Northwest Hydropower News Archives 2010 & Older

Return to Previous PageChinook repeat perilous journey

Salmon must endure same obstacles when returning up Oregon Rivers to spawn, then die

By Beth Casper and Stefanie Knowlton

Directed by her nose and an inexplicable sense of direction, an adult female Chinook will find her way back from the coast of Alaska to her birthplace on the North Santiam River.

She’s more than 15 pounds heavier than her birthweight and nearly ready to spawn.

But her journey back to where she hatched is just as perilous as the one to sea.

After surviving dams, storms and ocean predators, at least 15 percent of spring Chinook making it back to the North Santiam River die before completing their most important task: spawning.

And two years in a row, 2003 and 2004, nearly 70 percent of spring Chinook on the North Santiam died before spawning.

Their pre-spawning mortality is part of the reason fish biologists say spring Chinook on the North Santiam are likely to go extinct in the next 40 years.

In an attempt to reverse the trend, federal and state officials are prepared to spend hundreds of millions of dollars to ease the effects of the 463-foot Detroit Dam, which blocks fish passage and critical habitat and also alters water temperatures so much that fish adjust their life cycle. Officials also plan to improve habitat, and fix problems related to hatchery fish and their facility.

The work will be guided by a soon-to-be-released state recovery plan and a federal plan, called a biological opinion, that explains how it would reduce the impact of the 13 Willamette Basin dams on endangered fish, including Chinook.

If the efforts are successful, river visitors may see what 80-year-old Duane Wagner of Mehama experienced growing up on the North Santiam: a river thick with fish at spawning time.

Where to spawn?

When the female spring Chinook makes it to the mouth of the North Santiam River, she’ll seek out many of the same sanctuaries she used on the way out to sea. But this fish will be focused on avoiding shallow water, which tends to be warm. Water at 59 degrees is stressful to fish and 68-degree water can kill fish.

She’ll also have to navigate obstacles that slow or halt her upstream progress — either Lower Bennett Dam to get around the north side of Geren Island or Upper Bennett Dam to get around the south side.

At Lower Bennett Dam, fish can use a ladder, or series of steps flowing with water, to get over the dam. Fish ladders allow a fish to make the leap over a dam more gradually.

Still, 90 percent or more of a spring Chinook run will choose the south channel and take their chances over Upper Bennett Dam.

This female fish is in luck. She heads up the half-million dollar fish ladder installed in 2005 at Upper Bennett Dam. Generations of fish before her stressed themselves often to death trying again and again to jump the dam’s more than 5-foot-high concrete face, only to fall back onto the 10-foot-wide sill that extends from its base.

The ladder has helped reduce the stress that can lead to pre-spawning deaths.

“Fish are much more apt to find the entrance to the fishway,” said Steve Mamoyac, district fish biologist for the Oregon Department of Fish and Wildlife. “It’s a better structure all around. We’ve been really impressed with what we’ve seen.”

Upriver about a dozen miles, under the Mill City bridge, fish rest and find cool temperatures in a deep 60-foot hole in the basalt rock.

Just a short jaunt upriver to Gates provides beautiful stretches of gravel for fish to spawn.

“There is a limit to the amount fish can adapt,” said Kirk Schroeder of the Oregon Department of Fish and Wildlife. “Fish can spawn below the dams, but it is not where they historically spawned. The vast majority were in higher reaches.”

While most spring Chinook try to get as high as they can in a watershed, about 30 percent spawned in the lower reaches before the dams were installed.

“If the habitat is there, the fish will come,” Mamoyac said.

“When salmon come back, they are ready to spawn,” Schroeder said. “They do what they can.”

Most spawning happens between late September and early October.

That means spring Chinook are traveling up the North Santiam in the summer — when river flows are at their lowest.

Whose water is it?

For the spawning female trying to reach her birthplace above Detroit Dam, she should have available at least hundreds of cubic feet per second as measured at three different locations along the river.

But those flows are only recommendations at this point — the only legal right to water for fish is a 345-cubic-feet-per-second water right on the North Santiam and a 50-cubic-feet-per-second water right in the north channel near Stayton. Neither of these are adequate for spawning spring Chinook.

The federal government’s biological opinion addresses the issue of flow by requiring a certain amount of water to be released from Detroit Reservoir each season — 1,000 cubic feet per second in the summer and 1,500 cubic feet per second starting Sept. 1 for spawning spring Chinook.

The requirements are meant to ensure adequate water in-stream for fish, but they are sure to cause conflict with recreationists and business owners on Oregon’s most popular recreation lake.

“We didn’t provide a full pool even in years where we were not releasing the amount of water required in the biological opinion,” said Mindy Simmons, the Willamette program manager for the Army Corps of Engineers.

The Detroit community is already preparing for the inevitable lower lake levels. Two boat ramps at Mongold Day Use Area have been extended, and another one has been built to reach the very low reservoir levels in the winter.

“They were fighting Mother Nature for the water, and now they are fighting the biological opinion for the water,” said Dave White of the Federal Lakes Recreation Committee for Detroit Lake.

White said one of the two marina owners in Detroit is thinking about digging out the boat docks to maintain access to them even during lower lake levels.

Water users downstream could affect fish as well, particularly in low-water years. Thirty water contracts on the river have rights to the stored water behind the dam.

The biological opinion, in anticipation of future water conflicts, restricted any new water contracts on the North Santiam River.

And the city of Salem, with one of the oldest rights to water in the river, uses as many as 54 million gallons per day. That’s anticipated to rise to as much as 68 million gallons per day by 2025.

So far, aside from the 2001 drought, water officials have not had to curtail water use on the North Santiam River. But experts predict that the combined pressures of global warming and population growth will create conflicts over water in the future — conflicts that may prove difficult for fish.

Guided by humans

Compelled to swim as far upriver as possible, the female Chinook continues her journey and eventually will encounter the Minto fish ladder upstream from Packsaddle Park.

Every step will be guided by human hands after this point.

On the north bank rests an aging 1950s building with a metal sorting table and holding tanks separated by tall bars. The federal government built the structure to capture, kill and breed high numbers of fish in the quickest way possible in order to offset the reduced fish runs from installing Detroit and Big Cliff dams in 1953.

There was no distinction between hatchery or wild fish or any thought that the distinction would someday be essential to saving fish species, including spring Chinook.

In 1998, the Oregon Department of Fish and Wildlife began clipping fins on hatchery spring Chinook in the North Santiam in an effort to protect wild fish. The numbers show that these hatchery fish have all but replaced the wild population, outnumbering them 10 to one and sometimes more.

And even those with fins aren’t always wild. Some hatchery fish miss the clippers or actually grow their fins back.

“There’s not a whole lot, if any, wild fish left in this system,” said Greg Grenbemer who oversees the ODFW hatchery program on the North Santiam.

That’s a problem for long-term survival of the species.

“Hatchery fish do not survive as well as wild fish,” said Dave Jepsen, ODFW fish biologist in charge the state’s recovery plan.

When wild fish interbreed with hatchery ones, those characteristics can get passed on to the next generation, he said.

That’s why the focus is on saving wild fish and at the same time reducing the number of hatchery fish spawning in the river.

For the female Chinook on her journey to where she hatched, she approaches the aging ODFW building and encounters a manmade velocity barrier that stops her migration.

She ducks into an underwater opening on the north side of the river and begins flopping up the fish ladder with hundreds of other fish. At the top, she swims through a gate and finds herself trapped in a holding tank.

An elevator lifts the trapped fish 20 feet up and into a chute, over a grate where the water falls away and into anesthetic. Hatchery employees pluck the stunned fish out of the bucket and examine them.

Hatchery fish, those with clipped fins, go into holding tanks and either get released above the dam to spawn and die or about 300 pair suffer a quick blow to the head with a baseball bat so employees can harvest their eggs and sperm for the next generation. These fish die within a week after spawning regardless, and it’s more efficient to breed this way.

Wild fish, like this female, go into holding tanks destined for release downstream in the hopes they will spawn on their own. Hatchery fish are the only ones trucked to the historic beds above Detroit — their offspring’s journey through the dam’s spillways or turbines is too dangerous to risk losing wild fish.

Both wild and hatchery fish are then tagged with an inch-long plastic tag inserted with a needle gun. The tags help researchers follow fish movements and survival based on temperature, flow and migration dates.

All the human handling at Minto isn’t ideal for fish survival — and likely contributes to death before spawning.

“There’s stress at every point,” Grenbemer said. “We need to be less hands-on.”

In three years, the state hopes to open a new collection facility with a fish ladder stretching 600 feet up and over Highway 22. Instead of cages and elevators, a series of water-filled tubes will direct fish so they’ll never have to leave the water or be touched except for collecting fish for brood stock or to get tagged if the practice continues. It will cost $25 million to $30 million.

For now, though, this tough female takes another elevator ride to where she’s scooped up by hatchery employees and loaded into a truck with other wild fish before getting released into a deep pool in the middle of the Little North Fork River.

In a few months she’ll carve out a nest in a gravel bed, lay her eggs and die. Her body will provide nutrients to the stream that will soon support her brood.

“To see the adults come back, it puts closure to that year’s hard work,” said Greg Grenbemer. “We know we’re going to have another generation.”

Hope for the future

Environmentalists and state officials are cautiously optimistic about plans in place to save the wild spring Chinook.

“The bi-op (biological opinion) drastically improves the trend that has happened over the last 50 years,” said Travis Williams, executive director of Willamette Riverkeeper, which sued the federal government to release the biological opinion.

He doesn’t believe it’s the final solution for salmon on the Willamette, but he is confident wild Chinook will be in the river 20 years from now.

“The cup is 20 percent full,” he said, “It’s not 80 percent empty.”

At least one river advocate feels the efforts don’t go far enough.

“We’re looking at historically the most productive salmon and steelhead river in the whole Willamette Valley,” said fishing guide Bill Sanderson. “They’re not mitigating for that loss, and that’s heartbreaking to me.”

The plan sets too low a target for wild fish recovery, he said, and recommends rethinking hatchery practices, which could reduce hatchery fish numbers and fishing.

But if successful, the effort could restore thousands of wild Chinook to the North Santiam River, which at best has a mere 100 right now. Perhaps the efforts will bring back memories for people who witnessed salmon returning in droves.

Duane Wagner of Mehama used to swim with the fish below Mehama Bridge.

“You bet I miss the salmon runs,” the 80-year-old said. “It used to be you could line the banks of the river, and people were catching fish when the runs were on.” or (503) 589-5994 or or (503) 399-6735.


See this story at to read:

-Oregon’s Draft Upper Willamette River Conservation and Recovery Plan.

-Interim Temperatures Operation Study details impacts of water temperatures on fish and the effort to achieve historic temperatures below the dams.

-The Willamette Basin Biological Opinion is a legal document produced by the National Marine Fisheries Service that directs agencies on how to recover spring Chinook salmon in the Willamette Basin.

-Evaluation of Fish Passage Conditions for Juvenile Salmonoids Using Sensor Fish at Detroit Dam.

-The North Santiam Court Decree from the 1930s that granted the oldest water right (of 50 cubic feet per second) on the North Santiam to fish.

Statesman Journal
Salem, OR
January 11, 2010

This entry was posted in Environment, News and tagged , . Bookmark the permalink.