Record sockeye salmon run on Columbia now threatened by hot water

Smashing records, sockeye salmon are booming up the Columbia River in a run expected to top 700,000 fish before it’s over. But a punishing heat wave has made river temperatures so hot many may never make it their last miles home.

With water temperatures hotter than 80 degrees in the Okanogan River, sockeye are stacking up at its mouth and waiting rather than entering the tributary to get to their spawning grounds across the U.S.-Canada border.

Called a thermal barrier, warm water is as real as a wall for a cold-water fish like sockeye. More than a quarter-million sockeye died in the Lower Columbia in 2015 just the same way: The water got too hot for them to travel.

“I think there is a good chance that happens again, barring a break in temperatures or a rain event,” said Cody Desautel, executive director of the Confederated Tribes of the Colville Indian Reservation. “That thermal barrier set up early, just in time for this big run. With that many fish coming. And very few have made into the Canadian lake system yet.”

It’s just one more impact of a changing, warming climate that Colville has been experiencing, including wildfires that have burned 700,000 acres of tribal lands from 2015 to 2021, Desautel said. “All the bad things that happen with climate, we seem to be having at Colville.”

The tribes are thinking through what to do if the run stays stuck in the Columbia and just won’t move. One option is to increase harvest for the tribes and others they share with. That could help offset reductions in harvest of other runs, including summer chinook, Desautel said. The tribe might also tag and move some of the fish to cold-water habitat above Grand Coulee Dam, where it is undertaking a reintroduction program to help boost production in the Columbia. “Maybe we can supplement some of the reintroduction work now; that is one silver lining.”

Trucking the fish to Lake Okanagan across the border would help get some 20,000 sockeye to the spawning grounds, but that would take a special permit from Canada. There isn’t a lot of time to figure it out, with the fish and the heat building at the same time.

U.S. Sen. Maria Cantwell, who has helped bring more than half a billion dollars for salmon recovery to Washington since 2022, was concerned. “We can’t tolerate that; we are all working too hard for that to happen. It may be our harbinger for challenges in the future, but we have to come up with answers.”

She said the two nations must work together to find solutions to save the run.

The thermal threat is an ironic twist in what is otherwise good news. The fish run is so big in part because of better management: Dam operators on the Canadian side of the border have been using a computer model since 2004 that helps them improve water releases from the dams for sockeye. Too much and sockeye nests are blasted. Too little and they dry out. Just right and, ka-boom, hundreds of thousands of baby sockeye make it downstream to take on the rest of their life cycle. That includes survival at sea and the long trip through nine hydropower dams back to their home lakes in the Okanagan region of Canada.

The computer model is a nerdy fix that has worked magic to better manage the dams for sockeye. Douglas County Public Utility District, which operates Wells Dam, the last dam on the Upper Columbia before the sockeye enter the Okanogan River, pays for data collection for the model, as well its operation and maintenance. Canadian partners collect the climate, hydrology, temperature and biological data needed to plug into the model to help guide flows to aid sockeye.

Habitat restoration also is helping, and hatchery programs, too, Desautel noted. And lately, ocean conditions have improved to at least average conditions. But all that will be for naught if the sockeye are cooked in hot water.

Justin Yeager, fisheries supervisor for the National Oceanic and Atmospheric Administration in Ellensburg, said the same thing happened last year, at about the same time – albeit with a much smaller run of fish. The fish were stalled out for six weeks, waiting for the Okanogan River to cool. Of the fish that made it back over the ninth dam, only a portion got home to their spawning lake and an unknown number – tens of thousands of sockeye – probably died because of the hot water, Yeager said.

While this probably also happened historically, climate warming is making the problem worse, with hotter water arriving sooner and sticking around longer. “We have made it more challenging; the habitat is less accessible. We have made it hotter,” Yeager said.

It would help to take down Enloe Dam on the Similkameen River, which flows into the Okanogan, Yeager said. That would remove the reservoir that heats up in summer and help lower temperatures in the Okanogan. The dam produces no energy and is a relic from a long-gone mine.

Sockeye in the Columbia Basin are a complicated story. While the sockeye headed to B.C. are breaking records, endangered Snake River sockeye – the first in 1991 of 13 runs to be listed under the Endangered Species Act – continue to do terribly. So far, only a little more than 220 fish have made it over Lower Granite Dam. These sockeye undertake the longest migration of any sockeye in the world, at nearly 900 river miles, uphill all the way to Redfish Lake, in Idaho, at 6,547 feet above sea level. They, and Snake River chinook, are among salmon species expected to fare the worst in warming tributaries as climate change alters the environment they evolved with.

The Idaho Department of Fish and Game is probably going to truck sockeye to Redfish Lake to escape hot water, especially coming out of the Salmon River, which is running at hotter than 70 degrees, said Ritchie Graves, chief of the hydropower division for NOAA. He still winces at the sockeye slaughter of 2015, when more than a quarter million sockeye died from hot water, that time in the Lower Columbia.

The Washington State Department of Ecology found in 2020 that the Columbia and Lower Snake do not meet water quality standards for temperature under the Clean Water Act in summer and ordered the U.S. Army Corps of Engineers and Bureau of Reclamation to develop strategies at its dams to meet temperature standards.

Salmon survival is a complicated story. Different species have their own rearing nurseries, their particular timing of when they make their migration to sea, their own patterns of where they go in the ocean, and when they come back to their spawning grounds. All of these can add up to very different outcomes, from spring chinook and steelhead that are still struggling for survival to the sockeye boom and bust this very same year in different populations.

Columbia River sockeye have adapted to rising water temperatures caused by climate warming by migrating earlier in summer, shifting their migration period 11 days earlier from the 1950s to the 2010s, NOAA scientist Lisa Crozier and her collaborators reported in a 2011 paper. “It’s kind of a race. They have a very narrow window of time to make it,” Graves said. This year, hot water may defeat all their efforts and adaptations to survive.

Even surviving their river journey in a changing climate isn’t enough. Sockeye also have predators – and other salmon to deal with. Today sockeye contend with as many as 700 million pink salmon pumped into the ocean by a multitude of hatcheries – Russian, Alaskan and South Korean. “That is a lot of mouths to feed in the ocean,” Graves noted.

A suite of changes at mainstem dams on the Columbia have helped boost the survival of some salmon species, especially surface passage that has been added at the dams to let baby fish travel where they prefer to over the dam, in the upper water column. That has shaved travel time off their journey to the sea, Graves noted, as they don’t have to mill around looking for a way through the dams.

Spill has also been boosted and is now so high in the spring that dam operators at the Lower Snake River Dams at times are spilling more than 70% of the spring runoff, rather than running the water through the turbines to make electricity, to help baby fish in their journey to the sea.

The high spill levels are part of a court-ordered plan to boost fish survival in the Columbia agreed to by federal, state and tribal governments last winter to settle a long-running lawsuit over dam operations and Columbia Basin salmon survival.

Some years, enough of the pieces come together right, and the result is abundance. While historical runs of sockeye were estimated at about 2 million fish, this year’s run is already the highest ever recorded on the Columbia since the dams were built, beginning in the 1930s, Graves noted.

The question now is whether they will make it home.

Lynda V. Mapes: lmapes@seattletimes.com; Mapes specializes in coverage of the environment, natural history and Native American tribes.