Low West Coast Salmon Returns; Why The Variations?

Columbia Basin Bulletin

March 21, 2008  

Anticipated record low returns of chinook salmon to the Sacramento and Klamath rivers, and expected low Oregon coastal coho and chinook and Columbia River coho returns, will likely leave California and most of Oregon without an ocean fishing season.

And 2008 sport and commercial options being considered for northern Oregon and Washington are drastically more limited than usual.

Coho salmon are listed as either endangered or threatened under the Endangered Species Act in the central/northern California and southern Oregon watersheds.

Meanwhile, 2008 forecasts of salmon returns are a mixed bag for the Columbia . Its upriver spring chinook run is expected to be the third highest since at least 1980 and would reverse a downward trend that has been witnessed since a record 2001 return. The Willamette River spring chinook run is expected to be the lowest since the mid-1990s.

Oregon and Washington fisheries managers have decided that forecast scenario requires a flipflop of traditional strategies, allowing little sport and no commercial harvest in the Columbia mainstem below its confluence with the Willamette at Portland during the spring season.

Columbia upriver bright fall chinook returns are expected to surge a bit this year, and the Spring Creek hatchery tule fall chinook stock is forecast to rebound from low counts the past two years. But Lower River Wild fall chinook numbers are expected to plummet. The LRWs are part of the threatened Lower Columbia chinook "evolutionarily significant unit.

Researchers from NOAA's Northwest and Southwest Fisheries Science Centers are comparing data on the low food production of the California Current in 2005 that occurred when this year's returning salmon would have been entering the ocean from their natal streams to feed and grow.

The cold waters of the California Current flow southward from the northern Pacific along the West Coast and are associated with upwelling, an ocean condition caused by winds that bring nutrients to the ocean's surface and is the main source of nourishment for the ocean's food web.

In 2005 a southward shift in the jet stream, delayed favorable winds and upwelling for the California Current , which normally begins in spring. The winds instead arrived in mid-July, causing high surface water temperatures and very low nutrient production within the nearshore marine ecosystem.

"We are not dismissing other potential causes for this year's low salmon returns," Usha Varanasi, director of NOAA's Northwest Fisheries Service Science, said in a recent press release. "But the widespread pattern of low returns along the West Coast for two species of salmon indicates an environmental anomaly occurred in the California Current in 2005."

What's causing the variation?

If it is ocean conditions, "the simple answer is that you have to know where these fish go," said Bill Peterson, an oceanographer based at NOAA Fisheries Northwest Fishery Science Center 's Newport Field Station. Different stocks of young salmon follow a variety of paths upon entering saltwater.

The Pacific Fisheries Management Council left its meeting last week puzzling over the causes of the predicted steep decline of the Sacramento stock.

"The reason for the sudden collapse of the Sacramento fall chinook stock is not readily apparent. Ocean conditions have been poor, and there are a lot of things that can go wrong for salmon in freshwater," said David Ortmann, PFMC vice chairman.

The Sacramento River is the driver of commercial and recreational fisheries off California and southern Oregon . The minimum conservation goal for Sacramento fall chinook is 122,000-180,000 spawning adult salmon (this is the number of salmon needed to return to the river to maintain the health of the run).

As recently as 2002, 775,000 adults returned to spawn. This year, even with all ocean salmon fishing closed, the return of fall run chinook to the Sacramento is projected to be 58,200. Under the option that allows small fisheries in specific areas, returns would be approximately 51,900.

The Council in a letter to NOAA Fisheries requested that the agency's West Coast science centers take the lead in convening a multi-agency workgroup to (1) comprehensively evaluate all potential causative factors of the collapse of the 2004 and 2005 Sacramento River fall chinook stock, (2) explain how ocean conditions may be affecting West Coast salmon stocks on a regional level, and (3) advance ideas for improved forecasting of key West Coast salmon stocks. The intent is to have the workgroup report back to the Council at its September Council meeting in Boise for potential use in the 2009 salmon fishery management cycle.

The forecast for returns of coho stocks that fuel fisheries off Washington and northern Oregon is also weak, and fishing options in those areas range from 10 to 20 percent of last year's catch. Projected chinook returns in this area, however, are forecast to be about the same as last year.

A preliminary analysis found an average 27 percent of the parental stock returning in 12 streams monitored in California . Even though coho returns appear to improve along the coast from south to north, Oregon Coast coho salmon had less than 30 percent of their parental stock return. Most Washington coastal and Puget Sound stocks are forecast to do as well or better than last year.

The ocean salmon fishing closure off the California and Oregon coasts that was announced this week does not affect Oregon 's spring 2008 Columbia River and inland fisheries. These fisheries will continue as scheduled to provide angling opportunities:

On the West Coast, the PFMC makes recommendations to NOAA regarding fishing in federal waters. State fish and wildlife agencies regulate state and inland waters. On the Columbia River , recreational fishing opened on Sunday, March 16 in what promises to be a good season -- the upriver spring chinook salmon return to the Columbia 's mouth is projected to be 269,300.

On the Willamette River , spring chinook salmon fishing is open now. The projected run of 34,000 is below average and slightly below last year's.

The Columbia 's upriver spring chinook stock remain a considerable mystery, with few caught in ocean fisheries and little known about their ocean sojourn.

"They don't show up in an ocean fisheries anywhere," according to Curt Melcher, one of the Oregon Department of Fish and Wildlife's representatives to last week's PFMC meetings. There is anticipation of a big return to the river because, in large part, because of last year's "jack" return -- fish that went to the sea in 2006 -- was double the 10-year average. That is a sign that their brood mates could well return in big numbers.

Jacks are precocious, mostly male, fish that return after only a year in the ocean. Their broodmates will make their spawning run this year, next year and the year after.

When they enter the ocean after more than a year of freshwater rearing, spring chinook are bigger than fall chinook, which launch as subyearlings for the most part. That potentially could make them more able to survive good or back ocean conditions during those first few days and weeks in the ocean, when a large share of any outmigration's mortality is believed to occur.

"The spring chinook… they take off" to unknown areas of the Pacific soon after leaving the Columbia , Peterson said. Oregon coastal and Columbia coho, on the other hand, don't wander too far, maturing off the river mouth and coast. Likewise, the coastal chinook stocks.

Peterson and Melcher say the young fish can encounter different ocean conditions, depending on when they enter the ocean and where they go. As an example the Columbia spring chinook leave in spring, followed later by fall chinook and coho. The different stocks could be met by changed ocean conditions, depending on such things as the timing and strength of the annual upwellings that bring nutrients to the surface.

"It could be affecting them, but in different ways," Melcher said of the different fish stocks.

The low expectations for Columbia River wild and hatchery coho mirror significantly reduced salmon projections to many other areas of the West Coast, said Phil Anderson, deputy director of WDFW. The poor coho runs also overshadow a slight increase in hatchery chinook returns forecasted for portions of Washington .

Those low coho returns, along with tighter restrictions needed to protect both coho and chinook salmon populations listed under the federal Endangered Species Act, will severely limit salmon fisheries this year in the ocean, Anderson said.

"We haven't seen a Columbia River coho salmon forecast this low since the late '90s," he said. "Poor ocean conditions that persisted off the West Coast in 2005 and 2006 appear to be the primary factor in the dramatic decline of Columbia River coho, as well as chinook salmon originating from central Oregon and California river systems."

This year's Columbia River coho salmon return is expected to total about 196,000 fish, nearly 266,000 fewer salmon than last year's actual run.

Ocean fishing options for chinook and coho salmon fisheries were adopted last week by the PFMC at its meeting in Sacramento , Calif. The PFMC, which establishes fishing seasons in ocean water three to 200 miles off the Pacific coast, is expected to adopt final ocean fishing harvest levels from among the options at its April 7-12 meeting in Seattle .

Last year, the PFMC adopted recreational ocean fishing quotas of 16,250 chinook salmon and 117,600 coho. This year's recreational ocean options in the area North of Falcon are:

-- 22,500 chinook and 21,000 coho;

-- 17,500 chinook and 21,000 coho; and

-- 12,500 chinook and 12,600 coho.

Although Columbia River hatchery chinook forecasts are up, the ocean options for chinook are similar to those proposed last year, said Anderson . Those options, which are at near-record low levels, reflect the need to protect wild Columbia River chinook salmon, he said.

"To meet conservation objectives, most salmon fisheries in Washington 's waters will be even more restricted this year," Anderson said. "There are some opportunities to craft fisheries that target healthy hatchery stocks, and fishery managers will work with the public in the next couple of weeks to develop those fisheries."

Chinook and coho quotas approved by the PFMC will be part of a comprehensive 2008 salmon fishing package, which includes marine and freshwater fisheries throughout Puget Sound , the Columbia River and Washington 's coastal areas. State and tribal co-managers are currently developing those fisheries.

The co-managers will complete the final 2008 salmon fisheries package in conjunction with the PFMC process during its April meeting.

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