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Restoring the Lower Snake River

DaggerFallsLetters from the West

April 21, 2016

By Rocky Barker

Federal ocean scientists warn that continuing warm temperatures in the Pacific and a cyclical shift in climate signals dropping productivity for the salmon and steelhead.

The fate of the fish are important even beyond the sportsmen, tribes and businesses that rely on fishing for recreation or livelihoods. In addition to being the living embodiment of the wild character of the Pacific Northwest, the salmon’s health is tied to the future of dams, power rates, water for farming and barge transportation between Idaho and the Pacific.

The unprecedented mass of warm water thousands of square miles wide across the Pacific first appeared in 2014 and was dubbed by scientists as “the blob.” This year it has shown signs of dissipating. But the effects on ocean currents and the food chain continue, reducing the size and numbers of salmon seen off the coast, said Bill Peterson, a National Oceanic and Atmospheric Administration Fisheries oceanographer.

Meanwhile, a potentially longer shift in climate called the Pacific Decadal Oscillation appears to be returning, Peterson said. That’s bad because the oscillation coincides historically with a dramatic drop in ocean salmon productivity. In the 1990s, the last time the Columbia River and the Northwest saw such strong climate effects, the Snake River salmon nearly went extinct.

“If this keeps going, it’s looking like the 1990s again,” Peterson told the Statesman.


The harsher conditions salmon find in the Pacific come after unprecedented hot temperatures in the Columbia and Snake rivers in 2015 killed 99 percent of returning endangered Idaho sockeye salmon. Already, the U.S. Army Corps of Engineers has committed to fisheries officials to improve adult fish-passage facilities, to help salmon make the trip through the dams easier in warmer temperatures.

And NOAA Fisheries is trying to organize what it calls a Columbia Basin Partnership of states, tribes and other groups involved in salmon recovery to seek a path forward. Workshops are planned in May and June. And a federal judge in a decades-old lawsuit is poised to release a decision on the current federal plan to make the Columbia and Snake River dams meet the requirements of the federal Endangered Species Act.

Every plan issued since 1993 has been ruled deficient, but judges so far have stopped short of the measures that salmon advocates want — including removal of the four lower Snake Dams in Washington.

Even though hatchery salmon have flourished during the years of good ocean conditions, wild stocks still aren’t returning at rates that would recover the species, said Joseph Bogaard, executive director of the Save our Wild Salmon coalition of environmental groups, sportsmen, sporting businesses and tribes.

“It’s time to get people to pay attention,” Peterson said.


A lot of factors affect the health of Idaho’s sea-going salmon and steelhead: habitat and water flows and conditions in the Snake and Columbia tributaries; dams and the passage devices that fish use to navigate the dams; fishing techniques and seasons; and predators such as seals and birds. But ocean conditions are among the most critical, because the fish spend much of their lives maturing in the ocean, and the shape of the ocean is largely beyond human tinkering.

The remarkable improvement in salmon and steelhead runs since the 1990s is at least partly due to the favorable ocean cycle. Peterson has documented that when the north Pacific is warmer, the Columbia and Snake rivers’ salmon and steelhead productivity drops dramatically.

More voracious predators such as mackerel and even Humboldt squid show up, expanding their territory and eating the salmon. Food that young salmon eat, such as the small crustaceans known as krill, also disappears in warmer waters.

Until the blob showed up, the Pacific had been colder most years.

The blob primarily affected surface temperatures, which in turn most affect the coho salmon that stick pretty close to shore, Peterson said. But the counts of spring chinook jacks — fish that spent only a year in the ocean in 2015 and are a barometer for the larger chinook that spend two year and three years in the ocean — were down dramatically.

And the number of Chinook that have returned to Bonneville Dam on the lower Columbia so far this spring are one-tenth the number of last year.

“We’re looking at another year of lousy ocean conditions,” Peterson said. “The food chain is just a mess.”


No one was expecting the high Chinook returns the Columbia saw in 2015. And federal fisheries managers aren’t ready yet to write off this year’s run. Pete Hassemer, Idaho Fish and Game’s salmon and steelhead fishery manager, said he needs to wait another month before he gets worried.

“The spring (Chinook) count should be picking up right now,” Hassemer said. “Right now it’s going in the wrong direction.”

Stuart Ellis, harvest management biologist for the Columbia River Intertribal Fish Commission that represents the Yakama, Warm Springs, Nez Perce and Umatilla tribes, expects the run to be lower and later but still within the norm of the past decade.

“I don’t share that gloomy of an outlook, yet,” Ellis said.

In 1997, NOAA scientist Nate Mantua and his colleagues first showed that adult salmon catches in the northeast part of the Pacific correlated with the Pacific Decadal Oscillation. The cool years of 1947–1976 coincided with high returns of Chinook and coho salmon to Oregon, Idaho and Washington rivers. During the warm PDO cycle from 1977 to 1998, salmon numbers declined steadily.

Mantua doesn’t expect the current poor ocean conditions to last as long as they did in the 1990s. The El Niño climate pattern that has contributed to the warm ocean temperatures is shifting to the cool El Niña pattern and could reverse the oscillation like it did in 1998.

But even if that happens, the Columbia salmon will have faced three poor year of ocean conditions, which will inevitably have an impact on future runs.
“It’s not going to change overnight,” Mantua said.

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