The number of returning Columbia River fall chinook salmon next year will likely fall below 400,000 adult fish for the second year in a row, according to a preliminary forecast issued this week by the Oregon and Washington departments of fish and wildlife.

This year just under 400,000 fall chinook returned to the basin, less than the 460,000 predicted in preseason. The new forecast predicts that a lesser number of upriver fall bright fall chinook will return next year, perhaps slumping under 200,000 for the first time since 2000. The URBs are the largest component of the basin's fall chinook return.

The overall fall chinook return to the basin is likely to slip below the 2006 total, according to the 2007 "outlook."

The recent (through 2004) 10-year average return is 469,300 adults. The past 10 years' returns can be categorized in two distinct periods of strength. From 1996 through 2000, the returns ranged from 255,000 to 330,800. Run strength ballooned over the next five years, ranging from 548,900 to peaks of 893,100 in 2003 and 799,100 in 2004.

The runs' 2007 forecast strength is based in part on relatively weak returns of "jacks" this year from some of the individual stocks. Jacks are immature 2-year-old fish. Their strength can portend the strength of the next year's 3-year old return. Fall chinook can make their spawning mission at 3, 4, 5 or even 6 years of age. The forecasts weigh the expected strength of all age classes.

About 249,000 upriver brights returned in 2006, slightly less that the 273,900-fish prediction but very near the 10-year average. The jack return was, however, below average for the second year in a row.

Most of the URB fall chinook are wild fish bound for the mid-Columbia's Hanford Reach spawning grounds or Priest Rapids Hatchery with smaller components originating in the Yakima , Deschutes and Snake rivers.

Fall chinook forecasting done by the states in cooperation with tribes and federal agencies has been, relatively, accurate. Overall, the fall chinook run has come in between 78 and 189 percent of forecast over the past 1999-2005 period but most years forecasts were much closer.

The range of forecast success was tighter for upriver brights, between 75 and 175 percent, according to tables in the states' July Joint Staff Report. More often than not, more fish returned than predicted.

The Bonneville Pool Hatchery fall chinook return took a dip in 2005, a return of less than 40,000 fish. That was less than the 51,800 predicted and below the 10-year average.

The 2007 tule return could shrink further. The 2006 jack return was only 20 percent of the recent average. The forecast expects a return similar to the actual 2006 return.

BPH returns have also gone through bust and boom periods. From 1996-2000, the counts ranged from 20,200 to 33,800. During the next five years the counts ranged from 93,100 to a peak of 180,600 in 2003.

The BPH tule stock comes primarily from the Spring Creek Hatchery, released as juveniles into the Bonneville Dam pool. There is some natural tule production in Washington 's Wind, White Salmon and Klickitat rivers.

The Mid-Columbia bright fall chinook stock also returned in 2006 year's in fewer numbers than predicted, about 86,600 compared to a 98,000 forecast. The 2007 return is expected to be similar to this year's run.

The 2007 lower river hatchery stock return is expected to be similar to the 2006 return, less than 50,000. The lower river wild stock in 2006 was 16,600. The 2007 return will likely be less, according to the preseason forecast.

The preliminary 2006 return estimates the coho return at about 350,000. That was nearly 100,000 more than forecast but similar to the previous two years. A like number is anticipated in 2007.

For more information go to http://wdfw.wa.gov/fish/salmon_columbia_fallchin06-07.htm

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