OREGON STATE UNIVERSITY

On the contrary: Salmon should be facing boom years

06/15/1999

CORVALLIS, Ore. - Salmon in the Pacific Northwest may be headed for a strong period of recovery and favorable climate conditions, an expert at Oregon State University says, contrary to a new report by environmental groups that global warming is already causing their demise.

At a recent news conference sponsored by the World Wildlife Fund and the Marine Conservation Biology Institute, researchers suggested warmer ocean conditions found recently near Alaska could be linked to global warming, that negative environmental impacts have already begun and they may ultimately force salmon to abandon much of their Pacific Northwest habitat.

But fishery data just released and growing evidence for a 20-year "wet-dry" cycle in Oregon lead George Taylor, the state climatologist based at OSU, to pretty much the opposite conclusion.

"We're going to see that 1999 is a tremendously good year for salmon, that things started to improve four or five years ago and they should continue to get better for years," Taylor said. "This is consistent with our theories that much of the salmon problem in the Pacific Northwest can be linked to natural climate cycles which last 20-25 years."

In a recent conference with officials from the Oregon Department of Fisheries and Wildlife, Taylor said, it was revealed that spring chinook returns on the Willamette and Columbia River systems were higher than forecast for this year - about 46,000 spring chinook on the Willamette River had been predicted and 55,000 were actually counted.

Reports also said anchovies were showing up for the first time in a long time, shrimp populations are resurging and there's a big return on juvenile salmon in the Columbia River, Taylor said.

"This is shaping up to be our best year for salmon in a long time," Taylor said. "And as usually happens, the fishery runs in Alaska are getting worse. That's no coincidence."

As fishery experts and climatologists such as Taylor gain a greater understanding of what's going on in the ocean and streams, it's becoming more clear that what's good for Oregon and Washington fisheries is often just the opposite for Alaska. The same climatic forces that yield wet years in Oregon produce higher, colder river conditions to favor salmon survival onshore and better ocean upwelling offshore. Just the opposite often occurs about the same time off Alaska.

"There's a tremendous variation in this cycle with implications for salmon," Taylor said. "The fish get a double bonus when it's good and a double whammy when it's bad."

About 100 years of climate and fishery data point to alternating boom and bust cycles for salmon in Alaska and the Pacific Northwest, Taylor said. When salmon are plentiful in one region they are often scarce in the other.

There are undoubtedly human-induced effects on the fish, Taylor said, including dam construction and habitat destruction. But the natural climate cycles should probably be given far more attention than they have gotten in the past.

In 1939, Alaska's Bristol Bay sockeye salmon run was regarded as the greatest in history; the spring chinook catch on the Columbia River that year was one of the lowest in history. In 1994, Alaska set a new record for its salmon harvest; the same year, the Columbia spring chinook fishery was shut down and West Coast troll coho fishing banned.

But the worm turned in early 1995.

The last four years in the Pacific Northwest have been quite wet. The "La Nina" weather phenomenon often associated with cold, wet winters in this region occurred only once in 20 years prior to 1995, and three times in four years since then.

Researchers are even developing a better fundamental understanding of what drives these cycles, Taylor said. Scientists have identified a "conveyor belt" that transports warm ocean water from the Pacific through the Indian Ocean and into the Atlantic Ocean. This global scale current operates on a time scale of several decades, affects worldwide weather patterns and may even have been a triggering mechanism for the last Ice Age.

When the conveyor belt is active, there tend to be more Atlantic Ocean hurricanes, greater precipitation in the Sahel region of northern Africa, fewer El Nino events and more precipitation in the Pacific Northwest.

"We've even identified a tight correlation between Atlantic hurricanes and winter precipitation in Portland, Ore.," Taylor said. "Active hurricane years are almost always followed by wetter than average winter conditions in Portland, and inactive years by dry winters."

So right now, the conveyor belt is shifting into high gear. The Pacific Northwest should gear up for frequent floods, no droughts, about 75 percent of all years wetter than average, and relatively cool temperatures, Taylor said.

And - contrary to some reports - climate conditions should help Oregon's salmon thrive.