[6] 700 Sockeye Make It All The Way To Redfish Lake
More than half of the 1,200 or so tenacious sockeye counted at Lower Granite Dam have made the last 450 miles to their home waters in Idaho's Stanley Basin, nearly 7,000 feet above sea level.
The 700-fish-plus return is 50 more than made it back last year, signaling at least temporary success for the captive broodstock program that is trying to bring the Redfish Lake sockeye back from the brink of the early 1990s.
"Lonesome Larry" was the lone sockeye that returned in 1992. His precious bodily fluids were frozen as part of a recovery program that started in 1991, a last-ditch effort aimed at saving the run from extinction.
Fish managers and scientists are still debating why the latest returns are so high, but a combination of increased numbers of hatchery-raised smolts, better passage conditions and a huge boost in ocean productivity all likely played a role in the big returns.
A 2008 memo and later analysis by NOAA Fisheries found a strong correlation between estimated return rates of the Upper Columbia and Snake stocks, which suggested that changes in ocean productivity led to the big returns last year.
In addition, the scientists found no correlation between sockeye salmon SARs [smolt-to-adult return rates] and indices of mainstem flow and percentage spill at dams between McNary and Bonneville.
"This suggests that the primary factors influencing the variation in annual adult returns acted downstream from Bonneville Dam, and on both stocks in common," said the memo.
Two years ago, 52 sockeye were counted at Granite in 2007, but only four finished the last 450-mile trek to the trap at IDFG's Sawtooth Hatchery, near Redfish Lake. Managers had originally expected 50 to 100 to return.
Back in 2006, three sockeye returned to Redfish Lake. The average return over the past five years has been only 12 fish, but in 2000, when river conditions were relatively good, more than 200 of them made it all the way home, about two-thirds of the number counted at the dam that year.
The captive broodstock program really took off in 1998, when nearly 336,000 sockeye smolts were released into the Snake zone. In 1997, only 1,926 smolts were released, a year when flows in the basin were extremely high. From that migration, only 14 sockeye returned to the dam in 1999. -B. R.
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