Experimental Stocking of American Eels in the Susquehanna River Watershed and Implications for Eastern Elliptio Populations

Elaine Langone Center, Terrace Room

American eel populations have been declining along the Atlantic coast. Conowingo Dam, at mile 10 of the Susquehanna River, blocks American eels from accessing 43% of previously available habitat in the Chesapeake Bay watershed. Following the construction of large mainstem dams in the Susquehanna River, eels were stocked sporadically until 1980. In addition to very low abundance of eels found in the Susquehanna River watershed the freshwater mussel Eastern Elliptio, common in most mid-Atlantic streams and rivers, is relatively low in abundance. Laboratory tests conducted by USGS, Northern Appalachian Research Laboratory and USFWS, Maryland Fishery Resources Office (MFRO) suggest that American eels could provide an important link to Eastern Elliptio reproduction in the Susquehanna River. Eastern Elliptio larvae use American Eels as a host during this parasitic life stage. One reason for the low abundance in Eastern Elliptio in the Susquehanna River may be the low number of eels. MFRO has been working since 2006 to assess the best methods for capturing eels below Conowingo Dam and transporting them to upstream tributaries in the Susquehanna River Basin. Following baseline fish and mussel surveys, experimental eel stockings in two tributaries were conducted from 2010 to 2012 . Fish and mussel populations will be monitored until 2019 to assess the impacts of American Eel reintroduction on fish populations and Eastern Elliptio reproduction and recruitment.