Environmental DNA (eDNA): Non-Traditional
Sampling of Great Lakes Tributaries
BY ERIC STADIG, ALPENA FWCO – WATERFORD, MICHIGAN SUBSTATION
Muskegon River, Michigan. Credit: Steve Hensler, USFWS
Crews from multiple Alpena Fish and Wildlife Conservation Offices (FWCO)-Alpena and Waterford Substation, as well as crew members from Green Bay FWCO teamed up again to perform a large scale Asian carps (silver and bighead) eDNA sampling event. The collaboration of field crews, and an eDNA filtering crew have succeeded in completing multiple eDNA sampling trips in Lake Erie as well those in the St. Clair-Detroit River System tributaries (Raisin, Swan Crew, Rouge, Belle, and Black rivers), and also in Lake Michigan tributaries (Grand, and Muskegon rivers). The most recent sampling event included the Maumee and the Sandusky rivers.
The eDNA field sampling was executed spatially in each river by a downstream to upstream manner. Samples were collected in targeted areas where accumulation of potential Asian Carps eDNA is most likely to occur (backwaters, eddies, barge slips, island side channels, pooled areas, confluences, etc). Each two liter sample bottle was filled by skimming the surface water and collecting any floating material/surface film that may have traces of genetic material left behind in the water (eg. scales, cells, and feces).
Physical environmental conditions (wind direction, water temperature, depth, etc.) were noted at each sample site and the sample location was recorded using GPS. Safeguarding against DNA cross-contamination was an important step in this overall process, latex gloves were changed after each sample was collected. Sample blanks prefilled with deionized water, were tested to assure quality, including prevention of contamination in the transport vessels and/or during the sampling process.
Disinfection of boats occurred by applying a bleach solution to both boat and trailer once the vessel was out of the water ensuring no cross-contamination from moving one water body to another. Samples were filtered in the new Alpena FWCO eDNA trailer on site. Once the process was completed, samples were packed and shipped on dry ice to the US Fish and Wildlife Service (FWS) Whitney Genetics Lab for subsequent analysis.
Through the ease of using the eDNA trailer, and the hard work and commitment of the crews involved, everyone should be excited about the early detection efforts taking place via collaborative efforts among the USFWS offices and partners.