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Using eDNA to estimate distribution of fish species in a complex river system (presentation)
Citation:
Hatzenbuhler, C., W. Chadderton, J. Hoffman, S. Okum, B. Olds, E. Pilgrim, A. Trebitz, A. Tucker, AND M. Wrenshaw. Using eDNA to estimate distribution of fish species in a complex river system (presentation). Society for Freshwater Science, Detroit, MI, May 20 - 24, 2018.
Impact/Purpose:
This collaborative research project, involving EPA/ORD and researchers from academia and the Nature Conservancy, aims to advance methods for estimating fish distribution on the basis of eDNA, which is genetic material that organisms shed into the aqueous environment. Surveys based on eDNA offer the potential for efficient biological monitoring, but first require work to refine sampling and data analysis protocols and to understand how results compare to traditional organism-collection data. We accomplish the former through structured inter-lab and inter-method comparisons, and the latter by leveraging existing EPA/ORD fish distribution data sets. This research falls under SSWR research area 3.01, and contributes to the research activity “Advancing capability for Bioassessment through DNA-based taxonomic tools”.
Description:
Environmental DNA (eDNA) analysis of biological material shed by aquatic organisms is a noninvasive genetic tool that can improve efficiency and reduce costs associated with species detection in aquatic systems. eDNA methods are widely used to assess presence/absence of a target species, and have also recently demonstrated potential for estimating biodiversity in controlled environments. Here we apply eDNA methods to estimate distribution of fish species in a larger and more complex system, the St. Louis River Estuary, MN/WI. The St. Louis River provides a suitable study area because fish diversity and species distribution is well documented, thanks to past and ongoing fishery assessments and invasive species early detection monitoring efforts by the U.S. EPA, U.S. FWS, and state and tribal agencies. For analysis of fish eDNA, water samples were collected from 240 randomly selected sites extending from the Duluth-Superior Harbor and Allouez Bay up to the Fond du Lac Dam; 120 sites were sampled in mid-June and another 120 in late October. At 30 sites, an additional water sample was collected for an inter-lab comparison of results obtained using similar processing methods from independent labs. Composition and spatial distribution patterns derived from eDNA data are being compared to traditional adult and larval fish survey data to understand the different perspectives they give. Results from our study provide insight into the utility of eDNA methods for estimating fish distribution in large, complex aquatic systems and begin to inform us about how these methods can be operationalized for use by management agencies.