Once and Future King

Mark Floyd — Sun, 22 Feb 2009 22:14:27 +0000

Salmon seiners on the Columbia River, 1914 (Photo, courtesy of the U.S. Geologtical Survey)

Meriwether Lewis and William Clark were early witnesses to the majesty that is the salmon in the Pacific Northwest. When the explorers first came upon the confluence of the Yakima and Columbia rivers, they observed a scene that was both confusing and awe-inspiring. Wrote Clark:

“This river is remarkably Clear and Crouded with Salmon in manye places and I observe in assending great numbers of Salmon dead on the Shores, floating on the water and in the Bottoms which can be seen at the debth of 20 feet.”

Lewis and Clark may not have known about the wondrous life cycle of the salmon, but the aboriginal peoples of the Pacific Northwest certainly did. Salmon provided an abundant and predictable protein source that was cured, smoked and dried. It provided sustenance through bone-chilling winters and was traded to inland tribes for obsidian or other goods.

The value of salmon was soon recognized by others. In 1824, the Hudson’s Bay Company sent barrels of salted salmon to London. Although they spoiled, the industrialization of the resource had begun. By 1865, the first cannery was established on the Columbia, and by the end of the century, canneries could be found on the Rogue, Umpqua, Nehalem, Nestucca, Alsea, Coquille and Siletz rivers, and on Tillamook and Yaquina bays.

Over-fishing began to take its toll on the mighty salmon. As westward migration brought more people into the Northwest, dams were built and streamside forests were cut. Eroding soils buried spawning grounds in sediment, and complex river channels became pipelines. Wastes poured into once-pristine waters.

The finger of blame for declining salmon runs has pointed at these and other factors: sea lions, birds, aquaculture, development and hatcheries. Climate change and ocean conditions may trump them all.

Since Oregon’s commercial salmon fleet brought in nearly $50 million at the dock in 1988, revenues have steadily declined. Recreational fishing has boosted rural communities, but the salmon economy has stalled. In 2008, the commercial season was closed along the California and Oregon coasts. If the decline has been a process of death by a thousand cuts, restoring salmon runs may require the application of a thousand small bandages. We are finally admitting that we don’t know quite as much about salmon as we thought we did, but the research is catching up.

More than two-dozen scientists in four OSU colleges and colleagues in state and federal agencies are studying the salmon life-cycle. Their work is generating a rare feeling about the future of this Northwest treasure. It is called hope.

The following stories suggest what it will take for this symbol of the Northwest to thrive.

Running the Gauntlet

Salmon have struggled past dams for decades, but the harm may go deeper than we think. Certainly the towering hydroelectric dams on the Columbia River have served as a barrier to adult salmon migrating upstream to spawn. Then scientists discovered that hundreds of thousands of juvenile fish met their demise on the way downstream to the ocean, victims  of poorly designed fish passageways and spillways.

But the full risk of dams may be underappreciated, according to Carl Schreck, who has spent much of his career studying the young fish.

Schreck is a U.S. Geological Survey scientist with a courtesy appointment in OSU’s Department of Fisheries and Wildlife. A leading expert on the impacts of stress in fish, he received the Meritorious Presidential Rank Award last year at a White House ceremony for his contributions to fisheries science. His studies suggest that juvenile salmon may be harmed by the stress they endure as they navigate the Columbia’s hydro system. (Listen to Schreck describe his research here.)

“Stress in fish delays development,” Schreck says. “It also suppresses the immune system, which can increase the chance that fish will be susceptible to disease or parasites. Even though the data suggest that a certain percentage of juvenile salmon survive the freshwater phase of their migration, their weakened condition can be the difference when a young salmon (known as a smolt) needs to adapt to a saltwater environment.”

Additional risks stem from chemical contaminants and changes in water flow rates and temperatures. Despite the complexities, Schreck is optimistic that science and engineering are beginning to make a difference. New fish passage technologies and increased water release over spillways have improved smolts’ initial survival past the Columbia River dams, he says. But when smolts delay their migration for days before trying to navigate past the first dam, the added stress could be setting them up to fail once they enter the ocean.

One possible solution: start with a healthier smolt.

Shaun Clements is a former OSU research associate and colleague of Schreck, now working as a biologist with the Oregon Department of Fish and Wildlife. During a study of juvenile salmon on the Columbia, he compared the health and vigor of smolts that were captured at Lower Granite Dam. His research team inserted radio and acoustic transmitters into the young fish at the dams to trace their migration downriver.

“One day, we’d get a group of fish that were released from one hatchery and they’d be relatively weak, then a few days later we’d get a bunch of fish from a different hatchery, and they would be robust,” Clements says. “Hatcheries weren’t the only variable. Sometimes fish from the same hatchery would range from poor to excellent in quality, possibly due to environmental factors such as water temperature in the reservoirs.

“These same mechanisms may also apply to wild fish where we see different watersheds producing smolts of differing quality,” he adds. “The point is that the quality of smolts entering into the system can have an impact on their ability to survive the entire migration and the transition into the ocean.”

Good Breeding

Such differences among young salmon — why some are 98-pound weaklings and others strut their stuff — may be influenced by hatchery practices. In 2007, OSU geneticist Michael Blouin published a study on steelhead, a close relative of salmon, in the journal Science documenting a stunning loss of “reproductive success” at a Hood River, Oregon, hatchery. He reported that 15 percent fewer offspring of first-generation hatchery-raised fish returned to spawn as adults than did the offspring of wild fish. And second-generation hatchery fish produced about half the number of surviving offspring as first-generation fish. The first- and second-generation hatchery fish were raised in the same environment, so the difference between them must be based on genetics.

“We weren’t surprised by the effect,” Blouin says, “but we were certainly surprised at how quickly it happened.”

Scientists aren’t sure why. Certainly, hatcheries provide an artificial environment for young fish that offers plenty of food and little danger — conditions that could lead to vulnerability once they leave their concrete cocoon. In the wild, he says, natural selection continually purges fish species of genetic weaknesses.

Designing and managing hatcheries to emulate natural conditions may help offset the reverse Darwinism they engender, Blouin adds, but then the mortality rate for the fish would rise. “At some point, if we are down to a 3-percent survival rate for the fish, what’s the point of the hatcheries?”

Despite their flaws, hatcheries could play a role in helping salmon and steelhead runs rebound, but there are knowledge gaps to overcome. “We don’t know what genetic selective processes are going on at hatcheries,” Blouin says. “We do know that a population cannot be adapted to two different environments at the same time. If there is strong selection process for the artificial environment, then the fish will be maladapted to the wild.”

Blouin plans to conduct tests at the Oregon Hatchery Research Center near Alsea, a collaborative venture between OSU and the Oregon Department of Fish and Wildlife. He’ll focus on optimal growth rates for fish and at genetic differences between smolts that come from wild fish, hatchery fish and crosses.

Salmon diets are skin deep

Scientists at the Oregon Hatchery Research Center look for clues to salmon diets in an unlikely place: the mucus that fish produce on their skin.
Read more.

Rivers Transformed

Over the last 200 years, habitat loss for salmon and steelhead has been epidemic. On some river systems, dams have slowed currents, eliminated miles of habitat and blocked upstream spawning and rearing tributaries. Logging, agriculture and residential and urban development have had similar impacts on free-flowing rivers.

For thousands of years, Oregon’s anadromous fish have survived droughts, floods, landslides and other natural disruptions. The encroachment of humans has been a different story.

OSU fisheries ecologist Stan Gregory says one of the most damaging environmental changes caused by humans has been the transformation of complex, braided river systems into single-channel streams that essentially mimic pipelines.

“If you look at what many Northwest rivers were like a couple of hundred years ago,” Gregory says, “you would see multiple channels that spread the impact of flooding, slowed down currents and created holding places for migrating and resident fish. Development and the transition of the land from floodplain and riparian forests to pastures and housing tracts have eliminated that complexity from many river systems. Dams and flood control have reduced the beneficial effects of floods that create floodplains, scour pools, deposit riffles and create complex channels that provide cold-water habitats.”

Healthy streams with vibrant ecosystems have another benefit. They remove excess nitrogen that is generated by human activities (principally urban development and agriculture) and thus help maintain suitable fish habitat. In a study published in the journal Nature, Gregory and a team of 30 other scientists found that river systems that maintained their complexity could filter out 40 to 60 percent of the nitrogen taken up by the river system within 500 meters of the source where it entered the river.

“It does this by filtering the nitrogen through uptake by tiny organisms such as algae, fungi and bacteria that live on rocks, pieces of wood, leaves or streambeds, and releasing it harmlessly into the atmosphere,” Gregory says. “But to work effectively, the stream has to have an opportunity to absorb the nitrogen we put in the river instead of sending it immediately downstream.”

Understanding the importance of historic river channels is key to giving young salmonids adequate habitats for their seaward journey.

Taking Terns

Juvenile salmon and steelhead may spend a year or more in rivers and streams before entering the Pacific Ocean, where a host of potential predators await. But their freshwater adventure also is fraught with peril. Until recently scientists may have underestimated just how dangerous their trek is. Clues have begun to emerge from studies of Caspian terns, large gull-like birds with a taste for salmon.

By the late 1990s, the world’s largest Caspian tern population had become established on the Columbia River’s Rice Island, some 21 river miles from the ocean. The terns had seen their own habitat disappear, and they immediately took to this sandy dredge-deposited soil. Scientists began to wonder if there might be too many of the fish-eating seabirds in one location, so an OSU-led research team studied the terns’ diet.

The findings were startling. Researchers estimated that the single colony of nesting terns — about 9,000 pairs — were consuming as many as 12 million young salmon each year, an estimated 10 percent of the juvenile population from the entire Columbia River Basin that survived to the estuary.

“When we looked at what the terns on Rice Island consumed, we found that three-fourths of their diet was juvenile salmon and steelhead,” says Daniel Roby, OSU professor of fisheries and wildlife. “That is not good. Rice Island was, perhaps, the worst possible location for the world’s largest Caspian tern colony, if your goal is restoring the 13 threatened or endangered stocks of Columbia Basin salmon and steelhead.”

The findings prompted the U.S. Army Corps of Engineers to team up with OSU and move the colony to new habitat on East Sand Island, located just five miles from the ocean. Surrounded by saltier waters, the island offered terns a wider variety of fish, including herring and anchovies. Almost immediately, consumption of the juvenile salmon and steelhead was cut in half. “But,” Roby says, “that’s still too many endangered fish.”

So the OSU researchers partnered again with the corps to begin developing new nesting sites away from the Columbia River altogether. Last spring, they finished work on a newly constructed island on Crump Lake in the Warner Valley, near Lakeview, Oregon. In the first year, the project attracted 428 nesting pairs of Caspian terns. Thirty birds carried research bands identifying their origin and five were from East Sand Island, more than 300 miles away.

Other island nesting sites are being developed on Sumner Lake, the Fern Ridge Reservoir near Eugene, Lower Klamath National Wildlife Refuge near Klamath Falls and in the San Francisco Bay Area. As new sites become available, the corps will reduce the amount of tern nesting habitat along the Columbia.

Victory at Sea

Nothing has a greater impact on salmon survival than the oceans, where they can spend one to five years. Yet scientists acknowledge that what happens to salmon here is still largely a mystery. Water temperatures and prey abundance seesaw from year to year and place to place. No one really knows what that means for salmon.

During the last few years, scientists have begun pulling back the curtain. OSU studies of hypoxia, or “dead zones,” have led to a greater understanding of the ties between physical processes and biological responses. This complex intersection is where you’ll find Bill Peterson, a NOAA (National Oceanic and Atmospheric Administration) biologist who works at OSU’s Hatfield Marine Science Center in Newport.

For the past 10 years, Peterson has participated in a Bonneville Power Administration project analyzing the distribution of juvenile salmon off the West Coast and using genetic tracking to determine their rivers of origin. The findings help explain why the Columbia River can have a robust run of salmon during the same year the Sacramento River and the Willamette River have historic low returns.

After they leave their river systems, juvenile fish from many of Oregon’s coastal rivers, along with those from the Willamette and the Sacramento, congregate just off the Oregon coast. In 2005, when delayed upwelling caused a lack of biological productivity, there was little food, and many of that year’s young salmon starved. The effects were seen when few adults returned to spawn in 2008.

“Columbia River spring chinook stay off the Oregon coast for only a few weeks,” Peterson says. “In our 10 years of sampling, we’ve caught Columbia River juveniles just off our coast only in May and June. By July, perhaps earlier, they have left the area for parts unknown, whereas most coho salmon stay locally. If you look this year at chinook salmon in Alaska, they’re doing well. So it’s possible that Columbia River juveniles head to the same place as Alaska juveniles.”

Peterson speculates that young Columbia River salmon may migrate toward a unique ecosystem several hundred miles off the Northwest coast. In that deep, cold water, lipid-rich (high-fat) fishes known as myctophids, or “lantern-fish,” provide a bountiful diet for a variety of marine life.

Cold-water regimes also play a role, says Peterson, who has a courtesy appointment as a professor in OSU’s College of Oceanic and Atmospheric Sciences (COAS). His studies have found that juvenile salmon survival increases dramatically when cold-water zooplankton species are dominant. The copepods’ high lipid levels may enrich the oceanic food chain and allow salmon to grow fast enough to survive their first year at sea.

“Cold-water copepods hibernate during the winter, much like bears, and to survive the winter, they store high amounts of lipids, or fats,” Peterson says. “These copepods, in turn, are eaten by juvenile anchovies, herring, smelt and euphausiids (krill), boosting the fat and energy content of those species and making them highly nutritious delicacies for young salmon, as well as other predators.

“A fat salmon,” Peterson says, “is a happy salmon.”

And, he adds, there may be good news on the horizon. Last year, the Pacific Decadal Oscillation, a pattern of climate variability that shifts every 20 to 30 years, was the most negative, or cool, it’s been since the mid-1950s. The ocean was incredibly productive during 2008, and the salmon that did return appeared to be well-fed and healthy. Forecasting is always risky, he says, but salmon stocks will likely be on the upswing.

No Room at the Inn

So what does the future hold for Pacific Northwest salmon? If there is a cautionary note to recent strides, it comes from Robert Lackey, a senior scientist at the U.S. Environmental Protection Agency’s Western Ecology Division in Corvallis and a courtesy faculty member at OSU. In 2003, Lackey created the Salmon 2100 Project with OSU faculty members Denise Lach (College of Liberal Arts) and Sally Duncan (Institute for Natural Resources). They recruited 33 salmon scientists, policy analysts and wild-salmon advocates to offer their solutions for saving the fish by the year 2100. EPA awarded Lackey its highest honor, the EPA Gold Medal, for his work.

Their collective conclusion was that current recovery efforts would fail unless we take a substantially different path. There was also broad agreement that the changes necessary to save wild salmon may be politically or culturally unpalatable. Lackey says that scientists and resource managers need to take a strong, realistic look at the future and tackle the biggest factor affecting the future of salmon. It isn’t dams, or water quality, or even ocean conditions, he says.

It is us: “our choices, our priorities, our unwillingness to come to grips with simple tradeoffs.

“If society wishes to change the future for wild salmon, something must be done about the unrelenting growth of human population levels along the West Coast,” says Lackey. “By 2100, there could be 200 million to 250 million people in the region, quadrupling the population barely 90 years from now. Consider the demand for houses, schools, stadiums, expressways, automobiles, malls, golf courses and sewage treatment plants. Society’s options for sustaining wild salmon in significant numbers would just about be non-existent. Even given all this, there are still salmon recovery options that are likely to be ecologically viable and probably socially acceptable, but the range of options continues to narrow.”

OSU’s Schreck concurs and points out that climate change introduces an added dimension. The situation may be dire, he says, but it is not hopeless.

“Are we willing to give up the things we like to save the salmon?” Schreck asks. “We can plan for growth, make wise resource allocations, handle water and sewage requirements and limit our urban footprint. It’s not too late to help salmon recover — but we may have to be selective.

“There may be areas, rivers or watersheds, that can’t be recovered. We should first identify those places where fish runs are robust and make sure we protect them so they stay that way. Then we need to find those that are marginally in trouble and begin to fix them. But we need to get going now. There isn’t a lot of time to waste.”

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