From Flatline to Abundance

Restoring interior Columbia River Basin coho

Extinction, it turns out, is not forever, at least when the species in question is interior Columbia River Basin coho salmon.

Since the mid-1990s, when fish and wildlife agencies and tribes – particularly tribes – began working to restore coho, adult returns to tributaries of the Snake and upper Columbia rivers have increased from zero for some runs to more than 20,000 fish annually.

Coho that spawned in tributaries above Bonneville Dam were extinct by the late 1980s as the result of a number of impacts, including habitat alterations, construction of impassable dams on some tributaries, and historic overfishing in the ocean and in the Columbia below Bonneville.

Hatcheries built in the interior basin since the mid-1980s, managed or co-managed by tribes and state fish and wildlife agencies, were instrumental in rescuing the species from extinction. Representatives of tribes working on coho restoration discussed the effort with the Council’s Fish and Wildlife Committee at its May meeting. Funding for the coho restoration and facilities comes from several sources, including the Council’s Columbia River Basin Fish and Wildlife Program, the mid-Columbia public utility districts, the federal Mitchell Act, and the federal Pacific Coastal Salmon Recovery Fund.

Maureen Hess, program analyst in the Council’s Fish and Wildlife Division, said that because coho were essentially extinct in the interior Columbia, tribes turned to lower Columbia River hatcheries to begin the restoration work. Juvenile coho salmon from lower river hatcheries were transported upriver and were acclimated or direct released near potential spawning habitat in the interior Basin. Each year, a portion of the reintroduced coho returned as mature adults. Some spawned naturally, and within a few generations these fish were creating new, locally adapted stocks.

In the Umatilla River Basin, for example, coho were extinct by the 1980s, said Jon Lovrak, project leader for hatchery facilities for the Confederated Tribes of the Umatilla Indian Reservation. The 30-year average return of coho to the river, beginning in 1991, has grown to 5,035 fish. “It took time to get there, but it is in an upward trend,” he said. The tribe releases 500,000 coho smolts annually from its production facilities in the basin. Since 2014 the tribe has utilized only broodstock from the Umatilla basin. He said research suggests that smolt-to-adult returns are trending upward.

It's a similar story in other interior Columbia basin rivers.

Todd Newsome, a fisheries research scientist for the Yakama Nation Fisheries, said coho counts at Prosser Dam on the Yakima River dropped to zero by 1985. Beginning in 1986, coho from lower Columbia hatcheries were transferred to the Yakima Basin to begin rebuilding the runs. After years of research, a local broodstock was developed and fish were moved into historic coho habitat in the basin. This was successful, and last year the tribe completed a new coho hatchery, named for longtime Yakama Nations fisheries manager Melvin Sampson. Recent returns have been as high as 24,000 fish.

Farther upriver, the Yakama Nation is working to restore coho to two Columbia tributaries, the Methow and Wenatchee rivers. The goal is to reestablish naturally spawning coho populations to biologically sustainable levels, which will provide for harvest in most years, said Cory Kamphaus, northern ceded lands production supervisor for the Yakama Nation Fisheries. While restoration activities initially focused on the Methow, which historically had large numbers of coho, returns were initially poor and the program shifted emphasis to increase efforts in the Wenatchee River. Today, the combined returns to the Wenatchee and Methow rivers in recent years have been as high as about 65,000 fish, and in some years fewer than 5,000. These fish contribute between 30 and 40 percent of the coho harvest in the tribal fishery between Bonneville and McNary dams, Kamphaus said.

Similarly, coho were “fairly abundant” historically in the Lostine River, a tributary in the Grande Ronde subbasin, in Northeastern Oregon, said Kyle Bratcher, Northeast Oregon district fish biologist for the Oregon Department of Fish and Wildlife. But coho were extinct in the river by 1912, he said. This was due primarily to two things: the impact of weirs in the river that caught the entire runs of coho and sockeye, and failed efforts to propagate the fish. In 2017, coho juveniles from a lower river hatchery near Bonneville Dam were released in the Lostine River. The first adults began returning to the Lostine in 2018 and recently have averaged 540 fish. Natural spawning also is being documented, he said.

In the Clearwater River Basin, coho were extinct by 1927, largely as the result of an impassable dam completed that year, said Becky Johnson, fish production manager of the Nez Perce Tribe. The dam was not removed until 1972. Thus, when restoration work began in 1995, coho had been absent from the Clearwater for 70 years, she said. The tribe releases just over 1 million coho smolts annually. Adult returns to the Clearwater recently have been below 10,000 fish but were near or above 20,000 in 2014 and 2021, which is a long, long way from zero 30 years ago.

“Even at 25,000 fish, we’re still at about 10 percent of the historic average that used to return here,” she said. “It’s kind of like watching a flat-line patient and all of a sudden seeing a heartbeat, and you’re like, ‘oh, my gosh, they’re not going to die.’ So that’s where we are right now.”

Johnson said there are several important things to be learned from the experience of coho restoration in the interior Columbia Basin including, first, that hatcheries are an effective tool in reintroducing and restoring an extirpated species, but “it takes time to see something like this work and go into effect.”

Second, she said coho restoration represents a positive hatchery story. “I really appreciate that because there’s been so much negative hatchery press,” she said.

Third, she said it is important to view the restoration of one species in the context of restoring multiple species, as all fish that spawn in the wild play an important role in contributing to the next generation of adult returns as well as a role in ecosystem management by returning marine-derived nutrients to the habitat.

Fourth, she noted that coho restoration began with the management plan developed through the U.S. v. Oregon litigation over salmon and steelhead harvest in the Columbia River. She said most people know U.S. v. Oregon as a harvest management forum, but its purpose also is to “rebuild and enhance” upper Columbia River fish to provide tribal and non-tribal harvest. “So, I think this coho story exemplifies that; it’s a cool story to be part of,” she said.

Finally, she said, it should be noted that the tribes “did the heavy lifting” on coho restoration, a point noted after the presentations by Council members Louie Pitt of Oregon and Guy Norman of Washington.

Council Chair Norman recalled that as Washington’s representative to the U.S. v. Oregon forum in the 1990s, he remembers the skepticism many expressed toward using lower-river coho broodstock to rebuild interior Columbia runs.

“But I have to say today that, yes, the tribes did the heavy lifting; they had the long-term vision, and that plus adaptive management and dedication resulted in a very good example of a successful program – successful beyond my wildest dreams,” he said. “The tribes need to be applauded. This truly represents the kind of investments we need to make in the basin.”

Pitt, a member of the Warm Springs Tribe, also recalled the initial skepticism and noted that at the time he “was of the mind to wait and see how hatcheries could fit” in restoration efforts. But today, looking back, “it’s a positive thing that happened here; adaptive management approaches have proven that hatcheries are a good tool,” he said.

"The region has made amazing progress, and we're committed to furthering this progress to get even more coho returning in the years to come," said Fish and Wildlife Committee Chair Jeff Allen.