Skip to main content
Advanced Search

Filters: Tags: Estuaries and Near-Shore Environments (X)

16 results (8ms)   

View Results as: JSON ATOM CSV
The NRP had its beginnings in the late 1950's. Since that time, the program has grown to encompass a broad spectrum of scientific investigations. The sciences of hydrology, mathematics, chemistry, physics, ecology, biology, geology, and engineering are used to gain a fundamental understanding of the processes that affect the availability, movement, and quality of the Nation's water resources. Results of NRP's long-term research investigations often lead to the development of new concepts, techniques, and approaches that are applicable not only to the solution of current water problems, but also to future issues that may affect the Nation's water resources. Basic tools of hydrology that have been developed by the...
Categories: Project; Types: ScienceBase Project; Tags: Acid Mine Drainage, Aquatic Habitat, Arid Land Hydrology, Carbon Cycle, Contaminant Reactions and Transport, All tags...
Human activities from climate change to waste discharges to water management are modifying ecosystems across the earth, often in ways that are not well understood. This project addresses the problem of better understanding changes in aquatic ecosystems as driven by human disturbances interacting with natural processes. More specifically, the project studies a) the mechanisms of biological and ecological response to stressors such as metal contamination, nutrient enrichment, physical habitat alteration, climate change, and introduced species, and b) the influence of species, communities, and ecosystem processes on the distribution, transport, and fate of chemical contaminants (e.g., metals, nutrients). Most studies...
The objective of this research is to study and quantitatively describe the factors that influence the response of macroinvertebrates to both anthropogenic and natural environmental factors and assess the effects macroinvertebrates have on the physical, chemical, and biological quality of aquatic systems. This involves 1) studying macroinvertebrate distributions across a range of spatial and temporal scales representing a variety of environmental settings and influences, 2) identifying and measuring the effects of stressors that are macroinvertebrate-specific, 3) identifying the effects macroinvertebrates have on the physical, chemical, and biological environment, 4) developing and applying statistical models that...
Phytoplankton photosynthesis drives many biogeochemical and ecological processes in lakes, estuaries, and the ocean. For example, dynamic changes in pH, trace metal speciation, and concentrations of dissolved gases (oxygen, carbon dioxide, methane), inorganic nutrients (nitrate, phosphate, silicate), and organic compounds (amino acids, organosulfur compounds) are all closely associated with fluctuations in phytoplankton photosynthesis. Trophic linkages also exist, between the phytoplankton as primary producers and populations of consumer organisms including bacteria, zooplankton, benthic invertebrates, and fish. Our scientific understanding of lakes and estuaries as dynamic ecosystems is therefore dependent upon...
Human activities from climate change to waste discharges to water management are modifying ecosystems across the earth, often in ways that are not well understood. This project addresses the problem of better understanding changes in aquatic ecosystems as driven by human disturbances interacting with natural processes. More specifically, the project studies a) the mechanisms of biological and ecological response to stressors such as metal contamination, nutrient enrichment, physical habitat alteration, climate change, and introduced species, and b) the influence of species, communities, and ecosystem processes on the distribution, transport, and fate of chemical contaminants (e.g., metals, nutrients). Most studies...
This project seeks to quantify, predict, and project the relative role of plant physiology, among other ecosystem drivers, on carbon, nutrient, and trace-metal biogeochemistry. Approaches span landscape-to-molecular scales as necessary to understand how human and stochastic alterations of wetland structure influence wetland function. Research sites represent a wide range of salinity and management conditions, from rice agriculture to coastal and restored wetlands. Primary goals include evaluating management and modeling approaches to quantify wetland carbon sequestration, greenhouse gas budgets and/or mercury methylation and export.
My primary objective is to understand the function of the benthic community at various spatial scales with the goal of understanding and modeling the benthic community processes at the ecosystem level. Specifically, my goals are to (1) explore ecological and physical processes that are affected by the benthic community and that effect benthic community composition and function; (2) look at these processes at a variety of time scales (days to seasons and inter-annual time scales) so that hydrologic, climate, and exotic species effects on benthic communities and their ecosystems can be understood; (3) develop habitat and energetics models of dominant members of the benthic community that can be dynamically linked...
The overarching objective is to understand how anthropogenic sources of inorganic contaminants (metals) affect the structure and function of aquatic ecosystems. Elements of the research include: 1) develop and apply analytical methods and models to understand and predict metal bioavailability and bioaccumulation in aquatic organisms; 2) define effects of metal exposure on aquatic species; 3) communicate research findings to scientific and regulatory communities to support the management of water resources.
Research Objectives: To better understand the response of watershed hydrology, freshwater management and estuaries to climate variability and change. In the estuarine component of this research, there is an emphasis on the responses of physical processes that drive ecological variability and change.
Technical solutions to the problem of investigating and managing waste movement and disposal in regulated rivers, estuaries, and embayments require qualitative and quantitative assessment of the interactions between waste constituents undergoing dynamic transport. Mathematical, numerical, computer-simulation models offer one very powerful solution. Because water is both the vehicle by which the waste constituents are transported and the media in which the constituent interactions occur, the temporal and spatial variations of the flow appreciably govern the interactions both qualitatively and quantitatively. Design of the desired simulation models depends in large measure upon accurate mathematical/numerical representation...
The ecosystem of a tide-affected estuary consists of an extremely complicated balance of natural processes and human induced activities. Some of the basic characteristics of such a system, for example the San Francisco Bay estuarine system, are not well understood. A comprehensive description of the hydrodynamics and the related transport phenomena is still lacking. A better understanding of the effects among the interactive natural and human induced processes on this system requires advances in basic science relating the physical, chemical and biological estuarine processes. Circulation in a tidal estuary is generated in response to astronomical tides, inflow of fresh water, winds, and stratification due to salinity....
The physical/chemical variability in our rivers and estuaries is large, but causes and interactions are not clearly defined. Variations forced by weather and climate appear to be very important, but we don't yet understand how riverine-estuarine systems operate on very short and moderately long time scales. Furthermore, the effect of anthropogenic activities also may be important. Without such information we cannot understand and predict how these systems respond to variations in climate and human activities including changes in the amount, character, and timing of freshwater, toxic- waste, sediment and plant-nutrient inflows to these environments. Project objectives were to better understand the variability of...
Benthic sediment exchange processes are potentially a very significant source/ sink of nutrients and metals within an aquatic system. Too often the quantitative effects of these processes are only estimated when considering biogeochemical cycling and ecological responses. Understanding geochemical processes that control nutrient and transition metal chemistry of natural waters is requisite for predicting the effects man-induced events will have upon natural geochemical cycles and for determining their utilization as a natural resource (e.g. estuarine waters as food resources). Objectives of this project are to (1) study the important geochemical processes affecting the nutrient and metal composition of and exchange...
Temperature and salinity are two key estuarine habitat variables. Understanding how these variables are distributed around the bay leads to a better understanding of habitat types and distribution in the Bay. Additionally, understanding the distribution of salinity in the Bay allows us to better understand the transport processes that drive material transport and supply throughout the Bay. Time series of water temperature and specific conductance (salinity is calculated from conductivity and water temperature) are needed (1) to improve our understanding of the hydrodynamics of the estuary (e.g., gravitational circulation), (2) for calibration of multi-dimensional flow and transport models of the Bay, (3) to better...
Quantify the effect of aquatic and floodplain vegetation on sediment and nutrient budgets along several dimensions of hydrologic connectivity (longitudinally, laterally, and temporally) in the Difficult Run floodplain watershed; Determine if long term trends in anthropogenic nutrients are linked to improvements in submerged aquatic vegetation (SAV) diversity and abundance in other less urban estuaries, as they were in the highly urban, Potomac River; and Habitat evaluation and restoration of coastal wetlands and estuaries in the face of climate change and other stressors such as exotic species and eutrophication.
My primary research objective is to evaluate ecosystem health in freshwater systems using biologically meaningful measures of metal exposure. Resident aquatic organisms accumulate metal into their tissue by integrating the metal from their environment (dissolved and diet). Using physiological parameters derived from earlier experiments, I am developing a model to predict biomonitor tissue concentrations under various exposure conditions. The goal of this research is to link biological responses to changes in environmental condition (e.g., remediation and physical disturbances associated with floods). While this work was developed from the Clark Fork River study, the model is applicable to other impaired rivers and...