Fish and Aquatic Species

Forage fish are small pelagic schooling fish that play a key role in transferring energy between plankton and top marine predators. Many seabirds, marine mammals, and commercial fish species depend on forage fish to grow and survive.

Fish and aquatic habitats in Alaska support important commercial, sport, and subsistence fisheries and provide forage fish that support wildlife populations. The USGS Alaska Science Center conducts interdisciplinary research to inform local, state, federal, and international policy makers regarding conservation of fish, aquatic species, and their habitats. We work collaboratively with hydrologists...

Across the country, USGS scientists research amphibians to help other agencies manage this historically underappreciated and now declining group. Our scientists have learned that no single threat explains global amphibian declines; instead, a variety of local and global factors are contributing. Habitat loss, disease, contaminants, and other threats are all part of the pattern.

Due to the rapid decline in abundance of Yellow Lampmussel ( Lampsilis cariosa) and Tidewater Mucket ( Atlanticoncha ochracea), USGS and partners at the U.S. Fish and Wildlife Service (USFWS) and Central Michigan University (CMU) are conducting an assessment of genetic diversity and population structure to inform appropriate recommendations for conservation and management of each species. These...

We will examine evidence of heat stress in Yukon River Chinook salmon ( Oncorhynchus tshawytscha) using heat shock proteins and gene expression.

Migratory wildlife need to balance the benefits of migration and reproduction with the physiological costs. This is particularly challenging in dynamic environments like wetlands, where food levels can vary greatly from year to year. For shorebirds in the Great Basin region, saline or terminal lakes provide essential habitats during their annual life cycle. To understand how changes in hydrology...

Alaska's coastal and offshore waters provide foraging habitat for an estimated 100 million birds comprising more than 90 different species; from loons and seaducks that nest inland, to petrels and puffins that breed on islands off shore. All these birds depend on the sea to provide a wide variety of food types— from clams, crabs and urchins nearshore— to krill, forage fish, and squid offshore. The...

Nearshore systems provide habitat to a unique community of marine and diadromous (lives in both fresh and saltwater) fish and support high fish abundance.

American Shad ( Alosa sapidissima), Blueback Herring ( Alosa aestivalis), and Alewife ( Alosa pseudoharengus; collectively “alosines”) once supported large fisheries along the U.S. Atlantic Coast. However, impassable migration barriers, declines in habitat quality, and exploitation have led to declines in many spawning populations. Substantial resources have been invested to support the recovery...

A new study aims to collect information on sturgeon temporal and spatial distribution to inform offshore wind energy and sand leasing operations.

The Gulf sturgeon, Acipenser oxyrinchus desotoi, has been listed as Threatened since 1991. Beginning in 1986, USGS has been investigating sturgeon population abundance and ecology throughout its range, but mostly in the Suwannee River.

Flow cytometry is a technique for rapidly analyzing large numbers of animal cells using light-scattering, fluorescence, and absorbance measurements.