Using Environmental DNA to Study Brook Trout Populations in the Headwaters of the Chesapeake Bay

Abstract

Brook Trout (Salvelinus fontinalis), a cold-freshwater species native to eastern North America, are bioindicators of cold, clean water. Recent restoration efforts require improved monitoring methods to assess progress toward conservation goals. Environmental DNA (eDNA) is a potentially rapid, cost-effective method to detect Brook Trout presence from water samples. However, eDNA dynamics in aquatic ecosystems are not well understood for this species. We assessed how water temperature, distance from an eDNA source, and filter pore size affect Brook Trout eDNA concentrations. We found significantly higher Brook Trout eDNA concentration at 20 ℃ compared to 10 ℃ in a lab experiment. We were unable to obtain quantifiable eDNA concentration in a natural stream setting, likely due to insufficient water volume collection or filter material. This study highlights the importance of optimized eDNA collection methods for accurate and effective species detection to identify priority restoration streams for Brook Trout conservation.