Streams and rivers on Long Island and the Hudson River provide essential habitat for river herring (alewife and blueback herring) and juvenile American eels. Each spring, river herring return from the ocean to spawn in freshwater habitat, while juvenile American eels travel from the ocean to freshwater streams to live out most of their adult lives.
Fish that migrate between freshwater and saltwater throughout their lifecycle are known as diadromous. Obstructions to freshwater habitat such as dams, culverts, and development along shorelines has reduced corridors for migration and impacted local diadromous fish populations.
DEC, along with our partners Seatuck Environmental Association, Long Island Sound Study, South Shore Estuary Reserve, Peconic Estuary Partnership, Peconic Baykeeper, and Cornell Cooperative Extension collaborate to monitor and record runs of spawning river herring and the presence of eels in local waterways.
