The Pennsylvania Fish and Boat Commission (PFBC) and the West Virginia Division of Natural Resources (WVDNR) recently confirmed that environmental DNA (eDNA) from the invasive Asian silver carp has been found in two water samples collected from the Ohio River. Anglers concerned with the nation’s fisheries should pay attention to this finding. The rapidly reproducing invasive Asian carp (including bighead) pose a severe environmental threat by gobbling most of the algae needed by indigenous species. Originally imported for aquaculture, the fish escaped into the wild decades ago.
Unlike DNA taken from an actual fish, eDNA serves as an early warning of sorts by identifying traces of genetic material such as scales, excrement or mucous. Scientists note that eDNA does not confirm the presence of live or dead Asian carp because such genetic material can be transferred through bilge water, storm sewers or waterfowl droppings.
Of course, anglers can unwittingly contribute to the Asian carp plague by transporting these fish from one water body to another. It’s illegal to do so, but the first step to avoiding this major no-no is to learn how to differentiate invasive Asian carp from indigenous grass carp and common carp. The above video from the U.S. Fish and Wildlife Service lays it out clearly.