batch_auto_20260713 202607131256465730 BOEM ESP geoESPIS ESPIS@boem.gov Bureau of Ocean Energy Management Harnessing the Power of eDNA as a Real-time Assessment tool of Nearshore Arctic Marine Communities University of Alaska Fairbanks University of Alaska Fairbanks As global climate change rapidly impacts Arctic and subarctic marine ecosystems, scientists need tools that will rigorously quantify changes in biological communities. Arctic biodiversity monitoring is essential as glacial estuaries face recession, where the dynamic convergence of freshwater and marine environments has historically supported diverse ecological communities. Genomic sequencing tools such as environmental DNA (eDNA) metabarcoding complement conventional fisheries approaches (e.g., netting) by providing in-depth, rapid, and non-invasive assessments of species composition. We implemented eDNA metabarcoding to assess its utility as an ecological monitoring tool in 5 estuarine sites in Lower Cook Inlet, Kachemak Bay, Alaska with varying degrees of glacial coverage (0 – 60%). We analyzed eDNA samples between April – September 2021 – 2022 to tease apart seasonal and spatial patterns in fish diversity and to assess the extent to which environmental variables drive community composition. Results suggest a stronger influence of seasonal drivers on fish biodiversity than spatial drivers. Detections of fish taxa were higher using eDNA than conventional beach seining. The results of this study will build on existing baseline data to document changes in a region heavily impacted by climate change. 200766 U.S. Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program https://doi.org/10.13039/100012475 M21AC00014 10.67297/9A1E7D https://boem.gov/awardpages/100349