Fish Passage

USGS is working to identify an improved fishway entrance design for two at-risk species, blueback herring ( Alosa aestivalis) and alewife ( Alosa pseudoharengus).

USGS is working to establish a new East Coast fish ladder design that would help a multitude of aquatic species move easier in our waterways.

American Shad are the most numerous and economically important anadromous species on the east coast of the United States. Yet in many river systems their populations have experienced declines, primarily due to the impacts of dams and habitat loss.

Dams can be found in just about every major river, and for good reason. Society has received many benefits like flood control, hydropower, water supply storage, and places to recreate. However, many fish and other life in our rivers can’t swim around these barriers. Often, the best spot for a fish to live and reproduce is out of reach because they can’t pass by a dam. This has not gone unnoticed...

The American eel ( Anguilla rostrata) migrates into freshwater in the juvenile (glass eel and elver) stage, feeds and grows in freshwater habitats, and migrates downstream to the ocean to spawn as an adult. Migrating eels frequently encounter barriers in river environments, primarily in the form of dams, that limit access of juveniles to upstream growth habitat, and can injure or kill adult...