Northern Exposure

Research Implications for Pacific Northwest Salmon

The class helped build a record of research that provides Alaska fisheries managers and industry with data about salmon abundance and provides scientists in Alaska, the Pacific Northwest and elsewhere with information about basic salmon biology.

Among other things, fisheries and climate scientists are using UW data to correlate salmon runs with a 20- to 30-year climate cycle over the North Pacific. Called the Pacific Decadal Oscillation, researchers recently discovered that when the climate cycle is in its warm/dry phase, as it has been since 1977, Alaskan salmon runs are more abundant and Pacific Northwest salmon runs suffer. When the climate shifts to its cool/wet phase, Alaskan runs are weaker and the Northwest salmon have more favorable conditions.

Map of UW's six Alaska field stations

The UW's six field stations were built 30 to 50 years ago in southwestern Alaska. Map by Jeff Porterfield and Ken Shafer.

There is something about the climate cycle that affects ocean conditions and, in turn, the salmon. For Alaska, Hilborn says the UW Alaska Salmon Program would like to investigate ocean conditions, and ways to keep track of them more thoroughly. Scientists are still struggling to understand what happened two years ago when the sockeye runs in Bristol Bay were half as large as projected. After ruling out numerous other causes as minor contributors, ocean conditions emerge as the key culprit but what happened remains unclear, Hilborn says.

For the Pacific Northwest, the study of ocean conditions and impacts on salmon in Alaska might provide a clearer picture of how ocean conditions affect runs in that area. Other than harvesting, the Alaskan runs being studied are unaffected by human activities, so it should be easier to see the natural connections. In the Lower 48, scientists must peel away the effects of urbanization, agriculture, power generation and other activities in order to study natural cycles.

It's important to understand how ocean conditions affect Pacific Northwest runs, Hilborn says. "In a few years, if the Pacific Decadal Oscillation shifts to the phase that favors our runs, we don't want to be patting ourselves on our backs for 'saving' salmon when we still haven't done enough as far as habitat, hatcheries and other problems salmon face," he says.

Zoologist Schindler says he may one day be able to extend the salmon abundance record back for centuries by taking core samples from the sediments of Alaskan lakes and analyzing their isotope composition. Correlating these numbers with climate records may reveal new climate patterns that affect salmon survival and the Alaskan ecosystem.

Researchers arrive at Nerka field station

Researchers and visitors arrive by float plane to the Nerka field station.

Pursuing these and other lines of research often means using techniques never tried before and sometimes ending up with more questions than when the work started—something the undergraduates also faced.

After their return to Seattle, the six attended weekly classes as part of a Fall Quarter seminar that capped their experiences and included presentations about their independent projects.

Senior Mariah Meek reported about her work trying to confirm if fish are as discriminating as what she observed among beach spawning salmon: It appeared that males in an area where the females had all spawned were unwilling to swim even a couple hundred meters to another area of the beach where females were still available.

"I had to think through the project and put it all together whereas, for most classes, I'm simply writing about what I've already read or been told is true," Meek says. "This kind of work has made a strong, lasting impression, on me. It confirms that this is the kind of work I want to be doing."

Sandra Hines, assistant director of the UW's News and Information Office, visited the UW Alaska field stations in August.

Read more about UW's innovative "Tools for Transformation" program.

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