A:
AIRD: Aquatic Invasions Research Directory - A free database designed to promote information transfer, coordination, and collaborative research on the invasion of aquatic ecosystems. [Ad Hoc Organizations, Smithsonian Institution, Smithsonian Environmental Research Center]

F:
Freshwater Ecosystems - Discusses water quality, drought management and watershed protection issues [Environmental Protection Agency (EPA)]

I:
Informatics and Collection Databases - Searchable lists of specimens, illustrations, anthropological collections, and summary information about the National Museum of Natural History collections. [Ad Hoc Organizations, Smithsonian Institution]

L:
Leetown Science Center - Homepage for the Leetown Science Center in West Virginia conducting research on aquatic and terrestrial organisms and their supporting ecosystems with links to directions, general description, library, projects, fact sheets, and facilities [Department of the Interior, U.S. Geological Survey (USGS)]

N:
National River Restoration Science Synthesis - A scientific synthesis of river restoration projects, with a searchable database. [Department of the Interior, U.S. Geological Survey (USGS), National Biological Information Infrastructure]

National Streamflow Information Program - Home page describing the operation and maintenance of 7000 streamgages, overview of the program, system for collection of streamflow data, maintaining of historic streamflow data, and available reports [Department of the Interior, U.S. Geological Survey (USGS)]

W:
Western Fisheries Research Center - Expertise in fish health research [Department of the Interior, U.S. Geological Survey (USGS)]