Erika A Burton, Barbara A Katzenback, Patricija Marjan, Gustavo Chiang, Paulina Bahamonde, Paul M Craig, Andrew Doxey, John Giesy, Mark R Servos (2022). Optimizing environmental DNA detection protocols to generate fish presence data in remote freshwater systems . Proceedings of the GWF Annual Open Science Meeting, May 16-18, 2022.

To protect freshwater fish communities, basic knowledge of their numbers, distribution, and habitat is required, but this information can be particularly difficult to obtain for remote systems. Remote freshwater systems can experience human impacts but are poorly understood due to lack of access and potential hazards. Rivers draining from the stratovolcano Melimoyu in northern Chilean Patagonia, where limited access, high flows, and considerable river debris makes traditional sampling from boats or wading impractical or dangerous. New biomonitoring techniques such as environmental DNA (eDNA) detection can be used to sensitively and non-invasively obtain data of species presence or even community structure through analysis of water samples. Environmental DNA is DNA derived from organisms but shed into their environment (e.g., via feces, mucous, shed cells). Detection of eDNA may provide an avenue for obtaining data about freshwater communities in remote systems such as Melimoyu. To evaluate the feasibility of eDNA sampling in remote systems, eDNA detection methods were used for three different fish species: invasive brown trout (Salmo trutta) and Atlantic salmon (Salmo salar), and native puye (Galaxias maculatus) in the rivers draining Volcán Melimoyu. Brown trout eDNA was detected at seven sites across four rivers, Atlantic salmon eDNA was not detected at any sample sites, and puye eDNA was detected in one river with high certainty. The efficacy and feasibility of using eDNA detection methods in remote areas was assessed to make recommendations for future eDNA studies at Melimoyu and other remote areas. Establishing best practices for eDNA surveys may allow researcher to gain insight into ecosystems that are poorly characterized and imperiled.

First Author: Erika A Burton, University of Waterloo, Canada
Additional Authors: Barbara A Katzenback, University of Waterloo, Canada. Patricija Marjan, University of Calgary, Canada. Gustavo Chiang, Universidad Andres Bello, Chile. Paulina Bahamonde, Universidad de Playa Ancha, Chile. Paul M Craig, University of Waterloo, Canada. Andrew Doxey, University of Waterloo, Canada., John Giesy, University of Saskatchewan, Canada. Mark R Servos, University of Waterloo, Canada