Environmental DNA Monitoring for Asian Carp in the Upper Mississippi River

Environmental DNA (eDNA) testing has recently been used in attempt to characterize the invasion front of Asian carp moving up the Mississippi River in Minnesota. Testing in 2011 was encouraged by the Minnesota Asian Carp Task Force composed of federal, state and local agencies. A private contractor conducted DNA analysis using techniques that varied from USACE protocols.  Sampling was based primarily on available funds and personnel. Initial sampling was at two sites below dams in the Mississippi River and a tributary. When one site produced positives, sampling was expanded to eight sites with 20-60 samples per site. Silver carp (Hypophthalmichthys molitrix) DNA was detected at all sites except above a barrier dam, which triggered intensified electrofishing and netting; however, no Asian carp were captured.  These inconsistencies led to a more systematic sampling scheme in 2012, which included collecting 50 samples from five sites near dams, two negative control lakes, and a positive control site. Samples were analyzed at a USGS eDNA laboratory using standard protocols (results pending). Lessons learned include the importance of having a response plan before using eDNA testing and the need to explain its strengths and weaknesses to stakeholders. (Funded by the Minnesota Environment and Natural Resources Trust Fund).