of representative estuarine ecosystems and coastal watersheds. In recent years, attention has focused on using high spatial and spectral resolution satellite imagery to map and monitor wetland plant communities in the NERRs, particularly invasive plant species. The utility of this technology for that purpose has yet to be assessed in detail. To that end, a specific high spatial resolution satellite imagery, QuickBird, was used to map plant communities and monitor invasive plants within the Hudson River NERR (HRNERR). The HRNERR contains four diverse tidal wetlands (Stockport Flats, Tivoli Bays, Iona Island, and Piermont), each with unique water chemistry (i.e., brackish, oligotrophic and fresh) and, consequently, unique assemblages of plant communities, including three invasive plants (Trapa natans, Phragmites australis, and Lythrum salicaria). A maximum-likelihood classification was used to produce 20-class land cover maps for each of the four marshes within the HRNERR. Conventional contingency tables and a fuzzy set analysis served as a basis for an accuracy assessment of these maps. The overall accuracies, as assessed by the contingency tables, were 73.6%, 68.4%, 67.9%, and 64.9% for Tivoli Bays, Stockport Flats, Piermont, and Iona Island, respectively. Fuzzy assessment tables lead to higher estimates of map accuracies of 83%, 75%, 76%, and 76%, respectively. In general, the open water/tidal channel class was the most accurately mapped class and Scirpus sp. was the least accurately mapped. These encouraging accuracies suggest that high-resolution satellite imagery offers significant potential for the mapping of invasive plant species in estuarine environments. ?? 2007 Elsevier Inc. All rights reserved.

Coastal and Estuarine Waters: Light Behavior. Coastal and Estuarine Waters: Optical Sensors and Remote Sensing.

EPA Science Inventory

This article summarizes the use of remote sensing techniques and technology to monitor coastal and estuarine waters. These waters are rich in mineral particles stirred up from the seabed by tides and waves and dissolved organic matter transported by rivers. The majority of the li...

Spatial Variability of Benthic-Pelagic Coupling in an Estuary Ecosystem: Consequences for Microphytobenthos Resuspension Phenomenon

PubMed Central

Ubertini, Martin; Lefebvre, Sébastien; Gangnery, Aline; Grangeré, Karine; Le Gendre, Romain; Orvain, Francis

2012-01-01

The high degree of physical factors in intertidal estuarine ecosystem increases material processing between benthic and pelagic compartments. In these ecosystems, microphytobenthos resuspension is a major phenomenon since its contribution to higher trophic levels can be highly significant. Understanding the sediment and associated microphytobenthos resuspension and its fate in the water column is indispensable for measuring the food available to benthic and pelagic food webs. To identify and hierarchize the physical/biological factors potentially involved in MPB resuspension, the entire intertidal area and surrounding water column of an estuarine ecosystem, the Bay des Veys, was sampled during ebb tide. A wide range of physical parameters (hydrodynamic regime, grain size of the sediment, and suspended matter) and biological parameters (flora and fauna assemblages, chlorophyll) were analyzed to characterize benthic-pelagic coupling at the bay scale. Samples were collected in two contrasted periods, spring and late summer, to assess the impact of forcing variables on benthic-pelagic coupling. A mapping approach using kriging interpolation enabled us to overlay benthic and pelagic maps of physical and biological variables, for both hydrological conditions and trophic indicators. Pelagic Chl a concentration was the best predictor explaining the suspension-feeders spatial distribution. Our results also suggest a perennial spatio-temporal structure of both benthic and pelagic compartments in the ecosystem, at least when the system is not imposed to intense wind, with MPB distribution controlled by both grain size and bathymetry. The benthic component appeared to control the pelagic one via resuspension phenomena at the scale of the bay. Co-inertia analysis showed closer benthic-pelagic coupling between the variables in spring. The higher MPB biomass observed in summer suggests a higher contribution to filter-feeders diets, indicating a higher resuspension effect in

Integrated quality assessment of sediments from harbour areas in Santos-São Vicente Estuarine System, Southern Brazil

NASA Astrophysics Data System (ADS)

Buruaem, Lucas Moreira; de Castro, Ítalo Braga; Hortellani, Marcos Antonio; Taniguchi, Satie; Fillmann, Gilberto; Sasaki, Silvio Tarou; Varella Petti, Mônica Angélica; Sarkis, Jorge Eduardo de Souza; Bícego, Márcia Caruso; Maranho, Luciane Alves; Davanso, Marcela Bergo; Nonato, Edmundo Ferraz; Cesar, Augusto; Costa-Lotufo, Leticia Veras; Abessa, Denis Moledo de Souza

2013-09-01

Santos-São Vicente Estuarine System is a highly populated coastal zone in Brazil and where it is located the major port of Latin America. Historically, port activities, industrial and domestic effluents discharges have constituted the main sources of contaminants to estuarine system. This study aimed to assess the recent status of sediment quality from 5 zones of Port of Santos by applying a lines-of-evidence approach through integrating results of: (1) acute toxicity of whole sediment and chronic toxicity of liquid phases; (2) grain size, organic matter, organic carbon, nitrogen, phosphorus, trace metals, polycyclic aromatic hydrocarbons, linear alkylbenzenes and butyltins; (3) benthic community descriptors. Results revealed a gradient of increasing contamination for metals and organic compounds, alongside with their geochemical carriers. Sediment liquid phases were more toxic compared to whole sediment. Low number of species and individuals indicated the impoverishment of benthic community. The use of site-specific sediment quality guidelines was more appropriate to predict sediment toxicity. The integration of results through Sediment Quality Triad approach and principal component analysis allowed observing the effects of natural stressors and dredging on sediment quality and benthic distribution. Even with recent governmental efforts to control, pollution is still relevant in Port of Santos and a threat to local ecosystems.

BOOK REVIEW: ESTUARINE SCIENCE: A SYNTHETIC APPROACH TO RESEARCH AND PRACTICE

EPA Science Inventory

This book is the product of fifty leading estuarine scientists most of whom attended a workshop convened for the purpose of "put[ting] together the case for synthesis of estuarine data and to show the capabilities of synthetic methods of research" (p. 2). The editor, John E. Hob...

Water use patterns of estuarine vegetation in a tidal creek system.

PubMed

Wei, Lili; Lockington, David A; Poh, Seng-Chee; Gasparon, Massimo; Lovelock, Catherine E

2013-06-01

Water availability is a key determinant of the zonation patterns in estuarine vegetation, but water availability and the use of different water sources over space and time are not well understood. We have determined the seasonal water use patterns of riparian vegetation over an estuarine ecotone. Our aim was to investigate how the water use patterns of estuarine vegetation respond to variations in the availability of tidal creek water and rain-derived freshwater. The levels of natural stable isotopes of oxygen and hydrogen were assessed in the stem of the mangrove Avicennia marina (tall and scrub growth forms), Casuarina glauca and Melaleuca quinquenervia that were distributed along transects from river/creek-front towards inland habitats. The isotopic composition of plant tissues and the potential water sources were assessed in both the wet season, when freshwater from rainfall is present, and the dry season, when mangrove trees are expected to be more dependent on tidal water, and when Casuarina and Melaleuca are expected to be dependent on groundwater. Our results indicate that rainwater during the wet season contributes significantly to estuarine vegetation, even to creek-side mangroves which are inundated by tidal creek water daily, and that estuarine vegetation depends primarily on freshwater throughout the year. In contrast, high intertidal scrub mangroves were found to use the greatest proportion of tidal creek water, supplemented by groundwater in the dry season. Contrary to prediction, inland trees C. glauca and M. quinquenervia were found also to rely predominantly on rainwater--even in the dry season. The results of this study reveal a high level of complexity in vegetation water use in estuarine settings.

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

Pollution biomarkers in estuarine animals: critical review and new perspectives.

PubMed

Monserrat, José M; Martínez, Pablo E; Geracitano, Laura A; Amado, Lílian Lund; Martins, Camila Martinez Gaspar; Pinho, Grasiela Lopes Leães; Chaves, Isabel Soares; Ferreira-Cravo, Marlize; Ventura-Lima, Juliane; Bianchini, Adalto

2007-01-01

In this review, recent developments in monitoring toxicological responses in estuarine animals are analyzed, considering the biomarker responses to different classes of pollutants. The estuarine environment imposes stressful conditions to the organisms that inhabit it, and this situation can alter their sensitivity to many pollutants. The specificity of some biomarkers like metallothionein tissue concentration is discussed in virtue of its dependence on salinity, which is highly variable in estuaries. Examples of cholinesterase activity measurements are also provided and criteria to select sensitive enzymes to detect pesticides and toxins are discussed. Regarding non-specific biomarkers, toxic responses in terms of antioxidant defenses and/or oxidative damage are also considered in this review, focusing on invertebrate species. In addition, the presence of an antioxidant gradient along the body of the estuarine polychaete Laeonereis acuta (Nereididae) and its relationship to different strategies, which deal with the generation of oxidative stress, is reviewed. Also, unusual antioxidant defenses against environmental pro-oxidants are discussed, including the mucus secreted by L. acuta. Disruption of osmoregulation by pollutants is of paramount importance in several estuarine species. In some cases such as in the estuarine crab Chasmagnathus granulatus, there is a trade off between bioavailability of toxicants (e.g. metals) and their interaction with key enzymes such as Na(+)-K(+)-ATPase and carbonic anhydrase. Thus, the metal effect on osmoregulation is also discussed in the present review. Finally, field case studies with fish species like the croaker Micropogonias furnieri (Scianidae) are used to illustrate the application of DNA damage and immunosuppressive responses as potential biomarkers of complex mixture of pollutants.

Tributyltin-resistant bacteria from estuarine and freshwater sediments.

PubMed Central

Wuertz, S; Miller, C E; Pfister, R M; Cooney, J J

1991-01-01

Resistance to tributyltin (TBT) was examined in populations from TBT-polluted sediments and nonpolluted sediments from an estuary and from fresh water as well as in pure cultures isolated from those sediments. The 50% effective concentrations (EC50s) for populations were higher at a TBT-polluted freshwater site than at a site without TBT, suggesting that TBT selected for a TBT-resistant population. In contrast, EC50s were significantly lower for populations from a TBT-contaminated estuarine site than for those from a site without TBT, suggesting that other factors in addition to TBT determine whether populations become resistant. EC50s for populations from TBT-contaminated freshwater sediments were nearly 30 times higher than those for populations from TBT-contaminated estuarine sediments. We defined a TBT-resistant bacterium as one which grows on trypticase soy agar containing 8.4 microM TBT, a concentration which prevented the growth of 90% of the culturable bacteria from these sediments. The toxicity of TBT in laboratory media was influenced markedly by the composition of the medium and whether it was liquid or solid. Ten TBT-resistant isolates from estuarine sediments and 19 from freshwater sediments were identified to the genus level. Two isolates, each a Bacillus sp., may be the first gram-positive bacteria isolated from fresh water in the presence of a high concentration of TBT. There was a high incidence of resistance to heavy metals: metal resistance indices were 0.76 for estuarine isolates and 0.68 for freshwater isolates.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1746939

Diet shifts and population dynamics of estuarine foraminifera during ecosystem recovery after experimentally induced hypoxia crises

NASA Astrophysics Data System (ADS)

Brouwer, G. M.; Duijnstee, I. A. P.; Hazeleger, J. H.; Rossi, F.; Lourens, L. J.; Middelburg, J. J.; Wolthers, M.

2016-03-01

This study shows foraminiferal dynamics after experimentally induced hypoxia within the wider context of ecosystem recovery. 13C-labeled bicarbonate and glucose were added to the sediments to examine foraminiferal diet shifts during ecosystem recovery and test-size measurements were used to deduce population dynamics. Hypoxia-treated and undisturbed patches were compared to distinguish natural (seasonal) fluctuations from hypoxia-induced responses. The effect of timing of disturbance and duration of recovery were investigated. The foraminiferal diets and population dynamics showed higher fluctuations in the recovering patches compared to the controls. The foraminiferal diet and population structure of Haynesina germanica and Ammonia beccarii responded differentially and generally inversely to progressive stages of ecosystem recovery. Tracer inferred diet estimates in April and June and the two distinctly visible cohorts in the test-size distribution, discussed to reflect reproduction in June, strongly suggest that the ample availability of diatoms during the first month of ecosystem recovery after the winter hypoxia was likely profitable to A. beccarii. Enhanced reproduction itself was strongly linked to the subsequent dietary shift to bacteria. The distribution of the test dimensions of H. germanica indicated that this species had less fluctuation in population structure during ecosystem recovery but possibly reproduced in response to the induced winter hypoxia. Bacteria seemed to consistently contribute more to the diet of H. germanica than diatoms. For the diet and test-size distribution of both species, the timing of disturbance seemed to have a higher impact than the duration of the subsequent recovery period.

THE PACIFIC COAST ESTUARINE INFORMATION SYSTEM: CREATING A BASELINE FOR THE FUTURE

EPA Science Inventory

Coastal researchers and managers have a growing need for ready access to a diversity of
data types, including estuarine-specific lists of native and nonindigenous species and estuarine/landscape characteristics. These data are key components in ecological risk assessments in g...

Effects of pharmaceuticals and personal care products on marine organisms: from single-species studies to an ecosystem-based approach.

PubMed

Prichard, Emma; Granek, Elise F

2016-11-01

Pharmaceuticals and personal care products (PPCPs) are contaminants of emerging concern that are increasing in use and have demonstrated negative effects on aquatic organisms. There is a growing body of literature reporting the effects of PPCPs on freshwater organisms, but studies on the effects of PPCPs to marine and estuarine organisms are limited. Among effect studies, the vast majority examines subcellular or cellular effects, with far fewer studies examining organismal- and community-level effects. We reviewed the current published literature on marine and estuarine algae, invertebrates, fish, and mammals exposed to PPCPs, in order to expand upon current reviews. This paper builds on previous reviews of PPCP contamination in marine environments, filling prior literature gaps and adding consideration of ecosystem function and level of knowledge across marine habitat types. Finally, we reviewed and compiled data gaps suggested by current researchers and reviewers and propose a multi-level model to expand the focus of current PPCP research beyond laboratory studies. This model includes examination of direct ecological effects including food web and disease dynamics, biodiversity, community composition, and other ecosystem-level indicators of contaminant-driven change.

Maps showing textural characteristics of benthic sediments in the Corpus Christi Bay estuarine system, south Texas

USGS Publications Warehouse

Shideler, Gerald L.; Stelting, Charles E.; McGowen, Joseph H.

1981-01-01

Corpus Christi Bay is a heavily used estuary on the south Texas coast in the northwest Gulf of Mexico (fig. 1).  The Bay is stressed by diverse activities which could substantially affect its ecosystem.  Such activities include shipping, resource production (oil, gas, and construction aggregate), commercial and sport fishing, and recreation.  Shipping activities alone have had a substantial impact on the bay.  For example, the past maintenance of navigation channels has required extensive dredging and spoil disposal within the estuarine system.  Numerous subaqueous spoil disposal sites and subaerial spoil banks are present throughout the bay (fig. 1), and the selection of future spoil disposal sites is becoming a critical local problem.  As activities in the bay increase, the need for effective environmental management becomes increasingly important, and effective management necessitates a good understanding of the bay's physical characteristics.  The objective of this study is to provide detailed information about the textural composition of bottom sediments within the estuarine system, information which could be used in making environmental-management decisions.  Visual descriptions of bottom sediments in Corpus Christi Bay and adjacent areas have been presented by McGowen and Morton (1979).  Additionally, a study of the textures of sediments on the Inner Continental Shelf adjacent to the bay has been presented by Shideler and Berryhill (1977).

A missing link in the estuarine nitrogen cycle?: Coupled nitrification-denitrification mediated by suspended particulate matter.

PubMed

Zhu, Weijing; Wang, Cheng; Hill, Jaclyn; He, Yangyang; Tao, Bangyi; Mao, Zhihua; Wu, Weixiang

2018-02-02

In estuarine and coastal ecosystems, the majority of previous studies have considered coupled nitrification-denitrification (CND) processes to be exclusively sediment based, with little focus on suspended particulate matter (SPM) in the water column. Here, we present evidence of CND processes in the water column of Hangzhou Bay, one of the largest macrotidal embayments in the world. Spearman's correlation analysis showed that SPM was negatively correlated with nitrate (rho = -0.372, P = 0.018) and marker genes for nitrification and denitrification in the water column were detected by quantitative PCR analysis. The results showed that amoA and nir gene abundances strongly correlated with SPM (all P < 0.01) and the ratio of amoA/nir strongly correlated with nitrate (rho = -0.454, P = 0.003). Furthermore, aggregates consisting of nitrifiers and denitrifiers on SPM were also detected by fluorescence in situ hybridization. Illumina MiSeq sequencing further showed that ammonia oxidizers mainly belonged to the genus Nitrosomonas, while the potential denitrifying genera Bradyrhizobium, Comamonas, Thauera, Stenotrophomonas, Acinetobacter, Anaeromyxobacter, Sulfurimonas, Paenibacillus and Sphingobacterium showed significant correlations with SPM (all P < 0.01). This study suggests that SPM may provide a niche for CND processes to occur, which has largely been missing from our understanding of nitrogen cycling in estuarine waters.

77 FR 25962 - Proposed Information Collection; Comment Request; Coastal and Estuarine Land Conservation...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-02

... Collection; Comment Request; Coastal and Estuarine Land Conservation Planning, Protection or Restoration... recipients for planning, conservation, acquisition, protection, restoration, or construction projects. The... Conservation Program (CELCP) to protect important coastal and estuarine areas that have significant...

A user's guide to coping with estuarine management bureaucracy: An Estuarine Planning Support System (EPSS) tool.

PubMed

Lonsdale, Jemma; Nicholson, Rose; Weston, Keith; Elliott, Michael; Birchenough, Andrew; Sühring, Roxana

2018-02-01

Estuaries are amongst the most socio-economically and ecologically important environments however, due to competing and conflicting demands, management is often challenging with a complex legislative framework managed by multiple agencies. To facilitate the understanding of this legislative framework, we have developed a GISbased Estuarine Planning Support System tool. The tool integrates the requirements of the relevant legislation and provides a basis for assessing the current environmental state of an estuary as well as informing and assessing new plans to ensure a healthy estuarine state. The tool ensures that the information is easily accessible for regulators, managers, developers and the public. The tool is intended to be adaptable, but is assessed using the Humber Estuary, United Kingdom as a case study area. The successful application of the tool for complex socio-economic and environmental systems demonstrates that the tool can efficiently guide users through the complex requirements needed to support sustainable development. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

MICROBIAL COMMUNITY DIVERSITY AND CARBON UTILIZATION IN ESTUARINE ECOSYSTEMS OF SOUTHEASTERN U.S.A.

EPA Science Inventory

Estuaries are very dynamic ecosystems with regard to the transport and transformation of organic matter. Detrital organic matter is abundant in most estuaries, however, the dynamics of detritus utilization is not well understood. Two questions that remain unanswered are the sou...

15 CFR 921.50 - General.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Reserve ecosystem, provide information needed by Reserve management and coastal management decision-makers, and improve public awareness and understanding of estuarine ecosystems and estuarine management issues...

15 CFR 921.50 - General.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Reserve ecosystem, provide information needed by Reserve management and coastal management decision-makers, and improve public awareness and understanding of estuarine ecosystems and estuarine management issues...

15 CFR 921.50 - General.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Reserve ecosystem, provide information needed by Reserve management and coastal management decision-makers, and improve public awareness and understanding of estuarine ecosystems and estuarine management issues...

North American coastal carbon stocks and exchanges among the coupled ecosystems of tidal wetlands and estuaries

NASA Astrophysics Data System (ADS)

Windham-Myers, L.; Cai, W. J.

2017-12-01

The development of the 2nd State of the Carbon Cycle Report (SOCCR-2) has recognized a significant role of aquatic ecosystems, including coastal zones, in reconciling some of the gaps associated with the North American carbon (C) budget. Along with a large community of coauthors, we report major C stocks and fluxes for tidal wetlands and estuaries of Canada, Mexico and the United States. We find divergent patterns between these coupled ecosystems, with tidal wetlands largely serving as CO2 sinks (net autotrophic), and open-water estuaries largely serving as CO2 sources (net heterotrophic). We summarized measurements across 4 continental regions - East Coast, Gulf of Mexico, West Coast, and High Latitudes - to assess spatial variability and datagaps in our understanding of coastal C cycling. Subtracting estuarine outgassing of 10 ± 10 Tg C yr-1 from the tidal wetland uptake of 23 ± 10 Tg C yr-1 leaves a net uptake of the combined system of 13 ± 14 Tg C yr-1. High uncertainty for net atmospheric C exchange in this combined coastal system is further complicated by spatially and temporally dynamic boundaries, as well as terrestrial C sources. Tidal wetlands are among the most productive ecosystems on earth and are capable of continuously accumulating organic C in their sediments as a result of environmental conditions that inhibit organic matter decomposition. Estuaries have more interannual variability in C dynamics than those of tidal wetlands, reflecting the estuarine balance of exchanges with terrestrial watersheds, tidal wetlands, and the continental shelf. Whereas tidal, subtidal and estuarine maps are of limited accuracy at larger scales, North America likely represents less than 1/10 of global distributions of coastal wetland habitats. Coupled land-ocean C flux models are increasingly robust but lacking much of the data needed for parameterization and validation. Accurate boundary maps and synoptic monitoring data on air-water CO2 exchange may be developed

Influence of organic carbon on estuarine benthic infauna of the US west coast

EPA Science Inventory

Total organic carbon (TOC) is often used as an indicator of eutrophication in estuarine environments. However, the determination of biologically relevant sediment TOC criteria to indicate estuarine condition is complicated by the relationship between TOC and grain size. Both va...

Ecosystem services in urban water investment.

PubMed

Kandulu, John M; Connor, Jeffery D; MacDonald, Darla Hatton

2014-12-01

Increasingly, water agencies and utilities have an obligation to consider the broad environmental impacts associated with investments. To aid in understanding water cycle interdependencies when making urban water supply investment decisions, an ecosystem services typology was augmented with the concept of integrated water resources management. This framework is applied to stormwater harvesting in a case study catchment in Adelaide, South Australia. Results show that this methodological framework can effectively facilitate systematic consideration and quantitative assessment of broad environmental impacts of water supply investments. Five ecosystem service impacts were quantified including provision of 1) urban recreational amenity, 2) regulation of coastal water quality, 3) salinity, 4) greenhouse gas emissions, and 5) support of estuarine habitats. This study shows that ignoring broad environmental impacts can underestimate ecosystem service benefits of water supply investments by a value of up to A$1.36/kL, or three times the cost of operating and maintenance of stormwater harvesting. Rigorous assessment of the public welfare impacts of water infrastructure investments is required to guide long-term optimal water supply investment decisions. Numerous challenges remain in the quantification of broad environmental impacts of a water supply investment including a lack of peer-reviewed studies of environmental impacts, aggregation of incommensurable impacts, potential for double-counting errors, uncertainties in available impact estimates, and how to determine the most suitable quantification technique. Copyright © 2014 Elsevier Ltd. All rights reserved.

Bowhead whales feed on plankton concentrated by estuarine and tidal currents in Academy Bay, Sea of Okhotsk

NASA Astrophysics Data System (ADS)

Rogachev, Konstantin A.; Carmack, Eddy C.; Foreman, Michael G. G.

2008-08-01

Academy Bay in the Sea of Okhotsk is an important summertime feeding ground for pelagic-feeding Bowhead whales ( Balaena mysticetus) in the western subarctic North Pacific. The present work combines satellite observations with physical (CTD, currents, tides) and biological (zooplankton sampling) measurements. Data obtained aboard the RV Lugovoe in August-September 2003 and July-August 2004 show dense populations of zooplankton (such as copepods Calanus glacialis, Pseudocalanus sp., pteropods Limacina helicina, and chaetognaths Sagitta sp.) that are concentrated by physical mechanisms within this critically important ecosystem. We show that near-bottom, cold water intrusions from the northern Sea of Okhotsk associated with the estuarine circulation advect arctic herbivorous calanoids ( Calanus glacialis) and mollusks Limacina helicina into the region. Satellite and in situ observations that include conductivity-temperature-depth (CTD) data and measurements of tidal currents are used to study the nature of the estuarine circulation. Results show an anticyclonic circulation, associated with the effect of earth's rotation. An analytical model shows horizontally convergent flows in the lower layer toward the western coast of the bay that push water upward along the steep slope. This together with zooplankton vertical migration leads to aggregation. Thus the combination of the residual eddy formation and swimming behavior act to concentrate zooplankton near the cape and to provide the necessary densities of planktonic food supply for Bowhead whales.

VARIATIONS IN THE SPECTRAL PROPERTIES OF FRESHWATER AND ESTUARINE CDOM CAUSED BY PARTITIONING ONTO RIVER AND ESTUARINE SEDIMENTS

EPA Science Inventory

The optical properties and geochemical cycling of chromophoric dissolved organic matter (CDOM) are altered by its sorption to freshwater and estuarine sediments. Measured partition coefficients (Kp) of Satilla River (Georgia) and Cape Fear River estuary (North Carolina) CDOM ran...

Effects of ecological interactions and environmental conditions on community dynamics in an estuarine ecosystem

NASA Astrophysics Data System (ADS)

Liu, H.; Minello, T.; Sutton, G.

2016-02-01

Coastal marine ecosystems are both productive and vulnerable to human and natural stressors. Examining the relative importance of fishing, environmental variability, and habitat alteration on ecosystem dynamics is challenging. Intensive harvest and habitat loss have resulted in widespread concerns related to declines in fisheries production, but causal mechanisms are rarely clear. In this study, we modeled trophic dynamics in Galveston Bay, Texas, using fishery-independent catch data for blue crab, shrimp, red drum, Atlantic croaker and spotted seatrout along with habitat information collected by the Texas Parks and Wildlife Department during 1984 - 2014. We developed a multispecies state-space model to examine ecological interactions and partition the relative effects of trophic interactions and environmental conditions on the community dynamics. Preliminary results showed the importance of salinity, density-dependence, and trophic interactions. We are continuing to explore these results from a perspective of fish community compensatory responses to exploitation, reflecting both direct and indirect effects of harvesting under the influence of climate variability.

New climatic targets against global warming: will the maximum 2 °C temperature rise affect estuarine benthic communities?

PubMed

Crespo, Daniel; Grilo, Tiago Fernandes; Baptista, Joana; Coelho, João Pedro; Lillebø, Ana Isabel; Cássio, Fernanda; Fernandes, Isabel; Pascoal, Cláudia; Pardal, Miguel Ângelo; Dolbeth, Marina

2017-06-20

The Paris Agreement signed by 195 countries in 2015 sets out a global action plan to avoid dangerous climate change by limiting global warming to remain below 2 °C. Under that premise, in situ experiments were run to test the effects of 2 °C temperature increase on the benthic communities in a seagrass bed and adjacent bare sediment, from a temperate European estuary. Temperature was artificially increased in situ and diversity and ecosystem functioning components measured after 10 and 30 days. Despite some warmness effects on the analysed components, significant impacts were not verified on macro and microfauna structure, bioturbation or in the fluxes of nutrients. The effect of site/habitat seemed more important than the effects of the warmness, with the seagrass habitat providing more homogenous results and being less impacted by warmness than the adjacent bare sediment. The results reinforce that most ecological responses to global changes are context dependent and that ecosystem stability depends not only on biological diversity but also on the availability of different habitats and niches, highlighting the role of coastal wetlands. In the context of the Paris Agreement it seems that estuarine benthic ecosystems will be able to cope if global warming remains below 2 °C.

A review of nickel toxicity to marine and estuarine tropical biota with particular reference to the South East Asian and Melanesian region.

PubMed

Gissi, Francesca; Stauber, Jennifer L; Binet, Monique T; Golding, Lisa A; Adams, Merrin S; Schlekat, Christian E; Garman, Emily R; Jolley, Dianne F

2016-11-01

The South East Asian Melanesian (SEAM) region contains the world's largest deposits of nickel lateritic ores. Environmental impacts may occur if mining operations are not adequately managed. Effects data for tropical ecosystems are required to assess risks of contaminant exposure and to derive water quality guidelines (WQG) to manage these risks. Currently, risk assessment tools and WQGs for the tropics are limited due to the sparse research on how contaminants impact tropical biota. As part of a larger project to develop appropriate risk assessment tools to ensure sustainable nickel production in SEAM, nickel effects data were required. The aim of this review was to compile data on the effects of nickel on tropical marine, estuarine, pelagic and benthic species, with a particular focus on SEAM. There were limited high quality chronic nickel toxicity data for tropical marine species, and even fewer for those relevant to SEAM. Of the data available, the most sensitive SEAM species to nickel were a sea urchin, copepod and anemone. There is a significant lack of high quality chronic data for several ecologically important taxonomic groups including cnidarians, molluscs, crustaceans, echinoderms, macroalgae and fish. No high quality chronic nickel toxicity data were available for estuarine waters or marine and estuarine sediments. The very sparse toxicity data for tropical species limits our ability to conduct robust ecological risk assessment and may require additional data generation or read-across from similar species in other databases (e.g. temperate) to fill data gaps. Recommendations on testing priorities to fill these data gaps are presented. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transfer of gold nanoparticles from the water column to the estuarine food web

NASA Astrophysics Data System (ADS)

Ferry, John L.; Craig, Preston; Hexel, Cole; Sisco, Patrick; Frey, Rebecca; Pennington, Paul L.; Fulton, Michael H.; Scott, I. Geoff; Decho, Alan W.; Kashiwada, Shosaku; Murphy, Catherine J.; Shaw, Timothy J.

2009-07-01

Within the next five years the manufacture of large quantities of nanomaterials may lead to unintended contamination of terrestrial and aquatic ecosystems. The unique physical, chemical and electronic properties of nanomaterials allow new modes of interaction with environmental systems that can have unexpected impacts. Here, we show that gold nanorods can readily pass from the water column to the marine food web in three laboratory-constructed estuarine mesocosms containing sea water, sediment, sea grass, microbes, biofilms, snails, clams, shrimp and fish. A single dose of gold nanorods (65 nm length × 15 nm diameter) was added to each mesocosm and their distribution in the aqueous and sediment phases monitored over 12 days. Nanorods partitioned between biofilms, sediments, plants, animals and sea water with a recovery of 84.4%. Clams and biofilms accumulated the most nanoparticles on a per mass basis, suggesting that gold nanorods can readily pass from the water column to the marine food web.

Minimal incorporation of Deepwater Horizon oil by estuarine filter feeders.

PubMed

Fry, Brian; Anderson, Laurie C

2014-03-15

Natural abundance carbon isotope analyses are sensitive tracers for fates and use of oil in aquatic environments. Use of oil carbon in estuarine food webs should lead to isotope values approaching those of oil itself, -27‰ for stable carbon isotopes reflecting oil origins and -1000‰ for carbon-14 reflecting oil age. To test for transfer of oil from the 2010 Deepwater Horizon spill into estuarine food webs, filter-feeding barnacles (Balanus sp.) and marsh mussels (Geukensia demissa) were collected from Louisiana estuaries near the site of the oil spill. Carbon-14 analyses of these animals from open waters and oiled marshes showed that oil use was <1% and near detection limits estimated at 0.3% oil incorporation. Respiration studies showed no evidence for enhanced microbial activity in bay waters. Results are consistent with low dietary impacts of oil for filter feeders and little overall impact on respiration in the productive Louisiana estuarine systems. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Phytoplankton blooms in estuarine and coastal waters: Seasonal patterns and key species

USGS Publications Warehouse

Carstensen, Jacob; Klais, Riina; Cloern, James E.

2015-01-01

Phytoplankton blooms are dynamic phenomena of great importance to the functioning of estuarine and coastal ecosystems. We analysed a unique (large) collection of phytoplankton monitoring data covering 86 coastal sites distributed over eight regions in North America and Europe, with the aim of investigating common patterns in the seasonal timing and species composition of the blooms. The spring bloom was the most common seasonal pattern across all regions, typically occurring early (February–March) at lower latitudes and later (April–May) at higher latitudes. Bloom frequency, defined as the probability of unusually high biomass, ranged from 5 to 35% between sites and followed no consistent patterns across gradients of latitude, temperature, salinity, water depth, stratification, tidal amplitude or nutrient concentrations. Blooms were mostly dominated by a single species, typically diatoms (58% of the blooms) and dinoflagellates (19%). Diatom-dominated spring blooms were a common feature in most systems, although dinoflagellate spring blooms were also observed in the Baltic Sea. Blooms dominated by chlorophytes and cyanobacteria were only common in low salinity waters and occurred mostly at higher temperatures. Key bloom species across the eight regions included the diatoms Cerataulina pelagica and Dactyliosolen fragilissimus and dinoflagellates Heterocapsa triquetra and Prorocentrum cordatum. Other frequent bloom-forming taxa were diatom genera Chaetoceros, Coscinodiscus, Skeletonema, and Thalassiosira. Our meta-analysis shows that these 86 estuarine-coastal sites function as diatom-producing systems, the timing of that production varies widely, and that bloom frequency is not associated with environmental factors measured in monitoring programs. We end with a perspective on the limitations of conclusions derived from meta-analyses of phytoplankton time series, and the grand challenges remaining to understand the wide range of bloom patterns and

Overview of integrative tools and methods in assessing ecological integrity in estuarine and coastal systems worldwide.

PubMed

Borja, Angel; Bricker, Suzanne B; Dauer, Daniel M; Demetriades, Nicolette T; Ferreira, João G; Forbes, Anthony T; Hutchings, Pat; Jia, Xiaoping; Kenchington, Richard; Carlos Marques, João; Zhu, Changbo

2008-09-01

In recent years, several sets of legislation worldwide (Oceans Act in USA, Australia or Canada; Water Framework Directive or Marine Strategy in Europe, National Water Act in South Africa, etc.) have been developed in order to address ecological quality or integrity, within estuarine and coastal systems. Most such legislation seeks to define quality in an integrative way, by using several biological elements, together with physico-chemical and pollution elements. Such an approach allows assessment of ecological status at the ecosystem level ('ecosystem approach' or 'holistic approach' methodologies), rather than at species level (e.g. mussel biomonitoring or Mussel Watch) or just at chemical level (i.e. quality objectives) alone. Increasing attention has been paid to the development of tools for different physico-chemical or biological (phytoplankton, zooplankton, benthos, algae, phanerogams, fishes) elements of the ecosystems. However, few methodologies integrate all the elements into a single evaluation of a water body. The need for such integrative tools to assess ecosystem quality is very important, both from a scientific and stakeholder point of view. Politicians and managers need information from simple and pragmatic, but scientifically sound methodologies, in order to show to society the evolution of a zone (estuary, coastal area, etc.), taking into account human pressures or recovery processes. These approaches include: (i) multidisciplinarity, inherent in the teams involved in their implementation; (ii) integration of biotic and abiotic factors; (iii) accurate and validated methods in determining ecological integrity; and (iv) adequate indicators to follow the evolution of the monitored ecosystems. While some countries increasingly use the establishment of marine parks to conserve marine biodiversity and ecological integrity, there is awareness (e.g. in Australia) that conservation and management of marine ecosystems cannot be restricted to Marine Protected

Chesapeake Bay nitrogen fluxes derived from a land-estuarine ocean biogeochemical modeling system: Model description, evaluation, and nitrogen budgets.

PubMed

Feng, Yang; Friedrichs, Marjorie A M; Wilkin, John; Tian, Hanqin; Yang, Qichun; Hofmann, Eileen E; Wiggert, Jerry D; Hood, Raleigh R

2015-08-01

The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land-estuarine-ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within-estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite-derived data, and a simulation using environmental conditions for 2001-2005 was conducted to quantify the Chesapeake Bay nitrogen budget. The 5 year simulation was characterized by large riverine inputs of nitrogen (154 × 10 9  g N yr -1 ) split roughly 60:40 between inorganic:organic components. Much of this was denitrified (34 × 10 9  g N yr -1 ) and buried (46 × 10 9  g N yr -1 ) within the estuarine system. A positive net annual ecosystem production for the bay further contributed to a large advective export of organic nitrogen to the shelf (91 × 10 9  g N yr -1 ) and negligible inorganic nitrogen export. Interannual variability was strong, particularly for the riverine nitrogen fluxes. In years with higher than average riverine nitrogen inputs, most of this excess nitrogen (50-60%) was exported from the bay as organic nitrogen, with the remaining split between burial, denitrification, and inorganic export to the coastal ocean. In comparison to previous simulations using generic shelf biogeochemical model formulations inside the estuary, the estuarine biogeochemical model described here produced more realistic and significantly greater exports of organic nitrogen and lower exports of inorganic nitrogen to the shelf.

Estuarine Landcover Along the Lower Columbia River Estuary Determined from Compact Ariborne Spectrographic Imager (CASI) Imagery, Technical Report 2003.

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

Garono, Ralph; Robinson, Rob

2003-10-01

Developing an understanding of the distribution and changes in estuarine and riparian habitats is critical to the management of biological resources in the lower Columbia River. In a recently completed comprehensive ecosystem protection and enhancement plan for the lower Columbia River Estuary (CRE), Jerrick (1999) identified habitat loss and modification as one of the key threats to the integrity of the CRE ecosystem. This management plan called for an inventory of habitats as key first step in the CRE long-term restoration effort. While previous studies have produced useful data sets depicting habitat cover types along portions of the lower CREmore » (Thomas, 1980; Thomas, 1983; Graves et al., 1995; NOAA, 1997; Allen, 1999), no single study has produced a description of the habitats for the entire CRE. Moreover, the previous studies differed in data sources and methodologies making it difficult to merge data or to make temporal comparisons. Therefore, the Lower Columbia River Estuary Partnership (Estuary Partnership) initiated a habitat cover mapping project in 2000. The goal of this project was to produce a data set depicting the current habitat cover types along the lower Columbia River, from its mouth to the Bonneville Dam, a distance of {approx}230-km (Fig. 1) using both established and emerging remote sensing techniques. For this project, we acquired two types of imagery, Landsat 7 ETM+ and Compact Airborne Spectrographic Imager (CASI). Landsat and CASI imagery differ in spatial and spectral resolution: the Landsat 7 ETM+ sensor collects reflectance data in seven spectral bands with a spatial resolution of 30-m and the CASI sensor collects reflectance data in 19 bands (in our study) with a spatial resolution of 1.5-m. We classified both sets of imagery and produced a spatially linked, hierarchical habitat data set for the entire CRE and its floodplain. Landsat 7 ETM+ classification results are presented in a separate report (Garono et al., 2003). This

76 FR 2085 - National Estuarine Research Reserve System; North Inlet-Winyah Bay, SC and San Francisco Bay, CA...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-12

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research... approval and availability of the revised management plans for the following National Estuarine Research... the North Inlet-Winyah Bay National Estuarine Research Reserve and San Francisco Bay National...

MEASURING THE ACUTE TOXICITY OF ESTUARINE SEDIMENTS

EPA Science Inventory

Estuarine sediments frequently are repositories and sources of anthropogenic contaminants. Toxicity is one method of assessing the environmental quality of sediments, yet because of the extreme range of salinities that characterize estuaries few infaunal organisms have both the p...

Evaluation of Marsh/Estuarine Water Quality and Ecological Models: An Interim Guide

DTIC Science & Technology

1982-01-01

benthic oxygen demand, benthic scour and deposition, photosynthesis and respiration of aquatic plants, and nitrification (Dobbins 1964; O’Connor 1967... photosynthesis , algal respiration, decom- position, and mixing processes play dominant roles, the understanding and characterization of significant pro...Adams, S. M. 1979. "A Mathematical Model of Trophic Dynamics in Estuarine Seagrass Communities," Marsh-Estuarine Systems Simulation, Dame, R. F., ed

Benthic infaunal community structuring in an acidified tropical estuarine system.

PubMed

Hossain, M Belal; Marshall, David J

2014-01-01

Recent studies suggest that increasing ocean acidification (OA) should have strong direct and indirect influences on marine invertebrates. While most theory and application for OA is based on relatively physically-stable oceanic ecological systems, less is known about the effects of acidification on nearshore and estuarine systems. Here, we investigated the structuring of a benthic infaunal community in a tropical estuarine system, along a steep salinity and pH gradient, arising largely from acid-sulphate groundwater inflows (Sungai Brunei Estuary, Borneo, July 2011- June 2012). Preliminary data indicate that sediment pore-water salinity (range: 8.07 - 29.6 psu) declined towards the mainland in correspondence with the above-sediment estuarine water salinity (range: 3.58 - 31.2 psu), whereas the pore-water pH (range: 6.47- 7.72) was generally lower and less variable than the estuarine water pH (range: 5.78- 8.3), along the estuary. Of the thirty six species (taxa) recorded, the polychaetes Neanthes sp., Onuphis conchylega, Nereididae sp. and the amphipod Corophiidae sp., were numerically dominant. Calcified microcrustaceans (e.g., Cyclopoida sp. and Corophiidae sp.) were abundant at all stations and there was no clear distinction in distribution pattern along the estuarine between calcified and non-calcified groups. Species richness increased seawards, though abundance (density) showed no distinct directional trend. Diversity indices were generally positively correlated (Spearman's rank correlation) with salinity and pH (p <0.05) and negatively with clay and organic matter, except for evenness values (p >0.05). Three faunistic assemblages were distinguished: (1) nereid-cyclopoid-sabellid, (2) corophiid-capitellid and (3) onuphid- nereid-capitellid. These respectively associated with lower salinity/pH and a muddy bottom, low salinity/pH and a sandy bottom, and high salinity/pH and a sandy bottom. However, CCA suggested that species distribution and community

A comparison of tourists and local visitors to National Estuarine Research Reserve sites

Treesearch

Allan Marsinko; William C. Norman; Tiffany J. McClinton

2001-01-01

The National Estuarine Research Reserve system serves as a laboratory and classroom where the effects of both natural and human activity can be monitored and studied. Visitors to twelve National Estuarine Research Reserve system sites were surveyed to obtain information about demographics, participation, experience with the system, activities, and opinions. Comparisons...

Coastal Zone Ecosystem Services: from science to values and decision making; a case study.

PubMed

Luisetti, T; Turner, R K; Jickells, T; Andrews, J; Elliott, M; Schaafsma, M; Beaumont, N; Malcolm, S; Burdon, D; Adams, C; Watts, W

2014-09-15

This research is concerned with the following environmental research questions: socio-ecological system complexity, especially when valuing ecosystem services; ecosystems stock and services flow sustainability and valuation; the incorporation of scale issues when valuing ecosystem services; and the integration of knowledge from diverse disciplines for governance and decision making. In this case study, we focused on ecosystem services that can be jointly supplied but independently valued in economic terms: healthy climate (via carbon sequestration and storage), food (via fisheries production in nursery grounds), and nature recreation (nature watching and enjoyment). We also explored the issue of ecosystem stock and services flow, and we provide recommendations on how to value stock and flows of ecosystem services via accounting and economic values respectively. We considered broadly comparable estuarine systems located on the English North Sea coast: the Blackwater estuary and the Humber estuary. In the past, these two estuaries have undergone major land-claim. Managed realignment is a policy through which previously claimed intertidal habitats are recreated allowing the enhancement of the ecosystem services provided by saltmarshes. In this context, we investigated ecosystem service values, through biophysical estimates and welfare value estimates. Using an optimistic (extended conservation of coastal ecosystems) and a pessimistic (loss of coastal ecosystems because of, for example, European policy reversal) scenario, we find that context dependency, and hence value transfer possibilities, vary among ecosystem services and benefits. As a result, careful consideration in the use and application of value transfer, both in biophysical estimates and welfare value estimates, is advocated to supply reliable information for policy making. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Barrier-island and estuarine-wetland physical-change assessment after Hurricane Sandy

USGS Publications Warehouse

Plant, Nathaniel G.; Smith, Kathryn E.L.; Passeri, Davina L.; Smith, Christopher G.; Bernier, Julie C.

2018-04-03

IntroductionThe Nation’s eastern coast is fringed by beaches, dunes, barrier islands, wetlands, and bluffs. These natural coastal barriers provide critical benefits and services, and can mitigate the impact of storms, erosion, and sea-level rise on our coastal communities. Waves and storm surge resulting from Hurricane Sandy, which made landfall along the New Jersey coast on October 29, 2012, impacted the U.S. coastline from North Carolina to Massachusetts, including Assateague Island, Maryland and Virginia, and the Delmarva coastal system. The storm impacts included changes in topography, coastal morphology, geology, hydrology, environmental quality, and ecosystems.In the immediate aftermath of the storm, light detection and ranging (lidar) surveys from North Carolina to New York documented storm impacts to coastal barriers, providing a baseline to assess vulnerability of the reconfigured coast. The focus of much of the existing coastal change assessment is along the ocean-facing coastline; however, much of the coastline affected by Hurricane Sandy includes the estuarine-facing coastlines of barrier-island systems. Specifically, the wetland and back-barrier shorelines experienced substantial change as a result of wave action and storm surge that occurred during Hurricane Sandy (see also USGS photograph, http://coastal.er.usgs.gov/hurricanes/sandy/photo-comparisons/virginia.php). Assessing physical shoreline and wetland change (land loss as well as land gains) can help to determine the resiliency of wetland systems that protect adjacent habitat, shorelines, and communities.To address storm impacts to wetlands, a vulnerability assessment should describe both long-term (for example, several decades) and short-term (for example, Sandy’s landfall) extent and character of the interior wetlands and the back-barrier-shoreline changes. The objective of this report is to describe several new wetland vulnerability assessments based on the detailed physical changes

Restoring Resiliency: Case Studies from Pacific Northwest Estuarine Eelgrass (Zostera marina L.) Ecosystems

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

Thom, Ronald M.; Diefenderfer, Heida L.; Vavrinec, John

2012-01-01

The purpose of many ecological restoration projects is to establish an ecosystem with fully developed structure and function that exhibits resistance to and resilience from disturbances. Coastal restoration projects in the Pacific Northwest provide opportunities to understand what is required to restore the resilience of eelgrass (Zostera marina L.) populations. Factors influencing resilience observed in three case studies of eelgrass restoration include minimum viable population, adaptations of transplant populations, and natural and anthropogenic disturbances at restoration sites. The evaluation of resiliency depends on selecting appropriate monitoring metrics and the frequency and duration of monitoring. Eelgrass area, cover and shoot densitymore » provide useful and reliable metrics for quantifying resilience of restored meadows. Further, five years of monitoring of these metrics provides data that can reasonably predict the long-term viability of a planted plot. Eelgrass appears to be a resilient ecosystem in general, though one that data suggest may exhibit tipping points brought about by compounded environmental conditions outside of its tolerance ranges. Explicit inclusion of resilience in the planning and practice of habitat restoration may reduce uncertainties and improve the performance of restored systems by increasing buffering capacity, nurturing sources of renewal (e.g., seeds and rhizomes), and managing for habitat forming and maintaining processes (e.g., sediment dynamics) at multiple scales.« less

Assessment of the trophic status of four coastal lagoons and one estuarine delta, eastern Brazil.

PubMed

Cotovicz Junior, Luiz Carlos; Brandini, Nilva; Knoppers, Bastiaan Adriaan; Mizerkowski, Byanka Damian; Sterza, José Mauro; Ovalle, Alvaro Ramon Coelho; Medeiros, Paulo Ricardo Petter

2013-04-01

Anthropogenic eutrophication of aquatic ecosystems continues to be one of the major environmental issues worldwide and also of Brazil. Over the last five decades, several approaches have been proposed to discern the trophic state and the natural and cultural processes involved in eutrophication, including the multi-parameter Assessment of Estuarine Trophic Status (ASSETS) index model. This study applies ASSETS to four Brazilian lagoons (Mundaú, Manguaba, Guarapina, and Piratininga) and one estuarine delta (Paraíba do Sul River), set along the eastern Brazilian coast. The model combines three indices based on the pressure-state-response (PSR) approach to rank the trophic status and forecast the potential eutrophication of a system, to which a final ASSETS grade is established. The lagoons were classified as being eutrophic and highly susceptible to eutrophication, due primarily to their longer residence times but also their high nutrient input index. ASSETS classified the estuary of the Paraíba do Sul river with a low to moderate trophic state (e.g., largely mesotrophic) and low susceptibility to eutrophication. Its nutrient input index was high, but the natural high dilution and flushing potential driven by river flow mitigated the susceptibility to eutrophication. Eutrophication forecasting provided more favorable trends for the Mundaú and Manguaba lagoons and the Paraíba do Sul estuary, in view of the larger investments in wastewater treatment and remediation plans. The final ASSETS ranking system established the lagoons of Mundaú as "moderate," Manguaba as "bad," Guarapina as "poor," and Piratininga as "bad," whereas the Paraíba do Sul River Estuary was "good."

Climate change impacts on U.S. coastal and marine ecosystems

USGS Publications Warehouse

Scavia, Donald; Field, John C.; Boesch, Donald F.; Buddemeier, Robert W.; Burkett, Virginia; Cayan, Daniel R.; Fogarty, Michael; Harwell, Mark A.; Howarth, Robert W.; Mason, Curt; Reed, Denise J.; Royer, Thomas C.; Sallenger, Asbury H.; Titus, James G.

2002-01-01

Increases in concentrations of greenhouse gases projected for the 21st century are expected to lead to increased mean global air and ocean temperatures. The National Assessment of Potential Consequences of Climate Variability and Change (NAST 2001) was based on a series of regional and sector assessments. This paper is a summary of the coastal and marine resources sector review of potential impacts on shorelines, estuaries, coastal wetlands, coral reefs, and ocean margin ecosystems. The assessment considered the impacts of several key drivers of climate change: sea level change; alterations in precipitation patterns and subsequent delivery of freshwater, nutrients, and sediment; increased ocean temperature; alterations in circulation patterns; changes in frequency and intensity of coastal storms; and increased levels of atmospheric CO2. Increasing rates of sea-level rise and intensity and frequency of coastal storms and hurricanes over the next decades will increase threats to shorelines, wetlands, and coastal development. Estuarine productivity will change in response to alteration in the timing and amount of freshwater, nutrients, and sediment delivery. Higher water temperatures and changes in freshwater delivery will alter estuarine stratification, residence time, and eutrophication. Increased ocean temperatures are expected to increase coral bleaching and higher CO2 levels may reduce coral calcification, making it more difficult for corals to recover from other disturbances, and inhibiting poleward shifts. Ocean warming is expected to cause poleward shifts in the ranges of many other organisms, including commercial species, and these shifts may have secondary effects on their predators and prey. Although these potential impacts of climate change and variability will vary from system to system, it is important to recognize that they will be superimposed upon, and in many cases intensify, other ecosystem stresses (pollution, harvesting, habitat destruction

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

EFFECT OF DIFLUBENZURON ON AN ESTUARINE CRUSTACEAN

EPA Science Inventory

Data are reported for tests exposing a small, estuarine crustacean, Mysidopsis bahia, to diflubenzuron (Dimilin, TH-6040, (1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)urea)) in flowing seawater. Tests were conducted in intermittent flows from a diluter or continuous flowing water i...

AN EVALUATION OF ELECTRODE INSERTION TECHNIQUES FOR MEASUREMENT OF REDOX POTENTIAL IN ESTUARINE SEDIMENTS

EPA Science Inventory

Eh measurements by electrodes are commonly used to characterize redox status of sediments in freshwater, marine and estuarine studies, due to the relative ease and rapidity of data collection. In our studies of fine-grained estuarine seabeds, we observed that Eh values measured i...

Environmental characteristics of the Mandovi-Zuari estuarine system in Goa

NASA Astrophysics Data System (ADS)

Qasim, S. Z.; Sen Gupta, R.

1981-11-01

Two rivers, the Mandovi and the Zuari, with their interconnecting canal, form an estuarine system in Goa on the west coast of India. Physical, chemical and biological features of this estuary are adapted to a seasonal rhythm induced by the annual cycle of the monsoon. Heavy precipitation and land runoff from June to September bring about large changes in temperature, salinity, flow pattern, dissolved oxygen and nutrients when the estuary becomes freshwater dominated. The monsoon season (July-September) is followed by a recovery period during the post-monsoon season (October-January) and thereafter a stable period of the pre-monsoon season (February-May) when the estuary becomes marine dominated. During the pre-monsoon (dry) season, the water in the estuarine system remains well mixed and the intrusion of salt water is felt as far as 65 km upstream in both the rivers; but during the monsoon season the rivers become stratified and a salt wedge is formed in each river which extends up to about 10 km upstream in the Mandovi and 12 km in the Zuari. The flow of the estuarine system is regulated by the entry of seawater with the incoming tide through Zuari which reaches Mandovi through the canal. The flow is reversed during the outgoing tide when the estuarine system is flushed. Dilution factors in both the estuaries are similar and vary from 1·2 to 8; highest values occur during the pre-monsoon season. Two shoals/sand bars occur permanently in Mandovi (Aguada Bay) close to a ramp-like inlet to the sea. This inlet poses no navigational problems for about 9 months during the dry season; but for a 3-month period during the monsoon, the waterway becomes hazardous and is closed to boat traffic. Heavy swell and intense wave activity lead to the transfer of sediments into the navigational inlet and the calm season brings the materials back to their original position with practically no overall change in the bathymetry of the bay. The oxygen cycle in the estuarine system is

Effects of hydrological forcing on the structure of a tropical estuarine food web

Treesearch

Trisha B. Atwood; Tracy N. Wiegner; Richard A. MacKenzie

2012-01-01

River flow can impact which sources of particulate organic matter (POM) fuel estuarine food webs. Here, we used stable carbon (C) and nitrogen (N) isotope analyses to compare how contributions of diff erent POM sources (terrestrial, estuarine, and marine) to the diets of zooplankton and juvenile fishes differed between low and high river flow conditions, as well as...

The developing framework of marine ecotoxicology: Pollutants as a variable in marine ecosystems?

USGS Publications Warehouse

Luoma, Samuel N.

1996-01-01

Marine ecosystems include a subset in which at least some interrelated geochemical, biochemical, physiological, population and community characteristics are changed by pollutants. Moderate contamination is relatively widespread in coastal and estuarine ecosystems, so the subset of ecosystems with at least some processes affected could be relatively large. Pollutant influences have changed and will probably continue to change on time scales of decades. Biological exposures and dose in such ecosystems are species-specific and determined by how the species is exposed to different environmental media and the geochemistry of individual pollutants within those media. Bioaccumulation models offer significant promise for interpreting such exposures. Biological responses to pollutants need to be more directly linked to exposure and dose. At the level of the individual this might be improved by better understanding relationships between tissue concentrations of pollutants and responses to pollutants. Multi-discipline field and laboratory studies combined with advanced understanding of some basic processes have reduced the ambiguities in interpreting a few physiological/organismic responses to pollutants in nature. Recognition of pollutant-induced patterns in population responses could lead to similar advances. A rational framework for ecotoxicology is developing, but its further advance is dependent upon better integration of ecotoxicology with basic marine ecology and biology.

White willow sexual regeneration capacity under estuarine conditions in times of climate change

NASA Astrophysics Data System (ADS)

Markus-Michalczyk, Heike; Hanelt, Dieter; Denstorf, Julian; Jensen, Kai

2016-10-01

Tidal wetlands provide both habitats for coastal populations and wildlife, and ecosystem services for human welfare. Building with nature regarding cost-effective coastal protection is of increasing interest. Much research has been carried out on plant reproduction capacities in mangroves and salt marshes, but less is known on this issue in tidal freshwater wetlands. Willows are being successfully used for bank stabilization in riverine habitats, however, today white willow softwood forests in tidal wetlands are highly fragmented, and restoration is required e.g. by the European Habitats Directive. Recently, tolerance to increasing salinity and tidal flooding was found for vegetative propagules of floodplain willows. However, the establishment of autochthonous sexual recruits is necessary to conserve the genetic diversity of local populations, and thus may be preferable in restoration. The germination and early seedling establishment of Salix alba (white willow) was experimentally studied under simulated estuarine conditions. The species tolerance to increasing salinity (0, 0.5, 1, 1.5, and 2) was tested in a climate chamber, and its tolerance to flooding at different tidal treatments (control, spring tide, daily tide 15 min and 2 h flooding) in the greenhouse. Germination was neither affected by increasing salinity nor by tidal flooding. Salix seedlings established up to salinity 1.5, but cotyledon performance and radicle growth was largely reduced at salinity 2. Under tidal flooding, seedling growth was similar in all treatments. However, in the treatments with daily tides seedling anchorage in the substrate took more than two weeks, and fewer seedlings reached a suitable length to approach the high water line. We assess S. alba sexual regeneration under estuarine conditions as generally possible. Further studies are needed on the effects of sedimentation-erosion processes on willow establishment in the field, especially on feedbacks between Salix survival and

Late Holocene estuarine-inner shelf interactions; is there evidence of an estuarine retreat path for Tampa Bay, Florida?

USGS Publications Warehouse

Donahue, B.T.; Hine, A.C.; Tebbens, S.; Locker, S.D.; Twichell, D.C.

2003-01-01

The purpose of this study was to determine if and how a large, modern estuarine system, situated in the middle of an ancient carbonate platform, has affected its adjacent inner shelf both in the past during the last, post-glacial sea-level rise and during the present. An additional purpose was to determine if and how this inner shelf seaward of a major estuary differed from the inner shelves located just to the north and south but seaward of barrier-island shorelines. Through side-scan sonar mosaicking, bathymetric studies, and ground-truthing using surface grab samples as well as diver observations, two large submarine sand plains were mapped - one being the modern ebb-tidal delta and the other interpreted to be a relict ebb-tidal delta formed earlier in the Holocene. The most seaward portion of the inner shelf studied consists of a field of lobate, bathymetrically elevated, fine-sand accumulations, which were interpreted to be sediment-starved 3D dunes surrounded by small 2D dunes composed of coarse molluscan shell gravel. Additionally, exposed limestone hardbottoms supporting living benthic communities were found as well. This modern shelf sedimentary environment is situated on a large, buried shelf valley, which extends eastward beneath the modern Tampa Bay estuary. These observations plus the absence of an incised shelf valley having surficial bathymetric expression, and the absence of sand bodies normally associated with back-tracking estuarine systems indicate that there was no cross-shelf estuarine retreat path formed during the last rise in sea level. Instead, the modern Tampa Bay formed within a mid-platform, low-relief depression, which was flooded by rising marine waters late in the Holocene. With continued sea-level rise in the late Holocene, this early embayment was translated eastward or landward to its present position, whereby a larger ebb-tidal delta prograded out onto the inner shelf. Extensive linear sand ridges, common to the inner shelves to

Remote sensing of estuarine fronts and their effects on pollutants

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Polis, D. F.

1975-01-01

The author has identified the following significant results. Imagery from LANDSAT 1 and 2 proved valuable in determining the location, type, and extent of estuarine fronts under different tidal conditions. Neither ships nor aircraft alone could provide as complete, synoptic, and repetitive an overview as did the satellites. Since estuarine fronts influence the movement of oil slicks and dispersion of other pollutants, cleanup operations depending on real time use of oil slick movement prediction models will benefit not only from aircraft tracking the actual slicks but also from real time satellite observations of surface currents and the location of frontal systems.

SPECIES INTERACTIONS BETWEEN ESTUARINE DETRITIVORES: INHIBITION OR FACILITATION?

EPA Science Inventory

Native Hawaiian estuarine detritivores; the prawn Macrobrachium grandimanus, and the neritid gastropod Neritina vespertina, were maintained in flow-through microcosms with conditioned leaves from two riparian tree species, Hau (Hibiscus tiliaceus) and guava (Psidium guajava). Th...

Assessing estuarine biota in southern California

Treesearch

Kevin D. Lafferty

2005-01-01

In southern California, most estuarine wetlands are gone, and what little habitat remains is degraded. For this reason, it is often of interest to assess the condition of estuaries over time, such as when determining the success of a restoration project. To identify impacts or opportunities for restoration, we also may want to know how a particular estuary, or area...

Human activities and climate variability drive fast-paced change across the world's estuarine-coastal ecosystems

USGS Publications Warehouse

Cloern, James E.; Abreu, Paulo C.; Carstensen, Jacob; Chauvaud, Laurent; Elmgren, Ragnar; Grall, Jacques; Greening, Holly; Johansson, John O.R.; Kahru, Mati; Sherwood, Edward T.; Xu, Jie; Yin, Kedong

2016-01-01

Time series of environmental measurements are essential for detecting, measuring and understanding changes in the Earth system and its biological communities. Observational series have accumulated over the past 2–5 decades from measurements across the world's estuaries, bays, lagoons, inland seas and shelf waters influenced by runoff. We synthesize information contained in these time series to develop a global view of changes occurring in marine systems influenced by connectivity to land. Our review is organized around four themes: (i) human activities as drivers of change; (ii) variability of the climate system as a driver of change; (iii) successes, disappointments and challenges of managing change at the sea-land interface; and (iv) discoveries made from observations over time. Multidecadal time series reveal that many of the world's estuarine–coastal ecosystems are in a continuing state of change, and the pace of change is faster than we could have imagined a decade ago. Some have been transformed into novel ecosystems with habitats, biogeochemistry and biological communities outside the natural range of variability. Change takes many forms including linear and nonlinear trends, abrupt state changes and oscillations. The challenge of managing change is daunting in the coastal zone where diverse human pressures are concentrated and intersect with different responses to climate variability over land and over ocean basins. The pace of change in estuarine–coastal ecosystems will likely accelerate as the human population and economies continue to grow and as global climate change accelerates. Wise stewardship of the resources upon which we depend is critically dependent upon a continuing flow of information from observations to measure, understand and anticipate future changes along the world's coastlines.

Striped Bass Spawning in Non-Estuarine Portions of the Savannah River

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

Martin, D.; Paller, M.

2007-04-17

Historically, the estuarine portions of the Savannah River have been considered to be the only portion of the river in which significant amounts of striped bass (Morone saxatilis) spawning normally occur. A reexamination of data from 1983 through 1985 shows a region between River Kilometers 144 and 253 where significant numbers of striped bass eggs and larvae occur with estimated total egg production near that currently produced in the estuarine reaches. It appears possible that there are two separate spawning populations of striped bass in the Savannah River.

Survival of Escherichia coli and Salmonella spp. in estuarine environments.

PubMed Central

Rhodes, M W; Kator, H

1988-01-01

Survival of Escherichia coli and Salmonella spp. in estuarine waters was compared over a variety of seasonal temperatures during in situ exposure in diffusion chambers. Sublethal stress was measured by both selective-versus-resuscitative enumeration procedures and an electrochemical detection method. E. coli and Salmonella spp. test suspensions, prepared to minimize sublethal injury, were exposed in a shallow tidal creek and at a site 7.1 km further downriver. Bacterial die-off and sublethal stress in filtered estuarine water were inversely related to water temperature. Salmonella spp. populations exhibited significantly less die-off and stress than did E. coli at water temperatures of less than 10 degrees C. Although the most pronounced reductions (ca. 3 log units) in test bacteria occurred during seasonally warm temperatures in the presence of the autochthonous microbiota, 10(2) to 10(4) test cells per ml remained after 2 weeks of exposure to temperatures of greater than 15 degrees C. Reductions in test bacteria were associated with increases in the densities of microflagellates and plaque-forming microorganisms. These studies demonstrated the survival potential of enteric bacteria in estuarine waters and showed that survival was a function of interacting biological and physical factors. PMID:3066291

Estuarine mixing behavior of colloidal organic carbon and colloidal mercury in Galveston Bay, Texas.

PubMed

Lee, Seyong; Han, Seunghee; Gill, Gary A

2011-06-01

Mercury (Hg) in estuarine water is distributed among different physical phases (i.e. particulate, colloidal, and truly dissolved). This phase speciation influences the fate and cycling of Hg in estuarine systems. However, limited information exists on the estuarine distribution of colloidal phase Hg, mainly due to the technical difficulties involved in measuring it. In the present study, we determined Hg and organic carbon levels from unfiltered, filtered (<0.45 μm), colloidal (10 kDa-0.45 μm), and truly dissolved (<10 kDa) fractions of Galveston Bay surface water in order to understand the estuarine mixing behavior of Hg species as well as interactions of Hg with colloidal organic matter. For the riverine end-member, the colloidal fraction comprised 43 ± 11% of the total dissolved Hg pool and decreased to 17 ± 8% in brackish water. In the estuarine mixing zone, dissolved Hg and colloidal organic carbon showed non-conservative removal behavior, particularly in the low salinity (<15 ppt) region. This removal may be caused by salt-induced coagulation of colloidal matter and consequent removal of dissolved Hg. The particle-water interaction, K(d) ([particulate Hg (mol kg(-1))]/[dissolved Hg (mol L(-1))]) of Hg decreased as particle concentration increased, while the particle-water partition coefficient based on colloidal Hg and the truly dissolved Hg fraction, K(c) ([colloidal Hg (mol kg(-1))]/[truly dissolved Hg (mol L(-1))]) of Hg remained constant as particle concentration increased. This suggests that the particle concentration effect is associated with the amount of colloidal Hg, increasing in proportion to the amount of suspended particulate matter. This work demonstrates that, colloidal organic matter plays an important role in the transport, particle-water partitioning, and removal of dissolved Hg in estuarine waters.

Estuarine Oceanography. CEGS Programs Publication Number 18.

ERIC Educational Resources Information Center

Wright, F. F.

Estuarine Oceanography is one in a series of single-topic problem modules intended for use in undergraduate and earth science courses. Designed for those interested in coastal oceanography or limnology, the module is structured as a laboratory supplement for undergraduate college classes but should be useful at all levels. The module has two…

Persistence and Degradation Pathways of Tributyltin in Freshwater and Estuarine Sediments

NASA Astrophysics Data System (ADS)

Dowson, P. H.; Bubb, J. M.; Lester, J. N.

1996-05-01

The degradation of tributyltin (TBT) in contaminated freshwater and estuarine sediments was investigated for a 330-day period under controlled laboratory conditions. Rates of TBT degradation at different depths within various sediments were established, where possible, using regression modelling, and revealed TBT half-lives ranging from 360 to 775 days in surficial sediments. There appeared to be very little difference between degradation rates in freshwater and estuarine sediments, although a notable increase in TBT half-life was evident in spiked sediments containing elevated TBT concen-trations. Degradation trends suggest that TBT either debutylates to dibutyltin (DBT) and monobutyltin (MBT) in aerobic sediments or degrades to DBT which subsequently desorbs to the overlying water column. In anaerobic sediment, the half-life of TBT was not discernible and appears to be in the order of tens of years. Biotic processes were the most important mechanisms for the decomposition of TBT in freshwater and estuarine sediments. The results are reviewed in the context of concentrations of TBT determined in marina and boatyard sediments in U.K. east coast estuaries.

Occurrence of Vibrio parahaemolyticus in Estuarine Waters and Oysters of New Hampshire

PubMed Central

Bartley, Clara H.; Slanetz, L. W.

1971-01-01

Vibrio parahaemolyticus was isolated from water and oysters collected from seven different sampling stations in the Great Bay and Little Bay estuarine areas of New Hampshire. The morphological and biochemical characteristics of 50 isolates conformed in general to those described for this organism in the literature. All isolates produced hemolysis on blood-agar. To date, there have been no reports of V. parahaemolyticus food poisoning outbreaks due to the consumption of fish or shellfish harvested from this estuarine region. PMID:5574329

Spatial and temporal variability of contaminants within estuarine sediments and native Olympia oysters: A contrast between a developed and an undeveloped estuary

USGS Publications Warehouse

Granek, Elise F.; Conn, Kathleen E.; Nilsen, Elena B.; Pillsbury, Lori; Strecker, Angela L.; Rumrill, Steve; Fish, William

2016-01-01

Chemical contaminants can be introduced into estuarine and marine ecosystems from a variety of sources including wastewater, agriculture and forestry practices, point and non-point discharges, runoff from industrial, municipal, and urban lands, accidental spills, and atmospheric deposition. The diversity of potential sources contributes to the likelihood of contaminated marine waters and sediments and increases the probability of uptake by marine organisms. Despite widespread recognition of direct and indirect pathways for contaminant deposition and organismal exposure in coastal systems, spatial and temporal variability in contaminant composition, deposition, and uptake patterns are still poorly known. We investigated these patterns for a suite of persistent legacy contaminants including polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) and chemicals of emerging concern including pharmaceuticals within two Oregon coastal estuaries (Coos and Netarts Bays). In the more urbanized Coos Bay, native Olympia oyster (Ostrea lurida) tissue had approximately twice the number of PCB congeners at over seven times the total concentration, yet fewer PBDEs at one-tenth the concentration as compared to the more rural Netarts Bay. Different pharmaceutical suites were detected during each sampling season. Variability in contaminant types and concentrations across seasons and between species and media (organisms versus sediment) indicates the limitation of using indicator species and/or sampling annually to determine contaminant loads at a site or for specific species. The results indicate the prevalence of legacy contaminants and CECs in relatively undeveloped coastal environments highlighting the need to improve policy and management actions to reduce contaminant releases into estuarine and marine waters and to deal with legacy compounds that remain long after prohibition of use. Our results point to the need for better understanding of the ecological and

Ecology of Vibrio vulnificus in estuarine waters of eastern North Carolina.

PubMed

Pfeffer, Courtney S; Hite, M Frances; Oliver, James D

2003-06-01

While several studies on the ecology of Vibrio vulnificus in Gulf Coast environments have been reported, there is little information on the distribution of this pathogen in East Coast waters. Thus, we conducted a multiyear study on the ecology of V. vulnificus in estuarine waters of the eastern United States, employing extensive multiple regression analyses to reveal the major environmental factors controlling the presence of this pathogen, and of Vibrio spp., in these environments. Monthly field samplings were conducted between July 2000 and April 2002 at six different estuarine sites along the eastern coast of North Carolina. At each site, water samples were taken and nine physicochemical parameters were measured. V. vulnificus isolates, along with estuarine bacteria, Vibrio spp., Escherichia coli organisms, and total coliforms, were enumerated in samples from each site by using selective media. During the last 6 months of the study, sediment samples were also analyzed for the presence of vibrios, including V. vulnificus. Isolates were confirmed as V. vulnificus by using hemolysin gene PCR or colony hybridization. V. vulnificus was isolated only when water temperatures were between 15 and 27 degrees C, and its presence correlated with water temperature and dissolved oxygen and vibrio levels. Levels of V. vulnificus in sediments were low, and no evidence for an overwintering in this environment was found. Multiple regression analysis indicated that vibrio levels were controlled primarily by temperature, turbidity, and levels of dissolved oxygen, estuarine bacteria, and coliforms. Water temperature accounted for most of the variability in the concentrations of both V. vulnificus (47%) and Vibrio spp. (48%).

Influence of organic carbon on estuarine benthic infauna of the US west coast - March 3, 2011

EPA Science Inventory

Total organic carbon (TOC) is often used as an indicator of eutrophication in estuarine environments. However, the determination of biologically relevant sediment TOC criteria to indicate estuarine condition is complicated by the relationship between TOC and grain size. Both va...

Habitat loss and gain: Influence on habitat attractiveness for estuarine fish communities

NASA Astrophysics Data System (ADS)

Amorim, Eva; Ramos, Sandra; Elliott, Michael; Franco, Anita; Bordalo, Adriano A.

2017-10-01

Habitat structure and complexity influence the structuring and functioning of fish communities. Habitat changes are one of the main pressures affecting estuarine systems worldwide, yet the degree and rate of change and its impact on fish communities is still poorly understood. In order to quantify historical modifications in habitat structure, an ecohydrological classification system using physiotopes, i.e. units with homogenous abiotic characteristics, was developed for the lower Lima estuary (NW Portugal). Field data, aerial imagery, historical maps and interpolation methods were used to map input variables, including bathymetry, substratum (hard/soft), sediment composition, hydrodynamics (current velocity) and vegetation coverage. Physiotopes were then mapped for the years of 1933 and 2013 and the areas lost and gained over the 80 years were quantified. The implications of changes for the benthic and demersal fish communities using the lower estuary were estimated using the attractiveness to those communities of each physiotope, while considering the main estuarine habitat functions for fish, namely spawning, nursery, feeding and refuge areas and migratory routes. The lower estuary was highly affected due to urbanisation and development and, following a port/harbour expansion, its boundary moved seaward causing an increase in total area. Modifications led to the loss of most of its sandy and saltmarsh intertidal physiotopes, which were replaced by deeper subtidal physiotopes. The most attractive physiotopes for fish (defined as the way in which they supported the fish ecological features) decreased in area while less attractive ones increased, producing an overall lower attractiveness of the studied area in 2013 compared to 1933. The implications of habitat alterations for the fish using the estuary include potential changes in the nursery carrying capacity and the functioning of the fish community. The study also highlighted the poor knowledge of the impacts of

Role of Phragmites australis (common reed) for heavy metals phytoremediation of estuarine sediments.

PubMed

Cicero-Fernández, Diego; Peña-Fernández, Manuel; Expósito-Camargo, Jose A; Antizar-Ladislao, Blanca

2016-01-01

The ability of Phragmites australis to take up heavy metals (Co, Ni, Mo, Cd, Pb, Cr, Cu, Fe, Mn, Zn, and Hg) and other trace elements (As, Se, Ba), from estuarine sediments was investigated using a pilot plant experimental approach. Bioaccumulation (BCF) and translocation factors (TF) were calculated in vegetative and senescence periods for two populations of P. australis, from contaminated (MIC) and non-contaminated (GAL) estuarine sediments, respectively, both growing in estuarine contaminated sediment (RIA) from ría del Carmen y Boo, Santander Bay, Spain. The highest BCF values were obtained for Ni (0.43), Ba (0.43) Mo (0.36), Cr (0.35), and Cd (0.31) for plants collected from site GAL following the senescence period. The highest BCF values recorded for plants collected from MIC following the senescence period were for Mo (0.22) and Cu (0.22). Following senescence, plants collected from GAL and MIC presented TF>1 for Ni, Mo, Se, and Zn, and in addition plants collected from MIC presented TF>1 for Ba, Cr, and Mn. A substantial increase of Micedo's rhizosphere, six times higher than Galizano's rhizosphere, suggested adaptation to contaminated sediment. The evaluated communities of P. australis demonstrated their suitability for phytoremediation of heavy metals contaminated estuarine sediments.

Estuarine Human Activities Modulate the Fate of Changjiang-derived Materials in Adjacent Seas

NASA Astrophysics Data System (ADS)

WU, H.

2017-12-01

Mega constructions have been built in many river estuaries, but their environmental consequences in the adjacent coastal oceans were often overlooked. This issue was addressed with an example of the Changjiang River Estuary, which was recently built with massive navigation and reclamation constructions in recent years. Based on the model validations against cruises data and the numerical scenario experiments, it is shown that the estuarine constructions profoundly affected the fates of riverine materials in an indeed large offshore area. This is because estuarine dynamics are highly sensitive to their bathymetries. Previously, the Three Gorges Dam (TGD) was thought to be responsible for some offshore environmental changes through modulating the river plume extension, but here we show that its influences are secondary. Since the TGD and the mega estuarine constructions were built during the similar period, their influences might be confused.

Estuarine turbidity, flushing, salinity, and circulation

NASA Technical Reports Server (NTRS)

Pritchard, D. W.

1972-01-01

The effects of estuarine turbidity, flushing, salinity, and circulation on the ecology of the Chesapeake Bay are discussed. The sources of fresh water, the variations in salinity, and the circulation patterns created by temperature and salinity changes are analyzed. The application of remote sensors for long term observation of water temperatures is described. The sources of sediment and the biological effects resulting from increased sediments and siltation are identified.

Using modelling to predict impacts of sea level rise and increased turbidity on seagrass distributions in estuarine embayments

NASA Astrophysics Data System (ADS)

Davis, Tom R.; Harasti, David; Smith, Stephen D. A.; Kelaher, Brendan P.

2016-11-01

Climate change induced sea level rise will affect shallow estuarine habitats, which are already under threat from multiple anthropogenic stressors. Here, we present the results of modelling to predict potential impacts of climate change associated processes on seagrass distributions. We use a novel application of relative environmental suitability (RES) modelling to examine relationships between variables of physiological importance to seagrasses (light availability, wave exposure, and current flow) and seagrass distributions within 5 estuarine embayments. Models were constructed separately for Posidonia australis and Zostera muelleri subsp. capricorni using seagrass data from Port Stephens estuary, New South Wales, Australia. Subsequent testing of models used independent datasets from four other estuarine embayments (Wallis Lake, Lake Illawarra, Merimbula Lake, and Pambula Lake) distributed along 570 km of the east Australian coast. Relative environmental suitability models provided adequate predictions for seagrass distributions within Port Stephens and the other estuarine embayments, indicating that they may have broad regional application. Under the predictions of RES models, both sea level rise and increased turbidity are predicted to cause substantial seagrass losses in deeper estuarine areas, resulting in a net shoreward movement of seagrass beds. Seagrass species distribution models developed in this study provide a valuable tool to predict future shifts in estuarine seagrass distributions, allowing identification of areas for protection, monitoring and rehabilitation.

75 FR 60720 - National Estuarine Research Reserve System

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-01

... DEPARTMENT OF COMMERCE National Oceanic and Atmospheric Administration National Estuarine Research Reserve System Correction In notice document 2010-24341 appearing on page 59696 in the issue of Tuesday, September 28, 2010 make the following corrections: 1. In the second column, in lines five and eight of the...

An Experimental Approach for Restoration of Salmon River Ecosystems

NASA Astrophysics Data System (ADS)

Stanford, J. A.

2005-05-01

River ecosystem theory predicts that dynamic, nonlinear physical and biological processes linking water, heat and materials (biota, sediment, plant-growth nutrients) flux and retention to fluvial landscape change in a habitat mosaic context drive salmon life histories and productivity in freshwater. Multidisciplinary studies and cross-site comparisons within a network of pristine salmon river observatories around the north Pacific Rim support these predictions. Billions of dollars have been spent on salmon-river restoration worldwide to little avail, mainly because salmon biology, rather than ecosystem process boundaries and bottlenecks, is driving restoration goals. I argue that entire river catchment restoration, in relation to these dynamic processes and bottlenecks and also coherent with the estuarine and marine implications of salmon life history parameters, is the only possibility for sustaining or restoring natural productivity and life history (genetic) diversity in salmon rivers. This can be done only in a few places owing to the continual press of human demands on river ecosystems, the morass of legal challenges to proactive salmon river restoration strategies and insufficient understanding of freshwater and marine linkages. The Elwha and Yakima Rivers in Washington, among a few others that I will name, offer real opportunities to restore entire watersheds for wild salmon. These restorations should be viewed as experimental manipulations in which outcomes may be evaluated against norms measured in the salmon river observatory network. Bias from hatcheries and harvest, among other anthropogenic interferences, must be eliminated for such experiments to be evaluated in light of contemporary river ecosystem theory. And, a much more synthetic understanding of freshwater and marine linkages must be forthcoming in concert with a much more robust general theory of river restoration.

Ecological fitness and virulence features of Vibrio parahaemolyticus in estuarine environments.

PubMed

Lovell, Charles R

2017-03-01

Vibrio parahaemolyticus is a commonly encountered and highly successful organism in marine ecosystems. It is a fast-growing, extremely versatile copiotroph that is active over a very broad range of conditions. It frequently occurs suspended in the water column (often attached to particles or zooplankton), and is a proficient colonist of submerged surfaces. This organism is an important pathogen of animals ranging from microcrustaceans to humans and is a causative agent of seafood-associated food poisoning. This review examines specific ecological adaptations of V. parahaemolyticus, including its broad tolerances to temperature and salinity, its utilization of a wide variety of organic carbon and energy sources, and its pervasive colonization of suspended and stationary materials that contribute to its success and ubiquity in temperate and tropical estuarine ecosystems. Several virulence-related features are examined, in particular the thermostable direct hemolysin (TDH), the TDH-related hemolysin (TRH), and the type 3 secretion system, and the possible importance of these features in V. parahaemolyticus pathogenicity is explored. The impact of new and much more effective PCR primers on V. parahaemolyticus detection and our views of virulent strain abundance are also described. It is clear that strains carrying the canonical virulence genes are far more common than previously thought, which opens questions regarding the role of these genes in pathogenesis. It is also clear that virulence is an evolving feature of V. parahaemolyticus and that novel combinations of virulence factors can lead to emergent virulence in which a strain that is markedly more pathogenic evolves and propagates to produce an outbreak. The effects of global climate change on the frequency of epidemic disease, the geographic distribution of outbreaks, and the human impacts of V. parahaemolyticus are increasing and this review provides information on why this ubiquitous human pathogen has

Progress and Challenges in Coupled Hydrodynamic-Ecological Estuarine Modeling

EPA Science Inventory

Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational po...

Biophysical processes leading to the ingress of temperate fish larvae into estuarine nursery areas: A review

NASA Astrophysics Data System (ADS)

Teodósio, Maria Alexandra; Paris, Claire B.; Wolanski, Eric; Morais, Pedro

2016-12-01

A series of complementary hypotheses have been proposed to explain the recruitment of marine and temperate pelagic fish larvae originated from pelagic eggs in coastal environments. In this review, we propose a new and complementary hypothesis describing the biophysical processes intervening in the recruitment of temperate fish larvae into estuaries. This new hypothesis, the Sense Acuity And Behavioral (SAAB) hypothesis, recognizes that recruitment is unlikely if the larvae drift passively with the water currents, and that successful recruitment requires the sense acuity of temperate fish larvae and their behavioral response to the estuarine cues present in coastal areas. We propose that temperate fish larvae use a hierarchy of sensory cues (odor, sound, visual and geomagnetic cues) to detect estuarine nursery areas and to aid during navigation towards these areas. The sensorial acuity increases along ontogeny, which coincides with increased swimming capabilities. The swimming strategies of post-flexion larvae differ from offshore areas to the tidal zone. In offshore areas, innate behavior might lead larvae towards the coast guided by a sun compass or by the earth's geomagnetic field. In areas under limited influence of estuarine plumes (either in energetic nearshore areas or offshore), post-flexion larvae display a searching swimming behavior for estuarine disconnected patches (infotaxis strategy). After finding an estuarine plume, larvae may swim along the increasing cue concentration to ingress into the estuary. Here, larvae exhibit a rheotaxis behavior and avoid displacement by longshore currents by keeping bearing during navigation. When larvae reach the vicinity of an estuary, merging diel rhythms with feeding and predator avoidance strategies with tidally induced movements is essential to increase their chances of estuarine ingress. A fish larva recruitment model developed for the Ria Formosa lagoon supports the general framework of the SAAB hypothesis. In

Study of pollutant distribution in the Guaxindiba Estuarine System--SE Brazil.

PubMed

Fonseca, E M; Baptista Neto, J A; Pereira, M P S; Silva, C G; Arantes, J D

2014-05-15

The Guaxindiba Estuarine System is located in the northeast portion of Guanabara Bay. Despite the location inside an environmental protection zone, the main affluent of the river runs through the extremely urbanized area of the cities of Niterói and São Gonçalo. In order to understand the contamination levels of the estuary, 35 surface sediment samples were collected along the river and estuarine area and analyzed for the presence of heavy metals, PAHs, organochlorated pesticides, polychlorinated biphenyl and other contaminants. The analyzed data revealed a greatly affected environment with respect to most of these substances. The results suggested propitious deposits of contaminants, with high concentrations of organic matter and fine sediment. The levels of heavy metal in the entire estuarine system were high compared with the local background. The total mean concentrations of As, Cd, Pb, Cu, Zn, Hg, Cr and Ni in the surface sediments were: 3.74; 0.03; 19.3; 15.0; 99.0; n.d.; 29.0; and 22.0mg/kg, respectively, confirming, in certain cases, the high capacity of the environment to concentrate pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Modeling the impact of watershed management policies on marine ecosystem services with application to Hood Canal, WA, USA

NASA Astrophysics Data System (ADS)

Sutherland, D. A.; Kim, C.; Marsik, M.; Spiridonov, G.; Toft, J.; Ruckelshaus, M.; Guerry, A.; Plummer, M.

2011-12-01

Humans obtain numerous benefits from marine ecosystems, including fish to eat; mitigation of storm damage; nutrient and water cycling and primary production; and cultural, aesthetic and recreational values. However, managing these benefits, or ecosystem services, in the marine world relies on an integrated approach that accounts for both marine and watershed activities. Here we present the results of a set of simple, physically-based, and spatially-explicit models that quantify the effects of terrestrial activities on marine ecosystem services. Specifically, we model the circulation and water quality of Hood Canal, WA, USA, a fjord system in Puget Sound where multiple human uses of the nearshore ecosystem (e.g., shellfish aquaculture, recreational Dungeness crab and shellfish harvest) can be compromised when water quality is poor (e.g., hypoxia, excessive non-point source pollution). Linked to the estuarine water quality model is a terrestrial hydrology model that simulates streamflow and nutrient loading, so land cover and climate changes in watersheds can be reflected in the marine environment. In addition, a shellfish aquaculture model is linked to the water quality model to test the sensitivity of the ecosystem service and its value to both terrestrial and marine activities. The modeling framework is general and will be publicly available, allowing easy comparisons of watershed impacts on marine ecosystem services across multiple scales and regions.

Climatically sensitive transfer of iron to maritime Antarctic ecosystems by surface runoff

NASA Astrophysics Data System (ADS)

Hodson, Andy; Nowak, Aga; Sabacka, Marie; Jungblut, Anne; Navarro, Francisco; Pearce, David; Ávila-Jiménez, María Luisa; Convey, Peter; Vieira, Gonçalo

2017-02-01

Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs. Here we show that surface runoff from three island groups of the maritime Antarctic exports more filterable (<0.45 μm) iron (6-81 kg km-2 a-1) than icebergs (0.0-1.2 kg km-2 a-1). Glacier-fed streams also export more acid-soluble iron (27.0-18,500 kg km-2 a-1) associated with suspended sediment than icebergs (0-241 kg km-2 a-1). Significant fluxes of filterable and sediment-derived iron (1-10 Gg a-1 and 100-1,000 Gg a-1, respectively) are therefore likely to be delivered by runoff from the Antarctic continent. Although estuarine removal processes will greatly reduce their availability to coastal ecosystems, our results clearly indicate that riverine iron fluxes need to be accounted for as the volume of Antarctic melt increases in response to 21st century climate change.

Survey of three-dimensional numerical estuarine models

USGS Publications Warehouse

Cheng, Ralph T.; Smith, Peter E.

1989-01-01

This paper surveys the existing 3-D estuarine hydrodynamic and solute transport models by a review of the commonly used assumptions and approximations, and by an examination of the methods of solution. The model formulations, methods of solution, and known applications are surveyed and summarized in tables. In conclusion, the authors present their modeling philosophy and suggest future research needs.

Connecting fishery sustainability to estuarine habitats and nutrient loading

EPA Science Inventory

The production of several important fishery species depends on critical estuarine habitats, including seagrasses and salt marshes. Relatively simple models can be constructed to relate fishery productivity to the extent and distribution of these habitats by linking fishery-depend...

Source Evaluation and Trace Metal Contamination in Benthic Sediments from Equatorial Ecosystems Using Multivariate Statistical Techniques

PubMed Central

Benson, Nsikak U.; Asuquo, Francis E.; Williams, Akan B.; Essien, Joseph P.; Ekong, Cyril I.; Akpabio, Otobong; Olajire, Abaas A.

2016-01-01

Trace metals (Cd, Cr, Cu, Ni and Pb) concentrations in benthic sediments were analyzed through multi-step fractionation scheme to assess the levels and sources of contamination in estuarine, riverine and freshwater ecosystems in Niger Delta (Nigeria). The degree of contamination was assessed using the individual contamination factors (ICF) and global contamination factor (GCF). Multivariate statistical approaches including principal component analysis (PCA), cluster analysis and correlation test were employed to evaluate the interrelationships and associated sources of contamination. The spatial distribution of metal concentrations followed the pattern Pb>Cu>Cr>Cd>Ni. Ecological risk index by ICF showed significant potential mobility and bioavailability for Cu, Cu and Ni. The ICF contamination trend in the benthic sediments at all studied sites was Cu>Cr>Ni>Cd>Pb. The principal component and agglomerative clustering analyses indicate that trace metals contamination in the ecosystems was influenced by multiple pollution sources. PMID:27257934

Ordination of the estuarine environment: What the organism experiences

EPA Science Inventory

Investigators customarily schedule estuary sampling trips with regard to a variety of criteria, especially tide stage and the day-night cycle. However, estuarine organisms experience a wide suite of continuously changing tide and light conditions. Such organisms may undertake i...

Growth and biosurfactant synthesis by Nigerian hydrocarbon-degrading estuarine bacteria.

PubMed

Adebusoye, Sunday A; Amund, Olukayode O; Ilori, Matthew O; Domeih, Dupe O; Okpuzor, Joy

2008-12-01

The ability of microorganisms to degrade petroleum hydrocarbons is important for finding an environmentally-friendly method to restoring contaminated environmental matrices. Screening of hydrocarbon-utilizing and biosurfactant-producing abilities of organisms from an estuarine ecosystem in Nigeria, Africa, resulted in the isolation of five microbial strains identified as Corynebacterium sp. DDV1, Flavobacterium sp. DDV2, Micrococcus roseus DDV3, Pseudomonas aeruginosa DDV4 and Saccharomyces cerevisae DDV5. These isolates grew readily on several hydrocarbons including hexadecane, dodecane, crude oil and petroleum fractions. Axenic cultures of the organisms utilized diesel oil (1.0% v/v) with generation times that ranged significantly (t-test, P < 0.05) between 3.25 and 3.88 day, with concomitant production of biosurfactants. Kinetics of growth indicates that biosurfactant synthesis occurred predominantly during exponential growth phase, suggesting that the bioactive molecules are primary metabolites. Strains DDV1 and DDV4 were evidently the most metabolically active in terms of substrate utilization and biosurfactant synthesis compared to other strains with respective emulsification index of 63 and 78%. Preliminary biochemical characterization indicates that the biosurfactants are heteropolymers consisting of lipid, protein and carbohydrate moieties. The hydrocarbon catabolic properties coupled with biosurfactant-producing capabilities is an asset that could be exploited for cleanup of oil-contaminated matrices and also in food and cosmetic industries.

Quantifying salinity-induced changes on estuarine benthic fauna: The potential implications of climate change

NASA Astrophysics Data System (ADS)

Little, S.; Wood, P. J.; Elliott, M.

2017-11-01

Coastal and estuarine systems worldwide are under threat from global climate change, with potential consequences including an increase in salinities and incursion of saltwater into areas currently subject to tidal and non-tidal freshwater regimes. It is commonly assumed that climate-driven increases in estuarine salinities and saline incursion will be directly reflected in an upstream shift in species distributions and patterns of community composition based on salinity tolerance. This study examined the responses of benthos to medium-term salinity changes in two macrotidal river-estuary systems in SE England to test whether these responses may be representative of climate-induced salinity changes over the long-term. The study reinforced the effect of salinity, related to tidal incursion, as the primary environmental driver of benthic species distribution and community composition. Salinity, however, acted within a hierarchy of factors followed by substratum type, with biotic competition and predator-prey relationships superimposed on these. The assumption that increasing salinities will be directly reflected in a shift in species distributions and patterns of community composition upstream over the long-term was shown to be over simplistic and not representative of a complex and highly variable system. Relative Sea Level Rise (RSLR) projections were predicted to increase estuarine salinities and saline incursion in the study estuaries, which together with projected reductions in river flow will have important consequences for estuarine structure and function, particularly in tidal limnetic zones, despite estuarine communities being pre-adapted to cope with fluctuating salinities. The study identified, however, that limnic-derived fauna inhabiting these zones may demonstrate greater tolerance to salinity change than is currently recognised, and may persist where salinity increases are gradual and zones unbounded.

Trace fossil assemblages in the tide-dominated estuarine system: Ameki Group, south-eastern Nigeria

NASA Astrophysics Data System (ADS)

Ekwenye, O. C.; Nichols, G.; Okogbue, C. O.; Mode, A. W.

2016-06-01

A systematic ichnological analysis with sedimentological study of the Eocene Ameki Group in south-eastern Nigeria, was conducted to infer depositional and biogenic processes operating during basin fill, identify discontinuities using substrate controlled ichnofacies, and identify the paleocological conditions that affected the diversity of the trace fossils. The Ameki Group represents a tide-dominated estuarine system characterised by a range of trace fossils assemblages. Eighteen individual ichnogenera and nineteen ichnospecies observed in the study area, were grouped into six recurring ichnofacies namely Scoyenia, Psilonichnus, Skolithos, Cruziana, Glossifungites and Teredolites. Skolithos and Cruziana ichnofacies are predominant in the estuarine deposits indicating that the sedimentary successions of the Eocene are dominantly of moderate to high energy marginal marine environments. The estuarine deposits (senus stricto) were controlled by low to fluctuating salinity levels, high sedimentation rate and fluctuating hydrodynamic energy. These resulted in the occurrence of low diversity of Scoyenia and Teredolites ichnofacies and low to moderate ichnodiversity of mixed Skolithos and depauperate Cruziana ichnofacies. Low levels of dissolved oxygen in quiescent water-embayment (open estuarine) resulted in low diversity of impoverished Cruziana ichnofacies. Glossifungites ichnofacies marked an amalgamated sequence boundary/marine flooding and an initial flooding surface at the base of the tidally influenced fluvial deposits.

Consequences of Increasing Hypoxic Disturbance on Benthic Communities and Ecosystem Functioning

PubMed Central

Villnäs, Anna; Norkko, Joanna; Lukkari, Kaarina; Hewitt, Judi; Norkko, Alf

2012-01-01

Disturbance-mediated species loss has prompted research considering how ecosystem functions are changed when biota is impaired. However, there is still limited empirical evidence from natural environments evaluating the direct and indirect (i.e. via biota) effects of disturbance on ecosystem functioning. Oxygen deficiency is a widespread threat to coastal and estuarine communities. While the negative impacts of hypoxia on benthic communities are well known, few studies have assessed in situ how benthic communities subjected to different degrees of hypoxic stress alter their contribution to ecosystem functioning. We studied changes in sediment ecosystem function (i.e. oxygen and nutrient fluxes across the sediment water-interface) by artificially inducing hypoxia of different durations (0, 3, 7 and 48 days) in a subtidal sandy habitat. Benthic chamber incubations were used for measuring responses in sediment oxygen and nutrient fluxes. Changes in benthic species richness, structure and traits were quantified, while stress-induced behavioral changes were documented by observing bivalve reburial rates. The initial change in faunal behavior was followed by non-linear degradation in benthic parameters (abundance, biomass, bioturbation potential), gradually impairing the structural and functional composition of the benthic community. In terms of ecosystem function, the increasing duration of hypoxia altered sediment oxygen consumption and enhanced sediment effluxes of NH4 + and dissolved Si. Although effluxes of PO4 3− were not altered significantly, changes were observed in sediment PO4 3− sorption capability. The duration of hypoxia (i.e. number of days of stress) explained a minor part of the changes in ecosystem function. Instead, the benthic community and disturbance-driven changes within the benthos explained a larger proportion of the variability in sediment oxygen- and nutrient fluxes. Our results emphasize that the level of stress to the benthic habitat

DEVELOPING A NATIONALLY CONSISTENT APPROACH FOR ASSESSING REGIONAL ASSOCIATIONS BETWEEN NUTRIENTS AND BENTHIC BIOLOGICAL CONDITION IN ESTUARINE WATERS

EPA Science Inventory

Identifying candidate water quality criteria in estuarine waters is confounded by differences among estuaries and biogeographic regions. Addressing these differences is paramount to assess estuarine water quality impairment successfully. We outline an approach to investigate rela...

75 FR 56507 - Extension of Award Period for FY 2007 Coastal and Estuarine Land Conservation Program Grants

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

... Assistant Administrator for Management and CFO/CAO, Ocean Services and Coastal Zone Management. [FR Doc...-01] RIN 0648-ZC21 Extension of Award Period for FY 2007 Coastal and Estuarine Land Conservation....gov . SUPPLEMENTARY INFORMATION: The Coastal and Estuarine Land Conservation Program was established...

Invasive Marine and Estuarine Animals of California

DTIC Science & Technology

2005-08-01

displace local fauna. Such effects may occur immediately, after some period of delay, or never be realized at all depending on the characteristics...urbanization. Species are introduced by a variety of different mechanisms ; however, most estuarine and marine species introductions are associated with...adults can live up to five years and are omnivorous. Their planktonic larvae grow best in relatively high salinities (~25 ppt), while late stage

Resolving drivers of variability in estuarine metabolism from sustained observations of water quality in the SE US

EPA Science Inventory

We examine trends in water quality in long-term monitoring (10-15 y) data collected at 5 estuarine systems of NOAA’s National Estuarine Research Reserve System: Grand Bay, MS; Weeks Bay, AL; Apalachicola Bay, FL; Rookery Bay, FL, and Guana Tolomatos and Matanzas Rivers, FL. These...

Causes of highway road dust toxicity to an estuarine amphipod: Evaluating the effects of nicotine.

PubMed

Hiki, Kyoshiro; Nakajima, Fumiyuki; Tobino, Tomohiro

2017-02-01

Urban road dust can potentially have adverse effects on ecosystems if it is discharged into receiving waters. This study investigated the causes of highway road dust toxicity by performing sediment toxicity identification evaluation (TIE) tests with an estuarine amphipod, Grandidierella japonica. In addition to metals and polycyclic aromatic hydrocarbons, which are traditionally considered to be the major toxicants in road runoff, we focused on dissolved nicotine as a causative toxicant. The sediment TIE results suggested that organic contaminants contributed to the majority of toxicity, and that the contribution of unionized nicotine to the toxicity was the highest among the chemicals considered. However, additional mortality tests with 48-h pulsed nicotine exposure demonstrated that exposure to nicotine at the same concentration as the baseline level in TIE tests did not cause significant 10-day amphipod mortality. Thus, the road dust toxicity could not be explained only by unionized nicotine, thereby suggesting contributions from joint effects of the measured toxicants and the presence of other unmeasured factors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impacts of estuarine mixing on vertical dispersion of polycyclic aromatic hydrocarbons (PAHs) in a tide-dominated estuary.

PubMed

Liu, Feng; Hu, Shuai; Guo, Xiaojuan; Niu, Lixia; Cai, Huayang; Yang, Qingshu

2018-06-01

To examine the impacts of estuarine mixing on the dispersion of polycyclic aromatic hydrocarbons (PAHs), seasonal variations in the vertical distribution of dissolved PAHs in the Humen River mouth of the Pearl River Estuary, which is a tide-dominated estuary, were thoroughly examined. An analysis of the vertical distribution of the concentration, composition and sources of PAHs indicates enhanced mixing of PAHs in January relative to June, which is strongly related to seasonal variations in the magnitude of estuarine mixing. Furthermore, the vertical distribution of PAHs initially indicated an increase and then a decrease from the surface layer to the bottom layer. In general, estuarine mixing promotes the vertical dispersion of PAHs, causing a more even PAHs distribution, while salinity stratification can trap PAHs, resulting in higher PAHs concentrations. Our study indicates that salinity variability stimulates significant dynamic effects regarding the dispersion of PAHs within estuarine environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact of silver nanoparticles on benthic prokaryotes in heavy metal-contaminated estuarine sediments in a tropical environment.

PubMed

Antizar-Ladislao, B; Bhattacharya, B D; Ray Chaudhuri, S; Sarkar, S K

2015-10-15

Little knowledge is available about the potential impact of commercial silver nanoparticles (Ag-NPs) on estuarine microbial communities. The Hugli river estuary, India, is susceptible to heavy metals pollution through boat traffic, and there is the potential for Ag-NP exposure via effluent discharged from ongoing municipal and industrial activities located in close proximity. This study investigated the effects of commercial Ag-NPs on native microbial communities in estuarine sediments collected from five stations, using terminal restriction fragment length polymorphism (T-RFLP) technique. An increase in the number of bacteria in consortium in sediments was observed following exposure to Ag-NPs. In general microbial communities may be resistant in estuarine systems to the antimicrobial effects of commercial Ag-NPs, but key microorganisms, such as Pelobacter propionicus, disappeared following exposure to Ag-NPs. In conclusion, the T-RFLP analysis indicated that Ag-NPs have the potential to shape estuarine sediment bacterial community structure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ecology of an estuarine mysid shrimp in the Columbia River (USA)

USGS Publications Warehouse

Haskell, C.A.; Stanford, J.A.

2006-01-01

The estuarine mysid, Neomysis mercedis, has colonized John Day and other run-of-the-river Reservoirs of the Columbia River, over 400 km from the estuary. In John Day Reservoir N. mercedis numbers peaked (2 m-3) in August in areas near the dam in association with lower water velocity and softer bottom than at the upstream sampling sites. Neomysis broods were primarily released in late spring and early fall. Gut content analysis showed that Neomysis feeds mostly on cladoceran zooplankton and rotifers in John Day Reservoir. Diel vertical migration was documented, with daytime distribution restricted to the bottom and preferentially to the soft-textured sediments in the deepest areas. Common pelagic fishes in the reservoir, especially juvenile American shad (Alosa sapidissima) and chinook salmon (Oncorhynchus tshawytscha), are daytime zooplankton feeders that cannot prey on Neomysis owing to mysid diel vertical migration. Thus, Neomysis has become an important food web component in John Day Reservoir. We also collected N. mercedis further upstream in Lower Granite Reservoir, where another estuarine crustacean, Corophium salmonis, also is reported, underscoring the need to better understand the role of these estuarine invertebrates in the trophic ecology of the Columbia River. Copyright ?? 2006 John Wiley & Sons, Ltd.

Temporal variation in development of ecosystem services from oyster reef restoration

USGS Publications Warehouse

LaPeyre, Megan K.; Humphries, Austin T.; Casas, Sandra M.; La Peyre, Jerome F.

2014-01-01

Restoration ecology relies heavily on ecosystem development theories that generally assume development of fully functioning natural systems over time, but often fail to identify the time-frame required for provision of desired functions, or acknowledge different pathways of functional development. In estuaries, a decline of overall habitat quality and functioning has led to significant efforts to restore critical ecosystem services, recently through the creation and restoration of oyster reefs. Oyster reef restoration generally occurs with goals of (1) increasing water quality via filtration through sustainable oyster recruitment, (2) stabilizing shorelines, and (3) creating and enhancing critical estuarine habitat for fish and invertebrates. We restored over 260 m2 of oyster reef habitat in coastal Louisiana and followed the development and provision of these ecosystem services from 2009 through 2012. Oysters recruited to reefs immediately, with densities of oysters greater than 75 mm exceeding 80 ind m−2 after 3 years, and provision of filtration rates of 1002 ± 187 L h−1 m−2; shoreline stabilization effects of the created reefs were minimal over the three years of monitoring, with some evidence of positive shoreline stabilization during higher wind/energy events only; increased nekton abundance of resident, but not larger transient fish was immediately measurable at the reefs, however, this failed to increase through time. Our results provide critical insights into the development trajectories of ecosystem services provided by restored oyster reefs, as well as the mechanisms mediating these changes. This is critical both ecologically to understand how and where a reef thrives, and for policy and management to guide decision-making related to oyster reef restoration and the crediting and accounting of ecosystem services.

Macroalgal blooms alter community structure and primary productivity in marine ecosystems.

PubMed

Lyons, Devin A; Arvanitidis, Christos; Blight, Andrew J; Chatzinikolaou, Eva; Guy-Haim, Tamar; Kotta, Jonne; Orav-Kotta, Helen; Queirós, Ana M; Rilov, Gil; Somerfield, Paul J; Crowe, Tasman P

2014-09-01

Eutrophication, coupled with loss of herbivory due to habitat degradation and overharvesting, has increased the frequency and severity of macroalgal blooms worldwide. Macroalgal blooms interfere with human activities in coastal areas, and sometimes necessitate costly algal removal programmes. They also have many detrimental effects on marine and estuarine ecosystems, including induction of hypoxia, release of toxic hydrogen sulphide into the sediments and atmosphere, and the loss of ecologically and economically important species. However, macroalgal blooms can also increase habitat complexity, provide organisms with food and shelter, and reduce other problems associated with eutrophication. These contrasting effects make their overall ecological impacts unclear. We conducted a systematic review and meta-analysis to estimate the overall effects of macroalgal blooms on several key measures of ecosystem structure and functioning in marine ecosystems. We also evaluated some of the ecological and methodological factors that might explain the highly variable effects observed in different studies. Averaged across all studies, macroalgal blooms had negative effects on the abundance and species richness of marine organisms, but blooms by different algal taxa had different consequences, ranging from strong negative to strong positive effects. Blooms' effects on species richness also depended on the habitat where they occurred, with the strongest negative effects seen in sandy or muddy subtidal habitats and in the rocky intertidal. Invertebrate communities also appeared to be particularly sensitive to blooms, suffering reductions in their abundance, species richness, and diversity. The total net primary productivity, gross primary productivity, and respiration of benthic ecosystems were higher during macroalgal blooms, but blooms had negative effects on the productivity and respiration of other organisms. These results suggest that, in addition to their direct social and

Shock, Stress or Signal? Implications of Freshwater Flows for a Top-Level Estuarine Predator

PubMed Central

Taylor, Matthew D.; van der Meulen, Dylan E.; Ives, Matthew C.; Walsh, Chris T.; Reinfelds, Ivars V.; Gray, Charles A.

2014-01-01

Physicochemical variability in estuarine systems plays an important role in estuarine processes and in the lifecycles of estuarine organisms. In particular, seasonality of freshwater inflow to estuaries may be important in various aspects of fish lifecycles. This study aimed to further understand these relationships by studying the movements of a top-level estuarine predator in response to physicochemical variability in a large, temperate south-east Australian estuary (Shoalhaven River). Mulloway (Argyrosomus japonicus, 47–89 cm total length) were surgically implanted with acoustic transmitters, and their movements and migrations monitored over two years via fixed-position VR2W acoustic receivers configured in a linear array along the length of the estuary. The study period included a high degree of abiotic variability, with multiple pulses (exponentially high flows over a short period of time) in fresh water to the estuary, as well as broader seasonal variation in flow, temperature and conductivity. The relative deviation of fish from their modal location in the estuary was affected primarily by changes in conductivity, and smaller fish (n = 4) tended to deviate much further downstream from their modal position in the estuary than larger fish (n = 8). High-flow events which coincided with warmer temperatures tended to drive mature fish down the estuary and potentially provided a spawning signal to stimulate aggregation of adults near the estuary mouth; however, this relationship requires further investigation. These findings indicate that pulse and press effects of freshwater inflow and associated physicochemical variability play a role in the movements of mulloway, and that seasonality of large freshwater flows may be important in spawning. The possible implications of river regulation and the extraction of freshwater for consumptive uses on estuarine fishes are discussed. PMID:24752585

Estuarine wetland evolution including sea-level rise and infrastructure effects.

NASA Astrophysics Data System (ADS)

Rodriguez, Jose Fernando; Trivisonno, Franco; Rojas, Steven Sandi; Riccardi, Gerardo; Stenta, Hernan; Saco, Patricia Mabel

2015-04-01

Estuarine wetlands are an extremely valuable resource in terms of biotic diversity, flood attenuation, storm surge protection, groundwater recharge, filtering of surface flows and carbon sequestration. On a large scale the survival of these systems depends on the slope of the land and a balance between the rates of accretion and sea-level rise, but local man-made flow disturbances can have comparable effects. Climate change predictions for most of Australia include an accelerated sea level rise, which may challenge the survival of estuarine wetlands. Furthermore, coastal infrastructure poses an additional constraint on the adaptive capacity of these ecosystems. Numerical models are increasingly being used to assess wetland dynamics and to help manage some of these situations. We present results of a wetland evolution model that is based on computed values of hydroperiod and tidal range that drive vegetation preference. Our first application simulates the long term evolution of an Australian wetland heavily constricted by infrastructure that is undergoing the effects of predicted accelerated sea level rise. The wetland presents a vegetation zonation sequence mudflats - mangrove - saltmarsh from the seaward margin and up the topographic gradient but is also affected by compartmentalization due to internal road embankments and culverts that effectively attenuates tidal input to the upstream compartments. For this reason, the evolution model includes a 2D hydrodynamic module which is able to handle man-made flow controls and spatially varying roughness. It continually simulates tidal inputs into the wetland and computes annual values of hydroperiod and tidal range to update vegetation distribution based on preference to hydrodynamic conditions of the different vegetation types. It also computes soil accretion rates and updates roughness coefficient values according to evolving vegetation types. In order to explore in more detail the magnitude of flow attenuation due to

Habitat Mapping and Classification of the Grand Bay National Estuarine Research Reserve using AISA Hyperspectral Imagery

NASA Astrophysics Data System (ADS)

Rose, K.

2012-12-01

Habitat mapping and classification provides essential information for land use planning and ecosystem research, monitoring and management. At the Grand Bay National Estuarine Research Reserve (GRDNERR), Mississippi, habitat characterization of the Grand Bay watershed will also be used to develop a decision-support tool for the NERR's managers and state and local partners. Grand Bay NERR habitat units were identified using a combination of remotely sensed imagery, aerial photography and elevation data. Airborne Imaging Spectrometer for Applications (AISA) hyperspectral data, acquired 5 and 6 May 2010, was analyzed and classified using ENVI v4.8 and v5.0 software. The AISA system was configured to return 63 bands of digital imagery data with a spectral range of 400 to 970 nm (VNIR), spectral resolution (bandwidth) at 8.76 nm, and 1 m spatial resolution. Minimum Noise Fraction (MNF) and Inverse Minimum Noise Fraction were applied to the data prior to using Spectral Angle Mapper ([SAM] supervised) and ISODATA (unsupervised) classification techniques. The resulting class image was exported to ArcGIS 10.0 and visually inspected and compared with the original imagery as well as auxiliary datasets to assist in the attribution of habitat characteristics to the spectral classes, including: National Agricultural Imagery Program (NAIP) aerial photography, Jackson County, MS, 2010; USFWS National Wetlands Inventory, 2007; an existing GRDNERR habitat map (2004), SAV (2009) and salt panne (2002-2003) GIS produced by GRDNERR; and USACE lidar topo-bathymetry, 2005. A field survey to validate the map's accuracy will take place during the 2012 summer season. ENVI's Random Sample generator was used to generate GIS points for a ground-truth survey. The broad range of coastal estuarine habitats and geomorphological features- many of which are transitional and vulnerable to environmental stressors- that have been identified within the GRDNERR point to the value of the Reserve for

Relating watershed nutrient loads to satellite derived estuarine water quality

EPA Science Inventory

Nutrient enhanced phytoplankton production is a cause of degraded estuarine water quality. Yet, relationships between watershed nutrient loads and the spatial and temporal scales of phytoplankton blooms and subsequent water quality impairments remain unquantified for most systems...

LANDSCAPE METRICS THAT ARE USEFUL FOR EXPLAINING ESTUARINE ECOLOGICAL RESPONSES

EPA Science Inventory

We investigated whether land use/cover characteristics of watersheds associated with estuaries exhibit a strong enough signal to make landscape metrics useful for predicting estuarine ecological condition. We used multivariate logistic regression models to discriminate between su...

Lower Columbia River and Estuary Ecosystem Restoration Program Reference Site Study: 2011 Restoration Analysis - FINAL REPORT

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

Borde, Amy B.; Cullinan, Valerie I.; Diefenderfer, Heida L.

The Reference Site (RS) study is part of the research, monitoring, and evaluation (RME) effort developed by the Action Agencies (Bonneville Power Administration [BPA], U.S. Army Corps of Engineers, Portland District [USACE], and U.S. Bureau of Reclamation) in response to Federal Columbia River Power System (FCRPS) Biological Opinions (BiOp). While the RS study was initiated in 2007, data have been collected at relatively undisturbed reference wetland sites in the LCRE by PNNL and collaborators since 2005. These data on habitat structural metrics were previously summarized to provide baseline characterization of 51 wetlands throughout the estuarine and tidal freshwater portions ofmore » the 235-km LCRE; however, further analysis of these data has been limited. Therefore, in 2011, we conducted additional analyses of existing field data previously collected for the Columbia Estuary Ecosystem Restoration Program (CEERP) - including data collected by PNNL and others - to help inform the multi-agency restoration planning and ecosystem management work underway in the LCRE.« less

Winnowing and Flocculation in Bio-physical Cohesive Substrate: A Flume Experimental and Estuarine Study

NASA Astrophysics Data System (ADS)

Ye, L.; Parsons, D. R.; Manning, A. J.

2016-12-01

Cohesive sediment, or mud, is ubiquitously found in most aqueous environments, such as coasts and estuaries. The study of cohesive sediment behaviors requires the synchronous description of mutual interactions of grains (e.g., winnowing and flocculation), their physical properties (e.g., grain size) and also the ambient water. Herein, a series of flume experiments (14 runs) with different substrate mixtures of sand-clay-EPS (Extracellular Polymeric Substrates: secreted by aquatic microorganisms) are combined with an estuarine field survey (Dee estuary, NW England) to investigate the behavior of suspensions over bio-physical cohesive substrates. The experimental results indicate that winnowing and flocculation occur pervasively in bio-physical cohesive flow systems. Importantly however, the evolution of the bed and bedform dynamics and hence turbulence production can be lower when cohesivity is high. The estuarine survey also revealed that the bio-physical cohesion provided by both the clay and microorganism fractions in the bed, that pervasively exists in many natural estuarine systems, plays a significant role in controlling the interactions between bed substrate and sediment suspension and deposition, including controlling processes such as sediment winnowing, flocculation and re-deposition. Full understanding of these processes are essential in advancing sediment transport modelling and prediction studies across natural estuarine systems and the work will report on an improved conceptual model for sediment sorting deposition in bio-physical cohesive substrates.

A meeting of the waters: interdisciplinary challenges and opportunities in tidal rivers

USGS Publications Warehouse

Ensign, Scott H.; Noe, Gregory B.; Hupp, Cliff R.; Fagherazzi, Sergio

2012-01-01

At the interface of estuarine tides and freshwater rivers lie wetland and aquatic ecosystems, which experience dramatic effects of sea level rise. There, nontidal channels and riparian floodplains are transforming into tidal ecosystems, and tidal freshwater ecosystems are receiving increasing salinity. These river-floodplain systems have both fluvial characteristics, including meandering channels and expansive floodplain forests, and estuarine characteristics, including tides and intertidal wetlands [see Barendregt et al., 2009; Conner et al., 2007, and references therein]. Because tidal rivers lie at the disciplinary divide between fluvial and estuarine science, a knowledge gap has developed in scientists' understanding of the geomorphic and biogeochemical response of these environments to sea level rise, climate change, and anthropogenically driven variations in watershed exports.

Lead distribution in coastal and estuarine sediments around India.

PubMed

Chakraborty, Sucharita; Chakraborty, Parthasarathi; Nath, B Nagender

2015-08-15

This study describes the geochemical distribution of lead (Pb) and identifies the critical factors that significantly control Pb distribution and speciation in coastal and estuarine sediments around India by using published data from the literature. Crustal sources influence the abundance of Pb in coastal sediment from the south-east and central-west coast of India. Parts of north-east, north-west, and south-west coast of India were polluted by Pb. Distribution of Pb in sediments, from the north-east and north-west coasts of India, were controlled by Fe-Mn oxyhydroxide mineral phases of the sediments. However, organic carbon (OC) seemed to be a dominant factor in controlling the distribution of Pb in sediments from the central-east and south-west coasts of India. The outcome of this study may help in decision-making to predict the levels of Pb from natural and anthropogenic sources and to control Pb pollution in coastal and estuarine sediments around India. Copyright © 2015 Elsevier Ltd. All rights reserved.

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.

Method 366.0 Determination of Dissolved Silicate in Estuarine and Coastal Watersby Gas Segmented Continuous Flow Colorimetric Analysis

EPA Science Inventory

This method provides a procedure for the determination of dissolved silicate concentration in estuarine and coastal waters. The dissolved silicate is mainly in the form of silicic acid, H SiO , in estuarine and 4 4 coastal waters. All soluble silicate, including colloidal silici...

Trace elements and heavy metals in the Grand Bay National Estuarine Reserve in the northern Gulf of Mexico

USDA-ARS?s Scientific Manuscript database

The Grand Bay National Estuarine Research Reserve has the highest biotic diversity of habitats and offer a reserve of food resources and commercially significant species. Rapid human civilization has led to accumulation of heavy metals and trace elements in estuaries. The Grand Bay National Estuarin...

Estuarine Macroinvertebrate Pollution Indicator Species in the Virginian Biogeographic Province

EPA Science Inventory

Macroinvertebrates are commonly used as biomonitors to detect pollution impacts in estuaries. In this study we identified estuarine benthic invertebrates that could be used to detect presence or absence of pollution in the Virginian Biogeographic Province using available monitor...

Prozac in the water: Chronic fluoxetine exposure and predation risk interact to shape behaviors in an estuarine crab.

PubMed

Peters, Joseph R; Granek, Elise F; de Rivera, Catherine E; Rollins, Matthew

2017-11-01

Predators exert considerable top-down pressure on ecosystems by directly consuming prey or indirectly influencing their foraging behaviors and habitat use. Prey is, therefore, forced to balance predation risk with resource reward. A growing list of anthropogenic stressors such as rising temperatures and ocean acidification has been shown to influence prey risk behaviors and subsequently alter important ecosystem processes. Yet, limited attention has been paid to the effects of chronic pharmaceutical exposure on risk behavior or as an ecological stressor, despite widespread detection and persistence of these contaminants in aquatic environments. In the laboratory, we simulated estuarine conditions of the shore crab, Hemigrapsus oregonensis, and investigated whether chronic exposure (60 days) to field-detected concentrations (0, 3, and 30 ng/L) of the antidepressant fluoxetine affected diurnal and nocturnal risk behaviors in the presence of a predator, Cancer productus . We found that exposure to fluoxetine influenced both diurnal and nocturnal prey risk behaviors by increasing foraging and locomotor activity in the presence of predators, particularly during the day when these crabs normally stay hidden. Crabs exposed to fluoxetine were also more aggressive, with a higher frequency of agonistic interactions and increased mortality due to conflicts with conspecifics. These results suggest that exposure to field-detected concentrations of fluoxetine may alter the trade-off between resource acquisition and predation risk among crabs in estuaries. This fills an important data gap, highlighting how intra- and interspecific behaviors are altered by exposure to field concentrations of pharmaceuticals; such data more explicitly identify potential ecological impacts of emerging contaminants on aquatic ecosystems and can aid water quality management.

Synoptic events force biological productivity in Patagonian fjord ecosystems

NASA Astrophysics Data System (ADS)

Daneri, Giovanni

2016-04-01

The annual cycle of primary productivity of the Patagonian fjords has, to date, been described as a two phase system consisting of a short non productive winter phase (during June and July) and a productive phase extending from late winter (August) to autumn (May). Low levels of primary production, phytoplankton biomass and high concentrations of surface nutrients have been described as characterizing winter conditions while pulsed productivity events typifies the productivity pattern during the extended productive season. Pulsed productivity events characterize coastal waters where inorganic nutrients in surface layers are replenished following periods of intensive utilization by autotrophs. Freshwater input in Patagonian fjords in southern Chile (41-55°S) results in one of the largest estuarine regions worldwide. Here strong haline water column stratification prevents nutrient mixing to the surface layers thus potentially shutting off algal production. Our working hypothesis considered that in order to reconcile the observed pulsed productivity pattern, periodic breaking (associated to surface nutrient replenishment) and re-establishment of estuarine conditions (associated to water column stratification) would be required. Up to now however our understanding of the physical processes that control water column conditions in the Patagonian fjord area has been extremely limited. Here we present evidence linking the passage of synoptic low pressure fronts to pulsed productivity events in the Patagonian fjord area. These front controls and influence local processes of interaction between the fjord and the atmosphere generating a rapid water column response. In the specific case of the Puyuhuapi fjord we have been able to show that such synoptic fronts induce surface flow reversal and water column mixing. Phytoplankton blooming occurs after the passage of the synoptic front once calmer conditions prevail and estuarine conditions are re established. The occurrence of

Expected effects of residual chlorine and nitrogen in sewage effluent on an estuarine pelagic ecosystem

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

Hattis, D.; Lemerise, A.; Ratick, S.

1995-12-31

The authors used physical, toxicological, and system dynamic modeling tools to estimate the probable ecological effects caused by residual chlorine and nitrogen in sewage effluent discharged into Greenwich Cove, RI, USA. An energy systems model of the pelagic ecosystem in Narragansett Bay was developed and adapted for use in Greenwich Cove. This model allowed them to assess the indirect effects on organisms in the food web that result from a direct toxic effect on a given organism. Indirect food web mediated effects were the primary mode of loss for bluefish, but not for menhaden. The authors chose gross primary production,more » the flux of carbon to the benthos, fish out-migration, and fish harvest as outcome variables indicative of different valuable ecosystem functions. Organism responses were modeled using an assumption that lethal toxic responses occur as individual organism thresholds are exceeded, and that in general thresholds are lognormally distributed in a population of mixed individuals. They performed sensitivity analyses to assess the implications of different plausible values for the probit slopes used in the model. The putative toxic damage repair rate, combined with estimates of the exposure variability for each species, determined the averaging time that was likely to be most important in producing toxicity. Temperature was an important external factor in the physical, toxicological, and ecological models. These three models can be integrated into a single model applicable to other locations and stressors given the availability of appropriate data.« less

Defense Coastal/Estuarine Research Program (DCERP) Strategic Plan

DTIC Science & Technology

2007-09-01

atmospheric deposition. The source apportionment of nutrients from atmospheric deposition (especially nitrogen) to estuarine waters derived from direct...migrating wildlife, and nutrient release from soil weathering, atmospheric deposition represents the only source of new nutrients into the... apportionment to properly assess the contributions of off-site and on-site emission sources to regional levels of PM2.5. In preparing this DCERP Strategic

2016 Draft Estuarine/Marine Copper Aquatic Life Ambient Water Quality Criteria

EPA Pesticide Factsheets

Documents pertain to Aquatic Life Ambient Water Quality criteria for Copper (2016 Estuarine/marine). These documents contain the safe levels of Copper in water that should protect to the majority of species.

Low Functional β-Diversity Despite High Taxonomic β-Diversity among Tropical Estuarine Fish Communities

PubMed Central

Villéger, Sébastien; Miranda, Julia Ramos; Hernandez, Domingo Flores; Mouillot, David

2012-01-01

The concept of β-diversity, defined as dissimilarity among communities, has been widely used to investigate biodiversity patterns and community assembly rules. However, in ecosystems with high taxonomic β-diversity, due to marked environmental gradients, the level of functional β-diversity among communities is largely overlooked while it may reveal processes shaping community structure. Here, decomposing biodiversity indices into α (local) and γ (regional) components, we estimated taxonomic and functional β-diversity among tropical estuarine fish communities, through space and time. We found extremely low functional β-diversity values among fish communities (<1.5%) despite high dissimilarity in species composition and species dominance. Additionally, in contrast to the high α and γ taxonomic diversities, α and γ functional diversities were very close to the minimal value. These patterns were caused by two dominant functional groups which maintained a similar functional structure over space and time, despite the strong dissimilarity in taxonomic structure along environmental gradients. Our findings suggest that taxonomic and functional β-diversity deserve to be quantified simultaneously since these two facets can show contrasting patterns and the differences can in turn shed light on community assembly rules. PMID:22792395

Benthic and Pelagic Pathways of Methylmercury Bioaccumulation in Estuarine Food Webs of the Northeast United States

PubMed Central

Chen, Celia Y.; Borsuk, Mark E.; Bugge, Deenie M.; Hollweg, Terill; Balcom, Prentiss H.; Ward, Darren M.; Williams, Jason; Mason, Robert P.

2014-01-01

Methylmercury (MeHg) is a contaminant of global concern that bioaccumulates and bioamagnifies in marine food webs. Lower trophic level fauna are important conduits of MeHg from sediment and water to estuarine and coastal fish harvested for human consumption. However, the sources and pathways of MeHg to these coastal fisheries are poorly known particularly the potential for transfer of MeHg from the sediment to biotic compartments. Across a broad gradient of human land impacts, we analyzed MeHg concentrations in food webs at ten estuarine sites in the Northeast US (from the Hackensack Meadowlands, NJ to the Gulf of Maine). MeHg concentrations in water column particulate material, but not in sediments, were predictive of MeHg concentrations in fish (killifish and Atlantic silversides). Moreover, MeHg concentrations were higher in pelagic fauna than in benthic-feeding fauna suggesting that MeHg delivery to the water column from methylation sites from within or outside of the estuary may be an important driver of MeHg bioaccumulation in estuarine pelagic food webs. In contrast, bulk sediment MeHg concentrations were only predictive of concentrations of MeHg in the infaunal worms. Our results across a broad gradient of sites demonstrate that the pathways of MeHg to lower trophic level estuarine organisms are distinctly different between benthic deposit feeders and forage fish. Thus, even in systems with contaminated sediments, transfer of MeHg into estuarine food webs maybe driven more by the efficiency of processes that determine MeHg input and bioavailability in the water column. PMID:24558491

Identification and characterisation of isoprene-degrading bacteria in an estuarine environment.

PubMed

Johnston, Antonia; Crombie, Andrew T; El Khawand, Myriam; Sims, Leanne; Whited, Gregg M; McGenity, Terry J; Colin Murrell, J

2017-09-01

Approximately one-third of volatile organic compounds (VOCs) emitted to the atmosphere consists of isoprene, originating from the terrestrial and marine biosphere, with a profound effect on atmospheric chemistry. However, isoprene provides an abundant and largely unexplored source of carbon and energy for microbes. The potential for isoprene degradation in marine and estuarine samples from the Colne Estuary, UK, was investigated using DNA-Stable Isotope Probing (DNA-SIP). Analysis at two timepoints showed the development of communities dominated by Actinobacteria including members of the genera Mycobacterium, Rhodococcus, Microbacterium and Gordonia. Representative isolates, capable of growth on isoprene as sole carbon and energy source, were obtained from marine and estuarine locations, and isoprene-degrading strains of Gordonia and Mycobacterium were characterised physiologically and their genomes were sequenced. Genes predicted to be required for isoprene metabolism, including four-component isoprene monooxygenases (IsoMO), were identified and compared with previously characterised examples. Transcriptional and activity assays of strains growing on isoprene or alternative carbon sources showed that growth on isoprene is an inducible trait requiring a specific IsoMO. This study is the first to identify active isoprene degraders in estuarine and marine environments using DNA-SIP and to characterise marine isoprene-degrading bacteria at the physiological and molecular level. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

Chronic genetic damages in Geophagus brasiliensis exposed to anthropic impact in estuarine lakes at Santa Catarina coast--southern of Brazil.

PubMed

Benincá, Cristiane; Ramsdorf, Wanessa; Vicari, Taynah; de Oliveira Ribeiro, Ciro A; de Almeida, Marina I; Silva de Assis, Helena C; Cestari, Marta Margarete

2012-04-01

Biological monitoring through animals exposed to pollutants using biomarkers provides a promising tool for the identification of pollutants that may cause damage to human health and/or to sustainability of ecosystems. The effects of pollutants in fish tissues are important tools to understand the impact of human activities in natural ecosystems. The aim of this work was to study the water quality of two estuarine lakes in Santa Catarina, Brazil (Camacho Lake and Santa Marta Lake). Geophagus brasiliensis is a species widely distributed in Brazil and was used in this work. Comet assays in peripheral red blood and kidney cells, micronucleus tests in peripheral red blood cells, measurements of acetylcholinesterase activity in axial muscle and histopathological analysis of liver were used as biomarkers. Three sampling campaigns were undertaken in November 2004, June 2005 and November 2005. Thirty adult animals were sampled from each of three different sites (P1--Santa Marta Lake, P2 and P3--Camacho Lake). A negative control was sampled in a non-polluted site at Costa Ecological Park, Paraná. The positive control for genotoxicity was obtained by treating animals with copper sulphate. The results showed that both studied lakes are impacted by potential genotoxic substances. Severe lesions in liver of G. brasiliensis were also observed. The inhibition of acetylcholinesterase activity suggests the presence of pesticides or metals in the studied sites. This work shows that the water quality of Santa Marta and Camacho Lakes have been compromised and further control source of pollutants into these ecosystems is required.

Quantifying Atlantic Menhaden in Estuarine and Coastal Waters of Long Island, New York Using Acoustic Methods

NASA Astrophysics Data System (ADS)

Lucca, Brandyn Mark

Forage fish are an ecological cornerstone that trophically link primary production with pelagic predators such as piscivorous fish, marine mammals, seabirds, and humans. Atlantic menhaden (Brevoortia tyrannus) are one such forage fish species that can be found in both estuarine and coastal waters from the Gulf of Maine to Florida throughout the year. Alongside their ecological importance as prey for commercially important species such as striped bass and bluefin tuna, menhaden are fished to be used as bait or reduced into oil. New York has an especially rich history with the commercial harvesting of menhaden beginning in the late 17th century. Despite their relative ecological and economic importance, there is a paucity of quantitative data that describes the spatial and temporal distributions of menhaden in many regions throughout their geographic range. A promising method to study the distribution of menhaden is active acoustics which has been utilized in other fisheries to provide relatively time-efficient quantitative data with broad spatial coverage and high resolution. Acoustic surveys were conducted in two different habitats (estuarine, coastal) where menhaden are found during the 2014 and 2015. Menhaden aggregations were very patchy and there was evidence of significant clustering in both habitats. Coastal menhaden abundance and biomass were relatively constant throughout the summer with a peak in the late-summer. Conversely, estuarine menhaden abundance and biomass biomass peaked in late-spring and early-fall, and decreased by three orders of magnitude by mid-fall. Mean target strength (TS) of coastal menhaden was relatively constant which suggested no differences in the size classes of fish. Conversely estuarine TS distributions shifted throughout the sampling effort which were consistent with changes in the size classes of fish as they grow and migrate in and out of the estuarine habitat. This study demonstrates that active acoustics is a viable tool for

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,...

Climatically sensitive transfer of iron to maritime Antarctic ecosystems by surface runoff

PubMed Central

Hodson, Andy; Nowak, Aga; Sabacka, Marie; Jungblut, Anne; Navarro, Francisco; Pearce, David; Ávila-Jiménez, María Luisa; Convey, Peter; Vieira, Gonçalo

2017-01-01

Iron supplied by glacial weathering results in pronounced hotspots of biological production in an otherwise iron-limited Southern Ocean Ecosystem. However, glacial iron inputs are thought to be dominated by icebergs. Here we show that surface runoff from three island groups of the maritime Antarctic exports more filterable (<0.45 μm) iron (6–81 kg km−2 a−1) than icebergs (0.0–1.2 kg km−2 a−1). Glacier-fed streams also export more acid-soluble iron (27.0–18,500 kg km−2 a−1) associated with suspended sediment than icebergs (0–241 kg km−2 a−1). Significant fluxes of filterable and sediment-derived iron (1–10 Gg a−1 and 100–1,000 Gg a−1, respectively) are therefore likely to be delivered by runoff from the Antarctic continent. Although estuarine removal processes will greatly reduce their availability to coastal ecosystems, our results clearly indicate that riverine iron fluxes need to be accounted for as the volume of Antarctic melt increases in response to 21st century climate change. PMID:28198359

INDEX OF ESTUARINE BENTHIC INTEGRITY FOR GULF OF MEXICO ESTUARIES

EPA Science Inventory

A benthic index for northern Gulf of Mexico estuaries has been developed and successfully validated by the Environmental Monitoring and Assessment Program for Estuaries (EMAP-E) in the Louisianian Province. The benthic index is a useful indicator of estuarine condition that provi...

Simulating effects of highway embankments on estuarine circulation

USGS Publications Warehouse

Lee, Jonathan K.; Schaffranek, Raymond W.; Baltzer, Robert A.

1994-01-01

A two-dimensional depth-averaged, finite-difference, numerical model was used to simulate tidal circulation and mass transport in the Port Royal Sound. South Carolina, estuarine system. The purpose of the study was to demonstrate the utility of the Surface-Water. Integrated. Flow and Transport model (SWIFT2D) for evaluating changes in circulation patterns and mass transport caused by highway-crossing embankments. A model of subregion of Port Royal Sound including the highway crossings and having a grid size of 61 m (200ft) was derived from a 183-m (600-ft) model of the entire Port Royal Sound estuarine system. The 183-m model was used to compute boundary-value data for the 61-m submodel, which was then used to simulate flow conditions with and without the highway embankments in place. The numerical simulations show that, with the highway embankment in place, mass transport between the Broad River and Battery Creek is reduced and mass transport between the Beaufort River and Battery Creek is increased. The net result is that mass transport into and out of upper Battery Creek is reduced. The presence of the embankments also alters circulation patterns within Battery Creek.

Influence of the invasive Asian clam Corbicula fluminea (Bivalvia: Corbiculidae) on estuarine epibenthic assemblages

NASA Astrophysics Data System (ADS)

Ilarri, M. I.; Souza, A. T.; Antunes, C.; Guilhermino, L.; Sousa, R.

2014-04-01

One of the most widespread invasive alien species (IAS) in aquatic ecosystems is the Asian clam Corbicula fluminea. Several studies have shown that C. fluminea can cause large-scale changes in macrozoobenthic assemblages; however, very few attempted to investigate the effects of this IAS on mobile epibenthic species, such as fishes and crustaceans. In this context, the influence of C. fluminea on epibenthic species was investigated during one year by comparing the associated epibenthic fauna in three nearby sites of the Minho estuary (NW of the Iberian Peninsula), wherein the abiotic conditions are similar but the density of the Asian clam is highly different. From a total of 13 species, six were significantly influenced by C. fluminea; five responded positively, namely the brown shrimp Crangon crangon, the European eel Anguilla anguilla, the common goby Pomatoschistus microps, the brown trout Salmo trutta fario and the great pipefish Syngnathus acus, whereas the shore crab Carcinus maenas was negatively influenced. However, stomach contents analysis revealed that fish and crustacean species do not feed on C. fluminea, suggesting that this IAS is still not a large component of the diet of higher trophic levels in this estuarine ecosystem. Our results suggest that the structure provided by C. fluminea shells is likely to be one of the main factors responsible for the differences observed. C. fluminea physical structure seems to influence the epibenthic associated fauna, when found in densities higher than 1000 ind./m2, with sedentary small-bodied crustaceans and fishes being mainly attracted by the increasing in habitat complexity and consequent enhancement of heterogeneity and shelter availability.

Heavy metal pollution in immobile and mobile components of lentic ecosystems-a review.

PubMed

Meena, Ramakrishnan Anu Alias; Sathishkumar, Palanivel; Ameen, Fuad; Yusoff, Abdull Rahim Mohd; Gu, Feng Long

2018-02-01

With growing population and urbanization, there is an increasing exploitation of natural resources, and this often results to environmental pollution. In this review, the levels of heavy metal in lentic compartments (water, sediment, fishes, and aquatic plants) over the past two decades (1997-2017) have been summarized to evaluate the current pollution status of this ecosystem. In all the compartments, the heavy metals dominated are zinc followed by iron. The major reason could be area mineralogy and lithogenic sources. Enormous quantity of metals like iron in estuarine sediment is a very natural incident due to the permanently reducing condition of organic substances. Contamination of cadmium, lead, and chromium was closely associated with anthropogenic origin. In addition, surrounding land use and atmospheric deposition could have been responsible for substantial pollution. The accumulation of heavy metals in fishes and aquatic plants is the result of time-dependent deposition in lentic ecosystems. Moreover, various potential risk assessment methods for heavy metals were discussed. This review concludes that natural phenomena dominate the accumulation of essential heavy metals in lentic ecosystems compared to anthropogenic sources. Amongst other recent reviews on heavy metals from other parts of the world, the present review is executed in such a way that it explains the presence of heavy metals not only in water environment, but also in the whole of the lentic system comprising sediment, fishes, and aquatic plants.

Infrastructure effects on estuarine wetlands increase their vulnerability to sea level rise

NASA Astrophysics Data System (ADS)

Rodriguez, Jose; Saco, Patricia; Sandi, Steven; Saintilan, Neil; Riccardi, Gerardo

2017-04-01

At the regional and global scales, coastal management and planning for future sea level rise scenarios is typically supported by modelling tools that predict the expected inundation extent. These tools rely on a number of simplifying assumptions that, in some cases, may result in important miscalculation of the inundation effects. One of such cases is estuarine wetlands, where vegetation strongly depends on both the magnitude and the timing of inundation. Many coastal wetlands display flow restrictions due to infrastructure or drainage works, which produce alterations to the inundation patterns that can not be captured by conventional models. In this contribution we explore the effects of flow restrictions on inundation patterns under sea level rise conditions in estuarine wetlands. We use a spatially-distributed dynamic wetland ecogeomorphological model that not only incorporates the effects of flow restrictions due to culverts, bridges and weirs as well as vegetation, but also considers that vegetation changes as a consequence of increasing inundation. We also consider the ability of vegetation to capture sediment and produce accretion. We apply our model to an estuarine wetland in Australia and show that our model predicts a much faster wetland loss due to sea level rise than conventional approaches.

Insights on the Optical Properties of Estuarine DOM - Hydrological and Biological Influences.

PubMed

Santos, Luísa; Pinto, António; Filipe, Olga; Cunha, Ângela; Santos, Eduarda B H; Almeida, Adelaide

2016-01-01

Dissolved organic matter (DOM) in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal), the seasonality and the sources of the fraction of DOM that absorbs light (CDOM) were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters. Two sites, representative of the marine and brackish water zones of the estuary, and with different hydrological characteristics, were regularly surveyed along two years, in order to determine the major influences on CDOM properties. Terrestrial-derived compounds are the predominant source of CDOM in the estuary during almost all the year and the two estuarine zones presented distinct amounts, as well as absorbance and fluorescence characteristics. Freshwater inputs have major influence on the dynamics of CDOM in the estuary, in particular at the brackish water zone, where accounted for approximately 60% of CDOM variability. With a lower magnitude, the biological productivity also impacted the optical properties of CDOM, explaining about 15% of its variability. Therefore, climate changes related to seasonal and inter-annual variations of the precipitation amounts might impact the dynamics of CDOM significantly, influencing its photochemistry and the microbiological activities in estuarine systems.

AMBI indices and multivariate approach to assess the ecological health of Vellar-Coleroon estuarine system undergoing various human activities.

PubMed

Sigamani, Sivaraj; Perumal, Murugesan; Arumugam, Silambarasan; Preetha Mini Jose, H M; Veeraiyan, Bharathidasan

2015-11-15

Estuaries receive a considerable amount of pollutants from various sources. Presently an attempt has been made to assess whether the aquaculture discharges and dredging activities alter the ecological conditions of Vellar-Coleroon estuarine complex. The European Water Framework Directive (WFD) established a framework for the protection of marine waters. In this commission, a variety of indices were used, among them, AMBI (AZTI Marine Biotic Index) indices along with multivariate statistical approach is unique, to assess the ecological status by using macrobenthic communities. Keeping this in view, stations VE-1 and VE-4 in Vellar; CE-6 and CE-7 in Coleroon estuaries showed moderately disturbed with the AMBI values ranging between 3.45 and 3.72. The above said stations were situated near the shrimp farm discharge point and sites of dredging activities. The present study proves that various statistical and biotic indices have great potential in assessing the nature of the ecosystem undergoing various human pressures. Copyright © 2015 Elsevier Ltd. All rights reserved.

Building Capacity for Collaborative Decisions, Resilient Ecosystems, and Sustainable Practices: Water, Land, Communtiy and People in Estuarine Watersheds

EPA Science Inventory

Population growth, urban expansion, and the warming climate have and will continue to stress our coastal ecosystems. Decisions on how and when to respond with stewardship, adaptation, and mitigation are made by individuals, municipalities, states, and agencies. These decisions ...

Rain reverses diel activity rhythms in an estuarine teleost

PubMed Central

Payne, Nicholas L.; van der Meulen, Dylan E.; Gannon, Ruan; Semmens, Jayson M.; Suthers, Iain M.; Gray, Charles A.; Taylor, Matthew D.

2013-01-01

Activity rhythms are ubiquitous in nature, and generally synchronized with the day–night cycle. Several taxa have been shown to switch between nocturnal and diurnal activity in response to environmental variability, and these relatively uncommon switches provide a basis for greater understanding of the mechanisms and adaptive significance of circadian (approx. 24 h) rhythms. Plasticity of activity rhythms has been identified in association with a variety of factors, from changes in predation pressure to an altered nutritional or social status. Here, we report a switch in activity rhythm that is associated with rainfall. Outside periods of rain, the estuarine-associated teleost Acanthopagrus australis was most active and in shallower depths during the day, but this activity and depth pattern was reversed in the days following rain, with diurnality restored as estuarine conductivity and turbidity levels returned to pre-rain levels. Although representing the first example of a rain-induced reversal of activity rhythm in an aquatic animal of which we are aware, our results are consistent with established models on the trade-offs between predation risk and foraging efficiency. PMID:23173211

Environmental influences on the spatial ecology and spawning behaviour of an estuarine-resident fish, Macquaria colonorum

NASA Astrophysics Data System (ADS)

Walsh, C. T.; Reinfelds, I. V.; Ives, M. C.; Gray, C. A.; West, R. J.; van der Meulen, D. E.

2013-02-01

Estuarine-resident fishes are highly susceptible to the effects of environmental and anthropogenic impacts on their assemblages and habitats. We investigated the distribution, movement and spawning behaviour of estuary perch, Macquaria colonorum, in response to selected environmental variables using an acoustic telemetry array in a large tidal river in south-eastern (SE) Australia. Adult M. colonorum were monitored for up to two years, covering two consecutive spawning periods between September 2007 and 2009. Salinity, water temperature and river flows all had a significant relationship with their estuarine distribution. In particular, large-scale movements were influenced by large freshwater inflow events and the resultant reduction in salinity levels, together with the seasonal cooling and warming trends in water temperatures associated with spawning behaviour. During the winter months, male and female M. colonorum migrated from their upper estuarine home ranges to the lower estuarine spawning grounds in synchrony, with numbers of individual visits by both sexes consistently higher in the 'wetter' winter/spring period of 2008. Location, arrival, departure and occupation time within the spawning grounds were similar between sexes and years. Both resident and migrating M. colonorum exhibited strong diel, and to a lesser extent, tidal behavioural patterns, with fish more likely to be detected at night and during the ebb tides. It is postulated that the effect of environmental fluctuations on the distribution and movement of M. colonorum is influenced by behavioural mechanisms in response to osmoregulatory stress, predator-prey interactions and reproductive activity. The results also demonstrate the importance of accounting for autocorrelation inherent in telemetry data, and for developing management strategies that are more robust to the effect of future climate trends on estuarine fish populations.

The diamondback terrapin: The biology, ecology, cultural history, and conservation status of an obligate estuarine turtle

USGS Publications Warehouse

Hart, K.M.; Lee, D.S.; ,

2006-01-01

Ranging from Cape Cod to nearly the Texas-Mexico border, the diamondback terrapin (Malaclemys terrapin) is the only species of North American turtle restricted to estuarine systems. Despite this extensive distribution, its zone of occurrence is very linear, and in places fragmented, resulting in a relatively small total area of occupancy. On a global scale, excluding marine species, few turtles even venture into brackish water on a regular basis, and only two Asian species approach the North American terrapin's dependency on estuarine habitats. Here we describe some of the biological and behavioral adaptations of terrapins that allow them to live in the rather harsh estuarine environment. In this chapter we review the natural and cultural history of this turtle, discuss conservation issues, and provide information on the types of research needed to make sound management decisions for terrapin populations in peril.

Microgobius meeki as a potential bio-indicator of habitat disturbance in shallow estuarine areas: a useful tool for the assessment of estuarine quality.

PubMed

Reis-Filho, J A; Giarrizzo, T

2016-07-01

The relationships between changes in habitat quality (disturbed and undisturbed sites) and the population parameters (density, size distribution, reproductive activity and diet) of a goby Microgobius meeki were investigated in a tropical estuary to assess its value as an indicator of anthropogenic changes, predominantly the effects of sedimentation and mangrove removal in shallow estuarine areas. Fish sampling surveys were conducted bimonthly between June 2009 and May 2010 over the entire estuarine gradient of the Paraguaçu River estuary, located on the central Brazilian coast. A predictive model was developed to assess the population changes of this species in 10 other tropical estuaries with different dimensions, basin features and distinct levels of anthropogenic disturbance. General linear models were used to relate the population structure of M. meeki to sediment type, habitat type resulting from mangrove conservation status, anthropogenic pressure and environmental characteristics such as salinity, dissolved oxygen concentrations and temperature. Sediment type and the presence of mangrove forests were the most effective predictors of local variability in the population structure of M. meeki. Individuals with mature gonads and high rates of feeding activity were associated predominantly with undisturbed habitats. Estuaries and estuarine sectors with high levels of sedimentation in shallow marginal areas, anthropogenic pressure from domestic and industrial effluents, and evidence of mangrove deforestation yielded the lowest capture rates of both juvenile and adult M. meeki. Based on these findings, M. meeki is identified as a potential indicator of the consequences of anthropogenic disturbance in transitional waters. A simple, but efficient collection protocol, in which overt signs of distress can be promptly observed is proposed. Testing the generality of this approach across different systems might prove useful in a broader conservation biology context. �

Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays.

PubMed

Charry, Maria P; Keesing, Vaughan; Costello, Mark; Tremblay, Louis A

2018-01-01

Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus , two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus , and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.

Climate Change, Sea-Level Rise and Implications for Coastal and Estuarine Shoreline Management with Particular Reference to the Ecology of Intertidal Benthic Macrofauna in NW Europe

PubMed Central

Fujii, Toyonobu

2012-01-01

In many European estuaries, extensive areas of intertidal habitats consist of bare mudflats and sandflats that harbour a very high abundance and biomass of macrobenthic invertebrates. The high stocks of macrobenthos in turn provide important food sources for the higher trophic levels such as fish and shorebirds. Climate change and associated sea-level rise will have potential to cause changes in coastal and estuarine physical properties in a number of ways and thereby influence the ecology of estuarine dependent organisms. Although the mechanisms involved in biological responses resulting from such environmental changes are complex, the ecological effects are likely to be significant for the estuarine benthic macrofauna and hence the consumers they support. This paper reviews the utilisation patterns of estuarine intertidal habitats by shorebirds, fish and crustaceans, as well as factors affecting the distribution, abundance and biomass of estuarine macrobenthos that is known to be important food source for these estuarine predators. This study also provides simple conceptual models of the likely impacts of sea-level rise on the physical and biological elements of estuarine intertidal habitats, and implications of these results are discussed in the context of sustainable long term flood and coastal management in estuarine environments. PMID:24832510

15 CFR 921.30 - Designation of National Estuarine Research Reserves.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AND COASTAL RESOURCE MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Reserve... protection for reserve resources to ensure a stable environment for research; (3) Designation of the area as... agencies and/or private organizations) have been signed; and (7) The coastal state in which the area is...

15 CFR 921.30 - Designation of National Estuarine Research Reserves.

Code of Federal Regulations, 2012 CFR

2012-01-01

... AND COASTAL RESOURCE MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Reserve... protection for reserve resources to ensure a stable environment for research; (3) Designation of the area as... agencies and/or private organizations) have been signed; and (7) The coastal state in which the area is...

15 CFR 921.30 - Designation of National Estuarine Research Reserves.

Code of Federal Regulations, 2011 CFR

2011-01-01

... AND COASTAL RESOURCE MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Reserve... protection for reserve resources to ensure a stable environment for research; (3) Designation of the area as... agencies and/or private organizations) have been signed; and (7) The coastal state in which the area is...

15 CFR 921.30 - Designation of National Estuarine Research Reserves.

Code of Federal Regulations, 2013 CFR

2013-01-01

... AND COASTAL RESOURCE MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Reserve... protection for reserve resources to ensure a stable environment for research; (3) Designation of the area as... agencies and/or private organizations) have been signed; and (7) The coastal state in which the area is...

15 CFR 921.30 - Designation of National Estuarine Research Reserves.

Code of Federal Regulations, 2014 CFR

2014-01-01

... AND COASTAL RESOURCE MANAGEMENT NATIONAL ESTUARINE RESEARCH RESERVE SYSTEM REGULATIONS Reserve... protection for reserve resources to ensure a stable environment for research; (3) Designation of the area as... agencies and/or private organizations) have been signed; and (7) The coastal state in which the area is...

The Effects of Acidic and Hypoxic Conditions on the Estuarine Organisms Cyprinodon variegatus (Sheepshead Minnow) and Americamysis bahia (Mysid Shrimp)

EPA Science Inventory

The interactive and combined effects of coastal acidification and hypoxia on estuarine species is an increasing concern as these stressors change concomitantly. There is a need to understand how these environmental factors interact, as well as their effect on estuarine organisms....

CHEMOSENSORY ATTRACTION OF ZOOSPORES OF THE ESTUARINE DINOFLAGELLATES, PFIESTERIA PISCICIDA AND P. SHUMWAYAE, TO FINFISH MUCUS AND EXCRETA. (R825551)

EPA Science Inventory

Toxic strains of the estuarine dinoflagellates, Pfiesteria piscicida and P. shumwayae, can cause fish death and disease, whereas other estuarine `lookalike' species such as cryptoperidiniopsoids have not been ichthyotoxic under ecologically rel...

Applications of HCMM data to soil moisture snow and estuarine current studies. [Cooper River and Delaware Bay

NASA Technical Reports Server (NTRS)

Wiesnet, D. R. (Principal Investigator); Mcginnis, D. F.; Matson, M.

1980-01-01

The author has identified the following significant results. The HCMM thermal data are useful for monitoring estuarine surface thermal patterns. Estuarine thermal patterns, are, under certain conditions, indicative of the surface tidal current circulation patterns. Under optimum conditions, estuaries as small as the Cooper River (i.e., approximately 100 sq km) can be monitored for tidal/thermal circulation patterns by HCMM-type IR sensors.

Variation in ultrafiltered and LMW organic matter fluorescence properties under simulated estuarine mixing transects: 1. Mixing alone

NASA Astrophysics Data System (ADS)

Boyd, Thomas J.; Barham, Bethany P.; Hall, Gregory J.; Osburn, Christopher L.

2010-09-01

Ultrafiltered and low molecular weight dissolved organic matter (UDOM and LMW-DOM, respectively) fluorescence was studied under simulated estuarine mixing using samples collected from Delaware, Chesapeake, and San Francisco Bays (USA) transects. UDOM was concentrated by tangential flow ultrafiltration (TFF) from the marine (>33 PSU), mid-estuarine (˜16 PSU), and freshwater (<1 PSU) members. TFF permeates (<1 kDa) from the three members were used to create artificial salinity transects ranging from ˜0 to ˜36, with 4 PSU increments. UDOM from the end- or mid-members was added in equal amounts to each salinity-mix. Three-dimensional fluorescence excitation-emission matrix (EEMs) spectra were generated for each end-member permeate and UDOM through the full estuarine mixing transect. Fluorescence components such as proteinaceous, terrigenous, and marine derived humic peaks, and certain fluorescent ratios were noticeably altered by simulated estuarine mixing, suggesting that LMW DOM and UDOM undergo physicochemical alteration as they move to or from the freshwater, mid-estuarine, or coastal ocean members. LMW fluorescence components fit a decreasing linear mixing model from mid salinities to the ocean end-member, but were more highly fluorescent than mixing alone would predict in lower salinities (<8). Significant shifts were also seen in UDOM peak emission wavelengths with blue-shifting toward the ocean end-member. Humic-type components in UDOM generally showed lower fluorescent intensities at low salinities, higher at mid-salinities, and lower again toward the ocean end-member. T (believed to be proteinaceous) and N (labile organic matter) peaks behaved similarly to each other, but not to B peak fluorescence, which showed virtually no variation in permeate or UDOM mixes with salinity. PCA and PARAFAC models showed similar results suggesting trends could be modeled for DOM end- and mid-member sources. Changes in fluorescence properties due to estuarine mixing may be

RELEVANCE OF ROOTED VASCULAR PLANTS AS INDICATORS OF ESTUARINE SEDIMENT QUALITY

EPA Science Inventory

Toxicity assessments and numerical quality assessment guidelines for estuarine sediments are rarely based on information for aquatic plants. The effect of this lack of information on contaminated sediment evaluations is largely unknown. For this reason, the toxicities of whole se...

MICROBIAL DIVERSITY IN SURFACE SEDIMENTS: A COMPARISON OF TWO ESTUARINE CONTINUUMS

EPA Science Inventory

The microbial diversity in estuarine sediments of the Altamaha and Savannah Rivers in Georgia were compared temporally and spatially using phospholipid fatty acid (PLFA) analysis. Surface sediment samples collected along a salinity gradient were also analyzed for ATP, TOC, and C ...

Indicators of nutrient pollution in Long Island, New York, estuarine environments

EPA Science Inventory

Roughly eight million people live on Long Island, including Brooklyn and Queens, and despite improvements in wastewater treatment, nearly all its coastal waterbodies are impaired by excessive nitrogen. We used nutrient stoichiometry and stable isotope ratios in estuarine biota an...

Estuarine fish and turtles as intermediate and paratenic hosts of Gnathostoma binucleatum in Nayarit, Mexico.

PubMed

Guerrero, Cesar Alvarez; Alba-Hurtado, Fernando

2007-12-01

Human gnathostomosis is a severe public health problem in the State of Nayarit, Mexico. Between 1995 and 2005, the registration of human cases numbered 6,328, which makes it one of the largest focal points of the disease in the country. The present study determined the presence of natural hosts of Gnathostoma binucleatum larvae at the Laguna de Agua Brava in Nayarit, Mexico. A total of 5,450 fish and 247 turtles were sampled. Muscular tissue was ground and observed against the light using a 100-W lamp to identify advanced third-stage larvae. The estuarine species Cathorops fuerthii, Pomadasys macracanthus, Mugil curema, and Dormitator latifrons were found positive for presence of larvae, and annual prevalence was 4.8, 1.83, 2.16, and 4.0%, respectively. The species Oreochromys aureus and Chanos chanos were negative. The species of estuarine turtles Kinosternum integrum and Trachemys scripta were positive with annual prevalence of 79.1 and 52.5%, respectively. The criteria of identification of the Gnathostoma species were: mean number of nuclei in intestinal larval cells (2.3), larval morphometry with optic microscopy, larval morphometry with scanning electron microscopy, and number and sequence of ribosomal deoxyribonucleic acid of adult parasites obtained from experimental infection in dogs. The estuarine fish Pomadasys macracanthus and Mugil curema are reported as intermediate hosts for the first time and likewise the estuarine turtle Kinosternon integrum as a paratenic host.

Net ecosystem production and organic carbon balance of U.S. East Coast estuaries: A synthesis approach

USGS Publications Warehouse

Herrmann, Maria; Najjar, Raymond G.; Kemp, W. Michael; Alexander, Richard B.; Boyer, Elizabeth W.; Cai, Wei-Jun; Griffith, Peter C.; Kroeger, Kevin D.; McCallister, S. Leigh; Smith, Richard A.

2015-01-01

Net ecosystem production (NEP) and the overall organic carbon budget for the estuaries along the East Coast of the United States are estimated. We focus on the open estuarine waters, excluding the fringing wetlands. We developed empirical models relating NEP to loading ratios of dissolved inorganic nitrogen to total organic carbon, and carbon burial in the sediment to estuarine water residence time and total nitrogen input across the landward boundary. Output from a data-constrained water quality model was used to estimate inputs of total nitrogen and organic carbon to the estuaries across the landward boundary, including fluvial and tidal-wetland sources. Organic carbon export from the estuaries to the continental shelf was computed by difference, assuming steady state. Uncertainties in the budget were estimated by allowing uncertainties in the supporting model relations. Collectively, U.S. East Coast estuaries are net heterotrophic, with the area-integrated NEP of −1.5 (−2.8, −1.0) Tg C yr−1 (best estimate and 95% confidence interval) and area-normalized NEP of −3.2 (−6.1, −2.3) mol C m−2 yr−1. East Coast estuaries serve as a source of organic carbon to the shelf, exporting 3.4 (2.0, 4.3) Tg C yr−1 or 7.6 (4.4, 9.5) mol C m−2 yr−1. Organic carbon inputs from fluvial and tidal-wetland sources for the region are estimated at 5.4 (4.6, 6.5) Tg C yr−1 or 12 (10, 14) mol C m−2 yr−1 and carbon burial in the open estuarine waters at 0.50 (0.33, 0.78) Tg C yr−1 or 1.1 (0.73, 1.7) mol C m−2 yr−1. Our results highlight the importance of estuarine systems in the overall coastal budget of organic carbon, suggesting that in the aggregate, U.S. East Coast estuaries assimilate (via respiration and burial) ~40% of organic carbon inputs from fluvial and tidal-wetland sources and allow ~60% to be exported to the shelf.

On the use of the nephelometer in estuarine waters

USGS Publications Warehouse

Eaton, A.; Grant, V.; Bricker, O.; Wells, D.

1981-01-01

A study of the problems encountered in nephelometric determinations of suspended sediment loads in the Chesapeake Bay estuary has led to development of a technique which uses nephelometer readings as a guide for sampling at vertical profiles in an estuary. This permits optimum sampling for concentration profiles and allows one to use nephelometer/load ratios to characterize particles. ?? 1981 Estuarine Research Federation.

Occurrence, fate and effects of azoxystrobin in aquatic ecosystems: a review.

PubMed

Rodrigues, Elsa Teresa; Lopes, Isabel; Pardal, Miguel Ângelo

2013-03-01

The use of pesticides for crop protection may result in the presence of toxic residues in environmental matrices. In the aquatic environment, pesticides might freely dissolve in the water or bind to suspended matter and to the sediments, and might be transferred to the organisms' tissues during bioaccumulation processes, resulting in adverse consequences to non-target species. One such group of synthetic organic pesticides widely used worldwide to combat pathogenic fungi affecting plants is the strobilurin chemical group. Whereas they are designed to control fungal pathogens, their general modes of action are not specific to fungi. Consequently, they can be potentially toxic to a wide range of non-target organisms. The present work had the intent to conduct an extensive literature review to find relevant research on the occurrence, fate and effects of azoxystrobin, the first patent of the strobilurin compounds, in aquatic ecosystems in order to identify strengths and gaps in the scientific database. Analytical procedures and existing legislation and regulations were also assessed. Data gathered in the present review revealed that analytical reference standards for the most relevant environmental metabolites of azoxystrobin are needed. Validated confirmatory methods for complex matrices, like sediment and aquatic organisms' tissues, are very limited. Important knowledge of base-line values of azoxystrobin and its metabolites in natural tropical and estuarine/marine ecosystems is lacking. Moreover, some environmental concentrations of azoxystrobin found in the present review are above the Regulatory Acceptable Concentration (RAC) in what concerns risk to aquatic invertebrates and the No Observed Ecologically Adverse Effect Concentration (NOEAEC) reported for freshwater communities. The present review also showed that there are very few data on azoxystrobin toxicity to different aquatic organisms, especially in what concerns estuarine/marine organisms. Besides

NOAA Photo Library - National Estuarine Research Reserve System

Science.gov Websites

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An Estuarine Fish Bioassay for Sensitive Biomonitoring of Oil-related Contamination

EPA Science Inventory

An embryonic and larval bioassay using the estuarine fish, Fundulus heteroclitus, was modified for the rapid detection of bioavailable compounds that act through the aryl hydrocarbon receptor (AhR). The early development of fishes is particularly sensitive to AhR agonists, such ...

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...

Utilizing remote sensing of Thematic Mapper data to improve our understanding of estuarine processes and their influence on the productivity of estuarine-dependent fisheries

NASA Technical Reports Server (NTRS)

Browder, J. A. (Principal Investigator); Rosenthal, A.; May, L. N., Jr.; Bauman, R. H.; Gosselink, J. G.

1985-01-01

The purpose of the project is to refine and validate a probabilistic spatial computer model through the analyses of thematic mapper imagery. The model is designed to determine how the interface between marshland and water changes as marshland is converted to water in a disintegrating marsh. Coastal marshland in Louisiana is disintegrating at the rate of approximately 40 sq mi a year, and an evaluation of the potential impact of this loss on the landings of estuarine-dependent fisheries is needed by fisheries managers. Understanding how marshland-water interface changes as coastal marshland is lost is essential to the process of evaluating fisheries effects, because several studies suggest that the production of estuarine-dependent fish and shellfish may be more closely related to the interface between marshland and water than to acreage of marshland. The need to address this practical problem has provided an opportunity to apply some scientifically interesting new techniques to the analyses of satellite imagery. Progress with the development of these techniques is the subject of this report.

Insights on the Optical Properties of Estuarine DOM – Hydrological and Biological Influences

PubMed Central

Santos, Luísa; Pinto, António; Filipe, Olga; Cunha, Ângela; Santos, Eduarda B. H.

2016-01-01

Dissolved organic matter (DOM) in estuaries derives from a diverse array of both allochthonous and autochthonous sources. In the estuarine system Ria de Aveiro (Portugal), the seasonality and the sources of the fraction of DOM that absorbs light (CDOM) were inferred using its optical and fluorescence properties. CDOM parameters known to be affected by aromaticity and molecular weight were correlated with physical, chemical and meteorological parameters. Two sites, representative of the marine and brackish water zones of the estuary, and with different hydrological characteristics, were regularly surveyed along two years, in order to determine the major influences on CDOM properties. Terrestrial-derived compounds are the predominant source of CDOM in the estuary during almost all the year and the two estuarine zones presented distinct amounts, as well as absorbance and fluorescence characteristics. Freshwater inputs have major influence on the dynamics of CDOM in the estuary, in particular at the brackish water zone, where accounted for approximately 60% of CDOM variability. With a lower magnitude, the biological productivity also impacted the optical properties of CDOM, explaining about 15% of its variability. Therefore, climate changes related to seasonal and inter-annual variations of the precipitation amounts might impact the dynamics of CDOM significantly, influencing its photochemistry and the microbiological activities in estuarine systems. PMID:27195702

Ecosystem consequences of fish parasites

USGS Publications Warehouse

Lafferty, Kevin D.

2008-01-01

In most aquatic ecosystems, fishes are hosts to parasites and, sometimes, these parasites can affect fish biology. Some of the most dramatic cases occur when fishes are intermediate hosts for larval parasites. For example, fishes in southern California estuaries are host to many parasites. The most common of these parasites, Euhaplorchis californiensis, infects the brain of the killifish Fundulus parvipinnis and alters its behaviour, making the fish 10–30 times more susceptible to predation by the birds that serve as its definitive host. Parasites like E. californiensis are embedded in food webs because they require trophic transmission. In the Carpinteria Salt Marsh estuarine food web, parasites dominate the links and comprise substantial amount of biomass. Adding parasites to food webs alters important network statistics such as connectance and nestedness. Furthermore, some free-living stages of parasites are food items for free-living species. For instance, fishes feed on trematode cercariae. Being embedded in food webs makes parasites sensitive to changes in the environment. In particular, fishing and environmental disturbance, by reducing fish populations, may reduce parasite populations. Indirect evidence suggests a decrease in parasites in commercially fished species over the past three decades. In addition, environmental degradation can affect fish parasites. For these reasons, parasites in fishes may serve as indicators of environmental impacts.

Development of an estuarine assessment scheme for the management of a highly urbanised catchment/estuary system, Sydney estuary, Australia.

PubMed

Birch, G F; Gunns, T J; Chapman, D; Harrison, D

2016-05-01

As coastal populations increase, considerable pressures are exerted on estuarine environments. Recently, there has been a trend towards the development and use of estuarine assessment schemes as a decision support tool in the management of these environments. These schemes offer a method by which complex environmental data is converted into a readily understandable and communicable format for informed decision making and effective distribution of limited management resources. Reliability and effectiveness of these schemes are often limited due to a complex assessment framework, poor data management and use of ineffective environmental indicators. The current scheme aims to improve reliability in the reporting of estuarine condition by including a concise assessment framework, employing high-value indicators and, in a unique approach, employing fuzzy logic in indicator evaluation. Using Sydney estuary as a case study, each of the 15 sub-catchment/sub-estuary systems were assessed using the current scheme. Results identified that poor sediment quality was a significant issue in Blackwattle/Rozelle Bay, Iron Cove and Hen and Chicken Bay while poor water quality was of particular concern in Duck River, Homebush Bay and the Parramatta River. Overall results of the assessment scheme were used to prioritise the management of each sub-catchment/sub-estuary assessed with Blackwattle/Rozelle Bay, Homebush Bay, Iron Cove and Duck River considered to be in need of a high priority management response. A report card format, using letter grades, was employed to convey the results of the assessment in a readily understood manner to estuarine managers and members of the public. Letter grades also provide benchmarking and performance monitoring ability, allowing estuarine managers to set improvement targets and assesses the effectiveness of management strategies. The current assessment scheme provides an effective, integrated and consistent assessment of estuarine health and

[Resolving excitation emission matrix spectroscopy of estuarine CDOM with parallel factor analysis and its application in organic pollution monitoring].

PubMed

Guo, Wei-Dong; Huang, Jian-Ping; Hong, Hua-Sheng; Xu, Jing; Deng, Xun

2010-06-01

The distribution and estuarine behavior of fluorescent components of chromophoric dissolved organic matter (CDOM) from Jiulong Estuary were determined by fluorescence excitation emission matrix spectroscopy (EEMs) combined with parallel factor analysis (PARAFAC). The feasibility of these components as tracers for organic pollution in estuarine environments was also evaluated. Four separate fluorescent components were identified by PARAFAC, including three humic-like components (C1: 240, 310/382 nm; C2: 230, 250, 340/422 nm; C4: 260, 390/482 nm) and one protein-like components (C3: 225, 275/342 nm). These results indicated that UV humic-like peak A area designated by traditional "peak-picking method" was not a single peak but actually a combination of several fluorescent components, and it also had inherent links to so-called marine humic-like peak M or terrestrial humic-like peak C. Component C2 which include peak M decreased with increase of salinity in Jiulong Estuary, demonstrating that peak M can not be thought as the specific indicator of the "marine" humic-like component. Two humic-like components C1 and C2 showed additional behavior in the turbidity maximum region (salinity < 6) and then conservative mixing behavior for the rest estuarine region, while humic-like components C4 showed conservative mixing behavior for the whole estuarine region. However, the protein-like component C3 showed nonconservative mixing behavior, suggesting it had autochthonous estuarine origin. EEMs-PARAFAC can provide fluorescent fingerprint to differentiate the DOM features for three tributaries of Jiulong River. The observed linear relationships between humic-like components and absorption coefficient a (280) with chemical oxygen demand (COD) and biological oxygen demand (BOD5) suggest that the optical properties of CDOM may provide a fast in-situ way to monitor the variation of the degree of organic pollution in estuarine environments.

Growth Characteristics of an Estuarine Heterocystous Cyanobacterium

PubMed Central

Guimarães, Pablo; Yunes, João S.; Cretoiu, Mariana Silvia; Stal, Lucas J.

2017-01-01

A new estuarine filamentous heterocystous cyanobacterium was isolated from intertidal sediment of the Lagoa dos Patos estuary (Brazil). The isolate may represent a new genus related to Cylindrospermopsis. While the latter is planktonic, contains gas vesicles, and is toxic, the newly isolated strain is benthic and does not contain gas vesicles. It is not known whether the new strain is toxic. It grows equally well in freshwater, brackish and full salinity growth media, in the absence of inorganic or organic combined nitrogen, with a growth rate 0.6 d-1. Nitrogenase, the enzyme complex responsible for fixing dinitrogen, was most active during the initial growth phase and its activity was not different between the different salinities tested (freshwater, brackish, and full salinity seawater). Salinity shock also did not affect nitrogenase activity. The frequency of heterocysts was high, coinciding with high nitrogenase activity during the initial growth phase, but decreased subsequently. However, the frequency of heterocysts decreased considerably more at higher salinity, while no change in nitrogenase activity occurred, indicating a higher efficiency of dinitrogen fixation. Akinete frequency was low in the initial growth phase and higher in the late growth phase. Akinete frequency was much lower at high salinity, which might indicate better growth conditions or that akinete differentiation was under the same control as heterocyst differentiation. These trends have hitherto not been reported for heterocystous cyanobacteria but they seem to be well fitted for an estuarine life style. PMID:28670308

Trace element release from estuarine sediments of South Mosquito Lagoon near Kennedy Space Center

NASA Technical Reports Server (NTRS)

Menon, M. P.; Ghuman, G. S.; Emeh, C. O.

1979-01-01

Analytical partitioning of four trace metals in estuarine sediments collected from eight sites in South Mosquito Lagoon near Kennedy Space Center, in terms of four different categories was accomplished using four different extraction techniques. The concentrations of the four trace metals, Zn, Mn, Cd, and Cu, released in interstitial water extract, 1 N ammonium acetate extract, conc. HCl extract and fusion extract of sediments as well as their concentrations in water samples collected from the same location were determined using flame atomic absorption technique. From the analytical results the percentages of total amount of each metal distributed among four different categories, interstitial water phase, acetate extractable, acid extractable and detrital crystalline material, were determined. Our results suggest that analytical partitioning of trace metals in estuarine sediments may be used to study the mechanism of incorporation of trace metals with sediments from natural waters. A correlation between the seasonal variation in the concentration of acetate extractable trace metals in the sediment and similar variation in their concentration in water was observed. A mechanism for the release of trace metals from estuarine sediments to natural water is also suggested.

Estuarine retention of larvae of the crab Rhithropanopeus harrisii

NASA Astrophysics Data System (ADS)

Cronin, Thomas W.

1982-08-01

Larvae of estuarine organisms continually face possible export from the parent estuary. Retention of larvae of the estuarine crab Rhithropanopeus harrisii was investigated in the upper Newport River estuary, North Carolina. All of the developmental stages occurred in the same area of the estuary with similar horizontal distributions, and the concentrations of intermediate and late stages were not greatly reduced from those of the first larval stage. This was strong evidence for the continuous retention of larvae in the upper estuary. To determine mechanisms by which retention might be effected, field studies of the vertical distributions and migrations of these larvae were made. The four zoeal stages had similar but complex vertical migration patterns, which varied from study to study. These migrations centered on the depth of no net flow, reducing longitudinal transport during development. Cross-spectral analysis of the larval migrations and the environmental cycles of light, salinity and current speed revealed that each of these external cycles affected larval depth. Megalopae of R. harrisii also migrated vertically, but they were present in much lower concentrations than the zoeal stages, an indication of a change to benthic existence in this final larval form.

Applications of remote sensing to estuarine management

NASA Technical Reports Server (NTRS)

Munday, J. C., Jr.; Gordon, H. H.; Hennigar, H. F.

1977-01-01

Remote sensing was used in the resolution of estuarine problems facing federal and Virginia governmental agencies. A prototype Elizabeth River Surface Circulation Atlas was produced from photogrammetry to aid in oil spill cleanup and source identification. Aerial photo analysis twice led to selection of alternative plans for dredging and spoil disposal which minimized marsh damage. Marsh loss due to a mud wave from a highway dyke was measured on sequential aerial photographs. An historical aerial photographic sequence gave basis to a potential Commonwealth of Virginia legal claim to accreting and migrating coastal islands.

LOOP marine and estuarine monitoring program, 1978-95 : volume 3 : physical hydrography.

DOT National Transportation Integrated Search

1998-01-01

The complex region of interest is associated with the Mississippi River deltaic plain. The estuarine portion (Barataria Basin) has resulted from the subsidence of abandoned river distributaries and associated marsh; the offshore region is strongly in...

Multi-Ecosystem Assessment of Mercury Bioaccumulation in Fishes: Habitat, Landscape, and Biogeochemical Drivers of Fish Mercury

NASA Astrophysics Data System (ADS)

Eagles-Smith, C.; Ackerman, J.; Herring, G.; Willacker, J.; Flanagan, C.

2014-12-01

Mercury (Hg) is a globally distributed contaminant that threatens ecosystem health across aquatic environments. The complexity of the Hg cycle and its primary drivers, coupled with dynamic food web processes that govern biomagnification, result in marked spatial variability in Hg bioaccumulation across aquatic ecosystems. However, it is unclear if patterns of bioaccumulation are consistent in magnitude and direction across ecosystem types. We synthesized data from several studies spanning more than 200 individual sites, comprising four distinct ecosystem classifications (estuaries, sub-alpine lakes, rivers, and managed wetlands). Within each ecosystem, we compared fish Hg concentrations among replicated sub-habitats and also evaluated the influence of land use, landscape composition, and biogeochemical drivers on fish Hg concentrations. We found substantial variability in fish Hg concentrations among adjacent sub-habitats within ecosystems. In estuarine environments, fish Hg concentrations were 7.4x higher in seasonal-saline wetlands than adjacent tidal wetland habitats. In riverine alcoves, preliminary data suggest that fish Hg concentrations were 1.5x higher than in fishes from paired mainstem river habitat. Among managed wetland habitats, fish Hg concentrations in rice fields were 2x higher than those in managed seasonal wetlands that were subjected to identical wetting and drying patterns. Across ecosystems, dissolved organic carbon (DOC) concentrations in surface waters were consistently correlated with fish Hg concentrations, highlighting its importance in Hg methylation and transport processes. Yet, the strength and direction of the relationships varied among habitat types. For example, fish Hg concentrations were positively correlated with DOC concentrations in riverine environments, whereas we found a negative correlation in alpine lakes. Instead, the most important determinant of fish Hg concentrations in alpine lakes was conifer tree density within a

Information Needs Assessment for Coastal and Marine Management and Policy: Ecosystem Services Under Changing Climatic, Land Use, and Demographic Conditions.

PubMed

Goldsmith, Kaitlin A; Granek, Elise F; Lubitow, Amy

2015-12-01

Changing climatic, demographic, and land use conditions are projected to alter the provisioning of ecosystem services in estuarine, coastal, and nearshore marine ecosystems, necessitating mitigation and adaptation policies and management. The current paradigm of research efforts occurring in parallel to, rather than in collaboration with, decision makers will be insufficient for the rapid responses required to adapt to and mitigate for projected changing conditions. Here, we suggest a different paradigm: one where research begins by engaging decision makers in the identification of priority data needs (biophysical, economic, and social). This paper uses synthesized interview data to provide insight into the varied demands for scientific research as described by decision makers working on coastal issues in Oregon, USA. The findings highlight the need to recognize (1) the differing framing of ecosystem services by decision makers versus scientists; and (2) the differing data priorities relevant to inland versus coastal decision makers. The findings further serve to highlight the need for decision makers, scientists, and funders to engage in increased communication. This research is an important first step in advancing efforts toward evidence-based decision making in Oregon and provides a template for further research across the US.

Chesapeake Bay nitrogen fluxes derived from a land‐estuarine ocean biogeochemical modeling system: Model description, evaluation, and nitrogen budgets

PubMed Central

Friedrichs, Marjorie A. M.; Wilkin, John; Tian, Hanqin; Yang, Qichun; Hofmann, Eileen E.; Wiggert, Jerry D.; Hood, Raleigh R.

2015-01-01

Abstract The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land‐estuarine‐ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within‐estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite‐derived data, and a simulation using environmental conditions for 2001–2005 was conducted to quantify the Chesapeake Bay nitrogen budget. The 5 year simulation was characterized by large riverine inputs of nitrogen (154 × 109 g N yr−1) split roughly 60:40 between inorganic:organic components. Much of this was denitrified (34 × 109 g N yr−1) and buried (46 × 109 g N yr−1) within the estuarine system. A positive net annual ecosystem production for the bay further contributed to a large advective export of organic nitrogen to the shelf (91 × 109 g N yr−1) and negligible inorganic nitrogen export. Interannual variability was strong, particularly for the riverine nitrogen fluxes. In years with higher than average riverine nitrogen inputs, most of this excess nitrogen (50–60%) was exported from the bay as organic nitrogen, with the remaining split between burial, denitrification, and inorganic export to the coastal ocean. In comparison to previous simulations using generic shelf biogeochemical model formulations inside the estuary, the estuarine biogeochemical model described here produced more realistic and significantly greater exports of organic nitrogen and lower exports of inorganic nitrogen to the shelf. PMID:27668137

Invasive Estuarine and Marine Animals of the North Atlantic

DTIC Science & Technology

2005-08-01

may never be realized at all depending on the characteristics of the individual species and the conditions into which it is introduced. Figure 1...industrial development, and urbanization. Species are introduced by a variety of different mechanisms ; however, most estuarine and marine species...including the native species Bankia gouldii, are tolerant of a wide range of salinities and temperatures and low oxygen conditions. Shipworms are a

Transport of persistent organic pollutants by microplastics in estuarine conditions

NASA Astrophysics Data System (ADS)

Bakir, Adil; Rowland, Steven J.; Thompson, Richard C.

2014-03-01

Microplastics represent an increasing source of anthropogenic contamination in aquatic environments, where they may also act as scavengers and transporters of persistent organic pollutants. As estuaries are amongst the most productive aquatic systems, it is important to understand sorption behaviour and transport of persistent organic pollutants (POPs) by microplastics along estuarine gradients. The effects of salinity sorption equilibrium kinetics on the distribution coefficients (Kd) of phenanthrene (Phe) and 4,4‧-DDT, onto polyvinyl chloride (PVC) and onto polyethylene (PE) were therefore investigated. A salinity gradient representing freshwater, estuarine and marine conditions, with salinities corresponding to 0 (MilliQ water, 690 μS/cm), 8.8, 17.5, 26.3 and 35 was used. Salinity had no significant effect on the time required to reach equilibrium onto PVC or PE and neither did it affect desorption rates of contaminants from plastics. Although salinity had no effect on sorption capacity of Phe onto plastics, a slight decrease in sorption capacity was observed for DDT with salinity. Salinity had little effect on sorption behaviour and POP/plastic combination was shown to be a more important factor. Transport of Phe and DDT from riverine to brackish and marine waters by plastic is therefore likely to be much more dependent on the aqueous POP concentration than on salinity. The physical characteristics of the polymer and local environmental conditions (e.g. plastic density, particle residence time in estuaries) will affect the physical transport of contaminated plastics. A transport model of POPs by microplastics under estuarine conditions is proposed. Transport of Phe and DDT by PVC and PE from fresh and brackish water toward fully marine conditions was the most likely net direction for contaminant transport and followed the order: Phe-PE >> DDT-PVC = DDT-PE >> Phe-PVC.

Marine and Estuarine Ecology. Man and the Gulf of Mexico.

ERIC Educational Resources Information Center

Irby, Bobby N.; And Others

"Man and the Gulf of Mexico (MGM)" is a marine science curriculum developed to meet the marine science needs of tenth through twelfth grade students in Mississippi and Alabama schools. This MGM unit, which focuses on marine and estuarine ecology, is divided into six sections. The first section contains unit objectives, discussions of the…

Aggregation, sedimentation, dissolution and bioavailability of quantum dots in estuarine systems.

EPA Science Inventory

To understand their fate and transport in estuarine systems, the aggregation, sedimentation, and dissolution of CdSe quantum dots (QDs) in seawater were investigated. Hydrodynamic size increased from 40 to 60 nm to >1 mm within 1 h in seawater, and the aggregates were highly p...

PHYSIOLOGICAL DYSFUNCTION IN ESTUARINE MYSIDS AND LARVAL DECAPODS WITH CHRONIC PESTICIDE EXPOSURE

EPA Science Inventory

A variety of physiological functions was examined in an estuarine mysid (Mysidopsis bahia) during life-cycle exposures to four classes of pesticides. Pesticide exposure initially elevated respiration rates of juveniles. These increased metabolic requirements reduced the amount of...

Combined effects of acidification and hypoxia on the estuarine ctenophore, Mnemiopsis leidyi

EPA Science Inventory

Estuaries are transitive zones which experience large fluctuations in environmental parameters (temperature, dissolved oxygen, pH, etc.). The interactive effects of reduced dissolved oxygen (DO) and elevated pCO2 on estuarine organisms is not currently well understood. Ctenophore...

Accumulation and trace-metal variability of estuarine sediments, St. Bernard delta geomorphic region, Louisiana

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

Landrum, K.E.

1995-10-01

Prior to government regulation, little monitoring of metal discharges into the canals, bayous, and rivers that drain estuarine systems occured. Discharges of trace-metals by industries and municipalities into surface water bodies are presently regulated through the use of Federal and State mandated permit programs. Resource management of economically important estuarine systems has fostered increasing concern over the accumulation of trace-metal pollutants in water, sediments, and biota from these dynamic areas. The acid-leachable concentrations of fourteen trace-metals were determined for 125 bottom sediment samples and 50 core interval samples by plasma emission analysis. Bottom sediments of the St. Bernard estuarom complexmore » consist predominantly of silty clays and clayey silts derived from the erosion of the St. Bernard lobe of the Mississippi River delta and sediments associated with historic crevasses along the Mississippi River. Within the 2 cm core intervals, trace-metal concentrations of Ba, Cr, Cd, Pb, and Zn increased by 10% to 18% in sediments accumulated within the last 75 years. Trace-metal concentrations from sediments for the study area tend to have greater mean concentrations than Florida estuarine sediments, basinwide and Gulf Coast trace-metal comparisons, sediment geochronology. Rates varied from 0.12 to 0.21 cm/yr. Within the 2 cm core intervals, trace-metal concentrations of Ba, Cr, Cd, Pb, and Zn increased by 10% to 18% in sediments accumulated within the last 75 years. Natural trace-metal variability was examined through the use of an aluminum normalization model based on Florida and Louisiana estuarine sediments, basinwide and Gulf Coast trace-metal comparisons, sediment geochronology, and grain-size corrected data. Elevated concentrations of As, Ba, Cd, Pb, V and Zn were noted from sediments associated with oil and gas drilling and production, sandblasting and shipbuilding, dredging, and stormwater, municipal, and industrial

Is an ecosystem services-based approach developed for setting specific protection goals for plant protection products applicable to other chemicals?

PubMed

Maltby, Lorraine; Jackson, Mathew; Whale, Graham; Brown, A Ross; Hamer, Mick; Solga, Andreas; Kabouw, Patrick; Woods, Richard; Marshall, Stuart

2017-02-15

Clearly defined protection goals specifying what to protect, where and when, are required for designing scientifically sound risk assessments and effective risk management of chemicals. Environmental protection goals specified in EU legislation are defined in general terms, resulting in uncertainty in how to achieve them. In 2010, the European Food Safety Authority (EFSA) published a framework to identify more specific protection goals based on ecosystem services potentially affected by plant protection products. But how applicable is this framework to chemicals with different emission scenarios and receptor ecosystems? Four case studies used to address this question were: (i) oil refinery waste water exposure in estuarine environments; (ii) oil dispersant exposure in aquatic environments; (iii) down the drain chemicals exposure in a wide range of ecosystems (terrestrial and aquatic); (iv) persistent organic pollutant exposure in remote (pristine) Arctic environments. A four-step process was followed to identify ecosystems and services potentially impacted by chemical emissions and to define specific protection goals. Case studies demonstrated that, in principle, the ecosystem services concept and the EFSA framework can be applied to derive specific protection goals for a broad range of chemical exposure scenarios. By identifying key habitats and ecosystem services of concern, the approach offers the potential for greater spatial and temporal resolution, together with increased environmental relevance, in chemical risk assessments. With modifications including improved clarity on terminology/definitions and further development/refinement of the key concepts, we believe the principles of the EFSA framework could provide a methodical approach to the identification and prioritization of ecosystems, ecosystem services and the service providing units that are most at risk from chemical exposure. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights

Factors Influencing Expanded Use of Urban Estuarine Habitats by Foraging Wading Birds

EPA Science Inventory

Urban estuarine habitats are often utilized by wildlife for foraging and other activities despite surrounding anthropogenic impact or disturbance. However little is known of the ecological factors that determine habitat value of these and other remnant natural habitats. We exam...

Predicting effects of environmental change on river inflows to Tillamook Bay, Oregon

EPA Science Inventory

Estuarine river watersheds provide valued ecosystem services to their surrounding communities including drinking water, fish habitat, and regulation of estuarine water quality. However, the provisioning of these services can be affected by changes in the quantity and quality of ...

Eelgrass response to Changing Environmental Drivers: Lessons from PNW Mesocosm Studies

EPA Science Inventory

Seagrass communities are ecosystem engineers that provide important services in a dynamic estuarine environment. Seagrass is often seen as a sentinel species or indicator of estuarine health. Estuaries are increasingly impacted by natural and anthropogenic stressors, and loss o...

Turbine sound may influence the metamorphosis behaviour of estuarine crab megalopae.

PubMed

Pine, Matthew K; Jeffs, Andrew G; Radford, Craig A

2012-01-01

It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM) for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21-31% compared to silent control treatments, 38-47% compared to tidal turbine sound treatments, and 46-60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment.

Tropical Estuarine Macrobenthic Communities Are Structured by Turnover Rather than Nestedness

PubMed Central

Medeiros, Carlinda Raílly; Hepp, Luiz Ubiratan; Patrício, Joana; Molozzi, Joseline

2016-01-01

Turnover (i.e., species substitution) and nestedness (i.e., subsets of species from more diverse locations), the two main mechanisms used to explain the beta diversity of biological communities, have different implications for biodiversity conservation. To better understand how these mechanisms contribute to beta diversity, we tested the following hypotheses: (i) greater dissimilarity in community composition occurs between estuarine zones than other hierarchical level studied; (ii) beta diversity in these communities develops by turnover in estuaries with a lower degree of anthropogenic impact, but by nestedness in estuaries with a greater degree of anthropogenic impact; and (iii) the structuring mechanism is independent of season. We studied two tropical estuaries (dry and wet seasons) that vary in terms of land-use of the drainage basins. Subtidal benthic macroinvertebrates were sampled along the estuarine gradient in each of the two estuaries. The additive partitioning approach to species diversity was used to determine the hierarchical scale with the greatest dissimilarity in community composition. General beta diversity was measured using the Sorensen dissimilarity index, partitioning the turnover and nestedness components. The greatest dissimilarity in the composition of the communities occurred between the zones along the estuarine gradient in both seasons (dry = 58.6%; wet = 46.3%). In the estuary with a lower degree of anthropogenic influence, benthic macroinvertebrate diversity was generated by turnover regardless of the season. In the estuary with a greater degree of anthropogenic impact, beta diversity was structured by turnover during the dry season and a combination of both mechanisms during the wet season. We conclude that turnover is the principal mechanism responsible for beta diversity in benthic macroinvertebrate communities in tropical estuaries. PMID:27584726

Tropical Estuarine Macrobenthic Communities Are Structured by Turnover Rather than Nestedness.

PubMed

Medeiros, Carlinda Raílly; Hepp, Luiz Ubiratan; Patrício, Joana; Molozzi, Joseline

2016-01-01

Turnover (i.e., species substitution) and nestedness (i.e., subsets of species from more diverse locations), the two main mechanisms used to explain the beta diversity of biological communities, have different implications for biodiversity conservation. To better understand how these mechanisms contribute to beta diversity, we tested the following hypotheses: (i) greater dissimilarity in community composition occurs between estuarine zones than other hierarchical level studied; (ii) beta diversity in these communities develops by turnover in estuaries with a lower degree of anthropogenic impact, but by nestedness in estuaries with a greater degree of anthropogenic impact; and (iii) the structuring mechanism is independent of season. We studied two tropical estuaries (dry and wet seasons) that vary in terms of land-use of the drainage basins. Subtidal benthic macroinvertebrates were sampled along the estuarine gradient in each of the two estuaries. The additive partitioning approach to species diversity was used to determine the hierarchical scale with the greatest dissimilarity in community composition. General beta diversity was measured using the Sorensen dissimilarity index, partitioning the turnover and nestedness components. The greatest dissimilarity in the composition of the communities occurred between the zones along the estuarine gradient in both seasons (dry = 58.6%; wet = 46.3%). In the estuary with a lower degree of anthropogenic influence, benthic macroinvertebrate diversity was generated by turnover regardless of the season. In the estuary with a greater degree of anthropogenic impact, beta diversity was structured by turnover during the dry season and a combination of both mechanisms during the wet season. We conclude that turnover is the principal mechanism responsible for beta diversity in benthic macroinvertebrate communities in tropical estuaries.

Immigration and early life stages recruitment of the European flounder (Platichthys flesus) to an estuarine nursery: The influence of environmental factors

NASA Astrophysics Data System (ADS)

Amorim, Eva; Ramos, Sandra; Elliott, Michael; Bordalo, Adriano A.

2016-01-01

Connectivity between coastal spawning grounds and estuarine nurseries is a critical step in the life cycle of many fish species. Larval immigration and transport-associated physical-biological processes are determinants of recruitment success to nursery areas. The recruitment of the European flounder, Platichthys flesus, to estuarine nurseries located at the southern edge of the species distribution range, has been usually investigated during its juvenile stages, while estuarine recruitment during the earlier planktonic life stage remains largely unstudied. The present study investigated the patterns of flounder larval recruitment and the influence of environmental factors on the immigration of the early life stages to the Lima estuary (NW Portugal), integrating data on fish larvae and post-settlement individuals (< 50 mm length), collected over 7 years. Late-stage larvae arrived at the estuary between February and July and peak abundances were observed in April. Post-settlement individuals (< 50 mm) occurred later between April and October, whereas newly-settled ones (< 20 mm) were found only in May and June. Variables associated with the spawning, survival and growth of larvae in the ocean (sea surface temperature, chlorophyll a and inland hydrological variables) were the major drivers of flounder occurrence in the estuarine nursery. Although the adjacent coastal area is characterized by a current system with strong seasonality and mesoscale variability, we did not identify any influence of variables related with physical processes (currents and upwelling) on the occurrence of early life stages in the estuary. A wider knowledge on the influence of the coastal circulation variability and its associated effects upon ocean-estuarine connectivity is required to improve our understanding of the population dynamics of marine spawning fish that use estuarine nurseries.

The importance of benthic-pelagic coupling for marine ecosystem functioning in a changing world.

PubMed

Griffiths, Jennifer R; Kadin, Martina; Nascimento, Francisco J A; Tamelander, Tobias; Törnroos, Anna; Bonaglia, Stefano; Bonsdorff, Erik; Brüchert, Volker; Gårdmark, Anna; Järnström, Marie; Kotta, Jonne; Lindegren, Martin; Nordström, Marie C; Norkko, Alf; Olsson, Jens; Weigel, Benjamin; Žydelis, Ramunas; Blenckner, Thorsten; Niiranen, Susa; Winder, Monika

2017-06-01

Benthic-pelagic coupling is manifested as the exchange of energy, mass, or nutrients between benthic and pelagic habitats. It plays a prominent role in aquatic ecosystems, and it is crucial to functions from nutrient cycling to energy transfer in food webs. Coastal and estuarine ecosystem structure and function are strongly affected by anthropogenic pressures; however, there are large gaps in our understanding of the responses of inorganic nutrient and organic matter fluxes between benthic habitats and the water column. We illustrate the varied nature of physical and biological benthic-pelagic coupling processes and their potential sensitivity to three anthropogenic pressures - climate change, nutrient loading, and fishing - using the Baltic Sea as a case study and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. Traditionally measured benthic-pelagic coupling processes (e.g., nutrient exchange and sedimentation of organic material) are to some extent quantifiable, but the magnitude and variability of biological processes are rarely assessed, preventing quantitative comparisons. Changing oxygen conditions will continue to have widespread effects on the processes that govern inorganic and organic matter exchange among habitats while climate change and nutrient load reductions may have large effects on organic matter sedimentation. Many biological processes (predation, bioturbation) are expected to be sensitive to anthropogenic drivers, but the outcomes for ecosystem function are largely unknown. We emphasize how improved empirical and experimental understanding of benthic-pelagic coupling processes and their variability are necessary to inform models that can quantify the feedbacks among processes and ecosystem responses to a changing world. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Suspended matter and bottom deposits in the Mahury estuarine system (French Guiana): Environmental consequences

NASA Astrophysics Data System (ADS)

Jouanneau, J. M.; Pujos, M.

As part of a study carried out on the major rivers in French Guiana to identify and estimate the respective share of local rivers in the sedimentation of estuaries and the inshore continental shelf, results are reported on the Mahury after 2 periods of fieldwork carried out during one dry and one rainy season. The specific characteristics of the whole Mahury fluvio-estuarine system can be summed up as follows: the sands have invariable annual characteristics; they show evidence of a long history, first marine, then continental and finally fluviatile. They play little part in sedimentation on the continental shelf, and what part they do play is limited to the beaches. The fine sediments too have invariable annual characteristics. They fall, if we consider their mineralogical and elemental composition, on either side of a limit separating the fluviatile and estuarine zones. Here, the sediment stocks are respectively authigenic and allothogenic, while the clay association and elemental composition in the latter zone are evidence of an Amazonian origin. The contribution of the Mahury (Comté-Orapu) to fine estuarine sedimentation thus appears at present to be a very limited one, the Amazon being predominant over vast coastal areas, including the French Guiana estuaries.

Micro-spatial variation of elemental distribution in estuarine sediment and their accumulation in mangroves of Indian Sundarban.

PubMed

Bakshi, Madhurima; Ram, S S; Ghosh, Somdeep; Chakraborty, Anindita; Sudarshan, M; Chaudhuri, Punarbasu

2017-05-01

the accumulation process. Overall, the study of micro-spatial distribution of elements can act as a useful tool for determining health of estuarine ecosystem.

Discharge diversion in the Patía River delta, the Colombian Pacific: Geomorphic and ecological consequences for mangrove ecosystems

NASA Astrophysics Data System (ADS)

Restrepo, Juan D.; Cantera, Jaime R.

2013-10-01

In the Patía River delta, the best-developed delta on the western margin of South America, a major water diversion started in 1972. The diversion of the Patía flow to the Sanquianga River, the latter a small stream draining internal lakes from the Pacific lowlands, shifted the active delta plain from the south to the north and changed the northern estuarine system into an active delta plain. The Sanquianga Mangrove National Park, a mangrove reserve measuring 800 km2, lies in this former estuary, where major hydrologic and sedimentation changes are occurring. Overall, major environmental consequences of this discharge diversion in terms of geomorphic changes along distributary channels and ecological impacts on mangrove ecosystems are evidenced by: (1) distributary channel accretion by operating processes such as sedimentation, overbank flow, increasing width of levees, sedimentation in crevasses, interdistributary channel fill, and colonization of pioneer mangrove; (2) freshening conditions in the Sanquianga distributary channel, a hydrologic change that has shifted the upper estuarine region (salinity <1%) downstream; (3) downstream advance of freshwater vegetation, which is invading channel banks in the lower and mixing estuarine zones; (4) die-off of approximately 5200 ha of mangrove near the delta apex at Bocas de Satinga, where the highest sediment accumulation rates occur; and (5) recurrent periods of mangrove defoliation due to a worm plague. Further analyses indicate strong mangrove erosion along transgressive barrier islands on the former delta plain. Here tectonic-induced subsidence, relative sea-level rise, and sediment starving conditions due to the channel diversion, are the main causes of the observed retreating conditions of mangrove communities. Our data also indicate that the Patía River has the highest sediment load (27 × 106 t yr-1) and basin-wide sediment yield (1500 t km-2 yr-1) on the west coast of South America. Erosion rates from the Pat

Laboratory analysis of techniques for remote sensing of estuarine parameters using laser excitation

NASA Technical Reports Server (NTRS)

Exton, R. J.; Houghton, W. M.; Esaias, W.; Harriss, R. C.; Farmer, F. H.; White, H. H.

1983-01-01

The theoretical concepts underlying remote sensing of estuarine parameters using laser excitation are examined. The concepts are extended to include Mie scattering as a measure of the total suspended solids and to develop the water Raman signal as an internal standard. Experimental validation of the theory was performed using backscattered laser light from a laboratory tank to simulate a remote-sensing geometry. Artificially prepared sediments and biological cultures were employed to check specific aspects of the theory under controlled conditions. Natural samples gathered from a variety of water types were also analyzed in the tank to further enhance the simulation. The results indicate that it should be possible to remotely quantify total suspended solids, dissolved organics, attenuation coefficient, chlorophyll a, and phycoerythrin in estuarine water using laser excitation.

A Miocene wave-dominated estuarine system in the Paraíba Basin, northeastern Brazil

NASA Astrophysics Data System (ADS)

Gandini, Rosana; Rossetti, Dilce de Fátima; Netto, Renata Guimarães; Góes, Ana Maria

2017-11-01

A number of publications have documented the effect of the Miocene transgression on several coasts of the world. However, this event is incompletely documented along the Brazilian margin, despite the existence of an impressive record of Miocene deposits exposed mostly as several coastal cliffs along more than 5000 km of distance. The transgressive nature of Miocene deposits, so far recognized only in a few localities of northeastern Brazil, needs to be amplified in order to better characterize the impact of the Miocene transgression in eastern South America. In this work, we provide facies analysis of early/middle Miocene strata exposed in the Paraíba Basin, northeastern Brazil, aiming reconstruct the depositional paleoenvironments and analyze their evolution within the context of relative sea-level fluctuations data. The results revealed deposits characterized by several features that were related to the action of tidal currents, such as alternating thicker/thinner forest packages, abundant reactivation surfaces, mud drapes and oppositely-dipping (herringbone) cross sets. These sedimentary structures were associated with an ichnological assemblage indicative of marine-influenced and brackish water, best represented by Ophiomorpha, Planolites-Palaeophycus-Thalassinoides and Thallassinoides-Planolites-Palaeophycus ichnofabrics. Sedimentation occurred in environments consisting of estuarine channel, estuarine central basin, tidal inlet/tidal channel, tidal delta/washover, tidal flat/shoal and foreshore, which were related to an estuarine setting, at least in part of a wave-dominated type. Analysis of facies stratal patterns led to suggest that the estuarine deposits of the Paraíba Basin reflect a rise in relative sea level probably during the transgressive and/or highstand stage of a depositional sequence formed directly overlying Cretaceous rocks. This rise can be correlated with the worldwide early/mid Miocene marine transgression. However, while the eustatic sea

Comparative toxicity of pyrethroid insecticides to two estuarine crustacean species, Americamysis bahia and Palaemonetes pugio.

PubMed

DeLorenzo, Marie E; Key, Peter B; Chung, Katy W; Sapozhnikova, Yelena; Fulton, Michael H

2014-10-01

Pyrethroid insecticides are widely used on agricultural crops, as well as for nurseries, golf courses, urban structural and landscaping sites, residential home and garden pest control, and mosquito abatement. Evaluation of sensitive marine and estuarine species is essential for the development of toxicity testing and risk-assessment protocols. Two estuarine crustacean species, Americamysis bahia (mysids) and Palaemonetes pugio (grass shrimp), were tested with the commonly used pyrethroid compounds, lambda-cyhalothrin, permethrin, cypermethrin, deltamethrin, and phenothrin. Sensitivities of adult and larval grass shrimp and 7-day-old mysids were compared using standard 96-h LC50 bioassay protocols. Adult and larval grass shrimp were more sensitive than the mysids to all the pyrethroids tested. Larval grass shrimp were approximately 18-fold more sensitive to lambda-cyhalothrin than the mysids. Larval grass shrimp were similar in sensitivity to adult grass shrimp for cypermethrin, deltamethrin, and phenothrin, but larvae were approximately twice as sensitive to lambda-cyhalothrin and permethrin as adult shrimp. Acute toxicity to estuarine crustaceans occurred at low nanogram per liter concentrations of some pyrethroids, illustrating the need for careful regulation of the use of pyrethroid compounds in the coastal zone. Copyright © 2013 Wiley Periodicals, Inc., a Wiley company.

Suspended solids moderate the degradation and sorption of waste water-derived pharmaceuticals in estuarine waters.

PubMed

Aminot, Yann; Fuster, Laura; Pardon, Patrick; Le Menach, Karyn; Budzinski, Hélène

2018-01-15

This study focuses on the fate of pharmaceuticals discharged into an estuarine environment, particularly into the Turbidity Maximum Zone (TMZ). Batch experiments were set up to investigate the factors regulating the degradation of 53 selected pharmaceuticals. Treated effluents from Bordeaux city (France) were mixed with water from the estuarine Garonne River during 4weeks under 6 characterized conditions in order to assess the influence of suspended particulates, sterilization, untreated wastewater input and dilution on the degradation kinetics. Of the 53 pharmaceuticals monitored, 43 were quantified at the initial time. Only 7 exhibited a persistent behavior (e.g. carbamazepine, meprobamate) while biotic degradation was shown to be the main attenuation process for 38 molecules (e.g. abacavir, ibuprofen highly degradable). Degradation was significantly enhanced by increasing concentrations of suspended solids. A persistence index based on the half-lives of the compounds has been calculated for each of the 43 pharmaceuticals to provide a practical estimate of their relative stability. The stability of pharmaceuticals in estuarine environments is likely to be highly variable and attenuated primarily by changes in suspended solid concentration. Copyright © 2017 Elsevier B.V. All rights reserved.

Using stable isotopes and models to explore estuarine linkages at multiple scales

EPA Science Inventory

Estuarine managers need tools to respond to dynamic stressors that occur in three linked environments – coastal ocean, estuaries and watersheds. Models have been the tool of choice for examining these dynamic systems because they simplify processes and integrate over multiple sc...

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...

Fuzzy cognitive mapping in support of integrated ecosystem assessments: Developing a shared conceptual model among stakeholders.

PubMed

Vasslides, James M; Jensen, Olaf P

2016-01-15

Ecosystem-based approaches, including integrated ecosystem assessments, are a popular methodology being used to holistically address management issues in social-ecological systems worldwide. In this study we utilized fuzzy logic cognitive mapping to develop conceptual models of a complex estuarine system among four stakeholder groups. The average number of categories in an individual map was not significantly different among groups, and there were no significant differences between the groups in the average complexity or density indices of the individual maps. When ordered by their complexity scores, eight categories contributed to the top four rankings of the stakeholder groups, with six of the categories shared by at least half of the groups. While non-metric multidimensional scaling (nMDS) analysis displayed a high degree of overlap between the individual models across groups, there was also diversity within each stakeholder group. These findings suggest that while all of the stakeholders interviewed perceive the subject ecosystem as a complex series of social and ecological interconnections, there are a core set of components that are present in most of the groups' models that are crucial in managing the system towards some desired outcome. However, the variability in the connections between these core components and the rest of the categories influences the exact nature of these outcomes. Understanding the reasons behind these differences will be critical to developing a shared conceptual model that will be acceptable to all stakeholder groups and can serve as the basis for an integrated ecosystem assessment. Copyright © 2015 Elsevier Ltd. All rights reserved.

PREDICTING ESTUARINE SEDIMENT METAL CONCENTRATIONS AND INFERRED ECOLOGICAL CONDITIONS: AN INFORMATION THEORETIC APPROACH

EPA Science Inventory

Empirically derived values associating sediment metal concentrations with degraded ecological conditions provide important information to assess estuarine condition. However, resources limit the number, magnitude, and frequency of monitoring programs to gather these data. As su...

Quantifying site-specific physical heterogeneity within an estuarine seascape

USGS Publications Warehouse

Kennedy, Cristina G.; Mather, Martha E.; Smith, Joseph M.

2017-01-01

Quantifying physical heterogeneity is essential for meaningful ecological research and effective resource management. Spatial patterns of multiple, co-occurring physical features are rarely quantified across a seascape because of methodological challenges. Here, we identified approaches that measured total site-specific heterogeneity, an often overlooked aspect of estuarine ecosystems. Specifically, we examined 23 metrics that quantified four types of common physical features: (1) river and creek confluences, (2) bathymetric variation including underwater drop-offs, (3) land features such as islands/sandbars, and (4) major underwater channel networks. Our research at 40 sites throughout Plum Island Estuary (PIE) provided solutions to two problems. The first problem was that individual metrics that measured heterogeneity of a single physical feature showed different regional patterns. We solved this first problem by combining multiple metrics for a single feature using a within-physical feature cluster analysis. With this approach, we identified sites with four different types of confluences and three different types of underwater drop-offs. The second problem was that when multiple physical features co-occurred, new patterns of total site-specific heterogeneity were created across the seascape. This pattern of total heterogeneity has potential ecological relevance to structure-oriented predators. To address this second problem, we identified sites with similar types of total physical heterogeneity using an across-physical feature cluster analysis. Then, we calculated an additive heterogeneity index, which integrated all physical features at a site. Finally, we tested if site-specific additive heterogeneity index values differed for across-physical feature clusters. In PIE, the sites with the highest additive heterogeneity index values were clustered together and corresponded to sites where a fish predator, adult striped bass (Morone saxatilis), aggregated in a

Tidally-driven Surface Flow in a Georgia Estuarine Saltmarsh

NASA Astrophysics Data System (ADS)

Young, D.; Bruder, B. L.; Haas, K. A.; Webster, D. R.

2016-02-01

Estuarine saltmarshes are diverse, valuable, and productive ecosystems. Vegetation dampens wave and current energy, thereby allowing the estuaries to serve as a nursery habitat for shellfish and fish species. Tidally-driven flow transports nutrients into and out of the estuary, nourishing inshore and offshore vegetation and animals. The effects of vegetation on the marsh hydrodynamics and on the estuary creek and channel flow are, unfortunately, poorly understood, and the knowledge that does exist primarily originates from modeling studies. Field studies addressing marsh surface flows are limited due to the difficulty of accurately measuring the water surface elevation and acquiring concurrent velocity measurements in the dense marsh vegetation. This study partially bridges the gap between the model observations of marsh flow driven by water surface elevation gradients and flume studies of flow through vegetation. Three current meters and three pressure transducers were deployed for three days along a transect perpendicular to the main channel (Little Ogeechee River) in a saltmarsh adjacent to Rose Dhu Island (Savannah, Georgia, USA). The pressure transducer locations were surveyed daily with static GPS yielding highly accurate water surface elevation data. During flood and ebb tide, water surface elevation differences between the marsh and Little Ogeechee River were observed up to 15 cm and pressure gradients were observed up to 0.0017 m of water surface elevation drop per m of linear distance. The resulting channel-to-saltmarsh pressure gradients substantially affected tidal currents at all current meters. At one current meter, the velocity was nearly perpendicular to the Little Ogeechee River bank. The velocity at this location was effectively modeled as a balance between the pressure gradient and marsh vegetation-induced drag force using the Darcy-Weisbach/Lindner's equations developed for flow-through-vegetation analysis in open channel flow.

Detection of cyanotoxins (microcystins/nodularins) in livers from estuarine and coastal bottlenose dolphins (Tursiops truncatus) from Northeast Florida.

PubMed

Brown, Amber; Foss, Amanda; Miller, Melissa A; Gibson, Quincy

2018-06-01

Microcystins/Nodularins (MCs/NODs) are potent hepatotoxic cyanotoxins produced by harmful algal blooms (HABs) that occur frequently in the upper basin of the St. Johns River (SJR), Jacksonville, FL, USA. Areas downstream of bloom locations provide critical habitat for an estuarine population of bottlenose dolphins (Tursiops truncatus). Since 2010, approximately 30 of these dolphins have stranded and died within this impaired watershed; the cause of death was inconclusive for a majority of these individuals. For the current study, environmental exposure to MCs/NODs was investigated as a potential cause of dolphin mortality. Stranded dolphins from 2013 to 2017 were categorized into estuarine (n = 17) and coastal (n = 10) populations. Because estuarine dolphins inhabit areas with frequent or recurring cyanoblooms, they were considered as a comparatively high-risk group for cyanotoxin exposure in relation to coastal animals. All available liver samples from estuarine dolphins were tested regardless of stranding date, and samples from coastal individuals that stranded outside of the known cyanotoxin bloom season were assessed as controls. The MMPB (2-methyl-3-methoxy-4-phenylbutiric acid) technique was used to determine total (bound and free) concentrations of MCs/NODS in liver tissues. Free MCs/NODs extractions were conducted and analyzed using ELISA and LC-MS/MS on MMPB-positive samples to compare test results. MMPB testing resulted in low-level total MCs/NODs detection in some specimens. The Adda ELISA produced high test values that were not supported by concurrent LC-MS/MS analyses, indicative of false positives. Our results indicate that both estuarine and coastal dolphins are exposed to MCs/NODs, with potential toxic and immune health impacts. Copyright © 2018 Elsevier B.V. All rights reserved.

Influence of estuarine processes on spatiotemporal variation in bioavailable selenium

USGS Publications Warehouse

Stewart, Robin; Luoma, Samuel N.; Elrick, Kent A.; Carter, James L.; van der Wegen, Mick

2013-01-01

Dynamic processes (physical, chemical and biological) challenge our ability to quantify and manage the ecological risk of chemical contaminants in estuarine environments. Selenium (Se) bioavailability (defined by bioaccumulation), stable isotopes and molar carbon-tonitrogen ratios in the benthic clam Potamocorbula amurensis, an important food source for predators, were determined monthly for 17 yr in northern San Francisco Bay. Se concentrations in the clams ranged from a low of 2 to a high of 22 μg g-1 over space and time. Little of that variability was stochastic, however. Statistical analyses and preliminary hydrodynamic modeling showed that a constant mid-estuarine input of Se, which was dispersed up- and down-estuary by tidal currents, explained the general spatial patterns in accumulated Se among stations. Regression of Se bioavailability against river inflows suggested that processes driven by inflows were the primary driver of seasonal variability. River inflow also appeared to explain interannual variability but within the range of Se enrichment established at each station by source inputs. Evaluation of risks from Se contamination in estuaries requires the consideration of spatial and temporal variability on multiple scales and of the processes that drive that variability.

Genetic architecture of evolved tolerance to PCBs in the estuarine fish Fundulus heteroclitus

EPA Science Inventory

Populations of Atlantic killifish (F. heteroclitus) resident to coastal estuarine habitats contaminated with halogenated aromatic hydrocarbons (HAHs) exhibit heritable resistance to the early life-stage toxicity associated with these compounds. Beyond our knowledge of the aryl hy...

Abiotic characteristics and microalgal dynamics in South Africa's largest estuarine lake during a wet to dry transitional phase

NASA Astrophysics Data System (ADS)

Nunes, Monique; Adams, Janine B.; Bate, Guy C.; Bornman, Thomas G.

2017-11-01

The summer of 2012/2013 signified the end of the dry phase in the St Lucia estuarine system that lasted for over a decade. The increased rainfall coupled with the partial re-connection of the Mfolozi River to the estuarine system shifted St Lucia to a new limnetic state. With the increased availability of habitat due to the higher water level, it was expected that microalgal biomass and abundance would rapidly increase through recruitment from refuge areas i.e. South Lake and new introductions. Microalgal and physico-chemical data were collected at three sites within the Mfolozi/Msunduzi River and at 23 sites within the St Lucia estuarine system between June 2014 and February 2015. Results from this study indicated low biomass for both phytoplankton (<5 μg l-1) and microphytobenthos (<60 mg m-2) because of local and external drivers. These included limited nutrient and light availability, variable water residence times, biomass dilution and heterogeneity of the sediment. The high spatio-temporal variability limits the effectiveness of using the microalgal communities to detect change in the estuarine lake. In addition, significant intrasystem differences were observed between the three main lake basins and Narrows, due to the influence of the freshwater input from the Mfolozi River. This study provides insight into the spatio-temporal variability of physico-chemical conditions and microalgal communities during the 2014-2015 limnetic state.

Turbine Sound May Influence the Metamorphosis Behaviour of Estuarine Crab Megalopae

PubMed Central

Pine, Matthew K.; Jeffs, Andrew G.; Radford, Craig A.

2012-01-01

It is now widely accepted that a shift towards renewable energy production is needed in order to avoid further anthropogenically induced climate change. The ocean provides a largely untapped source of renewable energy. As a result, harvesting electrical power from the wind and tides has sparked immense government and commercial interest but with relatively little detailed understanding of the potential environmental impacts. This study investigated how the sound emitted from an underwater tidal turbine and an offshore wind turbine would influence the settlement and metamorphosis of the pelagic larvae of estuarine brachyuran crabs which are ubiquitous in most coastal habitats. In a laboratory experiment the median time to metamorphosis (TTM) for the megalopae of the crabs Austrohelice crassa and Hemigrapsus crenulatus was significantly increased by at least 18 h when exposed to either tidal turbine or sea-based wind turbine sound, compared to silent control treatments. Contrastingly, when either species were subjected to natural habitat sound, observed median TTM decreased by approximately 21–31% compared to silent control treatments, 38–47% compared to tidal turbine sound treatments, and 46–60% compared to wind turbine sound treatments. A lack of difference in median TTM in A. crassa between two different source levels of tidal turbine sound suggests the frequency composition of turbine sound is more relevant in explaining such responses rather than sound intensity. These results show that estuarine mudflat sound mediates natural metamorphosis behaviour in two common species of estuarine crabs, and that exposure to continuous turbine sound interferes with this natural process. These results raise concerns about the potential ecological impacts of sound generated by renewable energy generation systems placed in the nearshore environment. PMID:23240063

Estuarine intertidal habitat use by birds in a Pacific Northwest coastal estuary

EPA Science Inventory

Results of a year long study of the distribution of birds across five intertidal estuarine habitats reveal that tide level largely controls use of the habitats by birds. A total census of all birds observed from shoreline observation locations was made at five tide levels over s...

Heavy-mineral provenance in an estuarine environment, Willapa Bay, Washington, USA: palaeogeographic implications and estuarine evolution

USGS Publications Warehouse

Luepke Bynum, Gretchen

2007-01-01

Modern sediments from representative localities in Willapa Bay, Washington, comprise two principal heavy-mineral suites. One contains approximately equivalent amounts of hornblende, orthopyroxene, and clinopyroxene; this is derived from the Columbia River, which discharges into the Pacific Ocean a short distance south of the bay. The other suite, dominated by clinopyroxene, is restricted to sands of rivers flowing into the bay from the east. The heavy-mineral distributions within the bay suggest that sand discharged from the Columbia River, borne north by longshore transport and carried into the bay by tidal currents, accounts for nearly all of the sand within the interior of Willapa Bay today. Pleistocene deposits on the east side of the bay contain three heavy-mineral assemblages, two of which are identical to the modern assemblages described above. These assemblages reflect the relative influence of tidal and fluvial processes on the Late Pleistocene deposits (100,000–200,000 BP. Amino acid racemization in Quaternary shell deposits at Willapa Bay, Washington. Geochimica et Cosmochimica Acta 43, 1505–1520). They are also consistent with those processes inferred on the basis of sedimentary structures and stratigraphic relations in about two-thirds of the samples examined. Anomalies can be explained by recycling of sand from older deposits. The persistence of the two heavy-mineral suites suggests that the pattern of estuarine sedimentation in Late Pleistocene deposits closely resembled that of the modern bay. The third heavy-mineral suite is enriched in epidote and occurs in a few older Pleistocene units. On the north side of the bay, the association of this suite with southwest-directed foresets in cross-bedded gravel indicates derivation from the northeast, perhaps from an area of glacial outwash. The presence of this suite in ancient estuarine sands exposed on the northeast side of the bay suggests that input from this northerly source may have

Denitrification rates in estuarine sediments of Ashtamudi, Kerala, India.

PubMed

Salahudeen, Junaid Hassan; Reshmi, R R; Anoop Krishnan, K; Ragi, M S; Vincent, Salom Gnana Thanga

2018-05-03

Estuarine sediments are important sites for denitrification, which is microbially mediated reduction of nitrate to dinitrogen that also influences global climate change by co-production of nitrous oxide, a potent greenhouse gas. Physicochemical properties and nutrients of sediment samples that influence denitrification rate were studied in Ashtamudi estuarine sediments. They were pH, electrical conductivity (EC), salinity, nitrate-nitrogen (NO 3 - -N), exchangeable ammonia (NH 3 - -N), total kjeldahl nitrogen (TKN) and organic carbon (Corg). Sediment samples were collected from six stations during summer, monsoon of 2013 and 13 stations from monsoon 2014 and summer 2015. The sedimentary denitrification potential ranged from 0.49 ± 0.05 to 4.85 ± 0.782 mmol N 2 O m -2 h -1 . Maximum denitrification was observed in S4, which is attributed to a local anthropogenic source coupled with intense rainfall episode preceding the sampling season of monsoon 2013. However, this trend was not repeated in the subsequent monsoon samples. This shows that in Ashtamudi, monsoonal effects do not influence sedimentary denitrification. Among the various environmental variables, NO 3 - -N, Corg and NH 3 -N were the key factors that influence denitrification in the Ashtamudi estuarine sediments. Among these key factors, NO 3 - -N was the limiting factor for denitrification, and hence, it is of prime importance to understand the source of NO 3 - -N that fuel denitrification in the sediments. In Ashtamudi, the concentration of NO 3 - -N in overlying water was very less, which suggests reduced nitrogen yield in the estuary from the fluvial input of Kallada River and agricultural runoff. Sedimentary NO 3 - -N correlated with denitrification which reveals that denitrification is coupled with nitrification in the sediments. This is further explained by the fact that NH 3 -N positively correlated with denitrification. The anoxic sediments were the source of ammonia for nitrous oxide

Multi-platform assessment of turbidity plumes during dredging operations in a major estuarine system

NASA Astrophysics Data System (ADS)

Caballero, Isabel; Navarro, Gabriel; Ruiz, Javier

2018-06-01

Dredging activities in estuaries frequently cause deleterious environmental effects on the water quality which can impact flora, fauna, and hydrodynamics, among others. A medium- and high-resolution satellite-based procedure is used in this study to monitor turbidity plumes generated during the dredging operations in the Guadalquivir estuary, a major estuarine system providing important ecosystem services in southwest Europe. A multi-sensor scheme is evaluated using a combination of five public and commercial medium- and high-resolution satellites, including Landsat-8, Sentinel-2A, WorldView-2, WorldView-3, and GeoEye-1, with pixel sizes ranging from 30 m to 0.3 m. Applying a multi-conditional algorithm after the atmospheric correction of the optical imagery with ACOLITE, Sen2Cor and QUAC processors, it is demonstrated the feasibility to monitoring suspended solids during dredging operations at a spatial resolution unachievable with traditional satellite-based ocean color sensors (>300 m). The frame work can be used to map on-going, post and pre-dredging activities and asses Total Suspended Solids (TSS) anomalies caused by natural and anthropogenic processes in coastal and inland waters. These promising results are suitable to effectively improve the assessment of features relevant to environmental policies for the challenging coastal management and might serve as a notable contribution to the Earth Observation Program.

Nitrous oxide fluxes in estuarine environments: response to global change.

PubMed

Murray, Rachel H; Erler, Dirk V; Eyre, Bradley D

2015-09-01

Nitrous oxide is a powerful, long-lived greenhouse gas, but we know little about the role of estuarine areas in the global N2 O budget. This review summarizes 56 studies of N2 O fluxes and associated biogeochemical controlling factors in estuarine open waters, salt marshes, mangroves, and intertidal sediments. The majority of in situ N2 O production occurs as a result of sediment denitrification, although the water column contributes N2 O through nitrification in suspended particles. The most important factors controlling N2 O fluxes seem to be dissolved inorganic nitrogen (DIN) and oxygen availability, which in turn are affected by tidal cycles, groundwater inputs, and macrophyte density. The heterogeneity of coastal environments leads to a high variability in observations, but on average estuarine open water, intertidal and vegetated environments are sites of a small positive N2 O flux to the atmosphere (range 0.15-0.91; median 0.31; Tg N2 O-N yr(-1) ). Global changes in macrophyte distribution and anthropogenic nitrogen loading are expected to increase N2 O emissions from estuaries. We estimate that a doubling of current median NO3 (-) concentrations would increase the global estuary water-air N2 O flux by about 0.45 Tg N2 O-N yr(-1) or about 190%. A loss of 50% of mangrove habitat, being converted to unvegetated intertidal area, would result in a net decrease in N2 O emissions of 0.002 Tg N2 O-N yr(-1) . In contrast, conversion of 50% of salt marsh to unvegetated area would result in a net increase of 0.001 Tg N2 O-N yr(-1) . Decreased oxygen concentrations may inhibit production of N2 O by nitrification; however, sediment denitrification and the associated ratio of N2 O:N2 is expected to increase. © 2015 John Wiley & Sons Ltd.

Individual variation in ontogenetic niche shifts in habitat use and movement patterns of a large estuarine predator (Carcharhinus leucas).

PubMed

Matich, Philip; Heithaus, Michael R

2015-06-01

Ontogenetic niche shifts are common among animals, yet most studies only investigate niche shifts at the population level, which may overlook considerable differences among individuals in the timing and dynamics of these shifts. Such divergent behaviors within size-/age-classes have important implications for the roles a population-and specific age-classes-play in their respective ecosystem(s). Using acoustic telemetry, we tracked the movements of juvenile bull sharks in the Shark River Estuary of Everglades National Park, Florida, and found that sharks increased their use of marine microhabitats with age to take advantage of more abundant resources, but continued to use freshwater and estuarine microhabitats as refuges from marine predators. Within this population-level ontogenetic niche shift, however, movement patterns varied among individual sharks, with 47 % of sharks exhibiting condition-dependent habitat use and 53 % appearing risk-averse regardless of body condition. Among sharks older than age 0, fifty percent made regular movements between adjacent regions of the estuary, while the other half made less predictable movements that often featured long-term residence in specific regions. Individual differences were apparently shaped by both intrinsic and extrinsic factors, including individual responses to food-risk trade-offs and body condition. These differences appear to develop early in the lives of bull sharks, and persist throughout their residencies in nursery habitats. The widespread occurrence of intraspecific variation in behavior among mobile taxa suggests it is important in shaping population dynamics of at least some species, and elucidating the contexts and timing in which it develops and persists is important for understanding its role within communities.

Linking land use change to recreational fishery valuation with a spatially explicit behavior model: A case study from Tampa Bay, FL USA

EPA Science Inventory

Drawing a link between habitat change and production and delivery of ecosystem services is a priority in coastal estuarine ecosystems. This link is needed to fully understand how human communities can influence ecosystem sustainability. Mechanistic modeling tools are highly fun...

Utilization of organic matter by invertebrates along an estuarine gradient in an intermittently open estuary

NASA Astrophysics Data System (ADS)

Lautenschlager, Agnes D.; Matthews, Ty G.; Quinn, Gerry P.

2014-08-01

In intermittently open estuaries, the sources of organic matter sustaining benthic invertebrates are likely to vary seasonally, particularly between periods of connection and disconnection with the ocean and higher and lower freshwater flows. This study investigated the contribution of allochthonous and autochthonous primary production to the diet of representative invertebrate species using stable isotope analysis (SIA) during the austral summer and winter (2008, 2009) in an intermittently open estuary on the south-eastern coast of Australia. As the study was conducted towards the end of a prolonged period of drought, a reduced influence of freshwater/terrestrial organic matter was expected. Sampling was conducted along an estuarine gradient, including upper, middle and lower reaches and showed that the majority of assimilated organic matter was derived from autochthonous estuarine food sources. Additionally, there was an input of allochthonous organic matter, which varied along the length of the estuary, indicated by distinct longitudinal trends in carbon and nitrogen stable isotope signatures along the estuarine gradient. Marine seaweed contributed to invertebrate diets in the lower reaches of the estuary, while freshwater/terrestrial organic matter had increased influence in the upper reaches. Suspension-feeding invertebrates derived large parts of their diet from freshwater/terrestrial material, despite flows being greatly reduced in comparison with non-drought years.

Intertidal estuarine habitat utilization by birds in a Pacific Northwest coastal estuary

EPA Science Inventory

Results of a year long study of the distribution of birds across five intertidal estuarine habitats reveal that tide level largely controls use of the habitats by birds. A total census of all birds observed from shoreline locations was made at five tide levels over six, 2-month ...

Estuarine Response to River Flow and Sea-Level Rise under Future Climate Change and Human Development

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

Yang, Zhaoqing; Wang, Taiping; Voisin, Nathalie

Understanding the response of river flow and estuarine hydrodynamics to climate change, land-use/land-cover change (LULC), and sea-level rise is essential to managing water resources and stress on living organisms under these changing conditions. This paper presents a modeling study using a watershed hydrology model and an estuarine hydrodynamic model, in a one-way coupling, to investigate the estuarine hydrodynamic response to sea-level rise and change in river flow due to the effect of future climate and LULC changes in the Snohomish River estuary, Washington, USA. A set of hydrodynamic variables, including salinity intrusion points, average water depth, and salinity of themore » inundated area, were used to quantify the estuarine response to river flow and sea-level rise. Model results suggest that salinity intrusion points in the Snohomish River estuary and the average salinity of the inundated areas are a nonlinear function of river flow, although the average water depth in the inundated area is approximately linear with river flow. Future climate changes will shift salinity intrusion points further upstream under low flow conditions and further downstream under high flow conditions. In contrast, under the future LULC change scenario, the salinity intrusion point will shift downstream under both low and high flow conditions, compared to present conditions. The model results also suggest that the average water depth in the inundated areas increases linearly with sea-level rise but at a slower rate, and the average salinity in the inundated areas increases linearly with sea-level rise; however, the response of salinity intrusion points in the river to sea-level rise is strongly nonlinear.« less

Infilling of the Hudson River Estuary During the Late Holocene (3000ka to Present): Implications for Estuarine Stratigraphic Models

NASA Astrophysics Data System (ADS)

McHugh, C. M.; Pekar, S. F.; Ryan, W. B.; Carbotte, S.; Bell, R.; Burckle, L.

2002-12-01

Estuaries are widely preserved in the geologic record and the estuarine fill, contained between non-marine sediment, provides an excellent temporal marker for continental margin studies. Estuarine stratigraphic models have provided a framework within which to interpret the estuarine fill. However, estuarine systems differ greatly in the shape of their valleys, the tectonic boundaries they cross, and in sediment supply so that their position in the geologic record may be out of sequence with that predicted by the models. New insights into estuarine systems and models are provided by the Hudson River Estuary (HRE; New York State) based on >150 cores and grab sediment samples and acoustic images documenting in great detail how the HRE filled its earlier excavated valley during the latest Holocene (3ka to present). Radiocarbon and 137-Cs radioisotope ages, borehole, and core data document the sedimentation patterns of the estuary. Diatom assemblages provide estimates of the shallowing-upwards of the estuary as its basin filled with sediments. The three areas of the stratigraphic model present in the HRE, include zones formed within inner fluvial and outer marine areas, (containing coarse-grained, sands and gravels), and a central area (containing fine-grained, silts and clays), that are nearly filled with little room for sediments to accumulate at or near sea-level. This has resulted in sedimentary bypass for almost the entire length the estuary. South of Kingston, fine-grained sediments have ceased accumulating when the bottom approaches wave base. Upstream from Kingston, final filling occurs as sediments fill in the remaining accommodation, forming islands. This should result in the export of sediment to the coastal zone. Instead, localized areas of sediment trapping still exist, which are related to the Hudson Valley Highlands and to the location of the estuarine turbidity maximum that hold large volumes of sediment. As a result minor volumes of Recent sediment are

Functional redundancy and sensitivity of fish assemblages in European rivers, lakes and estuarine ecosystems.

PubMed

Teichert, Nils; Lepage, Mario; Sagouis, Alban; Borja, Angel; Chust, Guillem; Ferreira, Maria Teresa; Pasquaud, Stéphanie; Schinegger, Rafaela; Segurado, Pedro; Argillier, Christine

2017-12-14

The impact of species loss on ecosystems functioning depends on the amount of trait similarity between species, i.e. functional redundancy, but it is also influenced by the order in which species are lost. Here we investigated redundancy and sensitivity patterns across fish assemblages in lakes, rivers and estuaries. Several scenarios of species extinction were simulated to determine whether the loss of vulnerable species (with high propensity of extinction when facing threats) causes a greater functional alteration than random extinction. Our results indicate that the functional redundancy tended to increase with species richness in lakes and rivers, but not in estuaries. We demonstrated that i) in the three systems, some combinations of functional traits are supported by non-redundant species, ii) rare species in rivers and estuaries support singular functions not shared by dominant species, iii) the loss of vulnerable species can induce greater functional alteration in rivers than in lakes and estuaries. Overall, the functional structure of fish assemblages in rivers is weakly buffered against species extinction because vulnerable species support singular functions. More specifically, a hotspot of functional sensitivity was highlighted in the Iberian Peninsula, which emphasizes the usefulness of quantitative criteria to determine conservation priorities.

Influence of increasing temperature and salinity on herbicide toxicity in estuarine phytoplankton.

PubMed

DeLorenzo, Marie E; Danese, Loren E; Baird, Thomas D

2013-07-01

Ecological risk assessments are, in part, based on results of toxicity tests conducted under standard exposure conditions. Global climate change will have a wide range of effects on estuarine habitats, including potentially increasing water temperature and salinity, which may alter the risk assessment of estuarine pollutants. We examined the effects of increasing temperature and salinity on the toxicity of common herbicides (irgarol, diuron, atrazine, and ametryn) to the phytoplankton species Dunaliella tertiolecta. Static 96-h algal bioassays were conducted for each herbicide under four exposure scenarios: standard temperature and salinity (25°C, 20 ppt), standard temperature and elevated salinity (25°C, 40 ppt), elevated temperature and standard salinity (35°C, 20 ppt), and elevated temperature and elevated salinity (35°C, 40 ppt). The endpoints assessed were algal cell density at 96 h, growth rate, chlorophyll a content, lipid content, and starch content. Increasing exposure temperature reduced growth rate and 96-h cell density but increased the cellular chlorophyll and lipid concentrations of the control algae. Exposure condition did not alter starch content of control algae. Herbicides were found to decrease growth rate, 96 h cell density, and cellular chlorophyll and lipid concentrations, while starch concentrations increased with herbicide exposure. Herbicide effects under standard test conditions were then compared with those observed under elevated temperature and salinity. Herbicide effects on growth rate, cell density, and starch content were more pronounced under elevated salinity and temperature conditions. To encompass the natural variability in estuarine temperature and salinity, and to account for future changes in climate, toxicity tests should be conducted under a wider range of environmental conditions. Copyright © 2011 Wiley Periodicals, Inc.

Ecosystem health: I. Measuring ecosystem health

NASA Astrophysics Data System (ADS)

Schaeffer, David J.; Herricks, Edwin E.; Kerster, Harold W.

1988-07-01

Ecosystem analysis has been advanced by an improved understanding of how ecosystems are structured and how they function. Ecology has advanced from an emphasis on natural history to consideration of energetics, the relationships and connections between species, hierarchies, and systems theory. Still, we consider ecosystems as entities with a distinctive character and individual characteristics. Ecosystem maintenance and preservation form the objective of impact analysis, hazard evaluation, and other management or regulation activities. In this article we explore an approach to ecosystem analysis which identifies and quantifies factors which define the condition or state of an ecosystem in terms of health criteria. We relate ecosystem health to human/nonhuman animal health and explore the difficulties of defining ecosystem health and suggest criteria which provide a functional definition of state and condition. We suggest that, as has been found in human/nonhuman animal health studies, disease states can be recognized before disease is of clinical magnitude. Example disease states for ecosystems are functionally defined and discussed, together with test systems for their early detection.

Isolation of heterotrophic diazotrophic bacteria from estuarine surface waters.

PubMed

Farnelid, Hanna; Harder, Jens; Bentzon-Tilia, Mikkel; Riemann, Lasse

2014-10-01

The wide distribution of diverse nitrogenase (nifH) genes affiliated with those of heterotrophic bacteria in marine and estuarine waters indicates ubiquity and an ecologically relevant role for heterotrophic N2 -fixers (diazotrophs) in aquatic nitrogen (N) cycling. However, the lack of cultivated representatives currently precludes an evaluation of their N2 -fixing capacity. In this study, microoxic or anoxic N-free media were inoculated with estuarine Baltic Sea surface water to select for N2 -fixers. After visible growth and isolation of single colonies on oxic plates or in anoxic agar tubes, nifH gene amplicons were obtained from 64 strains and nitrogenase activity, applying the acetylene reduction assay, was confirmed for 40 strains. Two strains, one Gammaproteobacterium affiliated with Pseudomonas and one Alphaproteobacterium affiliated with Rhodopseudomonas were shown to represent established members of the indigenous diazotrophic community in the Baltic Sea, with abundances of up to 7.9 × 10(4) and 4.7 × 10(4)  nifH copies l(-1) respectively. This study reports media for successful isolation of heterotrophic diazotrophs. The applied methodology and the obtained strains will facilitate future identification of factors controlling heterotrophic diazotrophic activity in aquatic environments, which is a prerequisite for understanding and evaluating their ecology and contribution to N cycling at local and regional scales. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

Invasive Marine and Estuarine Animals of the Gulf of Mexico

DTIC Science & Technology

2005-09-01

some period of delay, or never be realized at all depending on the characteristics of the individual species and the conditions into which it is...and urbanization.’ Species are introduced by a variety of different mechanisms ; however, most estuarine and marine species introductions are...detected at Cape Canaveral in 1995, it was probably introduced on a fouled ship hull (USGS 2005). Shipworms are tolerant of a wide range of salinities

ADAPTIONS OF WILD POPULATIONS OF THE ESTUARINE FISH FUNDULUS HETEROCLITUS TO PERSISTENT ENVIRONMENTAL CONTAMINANTS

EPA Science Inventory

Many aquatic species, including the estuarine fish Fundulus heteroclitus (mummichogs), adapt to local environmental conditions. We conducted studies to evaluate whether highly exposed populations of mummichogs adapt to toxic environmental contaminants. These fish populations are ...

THE INFLUENCE OF INSECT JUVENILE HORMONE AGONISTTS ON METAMORPHOSIS AND REPRODUCTION IN ESTUARINE CRUSTACEANS

EPA Science Inventory

Comparative developmental and reproductive studies were performed on several species of estuarine crustaceans in response to three juvenile hormone agonists (JHAs) (methoprene, fenoxycarb, and pyriproxyfen). Larval development of the grass shrimp, Palaemonetes pugio, was greater ...

Adaptation of the Estuarine Fish, Fundulus heterclitus (Atlantic Killifish) to Polychlorinated Biphenyls (PCBs)

EPA Science Inventory

To characterize intra-specific variation in sensitivity to highly toxic pollutants in the non-migratory estuarine Atlantic killifish (Fundulus heteroclitus), we compared early life stage responses to the prototypical dioxin-like compound, 3,3’4,4’,5 hexachlorobiphenyl (PCB126). ...

VARIATION IN RESPONSIVENESS TO CONTAMINANTS IN WILD POPULATIONS OF ESTUARINE FISH, FUNDULUS HETERCLITUS

EPA Science Inventory

Populations of the non-migratory estuarine fish species Fundulus heteroclitus indigenous to a PCB-contaminated Superfund site (New Bedford Harbor, MA, USA) are markedly less sensitive to the toxic effects of local contaminants than those from a reference site. We characterized th...

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 SOUIRCES, TRANSPORT, AND FATE IN COUPLED WATERSHED-ESTUARINE SYSTEMS OF COASTAL ALABAMA

EPA Science Inventory

The processes regulating sources, transport, and fate of nutrients were studied in 3 coupled watershed-estuarine systems that varied mainly by differences in the dominant land use-land cover (LULC), i.e. Weeks Bay -- agriculture, Dog River -- urban, and Fowl River -- forest. Mea...

DEVELOPING A NATIONALLY CONSISTENT APPROACH FOR ASSESSING REGIONAL ASSOCIATIONS BETWEEN NUTRIENTS AND BENTHIC BIOLOGICAL CONDITION IN ESTUARINE WATERS. AN ANALYSIS USING NATIONAL COASTAL ASSESSMENT DATA

EPA Science Inventory

Identifying candidate water quality criteria in estuarine waters is confounded by differences among estuaries and biogeographic regions. Dealing with these differences is paramount to successfully addressing estuarine water quality impairment. As such, we outline an approach to...

Bioconcentration of endosulfan in different body tissues of estuarine organisms under sublethal exposure

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

Rajendran, N.; Venugopalan, V.K.

1991-01-01

The organochlorine pesticide endosulfan is applied in the agricultural fields as liquid in India. Investigations have revealed the occurrence and distribution of endosulfan in both biotic and abiotic components of Vellar estuary. The results from static bioassay studies revealed that fishes were more susceptible to the organochlorine pesticides than mollusks. Though the available information on the uptake of endosulfan by the estuarine organisms are limited to whole body tissues, no attempt has been made to find out the extent of uptake of pesticides by the different body tissues of the estuarine organisms. Hence the present study was planned to determinemore » the bioconcentration of endosulfan in different tissues of fishes Mugil cephalus, Mystus gulio, oyster Crassostrea madrasensis and clam Katelysia opima based on the measured concentration of endosulfan in the experimental medium of the continuous flow through system for a period of 10 d.« less

Summertime conditions of a muddy estuarine environment: the EsCoSed project contribution.

PubMed

Brocchini, Maurizio; Calantoni, Joseph; Reed, Allen H; Postacchini, Matteo; Lorenzoni, Carlo; Russo, Aniello; Mancinelli, Alessandro; Corvaro, Sara; Moriconi, Giacomo; Soldini, Luciano

2015-01-01

As part of the Estuarine Cohesive Sediments (EsCoSed) project, a field experiment was performed in a highly engineered environment, acting as a natural laboratory, to study the physico-chemical properties of estuarine sediments and the associated hydro-morphodynamics during different seasons. The present contribution focuses on the results obtained from the summertime monitoring of the most downstream part of the Misa River (Senigallia, Italy). The measured hydrodynamics suggested a strong interaction between river current, wave forcing and tidal motion; flow velocities, affected by wind waves traveling upstream, changed significantly along the water column in both direction and magnitude. Surficial salinities in the estuary were low in the upper reaches of the estuary and exceeded 10 psu before the river mouth. Montmorillonite dominated the clay mineral assemblage, suggesting that large, low density flocs with high settling velocities (>1 mm s(-1)) may dominate the suspended aggregate materials.

The combined use of the PLHC-1 cell line and the recombinant yeast assay to assess the environmental quality of estuarine and coastal sediments.

PubMed

Schnell, Sabine; Olivares, Alba; Piña, Benjamin; Echavarri-Erasun, Beatriz; Lacorte, Silvia; Porte, Cinta

2013-12-15

Sediment contamination poses a potential risk for both ecosystems and human health. Risk assessment is troublesome as sediments contain complex mixtures of toxicants, and traditional chemical analyses can neither provide information about potential hazards to organisms nor identify and measure all present contaminants. This work combines the use of the PLHC-1 cell line and the recombinant yeast assay (RYA) to assess the environmental quality of estuarine and coastal sediments. The application of multiple endpoints (cytotoxicity, generation of oxidative stress, presence of CYP1A inducing agents, micronucleus formation and estrogenicity) revealed that the organic extracts of those sediments affected by industrial activities or collected near harbours and untreated urban discharges showed significant cytotoxicity, micronuclei and CYP1A induction. The study highlights the usefulness of the applied bioassays to identify those sediments that could pose risk to aquatic organisms and that require further action to improve their environmental quality. Copyright © 2013 Elsevier Ltd. All rights reserved.

Ecological periodic tables for nekton and benthic macrofaunal community usage of estuarine habitats Slides

EPA Science Inventory

Ecological periodic tables for nekton and benthic macrofaunal community usage of estuarine habitats Steven P. Ferraro, U.S. Environmental Protection Agency, Newport, OR Background/Questions/Methods The chemical periodic table, the Linnaean system of classification, and the Her...

RESPONSES OF ESTUARINE BENTHIC INVERTEBRATES TO SEDIMENT BURIAL: THE IMPORTANCE OF MOBILITY AND ADAPTATION

EPA Science Inventory

Estuarine benthic organisms are frequently subjected to disturbance events caused by hydrodynamic processes that disrupt and move the sediment in which the animals reside, however the mechanisms by which physical disturbance processes affect infaunal and epifaunal populations and...

Can salt marsh plants influence levels and distribution of DDTs in estuarine areas?

NASA Astrophysics Data System (ADS)

Carvalho, Pedro N.; Rodrigues, Pedro Nuno R.; Evangelista, Rafael; Basto, M. Clara P.; Vasconcelos, M. Teresa S. D.

2011-07-01

Sediments are depositories of toxic substances such as organochlorine pesticides and there is a global need for their removal in contaminated environments. Studies that combine contaminated sediments and phytoremediation are relatively recent and their number has been increasing. This work aimed to investigate whether salt marsh plants (sea club-rush Scirpus maritimus, sea rush Juncus maritimus and sea purslane Halimione portulacoides) can favor DDT and metabolites remediation in estuarine environment. For this purpose the levels of DDT, DDE and DDD were compared in vegetated and non-vegetated sediments from an estuary in the North of Portugal ( in-situ study) and from another in the South of Portugal ( ex-situ study). Results obtained both in the in-situ study, involving S. maritimus and J. maritimus, and in the ex-situ study, involving H. portulacoides, indicated that these plants did not have a significant role in DDTs removal and/or degradation. Therefore, it seems that the tested plants cannot influence levels and distribution of DDTs in estuarine areas.

Size-selective toxicity effects of the antimicrobial tylosin on estuarine phytoplankton communities.

PubMed

Kline, Allison; Pinckney, James L

2016-09-01

The purpose of this study was to determine the lethal and sublethal effects of the antimicrobial tylosin on natural estuarine phytoplankton communities. Bioassays were used in experimental treatments with final concentrations of 5 to 1000 μg tylosin l(-1). Maximum percent inhibition ranged from 57 to 85% at concentrations of 200-400 μg tylosin l(-1). Half maximum inhibition concentrations of tylosin were ca. 5x lower for small phytoplankton (<20 μm) relative to larger phytoplankton (>20 μm) and suggests that small phytoplankton are more sensitive to tylosin exposure. Sublethal effects occurred at concentrations as low as 5 μg tylosin l(-1). Environmental concentrations of tylosin (e.g., 0.2-3 μg l(-1)) may have a significant sublethal effect that alters the size structure and composition of phytoplankton communities. The results of this study highlight the potential importance of cell size on toxicity responses of estuarine phytoplankton. Copyright © 2016 Elsevier Ltd. All rights reserved.

How tides and river flows determine estuarine bathymetries [review article

NASA Astrophysics Data System (ADS)

Prandle, D.

2004-04-01

For strongly tidal, funnel-shaped estuaries, we examine how tides and river flows determine size and shape. We also consider how long it takes for bathymetric adjustment, both to determine whether present-day bathymetry reflects prevailing forcing and how rapidly changes might occur under future forcing scenarios. Starting with the assumption of a 'synchronous' estuary (i.e., where the sea surface slope resulting from the axial gradient in phase of tidal elevation significantly exceeds the gradient in tidal amplitude ζ̂), an expression is derived for the slope of the sea bed. Thence, by integration we derive expressions for the axial depth profile and estuarine length, L, as a function of ζ̂ and D, the prescribed depth at the mouth. Calculated values of L are broadly consistent with observations. The synchronous estuary approach enables a number of dynamical parameters to be directly calculated and conveniently illustrated as functions of ζ̂ and D, namely: current amplitude Û, ratio of friction to inertia terms, estuarine length, stratification, saline intrusion length, flushing time, mean suspended sediment concentration and sediment in-fill times. Four separate derivations for the length of saline intrusion, LI, all indicate a dependency on D 2/f ÛU o ( Uo is the residual river flow velocity and f is the bed friction coefficient). Likely bathymetries for `mixed' estuaries can be delineated by mapping, against ζ̂ and D, the conditions LI/ L<1, EX/ L<1 ( EX is the tidal excursion) alongside the Simpson-Hunter criteria D/ U3<50 m -2 s 3. This zone encompasses 24 out of 25 `randomly' selected UK estuaries. However, the length of saline intrusion in a funnel-shaped estuary is also sensitive to axial location. Observations suggest that this location corresponds to a minimum in landward intrusion of salt. By combining the derived expressions for L and LI with this latter criterion, an expression is derived relating Di, the depth at the centre of the intrusion

Invasive Marine and Estuarine Animals of Hawaii and Other Pacific Islands

DTIC Science & Technology

2005-08-01

immediately, after some period of delay, Japanese Shore Crab, Hemigrapsus or may never be realized at all depending on the sanguineus (image courtesy of USGS...industrial development, and urbanization. Species are introduced by a variety of different mechanisms ; however, most estuarine and marine species...commonly called shipworms. Most ship- worms, including the native species Bankia gouldii, are tolerant of a wide range of salinities and temperatures

Nonlinear and Dissipation Characteristics of Ocean Surface Waves in Estuarine Environments

DTIC Science & Technology

2014-09-30

transformation and evolution . In addition these modules would allow for feedback between the surface wave and the energy dissipating feature. OBJECTIVES...dissipation on wave processes. 3) Develop and test low-dimension, reduced representations of estuarine effects for inclusion into operational wave models...Sheremet (PI), Miao Tian and Cihan Sahin (Ph.D. students) who are working on modeling nonlinear wave evolution in dissipative environments (mud), and

Diffusive gradients in thin films technique provide robust prediction of metal bioavailability and toxicity in estuarine sediments.

PubMed

Amato, Elvio D; Simpson, Stuart L; Jarolimek, Chad V; Jolley, Dianne F

2014-04-15

Many sediment quality assessment frameworks incorporate contaminant bioavailability as a critical factor regulating toxicity in aquatic ecosystems. However, current approaches do not always adequately predict metal bioavailability to organisms living in the oxidized sediment surface layers. The deployment of the diffusive gradients in thin films (DGT) probes in sediments allows labile metals present in pore waters and weakly bound to the particulate phase to be assessed in a time-integrated manner in situ. In this study, relationships between DGT-labile metal fluxes within 5 mm of the sediment-water interface and lethal and sublethal effects to the amphipod Melita plumulosa were assessed in a range of contaminated estuarine sediments during 10-day laboratory-based bioassays. To account for differing toxicities of metals, DGT fluxes were normalized to water (WQG) or sediment quality guidelines or toxicity thresholds specific for the amphipod. The better dose-response relationship appeared to be the one based on WQG-normalized DGT fluxes, which successfully predicted toxicity despite the wide range of metals and large variations in sediment properties. The study indicated that the labile fraction of metals measured by DGT is useful for predicting metal toxicity to benthic invertebrates, supporting the applicability of this technique as a rapid monitoring tool for sediments quality assessments.

Determining the direct upland hydrological contribution area of estuarine wetlands using Arc/GIS tools

EPA Science Inventory

The delineation of a polygon layer representing the direct upland runoff contribution to esturine wetland polygons can be a useful tool in estuarine wetland assessment. However, the traditional methods of watershed delineation using pour points and digital elevation models (DEMs)...

Performance of Passive Samplers for Monitoring Estuarine Water Column Concentrations: 1. Contaminants of Concern

EPA Science Inventory

Contaminants enter marine and estuarine environments and can potentially pose risk to human and ecological health. Measuring contaminants of concern (COC) in these aqueous media can be difficult due to their relatively low solubilities and tendency to associate with environmenta...

Influence of sediment organic carbon on estuarine benthic species of the US West Coast

EPA Science Inventory

Total organic carbon (TOC) is often used as an indicator of nutrient enrichment in estuarine environments. However, the determination of biologically relevant TOC criteria to indicate sediment quality is complicated by the relationship between TOC and grain size. Both variables...

A Method to Identify Estuarine Macroinvertebrate Pollution Indicator Species in the Virginian Biogeogarphic Province

EPA Science Inventory

Macroinvertebrates are commonly used as biomonitors to detect pollution impacts in estuaries. The goal of this research was to identify estuarine benthic invertebrates that could be used as indicator species to detect presence or absence of pollution in the Virginian Biogeograph...

Reoxidation of estuarine sediments during simulated resuspension events: Effects on nutrient and trace metal mobilisation

NASA Astrophysics Data System (ADS)

Vidal-Durà, Andrea; Burke, Ian T.; Stewart, Douglas I.; Mortimer, Robert J. G.

2018-07-01

Estuarine environments are considered to be nutrient buffer systems as they regulate the delivery of nutrients from rivers to the ocean. In the Humber Estuary (UK) seawater and freshwater mixing during tidal cycles leads to the mobilisation of oxic surface sediments (0-1 cm). However, less frequent seasonal events can also mobilise anoxic subsurface (5-10 cm) sediments, which may have further implications for the estuarine geochemistry. A series of batch experiments were carried out on surface and subsurface sediments taken from along the salinity gradient of the Humber Estuary. The aim was to investigate the geochemical processes driving major element (N, Fe, S, and Mn) redox cycling and trace metal behaviour during simulated resuspension events. The magnitude of major nutrient and metal release was significantly greater during the resuspension of outer estuarine sediments rather than from inner estuarine sediments. When comparing resuspension of surface versus subsurface sediment, only the outer estuary experiments showed significant differences in major nutrient behaviour with sediment depth. In general, any ammonium, manganese and trace metals (Cu and Zn) released during the resuspension experiments were rapidly removed from solution as new sorption sites (i.e. Fe/Mn oxyhydroxides) formed. Therefore Humber estuary sediments showed a scavenging capacity for these dissolved species and hence may act as an ultimate sink for these elements. Due to the larger aerial extent of the outer estuary intertidal mudflats in comparison with the inner estuary area, the mobilisation of the outer estuary sediments (more reducing and richer in sulphides and iron) may have a greater impact on the transport and cycling of nutrients and trace metals. Climate change-associated sea level rise combined with an increasing frequency of major storm events in temperate zones, which are more likely to mobilise deeper sediment regions, will impact the nutrient and metal inputs to the

Biodegradation of petroleum hydrocarbons in estuarine sediments: metal influence.

PubMed

Almeida, Raquel; Mucha, Ana P; Teixeira, Catarina; Bordalo, Adriano A; Almeida, C Marisa R

2013-02-01

In this work, the potential effect of metals, such as Cd, Cu and Pb, on the biodegradation of petroleum hydrocarbons in estuarine sediments was investigated under laboratory conditions. Sandy and muddy non-vegetated sediments were collected in the Lima River estuary (NW Portugal) and spiked with crude oil and each of the metals. Spiked sediments were left in the dark under constant shaking for 15 days, after which crude oil biodegradation was evaluated. To estimate microbial abundance, total cell counts were obtained by DAPI staining and microbial community structure was characterized by ARISA. Culturable hydrocarbon degraders were determined using a modified most probable number protocol. Total petroleum hydrocarbons concentrations were analysed by Fourier Transform Infrared Spectroscopy after their extraction by sonication, and metal contents were determined by atomic absorption spectrometry. The results obtained showed that microbial communities had the potential to degrade petroleum hydrocarbons, with a maximum of 32 % degradation obtained for sandy sediments. Both crude oil and metals changed the microbial community structure, being the higher effect observed for Cu. Also, among the studied metals, only Cu displayed measurable deleterious effect on the hydrocarbons degradation process, as shown by a decrease in the hydrocarbon degrading microorganisms abundance and in the hydrocarbon degradation rates. Both degradation potential and metal influence varied with sediment characteristics probably due to differences in contaminant bioavailability, a feature that should be taken into account in developing bioremediation strategies for co-contaminated estuarine sites.

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.

Estuarine Ecology of Juvenile Salmon in Western Alaska: a Review

USGS Publications Warehouse

Zimmerman, Christian E.; Hillgruber, Nicola

2009-01-01

In the late 1990s and early 2000s, large declines in numbers of chum salmon Oncorhynchus keta and Chinook salmon O. tshawytscha returning to the Arctic-YukonKuskokwim (AYK) region (Alaska, USA) illuminated the need for an improved understanding of the variables controlling salmon abundance at all life stages. In addressing questions about salmon abundance, large gaps in our knowledge of basic salmon life history and the critical early marine life stage were revealed. In this paper, results from studies conducted on the estuarine ecology of juvenile salmon in western Alaska are summarized and compared, emphasizing timing and distribution during outmigration, environmental conditions, age and growth, feeding, and energy content of salmon smolts. In western Alaska, water temperature dramatically changes with season, ranging from 0°C after ice melt in late spring/early summer to 19°C in July. Juvenile salmon were found in AYK estuaries from early May until August or September, but to date no information is available on their residence duration or survival probability. Chum salmon were the most abundant juvenile salmon reported, ranging in percent catch from <0.1% to 4.7% and most research effort has focused on this species. Abundances of Chinook salmon, sockeye salmon O. nerka, and pink salmon O. gorbuscha varied among estuaries, while coho salmon O. kisutch juveniles were consistently rare, never amounting to more than 0.8% of the catch. Dietary composition of juvenile salmon was highly variable and a shift was commonly reported from epibenthic and neustonic prey in lower salinity water to pelagic prey in higher salinity water. Gaps in the knowledge of AYK salmon estuarine ecology are still evident. For example, data on outmigration patterns and residence timing and duration, rearing conditions and their effect on diet, growth, and survival are often completely lacking or available only for few selected years and sites. Filling gaps in knowledge concerning salmon

Natural and Anthropocene fluxes of trace elements in estuarine sediments of Galician Rias

NASA Astrophysics Data System (ADS)

Álvarez-Vázquez, Miguel Ángel; Caetano, Miguel; Álvarez-Iglesias, Paula; Pedrosa-García, María del Canto; Calvo, Susana; De Uña-Álvarez, Elena; Quintana, Begoña; Vale, Carlos; Prego, Ricardo

2017-11-01

The Anthropocene has been proposed as a new geo-stratigraphic epoch where humans have become a global factor affecting the ecosystems. Estuarine sediments constitute a biogeochemical reservoir where trace elements (TEs) from natural sources mix with a fraction generated by human activities. This study assessed the natural lithogenic imprint of TEs from uncontaminated sedimentary records to study anthropogenic changes. Sediment cores were sampled in the estuarine part of the low populated and low industrialized rias of Ares (A), Betanzos (B) and Cedeira (C), which are located in the NW of the Iberian Peninsula. Cores were dated by the 210Pb method, covering up to the last century period. Sedimentation rates (in mm yr-1) were 3.4 ± 0.6 (older than 1961) and 8.2 ± 3.2 (younger than 1961) for core A, 0.9 ± 0.2 (<1940) and 4.2 ± 2.3 for core B, and 13.4 ± 1.4 for core C. The background fluxes of TEs were in the ranges of (in g m-2 yr-1) 50-560 for Al and Fe, 20-320 for POC and 8-100 for PS, and (in mg m-2 yr-1) 20-120 for As, 0.2-2.0 for Cd, 7-110 for Co, 40-870 for Cr, 20-230 for Cu, 0.1-0.6 for Hg, 290-2800 for Mn, 4-24 for Mo, 20-410 for Ni, 20-150 for Pb, 60-800 for V and 70-700 for Zn. The three cores showed an anthropogenic influence since the mid-20th century. The detected human impact during the Anthropocene was due to the Eume River damming and As-Pontes lignite mining (the largest mine open-pit in the Iberian Peninsula) in core A, by bridge/road constructions, vehicles emissions and river mouth urbanization in core B, and changes in land use in core C. Sediment accumulation rates increased 2.4 (core A) and 4.7 times (core B) while TEs fluxes increased 2.4 times in core A and between 3.6 and 5.1 times in core B. Pre-industrial sedimentary records showed the lithogenic differences of the drainage basins, mainly granitic watersheds for cores A and B and the prevalence of basic rocks of the Ortegal Geological Complex for core C. This explains the high

Water organic pollution and eutrophication influence soil microbial processes, increasing soil respiration of estuarine wetlands: site study in jiuduansha wetland.

PubMed

Zhang, Yue; Wang, Lei; Hu, Yu; Xi, Xuefei; Tang, Yushu; Chen, Jinhai; Fu, Xiaohua; Sun, Ying

2015-01-01

Undisturbed natural wetlands are important carbon sinks due to their low soil respiration. When compared with inland alpine wetlands, estuarine wetlands in densely populated areas are subjected to great pressure associated with environmental pollution. However, the effects of water pollution and eutrophication on soil respiration of estuarine and their mechanism have still not been thoroughly investigated. In this study, two representative zones of a tidal wetland located in the upstream and downstream were investigated to determine the effects of water organic pollution and eutrophication on soil respiration of estuarine wetlands and its mechanism. The results showed that eutrophication, which is a result of there being an excess of nutrients including nitrogen and phosphorus, and organic pollutants in the water near Shang shoal located upstream were higher than in downstream Xia shoal. Due to the absorption and interception function of shoals, there to be more nitrogen, phosphorus and organic matter in Shang shoal soil than in Xia shoal. Abundant nitrogen, phosphorus and organic carbon input to soil of Shang shoal promoted reproduction and growth of some highly heterotrophic metabolic microorganisms such as β-Proteobacteria, γ-Proteobacteria and Acidobacteria which is not conducive to carbon sequestration. These results imply that the performance of pollutant interception and purification function of estuarine wetlands may weaken their carbon sequestration function to some extent.

Water Organic Pollution and Eutrophication Influence Soil Microbial Processes, Increasing Soil Respiration of Estuarine Wetlands: Site Study in Jiuduansha Wetland

PubMed Central

Zhang, Yue; Wang, Lei; Hu, Yu; Xi, Xuefei; Tang, Yushu; Chen, Jinhai; Fu, Xiaohua; Sun, Ying

2015-01-01

Undisturbed natural wetlands are important carbon sinks due to their low soil respiration. When compared with inland alpine wetlands, estuarine wetlands in densely populated areas are subjected to great pressure associated with environmental pollution. However, the effects of water pollution and eutrophication on soil respiration of estuarine and their mechanism have still not been thoroughly investigated. In this study, two representative zones of a tidal wetland located in the upstream and downstream were investigated to determine the effects of water organic pollution and eutrophication on soil respiration of estuarine wetlands and its mechanism. The results showed that eutrophication, which is a result of there being an excess of nutrients including nitrogen and phosphorus, and organic pollutants in the water near Shang shoal located upstream were higher than in downstream Xia shoal. Due to the absorption and interception function of shoals, there to be more nitrogen, phosphorus and organic matter in Shang shoal soil than in Xia shoal. Abundant nitrogen, phosphorus and organic carbon input to soil of Shang shoal promoted reproduction and growth of some highly heterotrophic metabolic microorganisms such as β-Proteobacteria, γ-Proteobacteria and Acidobacteria which is not conducive to carbon sequestration. These results imply that the performance of pollutant interception and purification function of estuarine wetlands may weaken their carbon sequestration function to some extent. PMID:25993326

Phenylpyrazole insecticide fipronil induces male infertility in the estuarine meiobenthic crustacean Amphiascus tenuiremis.

PubMed

Cary, Tawnya L; Chandler, G Thomas; Volz, David C; Walse, Spencer S; Ferry, John L

2004-01-15

Copepods are the most abundant arthropods on earth and are often the most important secondary producers in estuarine/marine food webs. The new GABA (gamma-aminobutyric acid)-disrupting insecticide fipronil (FP) induces unique sex-specific reproductive dysfunction in male meiobenthic copepods, leading to trans-generational population depression at environmentally realistic concentrations (0.63 microg/L). Using a newly developed 96-well microplate lifecycle bioassay, more than 700 individual Stage-I juveniles were reared to adulthood in as short as 12 days in only 200 microL of control (CTL) or 0.63 microg-FP/L seawater solution. Individual virgin male: female pairs were then cross-mated for all possible combinations within and across rearing treatments and allowed to mate for an additional 12 days in CTL or 0.63 microg-FP/L solution. FP at 0.63 microg/L caused no significant lethality to any mating combinations but evoked 73% or 89% inhibition of reproduction when FP-reared males were mated with either a control- or FP-reared female in FP solution, respectively. In contrast, when CTL-reared males were mated with FP-reared females in FP solution, there was no difference in reproductive success compared to FP-free controls. When FP-reared males were mated with either female group in FP-free solution, these mating pairs displayed a 3-day delay in time to brood sac extrusion but ultimately did reproduce. As fipronil (1) has a high K(ow), (2) is persistent in sediments where meiobenthic copepods live, and (3) has been detected in estuarine waters >0.7 microg/L, it may pose high risk to copepod production in estuarine systems.

The Importance of Allochthonous Subsidies to an Estuarine Food Web along a Salinity Gradient

EPA Science Inventory

Estuarine food webs function within a heterogeneous mosaic and are supported by a mix of primary producers from both local and distant sources. Processes governing the exchange and consumption of organic matter (OM), however, are poorly understood. To study the contribution of ...

75 FR 8649 - Evaluation of State Coastal Management Programs and National Estuarine Research Reserves

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-25

... Ocean and Coastal Resource Management (OCRM) announces a rescheduled site visit and time for a public... Management Programs and National Estuarine Research Reserves AGENCY: National Oceanic and Atmospheric Administration (NOAA), Office of Ocean and Coastal Resource Management, National Ocean Service, Commerce. ACTION...

Enhancing Science Instruction through Student-Created PowerPoint Presentations

ERIC Educational Resources Information Center

Gerido, Leona; Curran, Mary Carla

2014-01-01

Technology use in science classes can enhance lessons and reinforce scientific content. The creation of multimedia projects is a great way to engage students in lessons about estuarine ecosystems. In this activity, students can learn about estuarine organisms and use their creativity to write a story, create artwork, and develop a multimedia…

Mercury concentrations in estuarine sediments, Lavaca and Matagorda bays, Texas, 1992

USGS Publications Warehouse

Brown, David S.; Snyder, Grant L.; Taylor, R. Lynn

1998-01-01

U.S. Environmental Protection Agency Method 7471 (Cold Vapor Atomic Absorption) was an acceptable analytical method for determining the total mercury concentrations in the Lavaca-Matagorda Bays estuarine sediment samples. Measurement of additional trace metals would aid in the characterization of total mercury concentrations and in the identification of concentrator/collector relations that are principally responsible for the adsorption of mercurous compounds to particulates in the bottom sediments.

Uptake and Fate of Tri-N-Butyltin Cation in Estuarine Bacteria,

DTIC Science & Technology

1982-04-02

as well as Yamada and co-workers [31] found trialkyltins, especially tripropyl- tin (TPT) and tributyltin ( TBT ), had the highest antiw-,’.?ial...tin-resistant estuarine bacteria was studied. The bacterial isolates accumulated tributyltin to 3.7 to 7.7 mg tin per g dry weight of cells by a non...chromatography-atomic absorption spectrophotometry and tin-selective purge and trap flame photometric gas chromatography for possible tributyltin

Discontinuous hindcast simulations of estuarine bathymetric change: A case study from Suisun Bay, California

USGS Publications Warehouse

Ganju, Neil K.; Jaffe, Bruce E.; Schoellhamer, David H.

2011-01-01

Simulations of estuarine bathymetric change over decadal timescales require methods for idealization and reduction of forcing data and boundary conditions. Continuous simulations are hampered by computational and data limitations and results are rarely evaluated with observed bathymetric change data. Bathymetric change data for Suisun Bay, California span the 1867–1990 period with five bathymetric surveys during that period. The four periods of bathymetric change were modeled using a coupled hydrodynamic-sediment transport model operated at the tidal-timescale. The efficacy of idealization techniques was investigated by discontinuously simulating the four periods. The 1867–1887 period, used for calibration of wave energy and sediment parameters, was modeled with an average error of 37% while the remaining periods were modeled with error ranging from 23% to 121%. Variation in post-calibration performance is attributed to temporally variable sediment parameters and lack of bathymetric and configuration data for portions of Suisun Bay and the Delta. Modifying seaward sediment delivery and bed composition resulted in large performance increases for post-calibration periods suggesting that continuous simulation with constant parameters is unrealistic. Idealization techniques which accelerate morphological change should therefore be used with caution in estuaries where parameters may change on sub-decadal timescales. This study highlights the utility and shortcomings of estuarine geomorphic models for estimating past changes in forcing mechanisms such as sediment supply and bed composition. The results further stress the inherent difficulty of simulating estuarine changes over decadal timescales due to changes in configuration, benthic composition, and anthropogenic forcing such as dredging and channelization.

Estuarine water quality in parks of the Northeast Coastal and Barrier Network: vital signs estuarine nutrient-enrichment monitoring, 2006-11

USGS Publications Warehouse

Caldwell, James M.; Nixon, Matthew E.; Neckles, Hilary A.; Pooler, Penelope S.

2015-01-01

This report summarizes results of water-quality monitoring within estuaries of the National Park Service Northeast Coastal and Barrier Network (NCBN) from 2006 through 2011. Data collection formed part of the NCBN Vital Signs Monitoring Program implemented to detect threats of estuarine nutrient enrichment. Data included here were collected from six parks at predetermined intervals: Cape Cod National Seashore, Massachusetts (2007, 2008, 2009, 2010, 2011); Fire Island National Seashore, New York (2009, 2011); Gateway National Recreation Area, New York and New Jersey (2010); Assateague Island National Seashore, Maryland and Virginia (2006, 2008, 2010); George Washington Birthplace National Monument, Virginia (2009, 2011); and Colonial National Historic Park, Virginia (2008, 2010). Monitoring variables consisted of dissolved-oxygen concentration, chlorophyll a concentration, attenuation of downwelling photosynthetically available radiation (PAR), turbidity, water temperature, and salinity. All monitoring was conducted during four-week summer index periods. The monitoring design incorporated data collection at multiple, complementary spatial and temporal scales. Within each park, a spatial survey was conducted once during the index period following a probability design using a grid of tessellated hexagons as the basis for sample site selection. The spatial survey was supplemented with weekly measurements at a subset of sites and continuous monitoring at a single reference site. Within parks, data were reported as area-weighted water-quality conditions during each index period, the location and extent of estuarine area within condition categories, and spatial and temporal trends. In addition, we used a repeated measures analysis of variance to determine the extent to which variability in three water quality metrics (chlorophyll a in surface water, dissolved oxygen in bottom water, and water clarity expressed by PAR attenuation) was explained by year to year changes in

Pairing Coral Geochemical Analyses with an Ecosystem Services Model to Assess Drivers and Impacts of Sediment Delivery within Micronesia's Largest Estuary, Ngeremeduu Bay

NASA Astrophysics Data System (ADS)

Lewis, S.; Dunbar, R. B.; Mucciarone, D.; Barkdull, M.

2017-12-01

Scientific tools assessing impacts to watershed and coastal ecosystem services, like those from land-use land conversion (LULC), are critical for sustainable land management strategies. Small island nations are particularly vulnerable to LULC threats, especially sediment delivery, given their small spatial size and reliance on natural resources. In the Republic of Palau, a small Pacific island country, three major land-use activities—construction, fires, and agriculture— have increased sediment delivery to important estuarine and coastal habitats (i.e., rivers, mangroves, coral reefs) over the past 30 years. This project examines the predictive capacity of an ecosystem services model, Natural Capital Project's InVEST, for sediment delivery using historic land-use and coral geochemical analysis. These refined model projections are used to assess ecosystem services tradeoffs under different future land development and management scenarios. Coral cores (20-41cm in length) were sampled along a high-to-low sedimentation gradient (i.e., near major rivers (high-impact) and ocean (low-impact)) in Micronesia's largest estuary, Ngeremeduu Bay. Isotopic indicators of seasonality (δ18O and δ13C values (% VPDB)) were used to construct the age model for each core. Barium, Manganese, and Yttrium were used as trace metal proxies for sedimentation and measured in each core using a laser ablation ICP-MS. Finally, the Natural Capital Project's InVEST sediment delivery model was paired with Geospatial data to examine the drivers of sediment delivery (i.e., construction, farms and fires) within these two watersheds. A thirty-year record of trace metal to calcium ratios in coral skeletons show a peak in sedimentation during 2006 and 2007, and in 2012. These results suggest historic peaks in sediment delivery correlating to large-scale road construction and support previous findings that Ngeremeduu Bay has reached a tipping point of retaining sediment. Natural Capital's project In

Historical Assessment of Hypoxia in Narragansett Bay Using Geochemical Markers

EPA Science Inventory

Eutrophication due to anthropogenic activities has affected aquatic ecosystems globally. Increased inputs of nitrogen and other nutrients to estuarine and marine ecosystems as a result of agricultural practices, urbanization and suburbanization have resulted in degradation of wat...

[Study on nutrient and salinity in soil covered with different vegetations in Shuangtaizi estuarine wetlands].

PubMed

Song, Xiao-Lin; Lü, Xian-Guo; Zhang, Zhong-Sheng; Chen, Zhi-Ke; Liu, Zheng-Mao

2011-09-01

Nutrient elements and salinity in soil covered by different vegetations including Phragmites australis (Clay.) Trin., Typha orientalis Presl., Puccinellia distans Parl, and Suaeda salsa in Shuangtaizi estuarine wetlands were investigated to study their distribution characteristics and to reveal the nutrient element variation during the vegetation succession processes. Results indicated that total potassium, total phosphorus and salinity were different significantly in soil between different plant communities while available phosphorus, total nitrogen, available nitrogen, available potassium, total sulfur, iron and soil organic carbon were different insignificantly. Correlation analysis suggested that soil organic carbon were related significantly to total nitrogen, available phosphorus, available potassium, which implied that decomposition of plant litter might be the mail source of soil nitrogen and available nutrient. Salinity was significantly related to total phosphorus and iron in soil. In Shuangtaizi estuarine wetland soil, ratios of carbon to nitrogen (R(C/N)) was in the range of 12.21-26.33 and the average value was 18.21, which was higher than 12.0. It indicated that soil organic carbon in Shuangtaizi estuarine mainly came from land but not ocean and plants contributed the most of soil organic matters. There was no significant difference in R(C/N) between soil from the four plant communities (F = 1.890, p = 0.151). R(C/N) was related significantly to sol salinity (r = 0.346 3, p = 0.035 8) and was increasing with soil salinity.

No estuarine intertidal bathymetry? No worries! Estimating intertidal depth contours from readily available GIS data

EPA Science Inventory

The importance of littoral elevation to the distribution of intertidal species has long been a cornerstone of estuarine ecology and its historical importance to navigation cannot be understated. However, historically, intertidal elevation measurements have been sparse likely due ...

RESPONSE OF GHOST SHRIMP (NEOTRYPAEA CALIFORNIENSIS) BIOTURBATION TO ORGANIC MATTER ENRICHMENT OF ESTUARINE INTERTIDAL SEDIMENTS

EPA Science Inventory

Populations of burrowing shrimp (Neotrypaea californiensis and Upogebia p;ugettensis) are the dominant invertebrate fauna on Pacific estuarine tide flats, occupying >80% of intertidal area in some estuaries. Burrowing shrimp are renowned for their bioturbation of intertidal sedi...

Disturbances to metal partitioning during toxicity testing of iron(II)-rich estuarine pore waters and whole sediments.

PubMed

Simpson, Stuart L; Batley, Graeme E

2003-02-01

Metal partitioning is altered when suboxic estuarine sediments containing Fe(II)-rich pore waters are disturbed during collection, preparation, and toxicity testing. Experiments with model Fe(II)-rich pore waters demonstrated the rates at which adsorptive losses of Cd, Cu, Ni, Mn, Pb, and Zn occur upon exposure to air. Experiments with Zn-contaminated estuarine sediments demonstrated large and often unpredictable changes to metal partitioning during sediment storage, removal of organisms, and homogenization before testing. Small modifications to conditions, such as aeration of overlying waters, caused large changes to the metal partitioning. Disturbances caused by sediment collection required many weeks for reestablishment of equilibrium. Bioturbation by benthic organisms led to oxidation of pore-water Fe(II) and lower Zn fluxes because of the formation of Fe hydroxide precipitates that adsorb pore-water Zn. For five weeks after the addition of organisms to sediments, Zn fluxes increased slowly as the organisms established themselves in the sediments, indicating that the establishment of equilibrium was not rapid. The results are discussed in terms of the dynamic nature of suboxic, Fe(II)-rich estuarine sediments, how organisms perturb their environment, and the importance of understanding chemistry in toxicity testing with whole sediments or pore water. Recommendations are provided for the handling of sediments for toxicity testing.

Response of Bacterial Metabolic Activity to Riverine Dissolved Organic Carbon and Exogenous Viruses in Estuarine and Coastal Waters: Implications for CO2 Emission

PubMed Central

Xu, Jie; Sun, Mingming; Shi, Zhen; Harrison, Paul J.; Liu, Hongbin

2014-01-01

A cross-transplant experiment between estuarine water and seawater was conducted to examine the response of bacterial metabolic activity to riverine dissolved organic carbon (DOC) input under virus-rich and virus-free conditions, as well as to exogenous viruses. Riverine DOC input increased bacterial production significantly, but not bacterial respiration (BR) because of its high lability. The bioavailable riverine DOC influenced bulk bacterial respiration in two contrasting ways; it enhanced the bulk BR by stimulating bacterial growth, but simultaneously reduced the cell-specific BR due to its high lability. As a result, there was little stimulation of the bulk BR by riverine DOC. This might be partly responsible for lower CO2 degassing fluxes in estuaries receiving high sewage-DOC that is highly labile. Viruses restricted microbial decomposition of riverine DOC dramatically by repressing the growth of metabolically active bacteria. Bacterial carbon demand in the presence of viruses only accounted for 7–12% of that in the absence of viruses. Consequently, a large fraction of riverine DOC was likely transported offshore to the shelf. In addition, marine bacteria and estuarine bacteria responded distinctly to exogenous viruses. Marine viruses were able to infect estuarine bacteria, but not as efficiently as estuarine viruses, while estuarine viruses infected marine bacteria as efficiently as marine viruses. We speculate that the rapid changes in the viral community due to freshwater input destroyed the existing bacteria-virus relationship, which would change the bacterial community composition and affect the bacterial metabolic activity and carbon cycling in this estuary. PMID:25036641

Response of bacterial metabolic activity to riverine dissolved organic carbon and exogenous viruses in estuarine and coastal waters: implications for CO2 emission.

PubMed

Xu, Jie; Sun, Mingming; Shi, Zhen; Harrison, Paul J; Liu, Hongbin

2014-01-01

A cross-transplant experiment between estuarine water and seawater was conducted to examine the response of bacterial metabolic activity to riverine dissolved organic carbon (DOC) input under virus-rich and virus-free conditions, as well as to exogenous viruses. Riverine DOC input increased bacterial production significantly, but not bacterial respiration (BR) because of its high lability. The bioavailable riverine DOC influenced bulk bacterial respiration in two contrasting ways; it enhanced the bulk BR by stimulating bacterial growth, but simultaneously reduced the cell-specific BR due to its high lability. As a result, there was little stimulation of the bulk BR by riverine DOC. This might be partly responsible for lower CO2 degassing fluxes in estuaries receiving high sewage-DOC that is highly labile. Viruses restricted microbial decomposition of riverine DOC dramatically by repressing the growth of metabolically active bacteria. Bacterial carbon demand in the presence of viruses only accounted for 7-12% of that in the absence of viruses. Consequently, a large fraction of riverine DOC was likely transported offshore to the shelf. In addition, marine bacteria and estuarine bacteria responded distinctly to exogenous viruses. Marine viruses were able to infect estuarine bacteria, but not as efficiently as estuarine viruses, while estuarine viruses infected marine bacteria as efficiently as marine viruses. We speculate that the rapid changes in the viral community due to freshwater input destroyed the existing bacteria-virus relationship, which would change the bacterial community composition and affect the bacterial metabolic activity and carbon cycling in this estuary.

CHARACTERIZING POPULATIONS OF THE ESTUARINE FISH FUNDULUS HETEROCLITUS INDIGENOUS TO SITES WITH DIFFERING ENVIRONMENTAL QUALITY

EPA Science Inventory

Populations of the non-migratory estuarine fish Fundulus heteroclitus were collected from New Bedford Harbor and distant clean sites to investigate whether indigenous populations have adapted genetically to the harbor's contamination. New Bedford Harbor, a major port in southe...

Per capita invasion probabilities: A linear model to predict rates of invasion via ballast water

EPA Science Inventory

Ballast water discharges are a major source of species introductions into marine, estuarine, and freshwater ecosystems. To mitigate the introduction of new invaders into these ecosystems, many agencies are proposing discharge standards that establish upper concentration limits f...

Ecosystem informaties for natural history data - Developing an integrated framework for biological and geographic data

EPA Science Inventory

Threats to the ecological integrity of marine and estuarine systems operate over many spatial scales, from nutrient enrichment at watershed/estuarine linkages to invasive species and climate change at regional/global scales. Decision support tools and information systems needed t...

75 FR 42068 - Evaluation of State Coastal Management Programs and National Estuarine Research Reserves

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

...) announces its intent to evaluate the performance of the Elkhorn Slough (California) National Estuarine... Secretary of Commerce, and adhered to the terms of financial assistance awards funded under the CZMA. Each..., Watsonville, California. ADDRESSES: Copies of the State's most recent performance reports, as well as OCRM's...

FATE & EFFECTS OF AGRICULTURAL PESTICIDES WITHIN WEEKS BAY WATERSHED, A NATIONAL ESTUARINE RESEARCH RESERVE

EPA Science Inventory

Lytle, J.S., T.F. Lytle and M.A. Lewis. In press. Fate and Effects of Agricultural Pesticides Within Weeks Bay Watershed, a National Estuarine Research Preserve. To be presented at the 24th Annual Meeting in North America of the Society of Environmental Toxicology and Chemistry: ...

Characterization of soil salinization in typical estuarine area of the Jiaozhou Bay, China

NASA Astrophysics Data System (ADS)

Li, Qifei; Xi, Min; Wang, Qinggai; Kong, Fanlong; Li, Yue

2018-02-01

In this study, the characteristics of soil salinization and the effects of main land use/land cover and other factors in typical estuarine area of the Jiaozhou Bay are investigated. Soil samples were collected in the parallel coastal zone, vertical coastal zone and longitudinal profile depth in the area to determine the soil salt content. The correlation analysis and principal component analysis are used to address the general characteristics of soil salinization in the study area. In the horizontal direction, there are moderate salinization, severe salinization and saline soil state. The farther from the sea (within 1.1 km), the lower the soil salinization degree. In the direction of longitudinal profile depth, there are severe salinization and saline soil state, and the soil salt content is accumulated in the surface and bottom. The Na+ and Cl- are the dominant cation and anion, respectively, the distributions of which are consistent with that of salt content. All the salinization indexes, except for soil pH, are of moderate/strong variability. The invasion of Spartina alterniflora results in the increase of soil salt content and salinization degree, the effects of which are mainly determined by the physiological characteristics and the growth years. The degree of soil salinization increased significantly in the aquaculture ponds, which is mainly caused by the use of chemicals. The correlation between soil salt content and Na+, Cl- is particularly significant. From the results of principal component analysis, Na+, Cl-, Ca2+, Mg2+ and SO42- could be used as main diagnostic factors for salinization in typical estuarine area of the Jiaozhou Bay. The effects of NaCl and sulfate on salt content further affect the degree of salinization in the estuarine area.

Decadal-timescale estuarine geomorphic change under future scenarios of climate and sediment supply

USGS Publications Warehouse

Ganju, N.K.; Schoellhamer, D.H.

2010-01-01

Future estuarine geomorphic change, in response to climate change, sea-level rise, and watershed sediment supply, may govern ecological function, navigation, and water quality. We estimated geomorphic changes in Suisun Bay, CA, under four scenarios using a tidal-timescale hydrodynamic/sediment transport model. Computational expense and data needs were reduced using the morphological hydrograph concept and the morphological acceleration factor. The four scenarios included (1) present-day conditions; (2) sea-level rise and freshwater flow changes of 2030; (3) sea-level rise and decreased watershed sediment supply of 2030; and (4) sea-level rise, freshwater flow changes, and decreased watershed sediment supply of 2030. Sea-level rise increased water levels thereby reducing wave-induced bottom shear stress and sediment redistribution during the wind-wave season. Decreased watershed sediment supply reduced net deposition within the estuary, while minor changes in freshwater flow timing and magnitude induced the smallest overall effect. In all future scenarios, net deposition in the entire estuary and in the shallowest areas did not keep pace with sea-level rise, suggesting that intertidal and wetland areas may struggle to maintain elevation. Tidal-timescale simulations using future conditions were also used to infer changes in optical depth: though sea-level rise acts to decrease mean light irradiance, decreased suspended-sediment concentrations increase irradiance, yielding small changes in optical depth. The modeling results also assisted with the development of a dimensionless estuarine geomorphic number representing the ratio of potential sediment import forces to sediment export forces; we found the number to be linearly related to relative geomorphic change in Suisun Bay. The methods implemented here are widely applicable to evaluating future scenarios of estuarine change over decadal timescales. ?? The Author(s) 2009.

Mercury methylation dynamics in estuarine and coastal marine environments — A critical review

NASA Astrophysics Data System (ADS)

Merritt, Karen A.; Amirbahman, Aria

2009-09-01

Considerable recent research has focused on methylmercury (MeHg) cycling within estuarine and coastal marine environments. Because MeHg represents a potent neurotoxin that may magnify in marine foodwebs, it is important to understand the mechanisms and environmental variables that drive or constrain methylation dynamics in these environments. This critical review article explores the mechanisms hypothesized to influence aqueous phase and sediment solid phase MeHg concentrations and depth-specific inorganic Hg (II) (Hg i) methylation rates (MMR) within estuarine and coastal marine environments, and discusses issues of terminology or methodology that complicate mechanism-oriented interpretation of field and laboratory data. Mechanisms discussed in this review article include: 1) the metabolic activity of sulfate reducing bacteria (SRB), the microbial group thought to dominate mercury methylation in these environments; 2) the role that Hg i concentration and/or speciation play in defining depth-specific Hg i methylation rates; and 3) the depth-dependent balance between MeHg production and consumption within the sedimentary environment. As discussed in this critical review article, the hypothesis of SRB community control on the Hg i methylation rate in estuarine and coastal marine environments is broadly supported by the literature. Although Hg i speciation, as a function of porewater inorganic sulfide and/or dissolved organic matter concentration and/or pH, may also play a role in observed variations in MMR, the nature and function of the controlling ligand(s) has not yet been adequately defined. Furthermore, although it is generally recognized that the processes responsible for MeHg production and consumption overlap spatially and/or kinetically in the sedimentary environment, and likely dictate the extent to which MeHg accumulates in the aqueous and/or sediment solid phase, this conceptual interpretation requires refinement, and would benefit greatly from the

Influence of organic carbon on estuarine benthic infauna of the US west coast - March 3

EPA Science Inventory

Total organic carbon (TOC) is often used as an indicator of nutrient enrichment in estuarine environments. However, the determination of biologically relevant TOC criteria to indicate sediment condition is complicated by the relationship between TOC and grain size. Both variabl...

Coherent assembly of phytoplankton communities in diverse temperate ocean ecosystems

PubMed Central

Li, William K.W; Glen Harrison, W; Head, Erica J.H

2006-01-01

The annual cycle of phytoplankton cell abundance is coherent across diverse ecosystems in the temperate North Atlantic Ocean. In Bedford Basin, on the Scotian Shelf and in the Labrador Sea, the numerical abundance of phytoplankton is low in spring and high in autumn, thus in phase with the temperature cycle. Temperature aligns abundance on a common basis, effectively adjusting apparent cell discrepancies in waters that are colder or warmer than the regional norm. As an example of holistic simplicity arising from underlying complexity, the variance in a community variable (total abundance) is explained by a single predictor (temperature) to the extent of 75% in the marginal seas. In the estuarine basin, weekly averages of phytoplankton and temperature computed from a 13 year time-series yield a predictive relationship with 91% explained variance. Temperature-directed assembly of individual phytoplankton cells to form communities is statistically robust, consistent with observed biomass changes, amenable to theoretical analysis, and a sentinel for long-term change. Since cell abundance is a community property in the same units for all marine microbes at any trophic level and at any phylogenetic position, it promises to integrate biological oceanography into general ecology and evolution. PMID:16822757

Invasive Marine and Estuarine Animals of the South Atlantic and Puerto Rico

DTIC Science & Technology

2005-09-01

after some period of delay, or may never be realized at all depending on the characteristics of the indi- vidual species and the conditions into which...with naviga- tion, industrial development, and urbanization. Species can be introduced by a variety of different mechanisms ; however, most estuarine...of salinities , temperatures, flow conditions, and oxygen concentrations. These filter-feeding molluscs are dispersed by planktonic larvae. The larvae

75 FR 43145 - Evaluation of State Coastal Management Programs and National Estuarine Research Reserves

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-23

..., 2010, at 6:30 p.m. at the Tom Ridge Environmental Center at Presque Isle, Room 112, 301 Peninsula Drive, Erie, Pennsylvania. ADDRESSES: Copies of the States' most recent performance reports, as well as OCRM's... North Inlet/Winyah Bay (South Carolina) National Estuarine Research Reserve and the Pennsylvania Coastal...

YAQUINA BAY NUTRIENT CRITERIA CASE STUDY: APPROACHES TO ESTUARINE NUTRIENT CRITERIA IN THE PACIFIC NORTHWEST

EPA Science Inventory

The presentation presents an introduction to the Yaquina Bay Nutrient Case Study which provides approaches for development of estuarine nutrient criteria in the Pacific Northwest. As part of this effort, a database of historic and recent data has been assembled consisting of phy...

An integrated genetic linkage map and comparative genome analysis for the estuarine Atlantic killifish, Fundulus heteroclitus

USDA-ARS?s Scientific Manuscript database

Background: Fundulus heteroclitus (Atlantic killifish), a non-migratory estuarine fish, exhibits high allelic and phenotypic diversity, partitioned among subpopulations that reside in disparate environmental conditions. An ideal candidate model organism for studying gene-environment reactions, th...

Sediment carbon and nutrient fluxes from cleared and intact temperate mangrove ecosystems and adjacent sandflats.

PubMed

Bulmer, Richard H; Schwendenmann, Luitgard; Lohrer, Andrew M; Lundquist, Carolyn J

2017-12-01

The loss of mangrove ecosystems is associated with numerous impacts on coastal and estuarine function, including sediment carbon and nutrient cycling. In this study we compared in situ fluxes of carbon dioxide (CO 2 ) from the sediment to the atmosphere, and fluxes of dissolved inorganic nutrients and oxygen across the sediment-water interface, in intact and cleared mangrove and sandflat ecosystems in a temperate estuary. Measurements were made 20 and 25months after mangrove clearance, in summer and winter, respectively. Sediment CO 2 efflux was over two-fold higher from cleared than intact mangrove ecosystems at 20 and 25months after mangrove clearance. The higher CO 2 efflux from the cleared site was explained by an increase in respiration of dead root material along with sediment disturbance following mangrove clearance. In contrast, sediment CO 2 efflux from the sandflat site was negligible (≤9.13±1.18mmolm -2 d -1 ), associated with lower sediment organic matter content. The fluxes of inorganic nutrients (NH 4 + , NO x and PO 4 3- ) from intact and cleared mangrove sediments were low (≤20.37±18.66μmolm -2 h - 1 ). The highest NH 4 + fluxes were measured at the sandflat site (69.21±13.49μmolm -2 h - 1 ). Lower inorganic nutrient fluxes within the cleared and intact mangrove sites compared to the sandflat site were associated with lower abundance of larger burrowing macrofauna. Further, a higher fraction of organic matter, silt and clay content in mangrove sediments may have limited nutrient exchange. Copyright © 2017 Elsevier B.V. All rights reserved.

The Effects of Acidic and Hypoxic Conditions on the Estuarine ...

EPA Pesticide Factsheets

The interactive and combined effects of coastal acidification and hypoxia on estuarine species is an increasing concern as these stressors change concomitantly. There is a need to understand how these environmental factors interact, as well as their effect on estuarine organisms. A method was developed for this research whereby four exposure treatments were created simultaneously: ambient, elevated pCO2, (~1300µatm, IPCC RCP 8.5 scenario), hypoxic (low dissolved oxygen, ~2 mg/L), and combined elevated pCO2 with low dissolved oxygen. An exposure with variant water quality parameters allows for the comparative study of organismal survival response to acidified and hypoxic conditions. The goal of this research is to determine acute species sensitivity, which is determined by survivability, to the combined effects of elevated pCO2 and hypoxia over a 5 day period, as well as possible differences in sensitivity between life-stages. Preliminary research on sheepshead minnow and mysid shrimp, indicates that mysid shrimp were tolerant of both elevated pCO2 and low DO exposure regardless of life-stage, whereas sheepshead minnows were more sensitive to the combined effects of acidification and hypoxia. This work is part of the first phase of the NECAH project, which is identifying species that are sensitive to the combined effects of acidification and hypoxia. The project describes the initial work on the first 2 species selected for testing and the final product will be

Efficiencies of freshwater and estuarine constructed wetlands for phenolic endocrine disruptor removal in Taiwan.

PubMed

Hsieh, Chi-Ying; Yang, Lei; Kuo, Wen-Chien; Zen, Yi-Peng

2013-10-01

We examined the distribution and removal efficiencies of phenolic endocrine disruptors (EDs), namely nonylphenol diethoxylates (NP2EO), nonylphenol monoethoxylates (NP1EO), nonylphenol (NP), and octylphenol (OP), in wastewater treated by estuarine and freshwater constructed wetland systems in Dapeng Bay National Scenic Area (DBNSA) and along the Dahan River in Taiwan. Water samples were taken bimonthly at 30 sites in three estuarine constructed wetlands (Datan, Pengcun and Linbian right bank (A and B)) in DBNSA, for eight sampling campaigns. The average removal efficiencies were in the range of 3.13-97.3% for wetlands in DBNSA. The highest average removal occurred in the east inlet to the outlet of the Tatan wetland. The most frequently detected compound was OP (57.7%), whose concentration was up to 1458.7 ng/L in DBNSA. NP was seen in only 20.5% of the samples. The temporal variation of EDs showed a decrease across seasons, where summer>spring>winter>autumn in these constructed wetlands. The removal efficiencies of EDs by estuarine wetlands, in decreasing order, were Datan>Pengcun>Linbian right bank in DBNSA. Water samples collected at 18 sites in three freshwater constructed wetlands (Daniaopi, Hsin-Hai I, and Hsin-Hai II) along the riparian area of Dahan River. NP2EO was the most abundant compound, with a concentration of up to 11,200 ng/L. Removal efficiencies ranged from 55% to 91% for NP1EO, NP2EO, and NP in Hsin-Hai I. The average removal potential of EDs in freshwater constructed wetlands, in decreasing order, was Hsin-Hai II>Daniaopi>Hsin-Hai I constructed wetlands. The lowest concentrations of the selected compounds were observed in the winter. The highest removal efficiency of the selected phenolic endocrine disruptors was achieved by Hsin-Hai I wetland. The calculated risk quotients used to evaluate the ecological risk were up to 30 times higher in the freshwater wetlands along Dahan River than in the estuarine (DBNSA) constructed wetlands, indicating

Ecosystem-based management and the wealth of ecosystems.

PubMed

Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K; Fenichel, Eli P

2017-06-20

We merge inclusive wealth theory with ecosystem-based management (EBM) to address two challenges in the science of sustainable management of ecosystems. First, we generalize natural capital theory to approximate realized shadow prices for multiple interacting natural capital stocks (species) making up an ecosystem. These prices enable ecosystem components to be better included in wealth-based sustainability measures. We show that ecosystems are best envisioned as portfolios of assets, where the portfolio's performance depends on the performance of the underlying assets influenced by their interactions. Second, changes in ecosystem wealth provide an attractive headline index for EBM, regardless of whether ecosystem wealth is ultimately included in a broader wealth index. We apply our approach to the Baltic Sea ecosystem, focusing on the interacting community of three commercially important fish species: cod, herring, and sprat. Our results incorporate supporting services embodied in the shadow price of a species through its trophic interactions. Prey fish have greater shadow prices than expected based on market value, and predatory fish have lower shadow prices than expected based on market value. These results are because correctly measured shadow prices reflect interdependence and limits to substitution. We project that ecosystem wealth in the Baltic Sea fishery ecosystem generally increases conditional on the EBM-inspired multispecies maximum sustainable yield management beginning in 2017, whereas continuing the current single-species management generally results in declining wealth.

Ecosystem-based management and the wealth of ecosystems

PubMed Central

Yun, Seong Do; Hutniczak, Barbara; Abbott, Joshua K.; Fenichel, Eli P.

2017-01-01

We merge inclusive wealth theory with ecosystem-based management (EBM) to address two challenges in the science of sustainable management of ecosystems. First, we generalize natural capital theory to approximate realized shadow prices for multiple interacting natural capital stocks (species) making up an ecosystem. These prices enable ecosystem components to be better included in wealth-based sustainability measures. We show that ecosystems are best envisioned as portfolios of assets, where the portfolio’s performance depends on the performance of the underlying assets influenced by their interactions. Second, changes in ecosystem wealth provide an attractive headline index for EBM, regardless of whether ecosystem wealth is ultimately included in a broader wealth index. We apply our approach to the Baltic Sea ecosystem, focusing on the interacting community of three commercially important fish species: cod, herring, and sprat. Our results incorporate supporting services embodied in the shadow price of a species through its trophic interactions. Prey fish have greater shadow prices than expected based on market value, and predatory fish have lower shadow prices than expected based on market value. These results are because correctly measured shadow prices reflect interdependence and limits to substitution. We project that ecosystem wealth in the Baltic Sea fishery ecosystem generally increases conditional on the EBM-inspired multispecies maximum sustainable yield management beginning in 2017, whereas continuing the current single-species management generally results in declining wealth. PMID:28588145

Estuarine intertidal sediment temperature variability in Zoster marina and Z. japonica habitats in Yaquina Bay, Oregon

EPA Science Inventory

Physical characterization of intertidal estuarine plant habitats over time may reveal distribution-limiting thresholds. Temperature data from loggers embedded in sediment in transects crossing Zostera marina and Z. japonica habitats in lower Yaquina Bay, Oregon display signific...

Estuarine water quality in parks of the Northeast Coastal and Barrier Network: Development and early implementation of vital signs estuarine nutrient-enrichment monitoring, 2003-06

USGS Publications Warehouse

Kopp, Blaine S.; Nielsen, Martha; Glisic, Dejan; Neckles, Hilary A.

2009-01-01

This report documents results of pilot tests of a protocol for monitoring estuarine nutrient enrichment for the Vital Signs Monitoring Program of the National Park Service Northeast Coastal and Barrier Network. Data collected from four parks during protocol development in 2003-06 are presented: Gateway National Recreation Area, Colonial National Historic Park, Fire Island National Seashore, and Assateague Island National Seashore. The monitoring approach incorporates several spatial and temporal designs to address questions at a hierarchy of scales. Indicators of estuarine response to nutrient enrichment were sampled using a probability design within park estuaries during a late-summer index period. Monitoring variables consisted of dissolved-oxygen concentration, chlorophyll a concentration, water temperature, salinity, attenuation of downwelling photosynthetically available radiation (PAR), and turbidity. The statistical sampling design allowed the condition of unsampled locations to be inferred from the distribution of data from a set of randomly positioned "probability" stations. A subset of sampling stations was sampled repeatedly during the index period, and stations were not rerandomized in subsequent years. These "trend stations" allowed us to examine temporal variability within the index period, and to improve the sensitivity of the monitoring protocol to detecting change through time. Additionally, one index site in each park was equipped for continuous monitoring throughout the index period. Thus, the protocol includes elements of probabilistic and targeted spatial sampling, and the temporal intensity ranges from snapshot assessments to continuous monitoring.

Method 365.5 Determination of Orthophosphate in Estuarine and Coastal Waters by Automated Colorimetric Analysis

EPA Science Inventory

This method provides a procedure for the determination of low-level orthophosphate concentrations normally found in estuarine and/or coastal waters. It is based upon the method of Murphy and Riley1 adapted for automated segmented flow analysis2 in which the two reagent solutions ...

Holocene estuarine sediments as a source of arsenic in Pleistocene groundwater in suburbs of Hanoi, Vietnam

NASA Astrophysics Data System (ADS)

Kuroda, Keisuke; Hayashi, Takeshi; Funabiki, Ayako; Do, An Thuan; Canh, Vu Duc; Nga, Tran Thi Viet; Takizawa, Satoshi

2017-06-01

Groundwater pollution by arsenic is a major health threat in suburban areas of Hanoi, Vietnam. The present study evaluates the effect of the sedimentary environments of the Pleistocene and Holocene deposits, and the recharge systems, on the groundwater arsenic pollution in Hanoi suburbs distant from the Red River. At two study sites (Linh Dam and Tai Mo communes), undisturbed soil cores identified a Pleistocene confined aquifer (PCA) and Holocene unconfined aquifer (HUA) as major aquifers, and Holocene estuarine and deltaic sediments as an aquitard layer between the two aquifers. The Holocene estuarine sediments (approximately 25-40 m depth, 9.6-4.8 cal ka BP) contained notably high concentrations of arsenic and organic matter, both likely to have been accumulated by mangroves during the Holocene sea-level highstand. The pore waters in these particular sediments exhibited elevated levels of arsenic and dissolved organic carbon. Arsenic in groundwater was higher in the PCA (25-94 μg/L) than in the HUA (5.2-42 μg/L), in both the monitoring wells and neighboring household tubewells. Elevated arsenic concentration in the PCA groundwater was likely due to vertical infiltration through the arsenic-rich and organic-matter-rich overlying Holocene estuarine sediments, caused by massive groundwater abstraction from the PCA. Countermeasures to prevent arsenic pollution of the PCA groundwater may include seeking alternative water resources, reducing water consumption, and/or appropriate choice of aquifers for groundwater supply.

The impact of channel capture on estuarine hydro-morphodynamics and water quality in the Amazon delta.

PubMed

Silva Dos Santos, Eldo; Pinheiro Lopes, Paula Patrícia; da Silva Pereira, Hyrla Herondina; de Oliveira Nascimento, Otávio; Rennie, Colin David; da Silveira Lobo O'Reilly Sternberg, Leonel; Cavalcanti da Cunha, Alan

2018-05-15

Due to progressive erosion of the new Urucurituba Channel, the Amazon River has recently captured almost all discharge from the lower Araguari River (Amapá-AP, Brazil), which previously flowed directly to the Atlantic Ocean. These recent geomorphological changes have caused strong impacts on the landscape and hydrodynamic patterns near the Araguari River mouth, especially the alteration of the riverine drainage system and its water quality. Landsat images were used to assess the estuarine landscape morphodynamic, particularly the expansion of the Urucurituba Channel, 80km from the Araguari River mouth, chronicling its connection to the Amazon River. The results suggest that the Urucurituba developed by headward migration across the Amazon delta; this is perhaps the first observation of estuarine distributary network development by headward channel erosion. The rate of Urucurituba Channel width increase has been ≈5m/month since 2011, increasing drainage capacity of the channel. We also collected in situ hydrodynamic measurements and analyzed 17 water quality parameters. Having 2011 as baseline, the flowrate of Araguari River has been diverted by up to 98% through Urucurituba Channel, with substantial changes in net discharge recorded at 3 monitoring stations. Statistically significant differences in water quality (p<0.05) were observed between 2011 and 2015, associated with the change in the flow pattern. Estuarine salinity and solids concentrations have increased. Overall, we demonstrate changes in landscape, hydrodynamics and water quality of the lower Araguari River. Copyright © 2017 Elsevier B.V. All rights reserved.

High genetic connectivity among estuarine populations of the riverbream Acanthopagrus vagus along the southern African coast

NASA Astrophysics Data System (ADS)

Oosthuizen, Carel J.; Cowley, Paul D.; Kyle, Scotty R.; Bloomer, Paulette

2016-12-01

Physical and/or physiological constraints are assumed to isolate fish populations confined to or dependent on estuarine habitats. Strong isolation by distance is thus expected to affect connectivity. Such structuring has important implications for sustainable utilisation and replenishment of estuarine stocks that are heavily exploited. Here we present a preliminary investigation of the phylogenetic relationships of the riverbream (Acanthopagrus species) along the southern African coast and the geographic genetic structure of what appears to be a locally endemic species or lineage. Mitochondrial DNA (mtDNA) cytochrome b sequences support the notion that the species occurring along the southern African coast is A. vagus and not A. berda as previously thought. Yet, the taxonomy of this widespread Indo-West Pacific species or species-complex requires more in-depth investigation. No genetic differentiation was detected among estuarine populations of A. vagus based on the analyses of mtDNA ND2 gene sequences and 10 polymorphic nuclear microsatellite markers. The star-like genealogy and statistical analyses are consistent with a recent population expansion event. Spatial analyses of microsatellite genotypes fail to reject the null hypothesis of panmixia, indicative of a recent population expansion or ongoing gene flow between different estuaries. The northern localities were identified as containing most of the observed variation. This study not only provides insight into the phylogenetic relationship of A. vagus relative to other Acanthopagrus species but also sheds light on the demographic history and contemporary gene flow of the species.

What role do beds of submerged macrophytes play in structuring estuarine fish assemblages? Lessons from a warm-temperate South African estuary

NASA Astrophysics Data System (ADS)

Sheppard, Jill N.; James, Nicola C.; Whitfield, Alan K.; Cowley, Paul D.

2011-11-01

Habitat variability is one of the factors influencing species richness within estuarine systems, and a loss of habitat can result in a restructuring of the estuarine ichthyofaunal assemblage, particularly if these conditions persist over long time periods. The potential effects of the loss of extensive submerged macrophyte beds ( Ruppia cirrhosa and Potamogeton pectinatus) on an estuarine fish assemblage were investigated through an analysis of a long-term seine net catch dataset from the temporarily open/closed East Kleinemonde Estuary, South Africa. Catch data for a 12-year period, encompassing six years of macrophyte presence and six years of macrophyte senescence, indicated that the loss of this habitat did not influence species richness but changes in the relative abundance of certain species were evident. A shift in dominance from vegetation-associated species to those associated with sandy environments ( e.g. members of the family Mugilidae) was observed. However, species wholly dependent on macrophytes such as the critically endangered estuarine pipefish Syngnathus watermeyeri were only recorded during years when macrophyte beds were present, while vegetation-associated species such as the sparid Rhabdosargus holubi persisted at lower levels of relative abundance. The reduced abundance of all vegetation-associated fish species during years of macrophyte senescence was probably reflective of declining food resources resulting from the loss of macrophyte beds and/or increased vulnerability to predation. Submerged beds of aquatic plants are therefore important habitats within temporarily open/closed estuaries, South Africa's dominant estuary type.

A rapid method for assessing the accumulation of microplastics in the sea surface microlayer (SML) of estuarine systems.

PubMed

Anderson, Zachary T; Cundy, Andrew B; Croudace, Ian W; Warwick, Phillip E; Celis-Hernandez, Omar; Stead, Jessica L

2018-06-21

Microplastics are an increasingly important contaminant in the marine environment. Depending on their composition and degree of biofouling, many common microplastics are less dense than seawater and so tend to float at or near the ocean surface. As such, they may exhibit high concentrations in the sea surface microlayer (SML - the upper 1-1000 μm of the ocean) relative to deeper water. This paper examines the accumulation of microplastics, in particular microfibres, in the SML in two contrasting estuarine systems - the Hamble estuary and the Beaulieu estuary, southern U.K., via a novel and rapid SML-selective sampling method using a dipped glass plate. Microplastic concentrations (for identified fibres, of 0.05 to 4.5 mm length) were highest in the SML-selective samples (with a mean concentration of 43 ± 36 fibres/L), compared to <5 fibres/L for surface and sub-surface bulk water samples. Data collected show the usefulness of the dipped glass plate method as a rapid and inexpensive tool for sampling SML-associated microplastics in estuaries, and indicate that microplastics preferentially accumulate at the SML in estuarine conditions (providing a potential transfer mechanism for incorporation into upper intertidal sinks). Fibres are present (and readily sampled) in both developed and more pristine estuarine systems.

Bioavailability of particle-associated silver, cadmium, and zinc to the estuarine amphipod Leptocheirus plumulosus through dietary ingestion

USGS Publications Warehouse

Schlekat, C.E.; Decho, Alan W.; Chandler, G.T.

2000-01-01

We conducted experiments to determine effects of particle type on assimilatory metal bioavailability to Leptocheirus plumulosus, an infaunal, estuarine amphipod that is commonly used in sediment toxicity tests. The following particles were used to represent natural food items encountered by this surface-deposit and suspension-feeding amphipod: bacterial exopolymeric sediment coatings, polymeric coatings made from Spartina alterniflora extract, amorphous iron oxide coatings, the diatom Phaeodactylum tricornutum, the chlorophyte Dunaliella tertiolecta, processed estuarine sediment, and fresh estuarine sediment. Bioavailability of the gamma-emitting radioisotopes 110mAg, 109Cd, and 65Zn was measured as the efficiency with which L. plumulosus assimilated metals from particles using pulse-chase methods. Ag and Cd assimilation efficiencies were highest from bacterial exopolymeric coatings. Zn assimilation efficiency exhibited considerable interexperimental variation; the highest Zn assimilation efficiencies were measured from phytoplankton and processed sediment. In general, Ag and Cd assimilation efficiencies from phytoplankton were low and not related to the proportion of metal associated with cell cytosol or cytoplasm, a phenomenon reported for other particle-ingesting invertebrates. Amphipod digestive processes explain differences in Ag and Cd assimilation efficiencies between exopolymeric coatings and phytoplankton. Results highlight the importance of labile polymeric organic carbon sediment coatings in dietary metals uptake by this benthic invertebrate, rather than recalcitrant organic carbon, mineralogical features such as iron oxides, or phytoplankton.

An assessment of anthropogenic and climatic stressors on estuaries using a spatio-temporal GIS-modelling approach for sustainability: Towamba estuary, southeastern Australia.

PubMed

Al-Nasrawi, Ali K M; Hamylton, Sarah M; Jones, Brian G

2018-06-03

Monitoring estuarine ecological-geomorphological dynamics has become a crucial aspect of studying the impacts of climate change and worldwide infrastructure development in coastal zones. Together, these factors have changed the natural eco-geomorphic processes that affect estuarine regimes and comprehensive modelling of coastal resources can assist managers to make appropriate decisions about their sustainable use. This study has utilised Towamba estuary (southeastern NSW, Australia), to demonstrate the value and priority of modelling estuarine dynamism as a measure of the rates and consequences of eco-geomorphic changes. This research employs several geoinformatic modelling approaches over time to investigate and assess how climate change and human activities have altered this estuarine eco-geomorphic setting. Multitemporal trend/change analysis of sediment delivery, shoreline positions and land cover, determined from fieldwork and GIS analysis of remote sensing datasets, shows significant spatio-temporal changes to the elevation and areal extent of sedimentary facies in the Towamba estuary over the past 65 years. Geomorphic growth (~ 2600 m 2 annually) has stabilised the estuarine habitats, particularly within native vegetation, salt marsh and mangrove areas. Geomorphic changes have occurred because of a combination of sediment runoff from the mostly unmodified terrestrial catchment, nearshore processes (ocean dynamics) and human activities. The construction of GIS models, verified with water and sediment samples, can characterise physical processes and quantify changes within the estuarine ecosystem. Such robust models will allow resource managers to evaluate the potential effects of changes to the current coastal ecosystems.

When gourmet is not enough: Organic matter sources supporting the production of Corbicula fluminea in an invaded estuary

EPA Science Inventory

The Asian clam Corbicula fluminea is one of the most pervasive species in freshwater ecosystems. Our objective was to characterize the food sources fuelling C. fluminea in the Minho river estuary (NW-Iberian Peninsula, Europe), an estuarine ecosystem in which C. fluminea presentl...

The morphological development of newly inundated intertidal areas: the mechanisms driving the early evolution of an estuarine environment designed and constructed by humans

NASA Astrophysics Data System (ADS)

Dale, Jonathan; Burgess, Heidi; Cundy, Andrew

2017-04-01

Intertidal saltmarsh and mudflat habitats are of global importance due to the ecosystem, economic and cultural services they provide. These services include wildlife habitat provision and species diversity, immobilisation of pollutants and protection from coastal flooding. Saltmarsh and mudflat environments are, however, being lost and degraded due to erosion caused by rising sea levels and increased storminess. These losses are exacerbated by anthropogenic influences including land reclamation, increased coastal development and the construction of coastal flood defences which prevent the landwards migration of saltmarsh and mudflat environments, resulting in coastal squeeze. To compensate for saltmarsh and mudflat losses areas of the coastal hinterland are being inundated by breaching defences and constructing new defences inland, thus extending or constructing new estuarine environments; a processes known as de-embankment or managed realignment. Morphological engineering and landscaping within managed realignment sites prior to site inundation varies depending on the aims of the scheme. However, there is a shortage of data on the morphological evolution within these sites post site inundation impeding the ability of coastal engineers to effectively design and construct future sites. To date there has been a focus on the colonisation of marine macro fauna and flora within newly inundated managed realignment sites, which can be relatively rapid and easily quantified. Little is known of the morphological evolution in response to altered sedimentary processes, its driving mechanisms and therefore the success and ecological sustainability of these sites. This study evaluates the post-inundation morphological development of the largest open coast managed realignment site in Europe, at Medmerry on the south coast of the United Kingdom. Inundated in September 2013, the Medmerry Managed Realignment Site consists of a mosaic of former agricultural land and areas of lower

Joint Ecosystem Modeling (JEM) ecological model documentation volume 2: roseate spoonbill (Platalea ajaja) landscape habitat suitability index v1.0.0

USGS Publications Warehouse

Romañach, Stephanie S.; Conzelmann, Craig; Daugherty, Adam; Lorenz, Jerome J.; Hunnicutt, Christina; Mazzotti, Frank J.

2011-01-01

Ecological conditions in the Greater Everglades have changed due to human activities, including the construction of canals to divert water away from the core of the landscape. Current and planned restoration projects are designed to produce a natural sheetflow of water across the landscape. This restoration of water flow should provide an increase in freshwater needed to restore natural salinities to the fringing estuarine ecosystem. In this report, we describe a Landscape Habitat Suitability Index model designed to evaluate alternative restoration plans for the benefit of a key species, the roseate spoonbill (Platalea ajaja). Model output has shown to be a good indicator of areas capable of supporting spoonbills. Use of this model will allow examination of the potential response of this key species to water management proposed through the Greater Everglades restoration process.

Importance of particle-associated bacterial heterotrophy in a coastal Arctic ecosystem

NASA Astrophysics Data System (ADS)

Garneau, Marie-Ève; Vincent, Warwick F.; Terrado, Ramon; Lovejoy, Connie

2009-01-01

estuarine stations with highest POM content. Particle-associated bacteria are an important functional component of this Arctic ecosystem. Under a warmer climate, they are likely to play an increasing role in coastal biogeochemistry and carbon fluxes as a result of permafrost melting and increased particle transport from the tundra to coastal waters.

Clay mineralogy indicates the muddy sediment provenance in the estuarine-inner shelf of the East China Sea

NASA Astrophysics Data System (ADS)

Zhao, Yifei; Zou, Xinqing; Liu, Qing; Wang, Chenglong; Ge, Chendong; Xu, Min

2018-02-01

The estuarine-inner shelf mud regions of the East China Sea (ECS) are valuable for studying the source-to-sink processes of fluvial sediments deposited since the Holocene. In this study, we present evidence of the provenance and environmental evolution of two cores (S5-2 and JC07) from the estuarine-inner shelf regions of the ECS over the past 100 years based on 210Pb dating, high-resolution grain size measurements and clay mineral analyses. The results indicate that the clay mineral assemblages of cores S5-2 and JC07 are dominated by illite, followed by kaolinite and chlorite, and present scarce amounts of smectite. A comparison of these clay mineral assemblages with several major sources reveals that the fine sediments on the estuarine-inner shelf of the ECS represent a mixture of provenances associated with the Yangtze and Yellow Rivers, as well as smaller rivers. However, the contribution of each provenance has varied greatly over the past hundred years, as indicated by the down-core variability due to strong sediment reworking and transport on the inner shelf and the reduction of the sediment load from the Yangtze River basin. In the mud region of the Yangtze River estuary, the sediment from 1930 to 1956 was primarily derived from the Yangtze River, although the Yellow River was also an important influence. From 1956 to 2013, the Yellow River contribution decreased, whereas the Yangtze River contribution correspondingly increased. In the Zhe-Min mud region, the Yangtze River contributed more sediment than did other rivers from 1910 to 1950; however, the Yangtze River contribution gradually decreased from 1950 to 2013. Moreover, the other small rivers accounted for minor contributions, and the East Asian winter monsoon (EAWM) played an important role in the sediment transport process in the ECS. Our results indicate that the weakening/strengthening of the EAWM and a decrease in the sediment load of the Yangtze River influenced the transport and fate of sediment

Estuarine density fronts and their effect on oil slicks

NASA Technical Reports Server (NTRS)

Klemas, V. (Principal Investigator); Polis, D. F.; Davis, G. R.

1976-01-01

The author has identified the following significant results. Estuarine fronts represent regions of extremely high gradient or discontinuity in various parameters of physical interest, the most important being the water velocity and density fields. Aircraft and boats were combined to study the behavior of different types of fronts in Delaware Bay and their effect on pollutants in order to provide a basis for improving an oil drift and spreading model. Imagery from the LANDSAT satellites provided the most effective means of determining the location and extent of frontal systems over all portions of the tidal cycle. This data is being used to modify the oil drift and spreading model.

Diversity and composition of estuarine and lagoonal fish assemblages of Socotra Island, Yemen.

PubMed

Lavergne, E; Zajonz, U; Krupp, F; Naseeb, F; Aideed, M S

2016-05-01

Estuarine and lagoonal surveys of Socotra Island and selected sites on the Hadhramout coast of Yemen were conducted with the objective of documenting and analysing fish diversity and assemblage structure. A total of 74 species in 35 families were recorded, among which 65 species in 32 families were from Socotra and 20 species in 17 families were from mainland Yemen. Twenty-one species represent new faunal records for Socotra. Including historic records re-examined in this study, the total fish species richness of estuaries and lagoons of Socotra Island reaches 76, which is relatively high compared to species inventories of well-researched coastal estuaries in southern Africa. Five species dominate the occurrence and abundance frequencies: Terapon jarbua, Hyporhamphus sindensis, Aphanius dispar, Ambassis gymnocephala and Chelon macrolepis. Rarefaction and extrapolation analyses suggest that the actual number of fish species inhabiting some of those estuaries might be higher than the one observed. Thus, additional sampling at specific sites should be conducted to record other less conspicuous species. Ordination and multivariate analyses identified four main distinct assemblage clusters. Two groups are geographically well structured and represent northern Socotra and mainland Yemen, respectively. The other two assemblage groups tend to be determined to a greater extent by the synchrony between physical (e.g. estuary opening periods) and biological (e.g. spawning and recruitment periods) variables than by geographical location. Finally, the single intertidal lagoon of Socotra represents by itself a specific fish assemblage. The high proportion of economically important fish species (38) recorded underscores the paramount importance of these coastal water bodies as nursery sites, and for sustaining vital provisioning ecosystem services. © 2016 The Fisheries Society of the British Isles.

Methods for the Determination of Chemical Substances in Marine and Estuarine Environmental Matrices - 2nd Edition

EPA Science Inventory

This NERL-Cincinnati publication, “Methods for the Determination of Chemical Substances in Marine and Estuarine Environmental Matrices - 2nd Edition” was prepared as the continuation of an initiative to gather together under a single cover a compendium of standardized laborato...

Predicting the Spatial Distribution of Organic Contaminants in an Estuarine System using a Random Forest Approach

EPA Science Inventory

Modeling the magnitude and distribution of estuarine sediment contamination by pollutants of historic (e.g. PCB) and emerging concern (e.g., personal care products, PCP) is often limited by incomplete site knowledge and inadequate sediment contamination sampling. We tested a mode...

Carbon and nitrogen isotope ratios of juvenile winter flounder as indicators of inputs to estuarine systems

EPA Science Inventory

Stable carbon and nitrogen isotope ratios were measured in the muscle tissues of young-of-the-year (YOY) winter flounder, Pseudopleuronectes americanus, collected from several estuarine systems along the coast of Rhode Island, USA. These systems included three coastal lagoons (Ni...

Final Environmental Assessment for Test Area D-84 Waterside Redevelopment

DTIC Science & Technology

2012-09-01

typically adapted for life in saturated soil conditions (U.S. Army, 1987). Wetlands are the most productive ecosystems in the world (Mitsch and...such as amphipods, Jancelets, polychaetes, gastropods , ghost shrimp, isopods, molluscs and/or crustaceans, within estuarine and marine habitats and...lancelets, polychaetes, gastropods , ghost shrimp, isopods, mollusks, and/or crustaceans within estuarine and marine habitats and substrates for subadult

Fish-based indicators of estuarine condition that do not require reference data

NASA Astrophysics Data System (ADS)

Tweedley, James R.; Warwick, Richard M.; Hallett, Chris S.; Potter, Ian C.

2017-05-01

The species composition of fish communities in 15 microtidal estuaries in south-western Australia, ranging from permanently-open to normally-closed, is shown to be related to the geomorphological and hydrological regimes and not to environmental condition. This study then explored the effectiveness of using qualitative taxonomic distinctness and ABC curves for fish data as indicators of the environmental condition in nearshore, shallow waters of these estuaries and, in the case of taxonomic distinctness, also of their offshore, deeper waters. Neither of these indices require spatial or temporal reference data, which may be either prohibitively expensive and time-consuming to collect or unavailable. Taxonomic distinctness, in both nearshore and offshore waters, varied consistently among estuaries in relation to their recorded environmental status, and is thus a good indicator of overall estuarine condition. ABC analyses, however, did not prove a good measure of the environmental condition of the estuaries, because their results largely reflect differences in accessibility of the estuary to marine estuarine-opportunist species and especially those that grow to a larger size. It is concluded that taxonomic distinctness indices provide a rapid and cost-effective method for assessing the environmental condition of estuaries, particularly those with limited spatial or temporal reference data.

Sublethal salinity stress contributes to habitat limitation in an endangered estuarine fish.

PubMed

Komoroske, Lisa M; Jeffries, Ken M; Connon, Richard E; Dexter, Jason; Hasenbein, Matthias; Verhille, Christine; Fangue, Nann A

2016-09-01

As global change alters multiple environmental conditions, predicting species' responses can be challenging without understanding how each environmental factor influences organismal performance. Approaches quantifying mechanistic relationships can greatly complement correlative field data, strengthening our abilities to forecast global change impacts. Substantial salinity increases are projected in the San Francisco Estuary, California, due to anthropogenic water diversion and climatic changes, where the critically endangered delta smelt (Hypomesus transpacificus) largely occurs in a low-salinity zone (LSZ), despite their ability to tolerate a much broader salinity range. In this study, we combined molecular and organismal measures to quantify the physiological mechanisms and sublethal responses involved in coping with salinity changes. Delta smelt utilize a suite of conserved molecular mechanisms to rapidly adjust their osmoregulatory physiology in response to salinity changes in estuarine environments. However, these responses can be energetically expensive, and delta smelt body condition was reduced at high salinities. Thus, acclimating to salinities outside the LSZ could impose energetic costs that constrain delta smelt's ability to exploit these habitats. By integrating data across biological levels, we provide key insight into the mechanistic relationships contributing to phenotypic plasticity and distribution limitations and advance the understanding of the molecular osmoregulatory responses in nonmodel estuarine fishes.

Back-barrier and seabed sediment dynamics in the Albemarle-Pamlico estuarine system, North Carolina

NASA Astrophysics Data System (ADS)

Walsh, J. P.; Corbett, D. R.

2016-02-01

Estuaries are critical habitats as well as places where people live, recreate, and make their livelihood. Additionally, they are sites where land and sea interact, and sediments, and associated pollutants and carbon, are deposited, remobilized and accumulated. Many processes, such as river discharge, waves, tides, and sea-level rise, are operating in estuaries to cause sediment dynamics, impacting humans and organisms as a result. Recent research we have been engaged in across the Albemarle-Pamlico Estuarine System (APES) has investigated the sediments dynamics of this important estuary. The APES is the second largest estuary in the continental United States, consisting of the Albemarle and Pamlico sounds and the Pamlico River and Neuse River sub-estuaries. Although expansive in size, the system is shallow with minimal tidal range. Water and sediment discharge into the APES is modest, and the existence of few inlets along the Outer Banks limits mixing with the Atlantic Ocean. Human impact on the drainage basin and estuarine system is moderate and increasing over time. Over the last five years, a considerable volume of sedimentary process data has been collected over various timescales and locations in the APES. More specifically, work has included: deployments of instrumented tripods to examine seabed dynamics; collection and analysis of shallow cores and GIS investigation of aerial photographs and other data. This wealth of data highlights several insights: 1) shorelines are generally eroding ( 0.25 m/y and rapidly >3 m/y in places), but rates are temporally and spatially variable; 2) seabed resuspension is frequent, yet net accumulation of 2-4 mm/y is widespread in deeper locations; and 3) storms cause episodic, localized impacts (e.g., barrier breaches) on this large, shallow estuarine system.

Ecosystem services

Treesearch

Trista Patterson

2014-01-01

Since its inception, the ecosystem service approach has stimulated interest from numerous planning, management, and partnership perspectives. To date, however, research that quantifies ecosystem services in the study area (in the form of explicit ecosystem service studies) has been limited. This chapter reviews and synthesizes the concept of ecosystem services,...

75 FR 67950 - Notice of Designation of the Lake Superior National Estuarine Research Reserve in Wisconsin

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-04

... Reserve is available upon request. Federal Domestic Assistance Catalog Number 11.420 (Coastal Zone..., Office of Ocean and Coastal Resource Management, National Ocean Service, National Oceanic and Atmospheric... Lake Superior National Estuarine Research Reserve in Wisconsin pursuant to Section 315 of the Coastal...

COMPLEMENTARY MONITORING DESIGNS TO DOCUMENT REGIONAL GRADIENTS, AND TEMPORTAL VARIATIONS OF DISSOLOVED OXYGEN IN ESTUARINE WATERS

EPA Science Inventory

The U.S. EPA National Coastal Assessment program is designed to address two broad questions: 1) what are the conditions of estuarine resources, how are they changing, and what causes those changes; 2) which monitoring designs, indicators, and protocols are appropriate for assessi...

Ecosystem Vulnerability Review: Proposal of an Interdisciplinary Ecosystem Assessment Approach

NASA Astrophysics Data System (ADS)

Weißhuhn, Peter; Müller, Felix; Wiggering, Hubert

2018-06-01

To safeguard the sustainable use of ecosystems and their services, early detection of potentially damaging changes in functional capabilities is needed. To support a proper ecosystem management, the analysis of an ecosystem's vulnerability provide information on its weaknesses as well as on its capacity to recover after suffering an impact. However, the application of the vulnerability concept to ecosystems is still an emerging topic. After providing background on the vulnerability concept, we summarize existing ecosystem vulnerability research on the basis of a systematic literature review with a special focus on ecosystem type, disciplinary background, and more detailed definition of the ecosystem vulnerability components. Using the Web of ScienceTM Core Collection, we overviewed the literature from 1991 onwards but used the 5 years from 2011 to 2015 for an in-depth analysis, including 129 articles. We found that ecosystem vulnerability analysis has been applied most notably in conservation biology, climate change research, and ecological risk assessments, pinpointing a limited spreading across the environmental sciences. It occurred primarily within marine and freshwater ecosystems. To avoid confusion, we recommend using the unambiguous term ecosystem vulnerability rather than ecological, environmental, population, or community vulnerability. Further, common ground has been identified, on which to define the ecosystem vulnerability components exposure, sensitivity, and adaptive capacity. We propose a framework for ecosystem assessments that coherently connects the concepts of vulnerability, resilience, and adaptability as different ecosystem responses. A short outlook on the possible operationalization of the concept by ecosystem vulnerabilty indices, and a conclusion section complete the review.

Ecosystem Vulnerability Review: Proposal of an Interdisciplinary Ecosystem Assessment Approach.

PubMed

Weißhuhn, Peter; Müller, Felix; Wiggering, Hubert

2018-06-01

To safeguard the sustainable use of ecosystems and their services, early detection of potentially damaging changes in functional capabilities is needed. To support a proper ecosystem management, the analysis of an ecosystem's vulnerability provide information on its weaknesses as well as on its capacity to recover after suffering an impact. However, the application of the vulnerability concept to ecosystems is still an emerging topic. After providing background on the vulnerability concept, we summarize existing ecosystem vulnerability research on the basis of a systematic literature review with a special focus on ecosystem type, disciplinary background, and more detailed definition of the ecosystem vulnerability components. Using the Web of Science TM Core Collection, we overviewed the literature from 1991 onwards but used the 5 years from 2011 to 2015 for an in-depth analysis, including 129 articles. We found that ecosystem vulnerability analysis has been applied most notably in conservation biology, climate change research, and ecological risk assessments, pinpointing a limited spreading across the environmental sciences. It occurred primarily within marine and freshwater ecosystems. To avoid confusion, we recommend using the unambiguous term ecosystem vulnerability rather than ecological, environmental, population, or community vulnerability. Further, common ground has been identified, on which to define the ecosystem vulnerability components exposure, sensitivity, and adaptive capacity. We propose a framework for ecosystem assessments that coherently connects the concepts of vulnerability, resilience, and adaptability as different ecosystem responses. A short outlook on the possible operationalization of the concept by ecosystem vulnerabilty indices, and a conclusion section complete the review.

An Evidence-Based Evaluation of the Cumulative Effects of Tidal Freshwater and Estuarine Ecosystem Restoration on Endangered Juvenile Salmon in the Columbia River: Final Report

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

Diefenderfer, Heida L.; Johnson, Gary E.; Thom, Ronald M.

The listing of 13 salmon and steelhead stocks in the Columbia River basin (hereafter collectively referred to as “salmon”) under the Endangered Species Act of 1973, as amended, has stimulated tidal wetland restoration in the lower 235 kilometers of the Columbia River and estuary for juvenile salmon habitat functions. The purpose of the research reported herein was to evaluate the effect on listed salmon of the restoration effort currently being conducted under the auspices of the federal Columbia Estuary Ecosystem Restoration Program (CEERP). Linking changes in the quality and landscape pattern of tidal wetlands in the lower Columbia River andmore » estuary (LCRE) to salmon recovery is a complex problem because of the characteristics of the ecosystem, the salmon, the restoration actions, and available sampling technologies. Therefore, we designed an evidence-based approach to develop, synthesize, and evaluate information to determine early-stage (~10 years) outcomes of the CEERP. We developed an ecosystem conceptual model and from that, a primary hypothesis that habitat restoration activities in the LCRE have a cumulative beneficial effect on juvenile salmon. There are two necessary conditions of the hypothesis: • habitat-based indicators of ecosystem controlling factors, processes, and structures show positive effects from restoration actions, and • fish-based indicators of ecosystem processes and functions show positive effects from restoration actions and habitats undergoing restoration. Our evidence-based approach to evaluate the primary hypothesis incorporated seven lines of evidence, most of which are drawn from the LCRE. The lines of evidence are spatial and temporal synergies, cumulative net ecosystem improvement, estuary-wide meta-analysis, offsite benefits to juvenile salmon, landscape condition evaluation, and evidence-based scoring of global literature. The general methods we used to develop information for the lines of evidence included field

Preface: Ecosystem services, ecosystem health and human communities

NASA Astrophysics Data System (ADS)

Plag, Hans-Peter

2018-04-01

This special issue contains a collection of manuscripts that were originally intended to be included in the special issue on "Physics and Economics of Ecosystem Services Flows" (Volume 101, guest editors H. Su, J. Dong and S. Nagarajan) and "Biogeochemical Processes in the Changing Wetland Environment" (Volume 103, guest editors J. Bai, L. Huang and H. Gao). All of them are addressing issues related to ecosystem services in different settings. Ecosystem services are of high value for both the ecosystems and human communities, and understanding the impacts of environmental processes and human activities on ecosystems is of fundamental importance for the preservation of these services.

Halogen radicals contribute to photooxidation in coastal and estuarine waters

PubMed Central

Parker, Kimberly M.; Mitch, William A.

2016-01-01

Although halogen radicals are recognized to form as products of hydroxyl radical (•OH) scavenging by halides, their contribution to the phototransformation of marine organic compounds has received little attention. We demonstrate that, relative to freshwater conditions, seawater halides can increase photodegradation rates of domoic acid, a marine algal toxin, and dimethyl sulfide, a volatile precursor to cloud condensation nuclei, up to fivefold. Using synthetic seawater solutions, we show that the increased photodegradation is specific to dissolved organic matter (DOM) and halides, rather than other seawater salt constituents (e.g., carbonates) or photoactive species (e.g., iron and nitrate). Experiments in synthetic and natural coastal and estuarine water samples demonstrate that the halide-specific increase in photodegradation could be attributed to photochemically generated halogen radicals rather than other photoproduced reactive intermediates [e.g., excited-state triplet DOM (3DOM*), reactive oxygen species]. Computational kinetic modeling indicates that seawater halogen radical concentrations are two to three orders of magnitude greater than freshwater •OH concentrations and sufficient to account for the observed halide-specific increase in photodegradation. Dark •OH generation by gamma radiolysis demonstrates that halogen radical production via •OH scavenging by halides is insufficient to explain the observed effect. Using sensitizer models for DOM chromophores, we show that halogen radicals are formed predominantly by direct oxidation of Cl− and Br− by 3DOM*, an •OH-independent pathway. Our results indicate that halogen radicals significantly contribute to the phototransformation of algal products in coastal or estuarine surface waters. PMID:27162335

Horizontal Trends in Larval Fish Diversity and Abundance Along an Ocean-Estuarine Gradient on the Northern KwaZulu-Natal Coast, South Africa

NASA Astrophysics Data System (ADS)

Harris, S. A.; Cyrus, D. P.; Beckley, L. E.

2001-08-01

The structure of the larval fish assemblages along an ocean-estuarine gradient in the St Lucia region on the northern KwaZulu-Natal coast of South Africa was examined using a combination of univariate, distributional and multivariate techniques. The data was comprised of a full annual set of ichthyoplankton samples taken from three types of environment: nearshore coastal waters, surf zone and within the St Lucia Estuary itself. The mean monthly densities of each species in each environment were used in the species matrix, and the mean monthly values of salinity, temperature and turbidity were used in the physical variables matrix. The mean species diversity and eveness index was significantly higher in the nearshore waters than the surf zone and estuary. The patterns of relative species abundances in each environment (K-dominance curves) showed that the estuarine environment was dominated by a few species in large numbers, the surf zone was intermediate, and the nearshore coast was the most diverse. Classification and multidimensional scaling (MDS) ordination analyses of larval fish densities grouped together into three main clusters based on the three different environments. The species similarity matrix (inverse analysis) clustered into four groups at the 10% similarity level. The MDS analysis of the same matrix showed that the groups separated out more or less according to the type of environment they occur in, and hence the level of estuarine dependence of the various species. Species belonging to each assemblage showed similarities with regards to their reproduction modes and/or preference to a particular physical condition. Some species were restricted to one environment, whilst others were common to two or all three environments. The occurrence of partially estuarine-dependent species in all three environments suggests that ocean-estuarine coupling is an important process for the recruitment success of these species. The ' best fitting ' physical variable

VARIATIONS IN LARVAL GROWTH AND METABOLISM OF AN ESTUARINE SHRIMP DURING TOXICOSIS BY AN INSECT GROWTH REGULATOR

EPA Science Inventory

Exposure of the estuarine shrimp, Ptiaemonetes pugio, to a juvenile hormone analogue (> 3 ug methoprene-1) throughout larval development inhibited successful completion of metamorphosis. Methoprene exposure retarded growth in early larval stages and postlarvae enhanced growth in ...

Nutrient Dynamics of Estuarine Invertebrates Are Shaped by Feeding Guild Rather than Seasonal River Flow

PubMed Central

Ortega-Cisneros, Kelly; Scharler, Ursula M.

2015-01-01

This study aimed to determine the variability of carbon and nitrogen elemental content, stoichiometry and diet proportions of invertebrates in two sub-tropical estuaries in South Africa experiencing seasonal changes in rainfall and river inflow. The elemental ratios and stable isotopes of abiotic sources, zooplankton and macrozoobenthos taxa were analyzed over a dry/wet seasonal cycle. Nutrient content (C, N) and stoichiometry of suspended particulate matter exhibited significant spatio-temporal variations in both estuaries, which were explained by the variability in river inflow. Sediment particulate matter (%C, %N and C:N) was also influenced by the variability in river flow but to a lesser extent. The nutrient content and ratios of the analyzed invertebrates did not significantly vary among seasons with the exception of the copepod Pseudodiaptomus spp. (C:N) and the tanaid Apseudes digitalis (%N, C:N). These changes did not track the seasonal variations of the suspended or sediment particulate matter. Our results suggest that invertebrates managed to maintain their stoichiometry independent of the seasonality in river flow. A significant variability in nitrogen content among estuarine invertebrates was recorded, with highest % N recorded from predators and lowest %N from detritivores. Due to the otherwise general lack of seasonal differences in elemental content and stoichiometry, feeding guild was a major factor shaping the nutrient dynamics of the estuarine invertebrates. The nutrient richer suspended particulate matter was the preferred food source over sediment particulate matter for most invertebrate consumers in many, but not all seasons. The most distinct preference for suspended POM as a food source was apparent from the temporarily open/closed system after the estuary had breached, highlighting the importance of river flow as a driver of invertebrate nutrient dynamics under extreme events conditions. Moreover, our data showed that estuarine

Nutrient Dynamics of Estuarine Invertebrates Are Shaped by Feeding Guild Rather than Seasonal River Flow.

PubMed

Ortega-Cisneros, Kelly; Scharler, Ursula M

2015-01-01

This study aimed to determine the variability of carbon and nitrogen elemental content, stoichiometry and diet proportions of invertebrates in two sub-tropical estuaries in South Africa experiencing seasonal changes in rainfall and river inflow. The elemental ratios and stable isotopes of abiotic sources, zooplankton and macrozoobenthos taxa were analyzed over a dry/wet seasonal cycle. Nutrient content (C, N) and stoichiometry of suspended particulate matter exhibited significant spatio-temporal variations in both estuaries, which were explained by the variability in river inflow. Sediment particulate matter (%C, %N and C:N) was also influenced by the variability in river flow but to a lesser extent. The nutrient content and ratios of the analyzed invertebrates did not significantly vary among seasons with the exception of the copepod Pseudodiaptomus spp. (C:N) and the tanaid Apseudes digitalis (%N, C:N). These changes did not track the seasonal variations of the suspended or sediment particulate matter. Our results suggest that invertebrates managed to maintain their stoichiometry independent of the seasonality in river flow. A significant variability in nitrogen content among estuarine invertebrates was recorded, with highest % N recorded from predators and lowest %N from detritivores. Due to the otherwise general lack of seasonal differences in elemental content and stoichiometry, feeding guild was a major factor shaping the nutrient dynamics of the estuarine invertebrates. The nutrient richer suspended particulate matter was the preferred food source over sediment particulate matter for most invertebrate consumers in many, but not all seasons. The most distinct preference for suspended POM as a food source was apparent from the temporarily open/closed system after the estuary had breached, highlighting the importance of river flow as a driver of invertebrate nutrient dynamics under extreme events conditions. Moreover, our data showed that estuarine