It's About Time: Seasonal eDNA Abundance Calibration for Three Diadromous Species.

Garner, James G.² * , Michelle Staudinger^1,2 , Adrian Jordaan¹ , John Sheppard³, Gwynne Hayes⁴, Eva Kozol² ,¹USGS, DOI Northeast Climate Adaptation Science Center, ²Department of Environmental Conservation, University of Massachusetts Amherst, ³MA Division of Marine Fisheries, New Bedford, MA, ⁴Mount Holyoke College, South Hadley, MA

Effective resource management and policy development requires relevant, real-time data. The high sensitivity of eDNA methods and relative ease of sample collection present managers and communities with a noninvasive, more accessible, and cost-effective opportunity to study aquatic organisms for which traditional sampling is difficult or impossible. With proper validation and appropriate analytical frameworks, eDNA-based abundance estimation techniques have the potential to enhance the use of eDNA methods in conservation and management of species like anadromous river herring (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), and American shad (Alosa sapidissima). This study represents a collaborative eDNA monitoring-through-management initiative with the Massachusetts Division of Marine Fisheries (MA DMF) diadromous fisheries team. Together we investigate the spatiotemporal relationship between seasonal eDNA signals and established and ongoing MA DMF electronic herring counts, video herring counts, smelt fyke net surveys, and American shad electrofishing surveys in three coastally connected systems (North/South Rivers, Jones River, Fore River). At all sites, eDNA samples were collected twice weekly throughout the entirety of each target species’ migratory season at sampling locations upstream and downstream of the ongoing established DMF surveys. eDNA signals will be calibrated to the MA DMF established techniques to better understand the relationship between river herring, rainbow smelt, and American shad abundances and eDNA signals through time. Results are anticipated to give fisheries resource managers the needed context and understanding of these techniques to assess if these powerful, next generation tools will be a beneficial addition to their adaptive management and monitoring frameworks.