eDNA Collection

Declining salmon runs have caused severe hardship in subsistence communities within the Arctic-Yukon-Kuskokwim (AYK) region. Monitoring salmon abundance in spawning tributaries is essential to managing sustainable fisheries and providing harvest opportunities while avoiding overfishing less productive populations.

The abundance of adult salmon returning to six Kuskokwim River tributaries is currently monitored annually with weirs, and additional spawning areas are indexed with aerial surveys. Less than half of the total Chinook salmon escapement in the Kuskokwim River basin is currently monitored, and not all projects are successfully operated every year, due in part to cost and logistical difficulties.

Through this project, KRITFC and our project partners collect water samples to count the amount of DNA shed into the water – otherwise known as “environmental DNA,” or “eDNA.” These eDNA samples provide a novel and low-cost approach to salmon assessment that complements and fills gaps in traditional weir counts, especially during events like high water that blowout weirs.

In 2022, KRITFC collected eDNA samples at the Kwethluk River weir (in partnership with U.S. Fish and Wildlife Service, Organized Village of Kwethluk, and University of Alaska Fairbanks). In 2023, we collected eDNA samples at the Kwethluk River weir, Takotna River weir (in partnership with Takotna Tribal Council and UAF), and George River weir (in partnership with Alaska Department of Fish & Game and UAF). The samples are processed by UAF at the end of the season, and results are forthcoming as of April 2024.