Midwest Fish & Wildlife Conference 2018

AUTHORS: Katherine Bockrath, Maren Tuttle-lau, Erica Mize, Emy Monroe - U.S. Fish & Wildlife Service

ABSTRACT: In aquatic conservation and wildlife management, identifying areas where rare and invasive species are present is key to making informed management decisions. Traditional survey methods, though highly effective and not to be replaced, can be financially costly as well as expensive in both time and personnel. The use of environmental DNA (eDNA) sampling allows for broad range, yet species targeted sampling; cutting costs and valuable personnel time. eDNA surveys provide managers with the opportunity to narrow down samplings sites for further targeted sampling through traditional survey methods. In order to have the utmost confidence that target DNA present in the environment is captured during eDNA sampling, we tested two eDNA capture and two eDNA extraction methods using low and high concentrations (copy number) of target DNA cloned into living cells. By using living cells, we are more accurately assessing how effective different methods are at capturing eDNA by allowing for stochasticity seen through cell clumping and non-even cell distribution in a water sample. Additionally, by cloning target DNA into living cells, we can control the quantity of our starting copy number so that we can directly compare the efficiency and effectiveness of each method throughout the process of eDNA handling and data analysis. We find that though we can consistently and accurately detect a target species through presence or absence when starting concentrations are low, stochasticity is a significant factor in our ability to consistently recover all the starting material by the end of sample processing. By recognizing that stochasticity is important for eDNA recovery, more accurate sampling models and eDNA processing protocols can be developed to increase eDNA sensitivity.