Environment

Acidic oceans and warm rivers that kill Idaho’s salmon might be norm in 50 years

These combined images show, at left, a healthy pteropod collected by NOAA and Oregon State University scientists, and at right, one that shows signs of damage from ocean acidification. The white lines on the grooves of the shell at right show areas where it is beginning to dissolve. The pock marks and white spots are signs of severe dissolution.
These combined images show, at left, a healthy pteropod collected by NOAA and Oregon State University scientists, and at right, one that shows signs of damage from ocean acidification. The white lines on the grooves of the shell at right show areas where it is beginning to dissolve. The pock marks and white spots are signs of severe dissolution. Provided by NOAA

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20 years later, Idaho's salmon are still in danger of disappearing forever

The salmon of the Northwest are the stuff of legends. Pioneers talked of rivers so thick that they were tempted to cross on the backs of the fish. But times have changed, the fish's numbers have plunged, and 13 species were placed on the endangered species list by 1995. Climate change and our network of hydropower dams have helped thwart attempts so far to find a sustainable solution. And it's possible some of our strategies - including our reliance on hatcheries - have backfired.

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What is the future of the Columbia River and its salmon? Look to 2015.

That year’s extraordinary combination of overheated river water and low flows killed hundreds of thousands of returning sockeye salmon, devastating a run that had rebounded from near-extinction.

Millions of new sockeye and steelhead smolts migrating the opposite way, to the Pacific, died throughout the river system; only 157 endangered sockeye made it back to the Sawtooth Valley this year.

By the middle of this century, scientists suggest, the temperatures we saw in 2015 will be the norm. The low snowpack and streamflows were examples of what the Pacific Northwest should expect at the end of this century due to rapid climate change caused by the burning of fossil fuels, climatologists say.

“2015 will look like an average year in the (2070s) and there will be extremely warmer years than that,” said Nate Mantua, a NOAA atmospheric scientist in Santa Cruz, Calif.

Scientists, politicians and energy officials have argued for decades over the best way to restore troubled salmon runs along the Columbia and Snake. Their focus has largely been on the dams and human development that reshaped the rivers. But regardless of what other steps we take for the fish, climate change could catch up with them in the coming decades and pose a major threat.

Already, scientists have seen regional snowmelt reach rivers an average of two weeks earlier than historical records indicate. The average temperature of the Columbia River and its tributaries has risen more than 1 degree Fahrenheit since 1960.

Climate modelers at the University of Washington’s Climate Impacts Group predict that the Pacific Northwest’s average annual temperatures will rise a total of 4 to 6 degrees Fahrenheit by 2050. High estimates suggest the increase could exceed 8 degrees, said Joe Casola, the group’s deputy director.

Salmon and steelhead that migrate in the summer and those that spawn and rear in lower-elevation tributaries to the Columbia may not survive these temperatures. In water of just 68 degrees, salmon will begin to die.

And the changes aren’t just affecting salmon. Warmer winters could mean less of our precipitation comes as snow, bringing lower river flows in the late summer and fall for farmers and hydroelectric power generators. Their needs always have dominated the decisions in the river in the past, and they will shape the debate over fish and river management now.

Past the rivers, unprecedented high temperatures in the North Pacific from 2014-16 raise the specter of a changing ocean ecosystem that may not be as productive for many species, including salmon. The Pacific Ocean is actually turning acidic, threatening mollusks that are critical elements of the food chain. All combined, this could have profound impacts on our ability to feed ourselves.

But there is hope.

Salmon that already spawn in the fall or winter may survive. So could those that adapt to avoid hot spots in the rivers — much as humans must adapt our food, farming and power needs to meet what is to come.

Biologists say the high-elevation, pristine spawning habitat in Central Idaho’s roadless and wilderness areas can serve as Noah’s Ark for these remarkable, adaptable fish if we give them a chance.

“Those rivers that are cold enough now for salmon are probably fine from a temperature perspective,” said Dan Isaak, a fisheries researcher with the Forest Service Rocky Mountain Research Station in Boise. “The exception would be the lowest part of the Snake and Salmon rivers.”

Canary in the coal mine, salmon in the stream

The fish that took the worst hit in 2015 appears to be the the one with the highest risk of going extinct because of climate change.

Snake River sockeye, the southernmost population of sockeye salmon in the world, nearly vanished in the 1990s. In 1992, only one returned to the Sawtooth Valley: Idaho’s famed Lonesome Larry. The Idaho Department of Fish and Game placed him into a captive breeding program, along with 15 other sockeye that held the valuable genetic code allowing them to travel 900 miles and climb to 6,500 feet above sea level.

The last truly wild sockeye salmon returned to Idaho in 1998. Fish and Game kept up its efforts, and in 2010 declared its project was successful enough to convert from a genetic conservation program to a recovery program. That year, 1,355 sockeye returned to Idaho, including 180 from the breeding program that spawned in the wild.

In 2014, a full 1,516 sockeye reached Idaho lakes and streams — a record since four key dams were built along the Snake River in the 1960s and ’70s, contributing to altered fish runs.

In 2015, fisheries biologists were optimistic when 4,000 adult endangered Snake sockeye returned in the spring from the Pacific to Bonneville Dam, the first major dam on the route in along the Columbia.

Then June temperatures spiked. Highs in the region rose to the upper 90s and 100s; temperatures in the Columbia River reached 73 degrees, warm enough to kill salmon. The Salmon River climbed to 76 degrees at White Bird.

Just 56 Idaho sockeye made the trip back to the Sawtooth Valley on their own. Another 35 were trucked to Fish and Game’s Eagle hatchery. None that reached the Columbia after July 16 completed the trip home.

The toll was just as sharp elsewhere. A full 475,000 sockeye headed for the Okanogon River in northeastern Washington reached Bonneville Dam, but just 2 percent actually returned to their spawning grounds.

“It was a huge wake-up call,” said Eric Johnson, a research biologist with Idaho Fish and Game.

Region in hot water

But water temperatures in the Columbia and Snake rivers have been high for years, the federally funded Fish Passage Center in Portland noted in a 2015 report. The reservoirs behind eight dams built along those rivers since 1938 have acted like giant solar collectors, often heating up the slowed waters to the 68-degree threshold of concern.

Removing four of those dams on the Lower Snake is one controversial, debated solution to aid salmon. The temperature issue has not been a central part of that debate until now.

Dam managers point out that the rivers could still reach 68 degrees even if the dams were gone. In turn, a white paper by Columbia Riverkeeper — a nonprofit focused on Columbia River water quality — suggests the dams greatly amplified the heat effect in 2015 and that a river’s faster flows if dams were gone would cycle hot water out of the system more quickly. A study by the Pacific Northwest National Laboratory in Washington shows that a river with no dams warms up faster and has greater, but briefer, summertime highs before cooling down more swiftly.

Authorities have a couple of existing tools. The U.S. Army Corps of Engineers after 2015 installed “intake chimneys” at several dams, bringing cooler water into several fish ladders where warm water blocked passage. The cold waters in Dworshak Reservoir on the North Fork of Idaho’s Clearwater River have been a critical tool for cooling the flows in the Snake, and salmon advocates want to see that used more often.

Michelle DeHart, director of the Fish Passage Center, said there are actions federal dam managers can take now when the rivers turn hot. In 2016 the center recommended studying drawing down the reservoir behind Lower Granite Dam on a seasonal basis or as an emergency tool. That would aid fish but end grain shipping and reduce power production.

“We’re looking at things we can do in a triage situation,” she said.

Out at sea

The picture doesn’t improve during the years salmon spend at sea.

Scientists say about 100 U.S. tons of carbon dioxide fall into the ocean every second. At Mauna Loa in Hawaii, carbon dioxide levels have risen from 317 parts per million in 1960 to 405 ppm this August.

You don’t have to go very far to find a changing Pacific ecosystem. Francis Chan, a marine ecologist at Oregon State University, reported on acidic “hotspots” in a three-year study released in May. His team found near-shore pH levels (lower means higher acidity) that went as low as 7.4, which is among the lowest recorded pH level ever observed in the surface ocean. The global mean pH is 8.1 for the surface ocean.

He found acidity levels just as high or higher this year at locations along the coast of Oregon.

“The acidity wasn’t way out in the ocean. It was literally in the surf,” Chan said.

These areas of high acidity brought waves of death to pteropods, tiny marine butterflies that are one of the primary food sources for juvenile salmon. The acid melts away the tiny mollusk’s shell.

Studies suggest that salmon behavior might be affected by swimming in an acidic ocean, reducing their homing ability and skill at avoiding predators. And again, the effects go far beyond salmon: Another example is Oregon and Washington oyster farms, which have suffered die-offs when acidic waters reached their intake pipes.

The good news is that the problem isn’t everywhere yet, Chan said, and the areas that measured high remained constant over three years. That means managers can develop tools to find and monitor sites of high and low acidity to ensure that sensitive species are protected.

What can we do?

There is good news across parts of the system, and there are indications of where humans could make a difference.

Eliminating fossil fuel burning and reducing greenhouse gases are the most important steps we must take, scientists agree. But even if we dramatically reduce greenhouse gases over the next 30 years, the changes seen now will continue to get worse.

In an announcement of the acidic ocean study, Chan gave advice that applies just as well to restoring salmon.

“Our first goal should be to not make things worse,” he said. Then, we must help sea life become more resilient. “The greater the diversity, the better chance of improving the adaptability of our marine species.”

In Idaho’s wild areas is tucked a valuable safeguard. Isaak, the Forest Service researcher, said Central Idaho’s high elevation and pristine ecosystems could become even better suited for salmon as the state warms. Water temperatures in some parts of the region are currently on the low end of the 41-to 55-degree zone in which salmon thrive.

But the salmon have to make it through the rest of the river chain.

Rick Williams is an independent fisheries biologist from Eagle whose work has help guide river managers for more than 20 years. He said salmon already use springs and cold-water tributaries all along the migratory corridor as refuge from warm water. These areas could be turned into actual refuges where fishing is prohibited.

Dworshak Reservoir, currently used for power production, recreation and flow augmentation, could become primarily a tool to cool down the Snake River.

For tributaries at lower elevations, we could add shade, woody debris and remove certain channels. Tribal restoration projects along those lines in eastern Oregon have lowered the surface temperatures of certain creeks by as much as 10 degrees.

The larger Columbia River remains a challenge. Federal dam managers are studying ways to address the higher temperatures there. But so far no solutions have been offered, said Amy Gaskill, a U.S. Army Corps spokeswoman from Portland.

And in the short term, poor ocean conditions are expected to weigh down salmon revival efforts for at least two to three years — and possibly for more than a decade.

Fish populations are at least larger now than they were at the start of the last low period for salmon, the late 1980s. But Snake River salmon have not been replacing themselves for the past decade. Their survival, said Ed Bowles, Oregon Fish and Wildlife Fisheries manager, will depend on spurts in productivity during favorable times, and more active management by humans in poor times.

And what of the dams?

The scientific debate about Snake River salmon and removing the four Snake dams is a lot like the debate over climate change. There is wide consensus that removing the dams would be the most effective, and perhaps only, way to recover the salmon. But the people and industries affected by dam removal — wheat shippers, Pacific Northwest utilities, the region’s political leaders — support fixes that keep the dams in place.

And regarding climate change, groups such as the Bonneville Power Administration or Northwest RiverPartners have an obvious counterargument: Hydropower is a carbon-free energy source, the kind experts say America’s energy grid should be more reliant on.

Terry Flores is executive director of Northwest RiverPartners, which represents regional industries that oppose dam removal. She said she welcomes the current review of the Columbia and Snake dam system’s effects on salmon.

“The Snake dam removal analysis could very likely show that these dams’ value to the Northwest is increasing, not decreasing, in part because of their key role in addressing climate change,” Flores said.

The BPA, the federal agency that markets the power from the dams, said replacing them with natural gas plants would increase the region’s carbon dioxide emissions by up to 2.6 million metric tons annually. That, they say, is the equivalent of adding 421,000 cars to the Northwest’s roads annually.

Advocates of renewable energy and of salmon recovery say the situation isn’t that simple once we account for how climate change will transform American energy production.

In the future, they say, the dams might continue to lose value to BPA and to taxpayers. The continued change as to when rivers peak will mean lower flows in late summer and less potential for the dams to generate power. A warmer West will change the time of greatest need for power to the summer, and that will cut into BPA’s ability to sell surplus winter power to California, a key source of revenue.

Williams and fellow biologist Jim Lichatowich have worked with river managers for more than two decades to find a way to save salmon and keep all four dams intact. They call for a new approach that sees salmon as more than just a food source to be managed and accounts for how the fish interact with the rest of their ecosystem. Many of the same measures used to restore salmon habitat — planting trees for shade, for example — also reduce greenhouse gases, said Pat Ford, the retired executive director of Save our Wild Salmon and a former board member of the Northwest Energy Coalition.

Like the salmon, the residents of the Pacific Northwest are people of place. With the rest of the world, we must find ways to farm, produce energy and live while reducing greenhouse gases and adapting to climate change.

“Can fish, farms and communities, from Salmon to Lewiston to Portland, find common ground as the rivers we all use get hotter?” Ford said. “I think that common ground is healthier lands and waters, and not leaving people or salmon behind.”

Rocky Barker: 208-377-6484, @RockyBarker

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