Lagging counts at Bonneville Dam's fish ladders have prompted fishery officials to scale back estimates of how many upriver spring chinook salmon will return to the mouth of the Columbia River this year.

The Technical Advisory Committee met Tuesday to review available data and concluded that the upriver run is unlikely to total 269,300 adult fish as was forecast in preseason. The run will likely number fewer than 200,000, the federal, state and tribal biologists concluded.

A run of 200,000 would still be the largest since 2004 when 221,000 adults returned to the mouth of the river and would still be the fifth largest on a record dating back to 1980. The four larger runs occurred in 2001-2004.

The lower Columbia mainstem sport fishery was closed as of April 21 to await news on the progress of the upriver run. The commercial fleet has had three mainstem outings this year, the last on April 15. Both fisheries did well. State officials say fishers hauled in about 27,000 chinook in all, with 6,000 of those going to gill-netters.

The Washington Department of Fish and Wildlife's Robin Ehlke estimates that non-tribal mainstem fishers, at a run size of 170,000 adult upriver chinook, would be at their "impact" limit with fish already in hand. The anglers and gill-netters are allowed a combined 2 percent impact on the upriver return, a management scheme designed to limit the take of wild fish within the run that are protected under the Endangered Species Act.

Tribal fishers have yet to tap their commercial allocation, although it is projected that through Saturday 7,500 salmon will have been caught for ceremonial and subsistence purposes in permitted gill-net fisheries and 1,000 netted or caught with hook and line from riverside platforms.

Under a fishery management agreement between states and tribes, treaty fishers are allowed a 9.1 percent harvest rate on upriver spring chinook. Based on a run of 200,000, that would be 18,200 fish.

The Columbia River Compact on Thurday a tribal commercial fishery that begins Monday in mainstem reservoirs above Bonneville and runs through Thursday. Columbia River Inter-Tribal Fish Commission fishery biologist Stuart Ellis said the anticipated chinook catch through Thursday is 5,000.

Also approved Thursday is the sale, until further notice, of salmon and steelhead caught from platforms and with hook and line. The tribes project that an additional 2,000 salmon will be caught from platforms between Monday and June 15.

Tribal members will be selling fish "over the bank" at a variety of sites up and down the river.

The 2008 Bonneville count through Wednesday was 40,365 upriver spring chinook, as compared to a 10-year average of 95,789 through April 30. This year's count is much higher than those of the past three years (30,692, 7,028 and 3,139 in 2007, 2006 and 2005, respectively), when passage was later timed than normal.

The past three years' total return to the mouth of the river ranged from 132,140 to 86,230. Those totals include fish harvested between the mouth and Bonneville while the dam counts do not.

According the 10-year average, 43 percent of the upriver run will have passed the first dam they encounter on their spawning journey by April 28. The recent three-year average shows only 20 percent passage by that date and that scenario seems likely this year.

"Fish passage could be delayed due to river conditions that are non-conducive to fish migrations," according to an April 29 TAC report. A cool spring has resulted in slow snowpack meltdown and lower flows and water temperatures than normal.

The report notes that the successful downriver fisheries are a sign that there is "an abundance of fish in the lower river system."

The report said TAC members do not believe Bonneville passage has reached its midway point yet. That normally happens on May 1. Last year it was reached on May 5 and in 2006 it was reached May 12.

The upriver spring chinook run is beginning to surge. Daily counts have slowly risen from 1,570 on April 25 to 6,645 Wednesday.

Ellis, also vice chair of TAC, said it would skyrocketing daily counts -- an average of 4,500 daily through June 15 -- to approach the preseason forecast. Through Wednesday only the one count had exceeded 4,000.

"Maybe we'll get a huge peak."