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River Herring

River herring at the Milford Project counting window on the Penobscot River, Maine. Photo: Tara Trinko Lake/NOAARiver herring at the Milford Project counting window on the Penobscot River, Maine. Photo: Tara Trinko Lake/NOAA

River herring (alewife and blueback herring) are migratory fish that range along the East Coast from Florida to Maine. They spend most of their life cycle in the marine environment, returning every four to five years to their natal rivers to spawn. Juvenile river herring typically migrate back to the marine environment in the fall. Once out of the river, they may use the estuary for extended periods before migrating in the open ocean.

Historically, river herring populations once reached into hundreds of millions. Returning to coastal rivers every spring, these fish supported one of the oldest fisheries in the United States. As prey of larger fish, river herring also supported important recreational and commercial species, such as cod, haddock, and striped bass.

Over the years, river herring populations have declined due to habitat loss associated with dams, road crossings and other development activities, overfishing as a direct fishery and as bycatch, pollution and other factors. Based on those declines, NOAA identified river herring as a “Species of Concern" and “Candidate Species” under the Endangered Species Act. Our staff is working to help recover river herring through a number of management measures, habitat protection initiatives and restoration projects. We work with a variety of partners -- federal and state agencies, non-profit organizations, tribes, commercial and recreational fishermen and others -- to conduct research and develop management measures for these species. We also work with stakeholders, including commercial fisheries and hydropower developers, to implement protective measures while supporting sustainable, productive industries.