An innovation designed to help juvenile Baker River sockeye salmon may have helped revive a population of steelhead.
Steelhead that don’t out-migrate don’t undergo the physical transformation necessary to survive in salt water. These fish are the same as rainbow trout. For years, the two dams at Puget Sound Energy’s (PSE) Baker River Hydroelectric Project prevented steelhead from leaving Baker Lake, so the population was effectively extinct.
“We haven’t put adult steelhead up in the reservoir in eight years,” said Jon-Paul Shannahan, fisheries biologist for the Upper Skagit Tribe. “Yet with the new floating surface collectors, we are annually seeing several hundred steelhead smolts leaving the basin.”
In 2008, PSE installed the first of two floating surface collectors to help sockeye salmon out-migrate. The second was installed in 2013. The barge-like apparatuses simulate river current to attract and collect juvenile fish from the Baker Lake reservoir before they are transported via tanker truck past the dams. The floating surface collectors have succeeded in releasing larger numbers of juvenile sockeye and coho salmon.
“We’re thrilled by the increase in sockeye returns we’ve seen from PSE’s floating surface collector and other collaborative fisheries projects,” said Scott Schuyler, Upper Skagit’s natural resources director.
Recently, fisheries managers have seen between 200 and 500 juvenile steelhead pass through the floating surface collectors as well. These fish are much larger than the sockeye smolts the collector was designed for.
“These are resident rainbow trout deciding to go to the ocean because they might have a better chance of survival, or perhaps the density has gotten too high in Baker Lake,” Shannahan said.
A highly collaborative partnership between Upper Skagit, Washington Department of Fish and Wildlife, PSE, Skagit River System Cooperative, North Cascade National Park, U.S. Forest Service and National Oceanic and Atmospheric Administration aims to quantify just how good the floating surface collector is at passing steelhead smolts.
Upper Skagit contributed six wild adult Skagit River steelhead, which are genetically the same as Baker River steelhead, for broodstock. The fish were spawned and raised at PSE’s hatchery in conditions that mimic natural rearing. About 11,000 juvenile steelhead were implanted with passive integrated transponder (PIT) tags before being released in two different locations: the upper Baker Lake Reservoir, and a couple of hundred yards in front of the floating surface collector.
The tags enable fisheries managers to monitor individual fish movement out of the reservoir, as well as evaluate survival of these fish when they return to the facility as adult steelhead.
“This study could greatly influence the future management of the Baker Lake reservoir and hatchery, as well as help us define recovery goals,” Shannahan said. “We plan on taking these results and weaving them into the Skagit Steelhead Recovery Plan under review.”