Aquatic Biology and Ecosystems

Regional groundwater availability studies enable information about groundwater to be integrated and consistent, so that this resource can be analyzed and understood on an aquifer–wide scale. These studies provide decision–makers with a better understanding of the status and trends in the Nation's groundwater availability.

The FIM Toolbox contains comprehensive information on the Flood Inundation Mapping program, including how to develop a flood inundation map library. Resources include process documents, scientific and technical requirements, forms and templates, outreach and educational materials, and contact information. The FIM Toolbox is updated as new resources become available.

The clams Potamocorbula amurensis and Corbicula fluminea were collected at a variety of sites in the San Francisco Bay/ Delta beginning July 1990 and ending February 2010. These invasive species were used as biosentinels of the fate, transport, and effects of trace metals in the San Francisco Bay ecosystem.

The goals of the Regional Stream Quality Assessment (RSQA) are to characterize multiple water-quality factors that are stressors to aquatic life (contaminants, nutrients, sediment, and streamflow alteration) and to develop a better understanding of the relation of these stressors to ecological conditions in streams throughout the region.

The USGS is undertaking a 3-year study of water availability and use to investigate competing societal and ecological needs in Southeastern Atlantic Coastal Basins of the Carolinas. This study will compile existing information, add new scientific data and interpretation, and develop tools to help resource managers and stakeholders address current and future water-use challenges.

The USGS is undertaking a 3-year study of water use, availability, and change in the Red River basin, which covers more than 93,000 square miles in New Mexico, Texas, Oklahoma, Arkansas, and Louisiana. Water resources are being stressed by increasing water demands and increasingly severe droughts, and a comprehensive water-resource assessment of the basin is needed to enable sustainable water use.

USGS is undertaking a 3-year study of water use, availability, and change in the Upper Rio Grande Basin. This study area runs 670 miles from its headwaters in Colorado through New Mexico and northern Mexico to Texas, and will compile existing information and add new scientific data and interpretation to help stakeholders face current and future water issues.

As one of several National Focus Area Studies within the USGS National Water Census (NWC), the USGS completed a 3-year study of water availability and use in the Delaware River Basin.

Research by the USGS National Water Quality Assessment (NAWQA) Project on water quality of rivers and streams covers a broad range of topics, from nonpoint pollution issues to vulnerability of aquatic ecosystems. Dive in and find out more about current water-quality conditions, how and where water quality is changing, and the latest information on pesticides, nutrients, and other contaminants.

Environmental sources of selenium (Se) such as from organic-enriched sedimentary deposits are geologic in nature and thus can occur on regional scales. A constructed map of the global distribution of Se source rocks informs potential areas of reconnaissance for modeling of Se risk including the phosphate deposits of southeastern Idaho and the coals of Appalachia.

Adverse effects of selenium (Se) on fish and waterfowl in wetlands receiving agricultural drainage occurred in the 1980s in the San Joaquin Valley of California. The identified mechanisms of Se enrichment helped resolve Se toxicity problems associated with irrigated agriculture in the arid West. Bioaccumulation of Se in ancient marine sediments is postulated as a primary pathway in source rocks.

The San Francisco Bay-Delta receives selenium (Se) internally from oil refineries and externally through riverine agricultural discharges. Predator species considered at risk from Se consume the estuary’s dominant bivalve, C. amurensis, an efficient bioaccumulator of Se. Modeling predicts site-specific ecological risk and derives a range of protective Se concentrations for use by decision-makers.