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
Herring as food the cancer-causing effect of PCBs and dioxins. The contaminant levels depend on the age of the fish which can be inferred from their size. Baltic herrings larger than 17 cm may be eaten twice a month, while herrings smaller than 17 cm can be eaten freely. Mercury in fish also influences the amount of fish that women who are pregnant or planning to be pregnant within the next one or two years may safely eat. Herring has been a staple food source since at least 3000 B.C. There are numerous ways the fish is served and many regional recipes: eaten