Project background

Since the 2000s, subsistence fishing communities throughout the Yukon River Basin have felt the effects of ongoing Chinook salmon declines and, more recently, severe declines in chum salmon runs - two species that remain critical to the economy, culture, education, and health of each community. Meanwhile, fisheries managers are finding it increasingly difficult to count salmon each summer without interruption when high water events can render their salmon counting equipment unusable until water subsides. As climate change persists, high water events are predicted to become more frequent, prompting the development of this project: testing a complementary approach to traditional salmon counting methods that is robust to high streamflow events. By filtering water samples from five Yukon River tributaries throughout Alaska, we will assess whether environmental DNA (eDNA) analyses can be used to adequately estimate the number of salmon moving through a river system.

Why is this research so critical?

eDNA sampling could be used as a tool:

• to fill data gaps of currently-monitored tributaries caused by intermittent funding, logistical challenges, and high streamflow events

• to assess relative run timing and abundance of salmon across a wider range of spawning tributaries

• as a lower-cost, less-intensive approach to salmon monitoring that produces relative index of abundance similar to that of an aerial survey but more resilient to weather disruptions and high turbidity

• support community-based salmon monitoring efforts

Long-term goal:

• • develop and fine-tune river-specific trainings and sampling protocols that state, federal, and tribal entities can sustainably employ as part of their long-term salmon monitoring projects