Locations of River Herring and Shad Runs in New England Available on the Northeast Ocean Data Portal

The Northeast Ocean Data Portal now has point locations for river herring and shad runs throughout New England. The NROC Tribal Caucus sought to centralize information about river herring and shad runs in New England to support scientific understanding and inform decision making for conservation and restoration of diadromous fish habitats and populations.

The term “river herring” refers to two species of diadromous forage fish, alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis). Shad (Alosa sapidissima) is the largest herring species in North America.

River herring and shad are migratory fish that move between riverine and ocean habitats throughout their life cycles (diadromous). These species are culturally, ecologically, and commercially important, with populations declining across the East Coast.

Fish runs are the specific migratory pathways that diadromous fish take to complete components of their lifecycle. In New England, many state governments, nonprofit organizations, and community science groups conduct surveys of fish runs to document their location and/or assess fish population size. Runs for river herring and shad represent pathways that these fish take as they migrate from the open ocean to lay eggs in freshwater.

The new River Herring and Shad Runs layer provides point locations of fish runs throughout the Northeastern U.S. with links to additional information on managing entities and fish counts.

To access the River Herring and Shad Runs layer, navigate to Fish > Diadromous Fish Runs.

The data in the River Herring and Shad Runs layer was compiled from several existing online maps and atlases, including: