Patapsco River Bloede's Dam leaves Daniels Dam, upstream, as the last remaining dam along the mainstem Patapsco River. Removal of Bloede's Dam in September, 2018 opened up of the Patapsco River watershed which will potentially restore spawning runs of at least six species of native anadromous fish: alewife ("Alosa pseudoharengus"), blueback herring ("Alosa aestivalis"), American shad ("Alosa sapidissima"), hickory shad ("Alosa mediocris"), striped bass ("Morone saxatilis"), sea lamprey ("Petromyzon marinus"), as only one species, sea lamprey, were found using the Bloede's Dam fish ladder in 2012. One catadromous species would likely also benefit, the American eel ("Anguilla rostrata"), a fish species which
Weymouth Back River Whitman's Pond was dammed to turn the machines which processed the natural bog iron for the Weymouth Iron Works. Later, the Commonwealth of Massachusetts installed a herring ladder to allow the herring to bypass the dam on their spawning runs. Historically the herring ran to Whitman's Pond, and beyond up Mill River and Swamp River, to Great Pond. River herring commonly refers to two species, Blueback herring ("Alosa aestivalis") and alewife ("(Alosa pseudoharengus)"). Today, 1/2 million river herring and Rainbow smelt ("Osmerus mordax") run up the river each year to spawn (although they are not able to ascend the fish