The number of coho soars after the fish were declared functionally extinct in 1985; more than 18,000 counted Thursday
LEWISTON – It’s been another tough year for anadromous fish runs in the Snake and Columbia rivers, but the coho brings a glimmer of good news.
As of Thursday, 18,360 adult coho have been counted passing the Lower Granite Dam on the Snake River. This is a modern day record for the dam, surpassing the previous record posted in 2014. It’s also good enough for a run that was declared functionally extinct in 1985.
“I think what we are seeing now is the accumulation of about 25 years of work by the tribe,” said Samuel Penney, president of the Nez Perce tribe.
Coho was hit hard by overfishing and habitat destruction in the late 19th and early 20th centuries, but the blow was the construction of the Lewiston Dam, which blocked access to spawning grounds in the Clearwater River from 1927 to 1972.
In 1996, about a decade after the coho was declared extinct, the tribe began an effort to reestablish run using hatchery stocks collected from the lower Columbia River. Progress has been slow, but in 2014 the recovery surged with a return of 18,098, sufficient for the first tribal and non-tribal fishing season in several decades.
Since then, the race – subject to the conditions of the Pacific Ocean – has bounced up and down. When in place, the race provides a small harvestable surplus.
Penney noted that juvenile coho face the same dangers en route to the ocean as chinook, rainbow trout, and sockeye salmon. This includes predation by non-native species like smallmouth bass and walleye, injuries and stress caused by passing through turbines or fish diversion systems at eight federal dams, and delays caused. by stagnant water reservoirs. Wild runs of chinook, sockeye and rainbow trout are listed as threatened or endangered under the Endangered Species Act.
While proud of this year’s record and the harvesting opportunity it offers tribal and non-tribal fishermen, Penney has also sought to provide perspective. Coho once thrived in the Snake River basin with an estimated annual return of around 200,000 fish.
“Overall the race, compared to historic races, is extremely weak,” he said.
The tribe releases an estimated 1.5 million coho smolts in places like Lapwai and Clear creeks on the Clearwater River and more recently in the Lostine River in northeast Oregon. If this year’s run reaches 20,000 returning adults, that will amount to a smolt-to-adult return rate of only 1.3%.
“We estimate that we lose 50 to 70% of these juvenile fish as they migrate downstream to the ocean. It’s a 500 mile trip over eight dams, ”Penney said. “We’re happy to have a record race, but it’s only a small part of the overall historic race.”
The tribe supports the breaking of the four lower dams of the Snake River as the best tool available to increase fish survival and ultimately recover wild races. The presence of coho salmon and fall chinook offers anglers alternative targets in the face of yet another poor return of rainbow trout which has seen bag limits reduced throughout the Snake River basin. Tribal fishermen, using a combination of gillnets and hooks, harvested around 600 coho this fall, said Jack Yearout, deputy harvest manager for the tribe’s fisheries resource management department.
“I think it would probably be one of our highest (coho) harvests, if not the highest harvest,” he said. “We expect to see more crops for a few more weeks. “
As of last week, sport fishermen had caught around 360 coho in the Clearwater River and 70 in the Snake River, according to surveys by the Idaho Department of Fish and Game. Anglers fishing the Grande Ronde River from the Oregon-Washington border to the Wildcat Bridge above Troy, Oregon, have captured small numbers of coho bound for the Lostine .
“Most of the people who fish out there are looking for rainbow trout and they mostly catch coho, by the way,” said Kyle Bratcher, a biologist in the Department of Fisheries and Wildlife. Oregon.
Some of the returning adults are trapped for spawning in the hatcheries. Others are allowed to spawn in the wild.
“If you go to Lapwai Creek right now, you can see the fish chasing and splashing around,” said Becky Johnson, production manager of the Nez Perce Tribe’s Fisheries Resource Management Department.