A Wild Recovery The Imnaha River Serves as a Lab
by Joe Rojas-Burke
WALLOWA-WHITMAN NATIONAL FOREST -- The Imnaha River rushes cold and fast down a narrow pine-scented canyon, clattering hard over gravel and boulders. Fragrant ponderosa that tower at the water's edge are flanked by thickets of dogwood and fountains of blue-fruited elderberry. Deep pools eddy behind the fallen, sun-bleached skeletons of giant spruce.
And here, nearly 600 miles inland from the sea and high in the Wallowa Mountains, chinook salmon roil upon prime spawning grounds, having swum past eight hydroelectric dams on the Columbia and Snake rivers. Startled by the splashing approach of booted feet, the fish -- streaks of dark-freckled green and shimmering red -- shoot against the current like arrows released from a bow.
Wild and fecund as the place appears, it is, in fact, an intensively managed laboratory for one of the nation's most far-reaching attempts to manipulate nature. Answers gleaned from it will help decide whether technology, costing hundreds of millions of dollars, can help salmon return in abundance to the Imnaha and other Snake River tributaries -- or whether dams must be demolished to save wild salmon runs.
Rich Carmichael, a biologist with the Oregon Department of Fish and Wildlife, squats to examine the pale carcass of a spawned-out salmon. The fish measures nearly 31/2 feet long. Its hooked jaws display a striking set of fangs.
"Now that's a big old bruiser," says the director of the department's Northeast Oregon fisheries research program.
Like many of the returning chinook -- up to three quarters in some years -- it began life in a dish of artificially inseminated eggs. Human hands fed it pellets during its growth to yearling size in a concrete pool, marked it by clipping off a small back fin, and implanted a wire tag encoded with age and lineage information in its snout.
Hatchery fish represent a large piece of the government's attempt to make up for the damage to fish and other wildlife caused by four dams built between 1961 and 1975 on the lower Snake River.
The effort has been costly. Construction of 10 hatcheries cost more than $170 million, and more than $15 million a year pours into operations and monitoring under the Lower Snake River Compensation Plan, established in 1976 by Congress. The money comes from the Bonneville Power Administration, the federal agency that markets electricity generated by the dams.
Critics, including many conservation groups, call the spending a waste. They contend that the hatcheries are filling rivers with domesticated stocks that crowd out native fish, but which are themselves ill-suited to reproducing in the wild.
Supporters, including tribes with treaty rights to salmon, counter that hatchery production is a driving force contributing to the Columbia River Basin's current salmon returns -- the largest in decades.
"It's clear as a bell that we have improved salmon runs," says John Platt, an official with the Columbia River Inter-Tribal Fish Commission, which represents four tribes in Oregon and Washington with treaty rights to Columbia Basin salmon.
Whether hatchery "supplementation" can provide long-term benefits to natural populations remains unclear, according to many authorities.
"The results aren't very encouraging," says Charles Coutant, an ecologist with the Oak Ridge National Laboratory and a member of a scientific board that reviewed the impact of hatchery supplementation on wild salmon. The independent panel, convened by the Northwest Power and Conservation Council, concluded that population gains from hatchery releases are not likely to persist once supplementation stops.
Haunted by history Conservation groups say breaching the four Snake River dams is the most cost-effective way to help salmon recover. But for policy-makers -- and President Bush, who recently insisted the dams would not face breaching -- hatcheries present a more practical solution than demolishing an infrastructure that supplies reliable electric power and opens the river for barge transport of millions of tons of wheat, barley, paper and other cargo.
"People really want hatcheries to do everything," says Ian Fleming, a fish ecologist and assistant professor at Oregon State University. The only rigorously established role for hatcheries, he says, is producing fish for commercial harvest.
Hanging over hatcheries is a long history of well-intentioned plans that went badly awry. Consider the Oregon Department of Fisheries attempt in 1902 to restore sockeye salmon to the Wallowas. The sockeye salmon runs had been rich enough to support two canneries on the glacially carved shores of Wallowa Lake. The population crashed after decades of overfishing and losses of many thousands of young fish swept into irrigation ditches.
The department captured as many returning sockeye as possible, and planted millions of eggs and hatchery-reared fry. But the releases were more than 40 miles downstream from the lake habitat now known as crucial for the first year in the sockeye lifecycle. Survival probably came close to zero. By 1905, no adult sockeye reached the trap set across the Grande Ronde River. The attempt to rebuild the run instead had dealt a death blow.
Hatchery science improved greatly by the 1980s, when the Oregon Department of Fish and Wildlife, along with the Nez Perce and Umatilla tribes, launched efforts to rebuild chinook and steelhead runs in the Grande Ronde and Imnaha basins. The four dams on the lower Snake River wiped out 48 percent of the predam numbers of outmigrating young chinook and steelhead, the federal government estimated.
For the Grande Ronde, managers of the Looking Glass Fish Hatchery brought in two chinook stocks widely used by hatcheries: one derived from a mixture of Columbia River and Snake River fish, the other from an Idaho chinook run extirpated in the wild after the construction of Hells Canyon dam complex.
Problems soon arose with both stocks. Disease outbreaks forced managers to stop using the Idaho lineage, Carmichael said. Large numbers of the remaining hatchery stock began straying into some of the last remaining strongholds of wild-spawning chinook in the basin, the Minam and Lostine rivers.
"Well over 50 percent of the fish spawning in some years were hatchery fish," Carmichael says.
Authorities, including from the National Marine Fisheries Service, pronounced hatchery strays a serious threat to wild salmon. Studies in peer-reviewed journals revealed the hazards. Some hatchery stocks failed to reproduce as effectively as wild fish that were better adapted to localized stream conditions. Young hatchery fish, raised to larger-than-normal size and released by the millions into river systems, could outcompete smaller wild fish and cut down their numbers. A river apart The Imnaha River program stands in sharp contrast. From the beginning, managers recognized the uniqueness of the native chinook, which tended to grow larger than in other rivers and which return later in the season with a larger proportion of 5-year-olds, Carmichael said. The hatchery program begun in 1982 used only native, wild fish for its brood stock. Managers switched to native-derived stock for the Grande Ronde after the 1992 listings under the Endangered Species Act.
The state and tribal co-managers have tried to minimize all the known threats of artificial production.
They built an elaborate trapping facility, called a weir, to give them control over the number of hatchery fish that reach spawning grounds. A screen across the river diverts fish up a concrete chute and into a holding pen. A biologist measures each fish, records its sex, scans it for imbedded tags.
Some get routed back to the river through a giant pipe. Others get held back to provide eggs and sperm. Any remaining hatchery fish get released into two creeks downstream of the weir, where naturally spawning populations have nearly disappeared.
At Looking Glass Fish Hatchery, collection for breeding takes place inside a steel building that looks part machine shop, part aquarium, part hospital operating room. Workers wear waterproof bib overalls and rubber knee boots, which they scrub in a disinfectant bath before entering.
One nets chinook from a swimming-pool-sized blue fiberglass tank in which the fish relentlessly circle. A plunge in an anesthetic bath stills thrashing fins. Another worker hauls fish out by the tail and delivers a death blow with a fat-headed mallet. The fish is weighed, placed on a rack and bled.
A biologist swabs the fish with yellow-brown iodine, a sterilizing agent, then squeezes eggs out of the fish. A copious gush of pinkish red eggs spills into a bucket.
Mating is no longer the random mix of eggs and sperm from many fish in one bucket. Biologists match pairs of mothers and fathers in a calculated matrix that tries to include a spectrum of genetic traits, such as size and timing of return. Carmichael said a majority of the offspring now produced have at least one wild parent, and last year the proportion reached 80 percent.
To create more natural rearing conditions, Looking Glass cut the density of fish held in concrete raceways, in some cases, to one-fifth the capacity. Managers years ago began releasing yearling fish at a smaller size, which encourages behavior closer to that of wild-spawned fish.
"We're rewriting the book," says Bob Lund, manager of the Looking Glass hatchery.
Measuring success On the Imnaha, Carmichael hollers above the noisy river to a member of a team traversing on foot for an annual count of salmon egg nests, called redds.
"Check this out," he says. "This redd is just enormous."
A single female, using her powerful tail as a shovel, has built a 10-foot wide mound of gravel; some cobbles are fist-sized or even bigger.
Two years ago, researchers forecast that Imnaha River chinook, unable to withstand the impact of hydroelectric dams, were headed toward extinction by 2007.
Last year, Carmichael's team counted more than 1,100 chinook redds, the highest number in decades. The chinook are moving beyond customary spawning areas. Three-inch juveniles are easy to spot this time of year in the many blue-tinged side channels and pools formed behind logjams.
Researchers say it is very hard to discern how much credit the hatchery program deserves. Last year's return of 1,139 wild-spawned Imnaha chinook, though relatively strong, fell short of the wild run in 1982 when the hatchery program began.
And the recent upturns in salmon runs coincide with a shift in a poorly understood climate cycle in 1998. Strong, upwelling currents began enriching coastal waters with organic matter and dramatically boosting survival of young salmon entering the sea.
Meanwhile, no conclusive studies have compared hatchery-supplemented rivers such as the Imnaha with "control" streams that have not been supplied with hatchery fish.
"You don't know what the wild populations would have done if there hadn't been any supplementation," says Fleming, the Oregon State ecologist.
Carmichael said he is confident the state and tribes have taken the right steps in the Imnaha River to minimize the threats of hatchery releases to wild fish. But he is also keenly aware of the mistakes of the past and heedful of the uncertainty of current science.
"It will be another 10 or 20 years before we have solid answers about whether we can use hatcheries to enhance natural production," he says.
"We are so early in the learning process, it would be foolish to conclude one way or another."
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