Big Sockeye Return To Columbia River, Some Endangered Snake River Sockeye Trapped At Lower Granite To Avoid Warming Waters

Though the number of endangered sockeye returning to the Snake River is higher than average this year — the seventh highest on record — warm water in the upper Salmon River is leading biologists to trap the sockeye at Lower Granite Dam and haul them to the Eagle Hatchery near Boise, ID. This comes as fishery managers have raised the forecasted run size for all sockeye salmon returning to the Columbia River basin for the third time this year.

Just last week the U.S. v Oregon Technical Advisory Committee, which forecasts pre-season and in-season salmon and steelhead runs on the Columbia, raised the sockeye forecast to 770,200 fish, a significant increase from the preseason forecast of 401,700. In late June, TAC had adjusted its pre-season forecast to 568,000 fish, and then again July 1 it raised that forecast to 735,300.

Also last week, TAC updated the expected summer Chinook salmon run to 41,000 at the Columbia River mouth. The previous forecast was 40,200 fish and the pre-season forecast was 52,600 summer Chinook. Chinook passing Bonneville Dam on or after Aug. 1 will be considered fall Chinook.

Idaho Fish and Game says that the upper Salmon River has been unseasonably warm, and potentially deadly to sockeye, which is why the agency is trapping and trucking the fish to the Eagle Hatchery instead of allowing them to naturally find their way to their spawning grounds. In fact, a temperature gauge in the upper Salmon River briefly exceeded 75 degrees Fahrenheit last week (https://pweb.crohms.org/tmt/agendas/2024/0724_2024.0724.Snake-River-Sockeye-adult-passage.pdf).

In total, Snake River sockeye salmon travel 900 miles from the Pacific Ocean to the Sawtooth Basin near Stanley, ID where the wild fish will spawn. Even after crossing Lower Granite Dam, the Snake River fish still have about 400 miles to reach the Sawtooth Basin. The first sockeye typically arrives at Sawtooth fish trap around the third week in July, IDFG said.

Idaho sockeye were listed under the federal Endangered Species Act in 1991, and only 23 sockeye returned between 1991 and 1999, including two years when no sockeye returned, IDFG said.

As of July 18, IDFG staff had trucked 142 sockeye from Lower Granite Dam and says it will truck more. The agency also trapped and trucked sockeye when conditions were similarly warm in 2015 and 2021, it said.

“We prefer to let these fish return naturally, but we have to balance that with knowing they’re heading toward a heat wave, so we decided to safely reroute some of them to Eagle to ensure we have fish to produce the next generation,” said Lance Hebdon, Idaho Fish and Game’s Fisheries Bureau Chief. “We are only trucking a portion of the fish, so we still expect some will make their full migration.”

Through July 23, more than 1,482 sockeye had reached Lower Granite Dam about 30 miles west of Lewiston. Sockeye returns at Lower Granite typically peak in mid-July, IDFG said, but fish will continue to return throughout summer. The run is the seventh-highest return to Lower Granite since fish counting began there in 1975, and more fish are due to arrive, IDFG said. https://www.dfw.state.or.us/fish/OSCRP/CRM/FS/24/06_27_24%20Summer%20Fact%20Sheet_3.pdf

Sockeye migrate through the lower Columbia River during June and July, with normal peak passage at Bonneville Dam around July 1. Until recently, the Columbia River sockeye run consisted only of the Okanogan, Wenatchee, and Snake River stocks, according to the joint river management staff report, “The 2024 OR WA Spring Chinook, Summer Chinook, Sockeye, Steelhead and Other Species.” published Feb. 2, 2024. However, sockeye were reintroduced into the Yakima River in 2009 and passage has been re-established at Round Butte Dam on the Deschutes River. The upper Columbia stocks are considered healthy populations and, along with the Yakima and Deschutes River populations, are not ESA-listed.

The July 23 Bonneville count is 752,854 fish. Last year on this date, 325,835 sockeye had passed Bonneville and the 10-year average is 326,310.

During the 1990s, sockeye heading for the Snake River basin averaged 11 fish per year. During the 2000s, Snake River sockeye returns averaged 306 fish. This increase continued into the 2010s, when returns averaged 1,124 fish, IDFG said. The annual sockeye runs to the Sawtooth Basin in the last decade have averaged 369 fish with a high of 1,579 in 2014 to a low of 17 in 2019.

The 1,482 fish that have passed Lower Granite Dam as of July 23 is higher than last year’s count on this date of 1,200 fish and significantly higher than the 10-year average of 752 fish.

Since an intensive sockeye recovery project started in the early 1990s that included Fish and Game and many other partners, IDFG has used a “spread the risk” strategy to ensure their survival, which aligns with trapping and hauling fish, the agency said. That strategy also includes having sockeye naturally migrating to the Pacific and back while others are raised to adults in hatcheries to ensure spawners are available if none – or only a few – sockeye return from the Pacific. The combined state, federal and tribal efforts have bolstered a sockeye population that was on the brink of extinction.

Water temperature in the Snake River is an issue that fishery managers at the interagency Technical Management Team is watching this week, although temperatures in the Lower Granite tailwater have been successfully maintained by the U.S. Army Corps of Engineers at around 67 degrees Fahrenheit this past week. The NOAA Fisheries biological opinion governing fish operations at 13 Columbia River dams, including the four lower Snake River dams, calls for tailwater temperatures at the dam to remain at or below 68 degrees. Temperatures higher than 68 degrees stress adult and juvenile salmon.

In addition, the Corps’ Willow Walker reported at TMT that there is enough cold water in the Dworshak Dam reservoir to maintain 68 degrees through August. Air temperatures in the Lewiston, ID area have dropped from the highs in the low 100s to the upper 80s and lower 90s, she said.

Still, anticipating a warm-up to over 100 degrees, fishery managers proposed this week that the Corps alter its tailwater temperature target at Lower Granite from the BiOp recommended 68 degrees to 69.5 degrees. This “relaxation” they hoped would extend the availability of the Dworshak water into August. The change has been adopted the last two years.

Also last week, the two-state Columbia River Compact extended the summer Tribal gillnet fishery by 2.5 days (July 22 – 24), the Tribal commercial platform and hook and line fishery through the end of the year and initiated the Yakama Nation tributary fishery in Drano Lake, and the Wind and Klickitat rivers.

Looking out to the fall fishery, including fall Chinook salmon and coho salmon, the Compact approved non-Treaty early fall mainstem commercial fishing on 9 days in August, along with a non-Treaty commercial mainstem seine fishery weekdays from August 8 through Sept. 6 and Sept. 9 through Oct. 31, as well as a series of commercial select area fishery periods.

For details, see the July 18 Compact Action Notice at https://www.dfw.state.or.us/fish/OSCRP/CRM/CAN/24/240718%20Compact%20Action%20Notice.pdf

The 2024 forecast for Coho is 279,900 adults, according to the Compact’s Fall Fact Sheet No. 1 (https://www.dfw.state.or.us/fish/OSCRP/CRM/FS/24/07-18-24%20Fall%20Fact%20Sheet%20No.%201.pdf), which includes 171,800 early stock and 108,100 late stock fish. The forecast is 71 percent of the recent 10-year average return of 394,100 coho. Dam passage is expected to total just over 60,000 adult Coho, consisting of 47,200 early stock and 12,900 late stock fish. The total passage expectation is 58 percent of the forecasted ocean abundance of Columbia River Coho destined for areas upstream of Bonneville Dam. No Coho have passed Bonneville Dam as of July 24.

TAC’s pre-season forecast for fall Chinook is 551,800 fish, which is less than the 2023 actual return of 720,237 adults and 82 percent of the 2014–2023 average return (670,833 adults). Bonneville Dam passage of upriver fall Chinook is expected to be 369,500. Based on the recent 10-year average timing curve, passage is typically 50 percent complete by September 9.

The 2024 early salmon forecasts are here. https://www.dfw.state.or.us/fish/OSCRP/CRM/docs/2024/2024_Spring-Summer%20Forecasts.pdf

For background, see:

— CBB, July 5, 2024, THOUGH SOCKEYE RETURN TO COLUMBIA RIVER IS BOOMING, ANGLER RETENTION SHUT DOWN TO PROTECT STRUGGLING, ESA-LISTED SNAKE RIVER SOCKEYE, https://columbiabasinbulletin.org/though-sockeye-return-to-columbia-river-is-booming-angler-retention-shut-down-to-protect-struggling-esa-listed-snake-river-sockeye/

— CBB, February 9, 2024, HARVEST MANAGERS PREDICT 2024 UPRIVER SPRING CHINOOK RETURN TO COLUMBIA RIVER 15 PERCENT SMALLER THAN 2023; EXPECT DROP IN WILD FISH TO SNAKE RIVER, https://columbiabasinbulletin.org/harvest-managers-predict-2024-upriver-spring-chinook-return-to-columbia-river-15-percent-smaller-than-2023-expect-drop-in-wild-fish-to-snake-river/

— CBB, December 13, 2023, EARLY COLUMBIA RIVER 2024 SALMON FORECASTS SHOW SPRING CHINOOK LOWER THAN LAST YEAR, SOCKEYE MAY SEE LARGE INCREASE, https://columbiabasinbulletin.org/early-columbia-river-2024-salmon-forecasts-show-spring-chinook-lower-than-last-year-sockeye-may-see-large-increase/

— CBB, July 14, 2022, BIGGEST COLUMBIA RIVER SOCKEYE RETURN SINCE 1938, DECENT PASSAGE AT LOWER GRANITE; WITH UPDATED FORECAST, CHINOOK FISHING EXTENDED, https://columbiabasinbulletin.org/biggest-columbia-river-sockeye-return-since-1938-decent-passage-at-lower-granite-with-updated-forecast-chinook-fishing-extended/

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Big Sockeye Return To Columbia River, Some Endangered Snake River Sockeye Trapped At Lower Granite To Avoid Warming Waters

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