NW Salmon Runs Dodge A Bullet

NW Fishletter #244, March 20, 2008

For years, Northwest fishermen have looked longingly at the huge salmon runs in California , fueled largely by stocks from the Sacramento River . But no more.

Federal scientists say a massive failure of the normal upwelling phenomenon in the spring and early summer of 2005 has led to a collapse of the Central Valley 's fall chinook runs -- mostly in the Sacramento and San Joaquin rivers and their tributaries.

As late as 2004, California sport and commercial fishers were hauling in more than half a million fall chinook south of Point Arena with another 300,000 fish left over to escape to Central Valley rivers.

This year, harvest managers forecast only about 157,000 fish bound for the Golden Gate , before any harvest at all. Only about 59,000 of those are expected to head for the Sacramento .

"We are not dismissing other potential causes for this year's low salmon returns," said Usha Varanasi, Director of NOAA Fisheries Service Science Center for the Northwest Region, in a March 3 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."

The scientists said a southerly shift in the jet stream in 2005 kept favorable northwest winds from building in early spring to kick-start the upwelling process. The northerly winds displace the surface water, causing nutrients to rise from the deep as cold water rises to fill the surface layer. The process causes the surface layer of the California Current to flow in a southerly direction through the spring and summer. The current moves north in winter months.

The bad news will likely catch up next year with the Klamath River , where most returning fish are four-year-olds as opposed to the Central Valley 's three-year-olds. But this year, the Klamath is expected to be home to quite a healthy return.

In fact, ocean abundance levels of the Klamath fall chinook -- 191,000 fish -- are estimated at higher levels than the Central Valley run, which is expected to be the lowest on record.

At last week's PFMC meeting, the Council recommended that NMFS take inseason action to close the Cape Falcon to Humbug Mountain commercial and recreational salmon fisheries between March 15 and at least April 30, close the Fort Bragg recreational salmon fishery between April 1 and at least April 14, and close the Fort Bragg commercial salmon fishery April 7-25.

They also identified three potential harvest options for dealing with the problem -- including the possibility of closing the commercial troll fishery from the OR/CA border south for the entire season.

The situation is a lot rosier in the Northwest, where the Washington Department of Fish and Wildlife's estimates of fall chinook runs on the Columbia River add up to more than 366,000 fish this year, an obvious improvement that reflects much better conditions off the Oregon and Washington coasts than in recent years.

Three chinook harvest options on the table for ocean fisheries north of Cape Falcon are similar to last year's -- when they picked an overall non-Indian catch of 35,000 chinook. But low estimates of coho escapement means coho fishing will be severely limited this year, compared to 2007.

The backbone of the Northwest fall run is the upriver bright stock from the Hanford Reach, which is estimated at about 163,000 chinook. Managers consider that a "strong" return. It's about 70 percent of the 10-year average.

The second largest component is the hatchery tule run heading back to the pool above Bonneville Dam. About 87,000 are expected, much better than the last two years (14,600 in 2007) and about even with the 10-year average.

The weakest link -- the ESA-listed lower Columbia wild fall chinook -- is not expected to do well, with only 3,800 estimated. Last year, about 4,300 returned, less than half the preseason prediction.

It's obvious that predicting fish returns can be a pretty iffy business, especially when Mother Nature throws a curve ball once in a while. The fish managers who predicted the Central Valley returns last year were off by a factor of 3. They relied on a simple regression based on jack counts to make their estimate. The 14,500 jacks that returned in 2006 was the lowest number on record up to that point and close to levels in 1990 and 1991.

The 2006 jack count wasn't great, but it still caused managers to bump harvest rates up 65 percent last year from 2006, when their low expectations for the Klamath run had them adjusting catches down accordingly.

The story of those decisions is contained in a table of figures in a preseason report released in late February. It shows that ocean chinook landings (sport and commercial) south of California's Point Arena (about 200 miles north of San Francisco) totaled nearly 112,000 chinook in 2007, more than 20,000 fish above the number of hatchery and natural fall chinook that made it back to the Sacramento and its tributaries. But the catch was only about one-third of what managers had expected.

And even worse news was that the Central Valley fall jack count had plunged to about 6,000 (only 2,000 in the Sacramento ) in 2007, from a long-term average in the 40,000 range.

In late January, the Council issued a statement saying Central Valley fall chinook conservation objectives would likely not be met even if the 2008 ocean fishing season was completely curtailed.

A total closure could have devastating impacts to coastal communities -- $60 million or more, according to the PFMC. On Mar. 20, the Council said it was asking NMFS to lead a multi-agency task force to investigate up to 50 potential causes for the Sacramento chinook collapse. It acknowledged that "many biologists believe a combination of human-caused and natural factors are to blame; including freshwater instream water withdrawals, habitat alterations, dam operations, construction, pollution, and changes in hatchery operations."

"After everyone asks how this could have happened, the question then becomes 'is there anything we can do to fix it?'" said Council chair Don Hansen in a press release. "The Council will take an immediate step to fix what it has authority to fix, which is appropriately managing the ocean fisheries that affect this valuable resource."

The issue struck home when mid-level policy makers in the Columbia Basin met Mar. 6 to hear a report by NOAA Fisheries scientists on ocean and estuary issues.

Researcher Ed Casillas explained how his group has been developing a series of biological and climate indicators to help scientists get a better idea of what to expect from future salmon runs.

Casillas said his group has told California harvest managers that if they had looked beyond the jack counts to what was actually occurring off the California coast in 2005, they would have had a cause for concern because "the world wasn't very good out there."

He said managers should look at additional indices to temper their forecasts so people won't be caught off guard.

Casillas said good conditions for fish off the Northwest coast began early in 2007, but fizzled fast. However, there was a lot of the kind of plankton around that young salmon like to eat.

Trawl catches of young coho were high in June, but the lowest in 10 years by September, while sea surface temperatures climbed very high in July and August. But overall, the NOAA Fisheries indicators showed much more hospitable conditions for both chinook and coho than a few years ago.

Casillas said managers should probably expect to see ocean conditions change more rapidly than in the past, when 20- to 30-year cycles of alternating warm and cool ocean climate regimes seemed more the norm. Since 2000, conditions have already flip-flopped from a few cool salmon-friendly years to a really warm year, followed by several intermediate years and now back into a cool year like conditions around the turn of the century.

But even taking ocean conditions into account doesn't automatically ensure success. Managers blew last year's Oregon wild coastal coho predictions big time, even with a model that factored in ocean conditions. The run came in more than 400 percent lower than their preseason estimate.

NOAA Fisheries scientist Pete Lawson told NW Fishletter that the poor coho returns had everybody "scratching their heads," since ocean conditions had been pretty good during the stock's tenure in the ocean, and that the high preseason prediction was based on those good conditions.

"Obviously, something has decoupled," Lawson said.

There was an odd decline in coastal upwelling in the spring of 2006, after it started off with a bang in April. However, winds changed, and upwelling stopped altogether in May, but perked up again later in the summer.

It may be just as well that the Columbia 's spring chinook run leaves the neighborhood as soon as it hits the ocean. This year's return to Bonneville Dam is expected to be possibly the third highest since 1938. 

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