UAF salmon productivity study looks to local experts as guides

In early 2022, researchers from the University of Alaska Fairbanks were interested in looking at the number of chinook salmon offspring that survive to adulthood in the Yukon and Kuskokwim rivers. Instead of setting out with their own set of questions, they decided to ask a quorum of what biologist Megan Feddern referred to as “salmon experts.”

“Agency employees at the state and federal level, community members, Elders — whoever was interested in sharing with us things that they had observed and things that they were interested in as it relates to Yukon and Kuskokwim salmon populations,” Feddern said.

At the time, Feddern was a postdoctoral researcher. She’s now a research fish biologist with the National Oceanic and Atmospheric Administration (NOAA). She and the other researchers hosted a virtual listening session as part of the 2022 Alaska Forum on the Environment and held a workshop in Fairbanks, asking the people who knew best what they were seeing change.

What stood out, in addition to the decline in salmon population, was the quality of the fish. Many people observed that fish populating the rivers in recent years were smaller than what they’d remembered.

“One of the really cool things about this project is just the extent to which we combined different data sources,” Feddern said.

Feddern said that with the help of hydrologist Rebecca Shaftel, one of the paper’s co-authors, the research cross referenced climate data — like precipitation and temperature reports — with locally collected salmon reports from over the past 30 years.

By using both types of data to examine a total of 26 chinook salmon populations, a link emerged between the decline in population productivity with smaller spawner body size and climate impacts. Salmon that are smaller are less likely to produce as many, or as nutritious of eggs as larger fish. In both rivers, the study was able to connect size to productivity, which represents the population’s ability to sustain itself over time.

The study also found a correlation between above average temperatures in the Yukon River and lower productivity. But temperatures in the Kuskokwim River did not seem to directly affect the chinook populations.

“Working with fish, you know, you often are just thinking about the climate and the fish themselves, but you can’t remove that from the communities, and the culture, and everything that those fish support and that those fish are a part of,” Feddern said.

Feddern said that they were able to find success in honoring the knowledge of others by informing a path of research with the testimonies of those impacted by the changing climate.

“And the true experts in this region aren’t folks like me who are sitting at their computer coding and modeling to try and address these questions, but are the people who have been observing these fish for generations. And so doing this work together, I think, is what is really important to have success,” Feddern said.

According to Feddern, on the second evening of the workshop that kicked off this study, the researchers and salmon experts shared a potluck meal, with local folks preparing dishes and out-of-towners bringing sharable snacks.

People from the Kuskokwim and Yukon rivers, including from the Canadian Yukon, were seated at the table, some passing over a day’s travel to bridge testimonies, hard data, and as Feddern put it, “ways of knowing.”