The 2011 return of fall chinook salmon to the Columbia River basin is expected to be the fifth largest since at least 1948, and nearly 200,000 fish higher than the recent 10-year average return, according to preseason forecasts released this week by the Washington Department of Fish and Wildlife and the U.S. v Oregon Technical Advisory Committee.
TAC is made up of federal, state and tribal fishery experts.
The forecast is buoyed by the expectation of a large upriver bright component, some 398,200 adult fish to the mouth of the Columbia River. Such a return would be the second largest since record-keeping began in 1964. The largest return was 420,700 in 1987.
The largest share of URB chinook are destined for the Hanford Reach section of the Columbia River, Priest Rapids Hatchery, and the Snake River with smaller portions headed for the Deschutes and Yakima rivers.
More than 60 percent of the 2011 upriver bright return is expected to be age 4 fish. The URBs, Bonneville Pool Hatchery tule fall chinook, most of which are produced at Spring Creek National Fish Hatchery in the Bonneville pool, and a portion of the Mid-Columbia bright chinook are produced above Bonneville Dam, which is located at river mile 146.
The upriver MCB component (Pool Upriver Brights or Pool Upriver Bright stocks) is comprised of brights that are reared at Little White Salmon, Irrigon, and Klickitat hatcheries and released in areas between Bonneville and McNary dams. Some natural production is believed to take place in the mainstem Columbia River below John Day Dam, and in the Wind, White Salmon, Klickitat and Umatilla rivers.
The total forecast is for a return of 760,600 Columbia River fall chinook this year, which would be greater than the actual 2010 return of 648,600. The URB return last year was 324,900, which was greater than the 310,800 February 2010 forecast.
The new TAC-WDFW forecast projects that the BPH return will number 116,400. That would be slightly less than the 130,800 total last year but greater than the 10-year average (105,900).
The preseason forecast is for a return of 37,600 BUBs, which would be similar to the 10-year average return of 47,500. The actual return last year was 29,400.
The anticipated PUB return is 62,400 adult fish, which would be the third largest return on a record dating back to 1986. Such a return would also be well above the 10-year average (43,800) and a 2010 return of 49,600.
The Lower River Hatchery stock fall chinook return in 2011 is pegged at 133,500, which would be the best return since 2003 and greater than the 10-year average (92,500). The return last year totaled 103,000.
The Lower River Wild stock forecast is for a return of 12,500. That would be an improvement over returns over the past four years but slightly less than the 10-year average (9,700).
The LRH stock is primarily produced in hatchery facilities (five in Washington and one in Oregon) while the LRW stock is naturally produced primarily in the Lewis River system, with smaller components also present in the Cowlitz and Sandy rivers, according to the July 2010 Joint Staff Report produced the Oregon Department of Fish and Wildlife and WDFW.
Some natural production of LRH stock likely occurs in many tributaries below Bonneville Dam, including the Coweeman, East Fork Lewis, and Grays rivers in Washington. LRH return to some Oregon tributaries including the Clatskanie, Scappoose and Sandy rivers.