For Pacific Salmon, a River of Uncertaintyby William K. Stevens
New York Times - October 5, 1999
Lower Granite Dam, Washington -- The big hydroelectric dam sits deep in a valley framed by softly rounded, grass-covered mountains that look from a distance as if they have been sanded down and then covered with beige and blond velvet. Great expanses of sun-dappled blue water, more reservoir or lake than river, stretch above and below the concrete-and-earth barrier. That is part of the problem.
The once fast-flowing Snake River is now so slow, and Lower Granite Dam so much of an impediment, that salmon -- totem fish of the Pacific Northwest and the focus of a landmark political, economic and environmental struggle -- cannot migrate up and down the Snake without the help of an elaborate man-made Rube Goldberg-like system.
So it was on a recent day as a state fisheries biologist, Fred Mensik, plucked a silvery, six-inch fish from water speeding through a trough.
"Chinook," Mensik said, identifying it as a member of the heftiest of the salmon species. If it lives long enough, the juvenile smolt, as it is called, could grow to 3 or 4 feet and 40 pounds or more. Mensik measured the fish, entered the information into a laptop computer and returned the fish to the trough, where it joined other smolts and migrating young steelhead (sea-run rainbow trout) on their way to a tank truck parked outside.
The truck would transport the juvenile fish nearly 250 miles downriver, past seven other dams in the Columbia River system, of which the Snake is a part. There the fish were released to resume a trip to the Pacific Ocean.
While Mensik and his co-workers were shepherding the fish downstream, adult salmon and steelhead -- big, powerful veterans of years at sea -- were climbing a fish ladder a few feet away, heading upstream to spawn and die. But there are so few going upstream that all these fish, along with all other salmon and steelhead that spawn in the Snake River, are listed as imperiled under the Endangered Species Act.
Will the elaborate, two-decade-old system for moving fish around the dams prove inadequate to save the salmon? The question is at the heart of a tense debate over whether to continue to rely on the transportation system or junk it and remove the earthen portions of Lower Granite and three other hydroelectric dams on the lower Snake.
Breaching those dams would help restore the natural flow along a 140-mile stretch of the river, and many scientists say it would be the single most effective remedy for the salmon's plight. The concrete portions of the dams, their humming turbines silenced, would become relics, abandoned monuments to a time when the only consideration was to conquer and harness nature, and to the dawn of an era in which coexisting with nature has been made a priority.
A decision on the dams, driven by a Federal lawsuit brought by environmentalists, is expected by early next year. If the Clinton Administration proposes breaching the dams, the issue would then go to Congress, which must appropriate the money.
Few if any conservation problems match this one for scale and complexity, or for its many connections with the modern economy. "The salmon involves our whole way of doing things," said Dr. Peter M. Kareiva, an ecologist who is directing a scientific assessment of the problem for the National Marine Fisheries Service. "There is no simple, easily defined enemy."
Many scientists and environmentalists say the question of whether to breach the dams is a no-brainer. They argue that the population of the Snake River salmon began to decline after the dams were built in the 1960's and 1970's, and that while the system for trucking and barging fish downstream and helping adults back up may have helped, it is inadequate.
"Prior to completion of the lower Snake River dams, Snake River stocks did as well or better than their downriver counterparts," said Ed Bowles, a scientist who is the salmon and steelhead recovery manager for the state of Idaho, which contains the Snake's watershed upstream of the four dams. "Since completion of the dams, we have every year done much worse."
But other scientists, particularly those of the marine fisheries service, say the situation is more complicated. The service's studies, which are being reviewed by an independent panel, suggest that while breaching the dams may be necessary to save some salmon stocks, it will not be enough. The wild salmon population has also been hurt by the destruction and degradation of spawning areas, overfishing and the introduction of hatchery-bred salmon and trout, according to the analysis. (Only about 20 percent of Snake River salmon today are the progeny of wild fish.)
Unless these problems are resolved, the analysis suggested, the wild salmon and trout will probably continue to decline, even if the dams are breached.
Breaching "is not going to be a silver bullet," said Dr. Michelle McClure, a biologist with the fisheries service who is helping to conduct the Federal analysis.
Moreover, said the fisheries service, which will draft the scientific opinion on which the decision about the dams will be based, the latest evidence suggests that trucking and barging young fish is more effective than was previously thought.
Whether that is true should become clear in 5 or 10 years, scientists with the fisheries service said.
One option, they said, would be to wait.
But other experts, including Bowles, said the answer was as apparent now as it would ever be. The fisheries service said any delay would increase the likelihood that some stocks of Snake River salmon would become extinct.
Pacific salmon are different from Atlantic salmon in that there are several species, and that different populations spawn at different times. Moreover, they spawn only once and then die (Atlantic salmon, and steelhead, can return to the ocean and spawn again, several times).
Conservation efforts have focused not so much on entire species of Pacific salmon as on specific stocks, a group of fish that spawn in the same locality, like a specific creek.
Individual stocks are important because each diverges genetically from other stocks as they reproduce. Such divergence is the touchstone of evolutionary adaptation, and so individual stocks are protected by the Endangered Species Act.
For many stocks of Snake River salmon, the marine fisheries service has found that the risk of extinction is considerable, sometimes even in the short term. For instance, surveys of a chinook stock that spawns in a spring in Marsh Creek, a beautiful alpine meadow stream in the Frank Church Wilderness of Idaho, found no spawners last spring or in the spring of 1995.
The studies by the fisheries service indicated that the Marsh Creek salmon had at least a 1-in-10 chance of virtual extinction (only one spawner a year) in the next decade, and that many stocks of chinook that spawned in the spring and summer had a 1-in-2 chance of extinction in the next century. The risk that all Snake River runs of spring and summer chinook will be extinct in 100 years was calculated at about 50 percent.
Other runs of chinook spawn in the fall, and their risk of extinction in the next century was calculated at 27 percent; for steelhead, even though their numbers are relatively robust, the risk was 93 percent. A fourth species, the Snake River sockeye salmon, is already close to extinction: only seven returned to their Idaho spawning grounds this year.
The Columbia-Snake system was once one of the most fecund salmon producers in the world, with the Snake drainage giving birth to about half of all salmon in that system.
But the dams, overfishing, destruction of spawning areas and the competition with hatchery fish cut severely into their numbers. Generally, the depletion has been worse the farther south one goes; salmon are not imperiled in Alaska, for example.
Some Columbia basin populations, ones whose passage was completely blocked by dams, have long since become extinct.
But on other stretches, like the lower Snake, the Army Corps of Engineers has engaged in a long, expensive effort to make the passage as easy as possible so that more fish will survive. The result has been the substitution, at a cost of more than $3 billion, of an artificial system for the natural one.
At Lower Granite Dam, for instance, juvenile fish coming downstream are diverted into an elaborate bypass system and then into either tank trucks or barges.
Most of the juvenile fish are alive when released below Bonneville Dam on the Columbia River, but an argument rages about whether many of them later die from the stress of transportation. Proponents of breaching the Snake dams argue that fish hatched below the dams show higher survival rates than do those hatched above and transported downstream.
But the fisheries service said new studies involving fish tracked with tiny radio transmitters suggested that there was no significant increase in mortality associated with barging and trucking. Other scientists counter that the sample is too small to draw conclusions.
And some environmentalists and scientists said that barging and trucking did nothing for adult fish, some of which fail to find the entrances to fish ladders or are too exhausted to spawn once they run the gantlet of the dams.
What is the bottom line?
The Federal computer simulations show that breaching the dams would increase the growth of spring and summer chinook by about 5 percent. But, Dr. McClure said, a 12 percent improvement would be necessary to avoid extinction.
If policy makers want to eliminate as much risk as possible, then dam breaching should be pursued along with other actions like a moratorium on fishing and improvements in other areas, such as increasing the quality of habitat, the fisheries service said.
Alternatively, the service said, policy makers might want to accept the possible extinction of the Marsh Creek stock and explore whether alternatives to dam breaching might work. Even if the dams are removed -- which will also affect navigation, reduce a a source of cheap electricity and, some politicians say, ruin the region's economy -- the actual breaching will take six or seven years, the Corps of Engineers says.
For fall chinook, virtually everyone agrees, dam breaching would be a boon. That is because they spawn not in tributary streams but in the main branches of the Snake and the Columbia. With the dams and their reservoirs in place, most of the water is too deep for spawning.
But by breaching the four lower Snake dams, the habitat for fall chinook would increase nearly 80 percent.
On the other hand, Dr. Kareiva said, it may be that fall chinook and steelhead could be rescued by some means short of dam breaching, like stricter curbs on fishing.
A group of Federal agencies, including the fisheries service and Corps of Engineers, is developing options for salmon recovery that would take into account a range of threats to the salmon life cycle. The agencies' reports are due by the end of the year, after which there will be public hearings. The agencies hope to settle on a recommendation by next spring.
Then the fate of the salmon will move more squarely into the realm of politics and economics.
In the end, the decision will probably boil down to how important Americans think it is to save the salmon.
New York Times Discussion Forum
Returning River to Salmon, Man to the Drawing Board, New York Times, 9/26/99
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