For the first time in more than three decades the Oregon Department of Fish and Wildlife will release a substantial number of spring chinook salmon into the Coast Fork Willamette River in hopes of establishing a recreational fishery between Cottage Grove and Springfield.
The department plans on March 12 to release about 210,000 chinook salmon smolts into several reaches of the Coast Fork Willamette downstream of Dorena and Cottage Grove reservoirs to the river’s confluence with the Middle Fork Willamette in Springfield.
If the initiative is successful, anglers could be pulling adult hatchery spring salmon out of the Coast Fork Willamette when the fish return as adults in 2014.
“We hope to create a little more intimate and dispersed salmon fishery,” said Jeff Ziller, fish biologist for ODFW’s South Willamette Watershed District. “The Coast Fork is not a giant river but it runs enough water in the springtime to provide the structure for a good spring chinook fishery.” He said this year’s release could produce returns of 1,000 to 2,000 chinook, which could develop “a pretty nice fishery.”
The 6-inch smolts are currently being reared at ODFW’s McKenzie Fish Hatchery. They are part of a crop of about 1.2 million spring chinook the hatchery produced for release last fall and this late winter. The vast majority of these smolts – one million of them – will be released into the McKenzie River, which is currently one of the largest salmon fisheries in the upper Willamette Basin.
Last year more than 6,000 hatchery spring chinook returned to the McKenzie. Many of these fish bypassed the hatchery and spawned in the McKenzie River, impacting the McKenzie’s wild chinook, which are listed for protection under the federal Endangered Species Act. The Upper Willamette River Salmon and Steelhead Conservation and Recovery Plan limits the number of hatchery fish that are allowed to stray onto wild salmon spawning grounds in the McKenzie River.
With passage provided ever since Leaburg Dam was built in 1929, the McKenzie wild salmon has long been “the only viable population in the upper Willamette” drainage, Ziller said. Other wild populations are greatly affected by dams, and by strayed hatchery fish.
Work is now under way to reintroduce salmon and steelhead to other Willamette drainage headwaters that were cutoff with construction of numerous high-head dams.
“We’re trying to do a better job of collecting those fish before they get over Leaburg Dam,” Ziller said of the returning hatchery fish.
That’s one of the reasons it was decided to move part of the production to the Coast Fork, which streams out of the relatively low elevation “old” Cascades, the ancient shoulders of the high Cascades. The river once did hold a small native population but because it has historically shrunk to a trickle – it is mainly rain fed, not spring fed as most of the tributaries are – it is less than ideal for cold-water loving spring chinook.
Ziller said occasionally juvenile salmon have been found up the Coast Fork, and the department at times has outplanted adult fish there in hopes a population would take root. With the two dams upstream now controlling, and prolonging, flows the fish may well fare better.
ODFW’s reallocation of 210,000 smolts from the McKenzie to the Coast Fork is part of a comprehensive effort to reduce the number of hatchery salmon spawning in the McKenzie River.
“We will continue to release a lot of fish into the McKenzie but we hope to release enough into the Coast Fork to establish a fishery,” said Ziller, who noted that one of the issues for anglers on the McKenzie is overcrowding.
Some movement over to the Coast Fork would help reduce the “combat fishing” below Leaburg Dam, Ziller said.
“We think there will be a lot of benefits from this program as the impact on the number of harvestable fish in the McKenzie will be minimal and we may create additional opportunity for a dispersed chinook fishery in the Coast Fork.”