Project
Using environmental (eDNA) to map the distribution of SARA-listed native lampreys in the Great Lakes
Native lampreys are vulnerable to the lampricides used to kill invasive sea lamprey, and northern brook lamprey (Ichthyomyzon fossor; NBL) and silver lamprey (I. unicuspis; SVL) are listed as Special Concern on Canada’s Species at Risk Act. Chestnut lamprey (I. castaneus) occurs in US tributaries of the Great Lakes, but its occurrence in Ontario has not been confirmed. The Sea Lamprey Control Program monitors the effect of sea lamprey control on non-target lamprey species, but its ability to do so has been hampered by challenges associated with cost-effectively surveying the many streams in which these species occur, especially those outside the Great Lakes basin and stream reaches above sea lamprey barriers. With prior GLFC funding, we developed eDNA assays for Great Lakes lampreys and showed that environmental DNA (eDNA) was more sensitive than electrofishing for detecting sea lamprey at low densities. Therefore, this study uses a combination of genus- and species-specific (Ichthyomyzon sp. and NBL/SVL or chestnut lamprey, respectively) eDNA assays to detect these lampreys in 58 Ontario tributaries. At present, larval NBL and SVL cannot be distinguished morphologically or genetically, but we have identified a genetic marker that may distinguish them; we are testing this marker to determine if it can identify NBL and SVL individually.