Relationship between American Fisheries Society standard fish sampling techniques and environmental DNA (eDNA) for characterizing fish presence, relative abundance, biomass, and species composition in Arizona standing waters

Authors: Christina R. Perez, Scott A. Bonar, Taylor Edwards, Bill Stewart, Jon Amberg, Bridget Ladell, Chris Rees, Curt Gill

Year: 2016 (xlviii)

Abstract

Recently, examination of deoxyribonucleic acids in water samples (environmental DNA or eDNA) has shown promise for identifying fish species present in water bodies. We compared fish presence, relative abundance (catch per unit effort), biomass (biomass per unit effort), and species composition measured through eDNA methods and established American Fisheries Society (AFS) standard sampling methods in a large Arizona reservoir (Theodore Roosevelt Lake) and 12 small (<24 ha) waterbodies. We observed no relationship between relative abundance and biomass of Largemouth Bass and Gizzard Shad measured by established methods and their DNA copies at individual sites or by lake section in Lake Roosevelt, but did find a relationship for the overall reservoir. Furthermore, eDNA reflected the relative proportions of Largemouth Bass and Bluegill in total electrofishing catch composition in some, but not all of 12 small Arizona waterbodies. The ease of eDNA sampling over established fish sampling makes it appealing to natural resource managers. However, further evaluation and refinement of eDNA techniques are necessary to identify its limitations and benefits in fish monitoring programs.