What impact do dams in general have on American eel populations by impeding and preventing upstream migration?
Here again little attention has been paid to this problem here in New England. For an example we can look to our south, to the Susquehanna River where some research has been done. The information below is from Maryland Department of Natural Resources, MBSS Newsletter March 1999, Volume 6, Number 1 “The most dramatic example of the decline of American eel abundance is dam construction on the Susquehanna River. Prior to the completion of Conowingo and three other mainstem dams in the 1920s, eels were common throughout the Susquehanna basin and were popular with anglers. To estimate the number of eels lost as a result of construction of Conowingo Dam, we used MBSS data on American eels from the Lower Susquehanna basin and extrapolated it to the rest of the basin above the dam. Our best conservative guess is that there are on the order of 11 million fewer eels in the Susquehanna basin today than in the 1920s. The magnitude of this loss is corroborated by the decline in the eel weir fishery
