Comparison Of Particle Capture Methods For Edna Surveillance

eDNA surveillance is an effective tool for the detection of aquatic species in areas of low population abundance (e.g. rare or threatened species and aquatic invasive species at the leading edge of an invasion front). However, the utility of this method depends upon our ability to maximize DNA collection in the field and DNA recovery in the laboratory. A variety of methods are currently employed to collect and process water samples for eDNA detection, but questions remain regarding the relative efficacy of these methods for the capture of target DNA in situ. Our objective was to compare recovery of target DNA across some of the most commonly used eDNA collection and processing methods, including filtration, centrifugation, and precipitation based methods. We tested the ability of each method to capture DNA of Asian carp (Hypophthalmichthys spp.) across a putative fish density gradient in a region of the Chicago Area Waterway System (CAWS) where these fish are thought to be rare.  We report the results of our comparisons from multiple sampling events in the CAWS. Our findings will increase the capacity of fisheries managers to implement robust and cost effective eDNA surveillance programs.