Hot late August and early September chinook salmon fishing could force closure of that sport fishery on the lower Columbia River mainstem as early as next week, according to Oregon and Washington officials.

Anglers are surging toward their allowed limit on upriver bright fall chinook salmon with near-record catches. The upriver brights are predominately from a strong Hanford Reach stock but some among their number are bound for the Snake River. The latter stock is listed under the Endangered Species Act.

Non-Indian fishers are allowed an 8.25 percent impact on the URB stock split evenly between sport and commercial fishers. The preseason forecast is for a return to the river mouth of 249,100 adult URBs. Oregon and Washington department of fish and wildlife officials estimate that the sport allocation could be filled as early as the middle of next week.

“The fishing is pretty hot right now,” the WDFW’s Robin Ehlke said during a Thursday sport hearing. “They’re catching 1,000 fish per day” in the river reaches from Bonneville Dam down to the mouth of the river.

Survey flights on Saturday and again on Wednesday saw more than 1,100 boats each day and catch estimates during the period are nearly one chinook per boat, Ehlke said.

The August sport catch of 4,990 adult chinook was the second highest on record (the record is 5,100 fish in 2002). Effort (34,641 angler trips) was on par with that found from 2000-2003 (record 41,600 angler trips in 2000).

Officials estimate that 16,500 angler trips were taken on the lower river during the first five days in September, with a catch of 3,400 chinook.

Base on the current upriver bright forecast and stock composition in the catch, sport anglers can catch up to 15,000 chinook this season. Based on information yielded to-date from coded wire tags implanted in the fish, 63 percent of the catch has been URB stock. That’s higher than the 56 percent anticipated so ESA impacts are mounting more quickly.

At the current effort and catch rate, Ehlke said that limit could be reached by midweek. The ODFW’s Tony Nigro and WDFW’s Cindy LeFleur met Thursday to consider sport fishing options and will meet again Monday to consider a closure.

“We should be prepared to act” on Monday, LeFleur said, potentially prohibiting the retention of chinook in the lower river “earlier than we anticipated.”

A meeting the multi-agency Technical Advisory Committee will meet Monday to develop, potentially, a run forecast update. An increase in the forecast could allow the sport fishery to continue a bit longer. A decrease in fishing effort could also result in a prolonged season.

On Thursday, TAC chairman Stuart Ellis told the sport hearing panel, and a Columbia River Compact convened earlier Thursday, that the preseason forecast for upriver fall chinook and steelhead remained unchanged, despite Bonneville Dam counts that are lagging slightly.

“We don’t see any reason for alarm right now,” Ellis said, but “it is certainly possible that the (overall) run may come in a little bit less than forecast,” particularly for the Bonneville Pool Hatchery tule chinook stock. TAC this week also decided that the upriver steelhead return appeared on track to meet the preseason forecast of 312,600 fish.

TAC members felt, however, that the upriver chinook return may be three to four days later than its average run timing. That could mean that the run could well be on target to meet the preseason projections. TAC on Monday will have the benefit of additional dam counts and other data when it tries to update the forecast.

Through Sept. 6, 100,976 brights and 14,067 tules had been counted passing Bonneville. Based on the recent five-year average timing 39 percent of the brights and 41 percent of the tules will have passed the dam through that date. The preseason forecast was for a tule return of 51,800 fish to the river mouth, down from last year’s actual return of 93,200.

Chinook counts at Bonneville mounted quickly from less than 1,000 daily during the third week of August to a peak count thus far of 14,793 this past Sunday. Steelhead have been leaping the dam at a rate of about 5,000 per day through August (154,325 total) and the first five says of September (25,133).

The Compact, which sets mainstem commercial seasons, on Thursday approved a 4 ½-day fishery for the Nez Perce, Umatilla, Warm Springs and Yakama tribes next week in the mainstem reservoirs above Bonneville. The fishery runs from 6 a.m. Monday through 6 p.m. Friday.

The tribes, in fisheries that began Aug. 21, will have caught an estimated 27,302 chinook, including 16,913 URBs, by the end of this week. It is estimated that next week’s fishery will yield a catch of about 20,000 chinook, including 12,000 URBS, and 14,825 steelhead.

Based on the current run forecasts, that estimated catch would amount of an 11.6 percent impact on the upriver chinook run and a 3.2 percent impact on the “B” steelhead run. The tribes are allowed a 23.04 percent impact on the URB stock and a 15 percent impact on the Snake River B steelhead, which are also listed under the Endangered Species Act.