To assess the response of anadromous river herring, alewife (Alosa pseudoharengus) and blueback herring (Alosa aestivalis), to the 2018 removal of Bloede Dam on the Patapsco River, MD by monitoring environmental DNA (eDNA), eggs, tagged fish (PIT tags), and adult fish (electrofishing samples) at locations upstream and downstream of the dam site during their spawning migrations.