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Testing and refinement of eDNA methodology to support ecological assessment within the St Louis River estuary
Citation:
Hatzenbuhler, C., G. Peterson, J. Barge, J. Hoffman, A. Trebitz, S. Okum, AND E. Pilgrim. Testing and refinement of eDNA methodology to support ecological assessment within the St Louis River estuary. St. Louis River Estuary Virtual Summit, Duluth, MN, March 01 - 03, 2021. https://doi.org/10.23645/epacomptox.14075498
Impact/Purpose:
The eDNA evaluation and methods refinement work described in this poster contributes to two distinct research areas at EPA/ORD. One is under SSWR research area 3.01A-2.1, which seeks to implement and refine early detection monitoring for aquatic invasive species in the Great Lakes. DNA metabarcoding of environmental DNA samples is one of the approaches being applied to generate species composition data for such monitoring. The second is under SHC research area 9.1.1, which seeks to evaluate the effectiveness of ecosystem restoration via place-based studies within the Great Lakes and elsewhere. The research effort described in this poster is modest, but serves to pilot methods for future applications of eDNA to biological assessments.
Description:
Environmental DNA (eDNA) is rapidly and easily collected and potentially yields high organism detectability, but understanding of the collection mechanics and utility for specific environmental assessments is still evolving. Despite a restricted field season in 2020, we were able to conduct two eDNA-related sampling efforts within the St. Louis River Estuary. One effort was to resolve eDNA collection methods – are surface and near-bottom samples different, and what level of replication is needed in different habitats (e.g., channel vs bays; vegetated vs open)? Samples to address these questions were collected from Little Pokegama Bay, which offers a range of water depth and vegetation cover with little habitat disturbance. These samples will undergo DNA metabarcoding and comparisons will be made on the basis of sequence abundance and species richness. Results will help inform general eDNA sampling for a broad range of applications, including early detection monitoring for invasive species. A second effort was to evaluate the utility of eDNA data in establishing pre-restoration biological conditions, where discerning differences over small (project level) spatial scales is of interest. Samples to address this question were collected at Pickle Pond and Erie Pier Ponds, which are slated for contaminant remediation and habitat restoration in 2021, and at their respective reference sites. Fish and invertebrate composition data produced by metabarcoding of these eDNA samples will be compared to data obtained from direct organism collections to evaluate if eDNA has the necessary specificity to resolve differences between impacted and control sites
URLs/Downloads:
DOI: Testing and refinement of eDNA methodology to support ecological assessment within the St Louis River estuary