What happens on the Yukon River leaves genetic traces; analysis of eDNA samples from a thousand-mile canoe expedition

Abstract

In the summer of 2022, I collected eDNA samples on a six-week self-supported expedition along the upper one thousand miles of the Yukon River. While traveling along the upper half of the river, I was able to take samples in many different ecosystems and from different classifications of tributaries that contribute to the main flow of the Yukon. The Yukon and some of the tributaries are known for having high sediment loads. My first five samples were focused on the headwaters of the main Yukon, and sampling upstream and downstream of the two dams supporting the community of Whitehorse. After this, I sampled at the confluences of major tributaries. The samples were then transported back to Fairbanks following the expedition. The fish DNA was extracted from the eDNA filters, and I have been doing the genetics since. Eventually, the samples will be processed utilizing metabarcoding techniques to determine which fish species were present at the various sample sites.