Herring are Back!

Six years after the removal of the 34-foot-high and 220-foot-wide Bloede Dam in Maryland, a 2023 study published in PLOS ONE found eDNA evidence of  river herring using the reopened habitat (read article here). For more than a century, Bloede Dam had been the first barrier that fish encountered on the Patapsco River when migrating up from the Chesapeake Bay. The dam had also been a serious public safety hazard for decades.

The removal of Bloede Dam is part of a larger effort to remove all four dams along 175 miles of the Patapsco River and restore habitat to alewife, herring, American shad, striped bass, and American eel. With help from the American Reinvestment and Recovery Act of 2009, Inter-Fluve worked with American Rivers, NOAA, Maryland DNR fisheries, Baltimore/Howard counties, USFWS, Patapsco Valley State Park staff, and the Friends of the Patapsco Valley State Park to develop designs for the removal of Bloede Dam (2018), and Simkins Dam (2010).

Photo credit: Chesapeake Bay Program