Salmon's Recovery Makes Dam-Busting Unnecessary
Northwest Salmon Numbers Seemingly Have More To Do With Ocean Currents Than The Now Fish-Friendly Dam And Turbine Operations
August 13, 1999
by Dennis T. Avery
CHURCHVILLE, Va.--There's a strong run of chinook salmon this year in the Columbia River, which snakes along the border of Oregon and Washington. That's good news.
The better news is that the rising salmon numbers are probably the beginning of an upward cycle in Pacific Northwest salmon that will continue for at least 20 years.
The salmon recovery is arriving in the nick of time to save at least several of the dams that provide irrigation water to millions of acres of prime farmland in the Snake and Columbia River valleys.
Without irrigation, much of the region's cropland would be unable to produce anything worth harvesting. With it, the climate and soils are perfect for growing potatoes.
The region's average potato yield is five times as high as those of India, six times those of China. Much of Asia is already importing potato products from the region, easing the pressure on Asia's own endangered wildlands.
For decades, however, environmental activists in the United States have raged about the dams that allegedly threaten the salmon in the Snake and Columbia Rivers.
They have waged an all-out campaign to declare the salmon an endangered species, breach the dams and "save" the salmon in Washington, Oregon and Idaho.
Fortunately, researchers are now documenting evidence that suggests the big factor governing the Pacific Northwest salmon population may not be the dams at all.
The number of salmon at any time may depend on a 25-year cycle in Pacific Ocean currents, including that of the California current, which runs south from Oregon to Baja California.
For years, dams, overfishing and logging have influenced the freshwater portion of the salmon's life cycle.
It seemed natural for policy-makers to assume that human activity was suppressing the salmon. This decade, however, fish and climate researchers have traced an ancient pattern of ocean and climate shunting the Pacific's eastward currents toward the Washington-Oregon coast.
When the current of cold water is aimed at Washington and Oregon, the salmon from the Pacific Northwest rivers find plenty of plankton to eat in the ocean--and their numbers increase.
When the current is aimed at Alaska, the Pacific Northwest may support only one-third as many salmon, while Alaska fishermen enjoy record salmon catches.
Making the shift even more dramatic, the warm water years that starve the Northwest's young salmon also bring the region dry weather and low river flows. This means more of these salmon smolts are caught by predators.
Matching fish catches with weather patterns back to 1900 shows that from the turn of the century until the mid-1920s, sea temperatures were low and Pacific Northwest salmon were abundant.
The cycle shifted in the mid-1920s, with high sea temperatures and low salmon numbers. The next cycle, with salmon abundant, ran from the mid- 1940s to 1976.
Since 1977, the Northwest's salmon have had little food and low river levels, while Alaska has harvested record numbers of the fish.
James Anderson of the Fisheries Institute at the University of Washington says salmon-friendly dam and turbine operations have helped raise salmon survival rates to 40 percent in the Columbia. But until very recently, salmon numbers stayed low and eco-activists blamed the dams.
Anderson says that the favorable plankton supply in the Pacific Ocean masked the negative impact of dams and turbines on salmon in the 1960s, then hid the favorable impacts of salmon recovery efforts after 1977.
Victor Kacynski, an Oregon fish consultant, says the amount of plankton in the California current in the 1990s was at least 75 percent lower than it was in the early 1970s.
Kacynski was the first to talk publicly about the current ocean pattern. He has been joined by experts like Nathan Mantua of the University of Washington and John McGowan of the Scripps Institution of Oceanography.
Now that the salmon numbers are returning in the Columbia River, perhaps the environmental movement will applaud the success of its salmon recovery measures and the additional knowledge science has gained on the salmon ecosystem.
Maybe now the eco-activists will drop their campaign to breach the dams, freeing the region's high-yield farmers to help supply the world's rising food demand.
Breaching the dams when the salmon numbers are rising would do little for the salmon of the Pacific Northwest. It would offer the environmental movement nothing but a staged demonstration of its political clout.
But it could destroy the livelihoods of Northwest farmers who employ irrigation. And, thinking globally, a shortage of U.S. food exports could force Asia to plow down the very wildlands that eco-activists say they want to preserve.
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Dennis T. Avery is based in Churchville, VA, and is director of the Hudson Institute's Center for Global Food Issues.