August 8, 2019
The first endangered sockeye salmon returned to the Redfish Lake Creek trap Aug. 2, later by nearly a week than the first that led the way last year and in 2017, according to the Idaho Department of Fish and Game. Since then, two more wild sockeye have reached the trap near Stanley, Idaho, for a total of two trapped females and one male, all unclipped fish, according to Russ Kiefer of IDFG. Just 61 of the Snake River sockeye, listed as endangered under the federal Endangered Species Act in 1991, have cleared Lower Granite Dam as of August 6. That’s 6 percent of the 10-year average on that date of 1,001. The average annual return between 2009-2018 has been 620 adults, ranging from a low of 91 adults in 2015 to 1516 adults in 2014, according to Eric Johnson, sockeye research biologist at IDFG. Recovery of Snake River sockeye salmon could take 50 to 100 years and over the next 25 years cost over $101 million, according to a Snake River Sockeye Salmon Recovery Plan released in 2015 by NOAA Fisheries. “The species remains at risk of extinction,” said NOAA of the endangered fish. Johnson said a combination of conditions is responsible for the low return of sockeye this year, including ocean conditions (2015 to 2017) that contributed to poor growth and survival for all salmon and steelhead. After migrating to the ocean, sockeye typically remain there for two years (5 percent will return after one year). “The ocean surface temperatures have been warmer than average and upwelling of cooler, nutrient-rich water has been limited and has impacted the food web in a way that the composition has shifted to a less desirable food items and a lower biomass of desirable food items,” he said. In addition, survival of Snake River sockeye juveniles migrating downstream took a hit in 2016 and 2017, with a survival estimate from Lower Granite to Bonneville Dam for combined hatchery and wild fish of just 17.6 percent, which was the fourth lowest survival estimate from 1998 to 2017, according to that year’s survival estimate by NOAA Fisheries’ Northwest Fisheries Science Center. That was the third consecutive year the juvenile Snake River sockeye survival had been below the 39.2 percent average. 2016 survival was 11.9 percent and 2015 was 37.3 percent. The highest survival – 82 percent – was in 2008. The lowest smolt survival was of juveniles reared in the newly constructed smolt production facility, the Springfield Hatchery. “The impacts were greater this year because we phased out hatchery sockeye smolt production at 2 other hatcheries that contributed to adult returns in 2017 and 2018,” Johnson said. “Rearing sockeye at the Sawtooth Fish Hatchery (near Stanley, ID) and the Oxbow Fish Hatchery (lower Columbia River near Cascade Locks) was discontinued in 2016 and 2017, respectively. “Hydrosystem survival of Springfield Hatchery reared sockeye has improved significantly in 2018 and 2019 as a result of acclimating fish for a 2-3 week period of time prior to release,” he continued. “The Springfield Hatchery has much ‘harder’ water compared to water leaving Redfish Lake and we have found that acclimating fish to an intermediate hardness for a period of time improved survival.” The water quality difference induced stress levels in smolts high enough to cause significant post-release mortality. Idaho has since adopted two strategies to counter the water chemistry difference, seeing positive results and survival rates to Bonneville Dam as high as 50 percent in 2018.
The preseason sockeye run size for the entire Columbia River basin was downgraded by one third to 62,800 fish based on the recent 5-year average run timing at Bonneville Dam. The preseason forecast was 94,400 fish. The U.S. v Oregon Technical Advisory Committee met July 8, downgrading the expected sockeye run (most of those sockeye will travel to mid-Columbia River tributaries, with few turning into the Snake River). Some 62,940 sockeye have passed Bonneville Dam as of Aug. 6, less than 20 percent of the Columbia River basin sockeye 10-year average of 319,741 on the same date. Last year the count at Bonneville was 193,669. Lower Granite is the farthest upstream of the four lower Snake River dams and the last dam the fish encounter before swimming into Idaho. In 2015 the sockeye encountered a thermal block – high water temperatures and low water – that decimated that year’s run. Water in the dam’s tailrace has been cooler this year, with the U.S. Army Corps of Engineers largely maintaining the under-68 degree temperature in the dam’s tailrace that is required by NOAA Fisheries’ 2019 Columbia/Snake River biological opinion of the federal hydropower system. Saturday, Aug. 3, the Corps increased the outflow at Dworshak Dam from 9,800 cubic feet per second to 11.8 kcfs, anticipating this week’s warmer weather. The additional water is through spill at the dam, which is on the North Fork of the Clearwater River. The cool Dworshak Reservoir water, which takes up to three days to arrive at Lower Granite, mixes with lower Snake River water and cools, among other things, the fish ladder sockeye use to move upstream and the juvenile fish passage facilities to aid juvenile fall chinook passing downstream. In a news release, the Corps’ Walla Walla District warned that downstream of the dam, water elevation will likely result in Clearwater River surface elevation increasing by about 7 inches at the at USGS gage located at Peck, Idaho. The Corps expects total dissolved gasses from the spill to remain below 110 percent, Washington State’s upper limit for TDG this time of year, and will be closely monitored. When water spills over the dam, gas is entrained and held in solution due to pressure differences in the water at depth, the Corps said. High TDG levels can be stressful for fish. The 2019 sockeye run through Lower Granite so far is below last year’s total of 276 fish, as well as the 2017 total of 228 fish, which was the lowest return in a decade, IDFG said. It is likely that the returns in 2019 will be lower. By Aug. 20 each year, about 33 to 70 percent of the fish at Redfish Lake have been trapped. Over the 10-year average 54 percent of fish have been trapped by Aug. 20. The 10-year average of trapped fish is 661. Idaho sockeye must complete a 900-mile migration from the Pacific Ocean that includes crossing eight dams and climbing 6,500-feet elevation to reach the Sawtooth Basin. When Idaho sockeye were listed in 1991 under the federal Endangered Species Act, only four adult sockeye returned to the Stanley Basin. The combined annual returns from 1991-99 was 23 fish, including two years when no sockeye returned to Idaho. Between 1996 and 2007, annual sockeye returns over Lower Granite averaged 52 fish. Since 2008, sockeye returns over Lower Granite have averaged 1,115 fish with an annual range of 228 to a high of 2,786 in 2014, IDFG said. Prior to the sockeye listing, only 58 wild sockeye returned to Idaho during the years 1985 to 1990. Before the turn of the twentieth century, an estimated 150,000 sockeye returned annually to the Snake River basin. The sockeye in those days ascended the Snake River to the Wallowa River basin in northeastern Oregon and the Payette and Salmon River basins in Idaho to spawn in natural lakes. Within the Salmon River basin, sockeye spawned in Warm Lake in the South Fork Salmon River basin, as well as in the Sawtooth Valley lakes: Stanley, Redfish, Yellowbelly, Pettit and Alturas lakes. A smaller Sawtooth Valley lake, Hellroaring Lake, may have also supported some sockeye. In 2013, the $13.5 million Springfield Hatchery was completed with the capability of producing up to one million juvenile Snake River sockeye salmon annually for release in the Sawtooth Basin of central Idaho, the headwaters of the Salmon River. The additional capacity moves the sockeye recovery effort from the conservation phase to a re-colonization phase where emphasis is on returning increasing numbers of ocean-run adults to use in hatchery spawning and to release to the natural habitat to spawn. The increase in adult fish may eventually mean recreational and tribal fishing seasons on Snake River sockeye, officials said during a 2013 ceremony marking the completion of the hatchery. “The story of the Snake River sockeye is one of perseverance: Their numbers were once so depressed by harvest, predation, habitat loss and dams that many in the scientific community declared them functionally extinct,” said Lorri Bodi, vice president of Environment, Fish & Wildlife for the Bonneville Power Administration at the time. “But these fish are survivors, and the state of Idaho, BPA, Shoshone-Bannock Tribes and other stakeholders weren’t willing to give up on improving conditions for these fish. The Springfield Hatchery is just one piece of a larger effort that has proven successful in bringing back the Snake River sockeye.” “This is a great example of how constructive collaboration can work – work for the species and work for the people we serve,” said then Gov. C.L. “Butch” Otter said in 2013. “Idaho has a lot of aquaculture expertise, and using hatcheries like this to help boost the runs is a smart investment.” “Opening this hatchery is a big step toward continuing to bring back Idaho’s unique sockeye,” Fish and Game Director Virgil Moore said at the time. “With the help and support of our partners in this effort, we look forward to the day when we can set a sockeye season for Idaho’s tribal and recreational anglers.”