Fisheries biologists say the recent surge in fall chinook returning to the Snake River is exciting, incredible and nothing short of amazing.
The numbers are so high that some people are asking what it might take for the threatened species to shed its protected status under the Endangered Species Act.
Quite a lot, it turns out, and it won’t happen any time soon.
But the fact that the question is being asked straight-faced is amazing:
• In 1990, just 78 adult wild fall chinook were counted at Lower Granite Dam.
• Last year, more than 27,000 wild, or natural origin, fall chinook, returned past the dam, while the total run, including hatchery fish, topped 55,000, plus about 20,000 jacks.
• This year, the total run could exceed 47,000 with more than 34,000 wild fish.
“It’s incredible,” said Billy Connor, a fisheries biologist for the U.S. Fish and Wild Service, who has spent much of his career working to save the fish.
He credits a high level of cooperation between several state and federal agencies, the Nez Perce Tribe and Idaho Power Co., working on a number of fronts that include harvest reform, hatchery programs, habitat work, dam passage and a big contribution from healthy ocean conditions during the past several years.
“We have incredible cooperation within our extended family. It’s all coming together and it’s important to recognize the work done in hatcheries and harvest, and improvements in passage, and climate conditions have been in our favor,” he said. “It’s a fascinating story. I think it’s pretty safe at this point to call it a success story.”
So many fish are expected to return this year that Idaho and others are seeking permission to allow anglers to keep wild fish. But recovery isn’t yet complete.
Ocean conditions remain a big unknown in recovery efforts
Many fisheries managers want to see how the run performs if ocean conditions deteriorate.
“It’s really nice to see this big bump right now, but if ocean conditions turn poor again we may see a substantial decline,” said Glen Mendel, district fish biologist for the Washington Department of Fish and Wildlife at Dayton. “We are going to have to wait and see and get more years of information.”
An initial target of 3,000 wild fish returning annually averaged over 10 years was set years ago, but it isn’t a formal goal. Officials at the fisheries division of the National Oceanic and Atmospheric Administration are working on a recovery plan for the fish that will for the first time lay out concrete standards that must be met for the fish to be taken off the endangered species list. It will look at wild fish abundance and other measures such as the productivity of wild fish, how well they are distributed and genetic diversity.
That recovery plan is expected to be released later this year. Although it is too soon to make a push for delisting, the federal fisheries agency is planning for the possibility.
Bumps in the road along the way include the difficulty in establishing the degree to which the wild run is self-sufficient. It has been buoyed by a unique approach of using hatcheries to both mitigate for declines caused by dams on the Snake and Columbia rivers and to boost spawning in the wild. That means many of the hatchery fish produced at places such as Lyons Ferry Hatchery on the Snake River and the Nez Perce Tribal Hatchery on the Clearwater are intended to return as adults and those not caught by anglers are supposed to spawn in the wild. Hatchery fish are acclimated and then released from a number of sites in the basin.
“It’s not just a concrete to concrete program,” said Becky Johnson, director of fish production for the Nez Perce Tribe. “We release fish in the habitat throughout the basin, so when they come back, if they are not caught, they spawn in nature.”
It has been so successful that at times 70 percent of fall chinook on spawning grounds have been hatchery fish. Since many of the returning wild fish are likely the offspring of hatchery fish that spawned in the river, it makes it difficult to measure the true productivity of the wild run. Put another way, would the wild fish numbers persist without help from hatcheries?
“Abundance is good. We have wild fish coming back, but we also need to assess if those adults are replacing themselves so the population is growing,” Gaar said. “There is a high proportion of hatchery-origin fish right now. Over the last 10 years, on average, the hatchery-origin returns have made up over 70 percent of fall chinook that pass on to natural spawning reaches.”
“It’s hard to truly evaluate how the wild population is doing. Is it really increasing if most of the fish are coming from a hatchery?”
What would seem a simple way to find that out would be to turn off the hatchery spigot and see what happens. But the hatchery fish are produced to mitigate for the dams and provide harvest opportunities for tribal and sport anglers. Hatchery production is called for in federal law that predates the listing of fall chinook under the ESA and is spelled out in a court-negotiated settlement known as U.S. v. Oregon.
“Those fish are legally required to be produced to mitigate for the hydro system,” Johnson said.
She has little doubt that without the hatchery program, numbers of wild fish would decline because of continued problems at the dam.
“The bottom line is only 30 to 50 percent of our juveniles make it to Bonneville Dam. There are modifying factors outside of this basin that we can’t control and in the ocean as well. We think if we turned the hatchery program off, the returns would decrease.”
Several studies running through 2018 are trying to determine the strength of natural production and to see if hatchery and wild fish spawning areas can be separated.
Joe Oatman, harvest director for the Nez Perce Tribe, said the performance of other species of wild fish such as spring chinook and steelhead that spawn in areas without hatchery influence aren’t doing as well as fall chinook.
Jay Hesse, a fisheries researcher for the tribe, said given the growth of wild returns since the 1990s it’s clear the hatchery program isn’t impeding wild fish.
“I think it demonstrates the hatchery program here is not a train wreck for natural fish production,” he said. “We are seeing increasing natural origin fish, so it’s not a fatal flaw to natural production.”