Anadromous fish are fish that spend much of their young lives at sea, but return to the freshwater portions of the Chesapeake Bay’s rivers to spawn. Anadromous fish in the Bay include American and hickory shad, blueback and alewife herrings, and striped bass. Throughout the watershed, development has resulted in more 2,500 blockages to anadromous fish. These culverts, dams, and other water-control structures either alter habitat or physically block access to the upstream habitat that is necessary for these species to successfully reproduce. Ultimately, the reductions in available spawning habitat have reduced populations in the Bay of many migratory species of fish. Staff at NOAA’s Chesapeake Bay Office examine these problems from both a habitat-restoration angle and as a fishery-management issue.

NOAA Chesapeake Bay Office habitat staff work with the Chesapeake Bay Program’s Fish Passage Workgroup to provide guidance to Bay watershed states in accomplishing fish passage and fish blockage removals.