BOISE – More than 40,000 sockeye salmon that were destined to help bolster Idaho’s breeding program died while at an Oregon hatchery late last month, wiping out about a quarter of the young fish slated for release in central Idaho mountain lakes next May.
The news comes just as Idaho had been celebrating robust numbers of endangered sockeye salmon returning to Redfish Lake near Stanley this summer.
A damaged valve at the Oxbow Fish Hatchery, located in Cascade Locks, Ore., is the culprit, the Department of Fish and Game said.
On Aug. 25, workers at the facility east of Portland along the Columbia River noticed sockeye numbers in an outdoor raceway were just over half what they should have been. They discovered many sockeye had been drawn through the damaged valve and into a void beneath the raceway, where they perished.
The fish, from brood year 2009, numbered 94,826; after the accident, the inventory was 51,609.
There are still another 100,000 sockeye from 2009 at the Sawtooth Fish Hatchery near Stanley, but the losses in Oregon mean state Fish and Game biologists will only have about 150,000 smolts in May 2011 to release ahead of a 900-mile journey from Redfish Lake to the Pacific Ocean.
That will reduce the sockeye salmon returning to Idaho’s captive brood-stock program from 2012 to 2014, said Jeff Heindel, Fish and Game’s conservation hatcheries supervisor.
Still, Heindel told federal officials at the NOAA National Marine Fisheries Service responsible for protected species in an Aug. 30 letter that he’s optimistic this setback won’t hurt overall recovery efforts.
“While an unfortunate loss … this loss does not impact the current recovery efforts for Snake River sockeye,” Heindel wrote. “Genetically diverse groups of captive brood are currently cultured at primary broodstock stations in both Washington and Idaho; current and future egg production will not be limited as a result of this loss at Oxbow.”
Idaho’s Snake River sockeye were listed as endangered in 1991. But Idaho is seeing more sockeye return to Redfish Lake than have arrived in years.
Biologists expect as many as 1,500 fish will make the trip into the mountains by fall, up from last year’s 833 and well above the three sockeye in 2006.
So many have arrived that a hatchery near Boise that was collecting the fish is full. As a result, some sockeye are being allowed to swim into Redfish Lake under their own power, the first time that has happened in two decades.