Scientists Tackle Salmon Scienceby N.S. Nokkentved
Times-News, April 21, 2000
MOSCOW -- The only thing that's clear about the issue of the recovery of endangered salmon is that there is no clear solution -- only difficult choices.
Scientists now agree that most salmon survive the trip down the river, either through the dams or around them in barges, though the reservoirs behind the four dams have changed the amount of time it takes them.
What they don't agree on is why so few endangered salmon in the Snake and the Columbia rivers don't come back to reproduce.
Several of the region's top fisheries scientists discussed the complexities of salmon science and salmon recovery Thursday at a two-day writing workshop at the University of Idaho.
One side argues that the stress of handling, transportation and the rigors of the dams makes the fish more vulnerable to the predators and ocean conditions that ultimately kill them -- it's a concept known as delayed mortality.
The other side maintains that delayed mortality is not related to the dams at all, but is the result of conditions in the ocean. Salmon numbers have continued to decline despite increased hatchery production and the increasing capture and transportation of young migrating salmon around federal dams in the lower Snake and Columbia rivers.
Scientists showed a variety of graphs that show declining numbers of fish along with seeming correlations of other conditions, such as dam constructions, river flows and ocean and weather conditions. But seeming correlation doesn't necessarily mean a cause and effect relationship, warned Ted Bjornn, University of Idaho fisheries research scientist and a member of the National Marine Fisheries Service salmon recovery team.
Charlie Petrosky, of the Idaho Department of Fish and Game, noted that since four federal dams on the lower Snake River were built, Snake River salmon returns have declined more than those of other salmon in rivers with fewer dams. In dry years, the difference is more marked.
The difference is that Snake River salmon have to pass four more dams, Petrosky said. His data suggested that if the problem is in the ocean, the Snake River salmon are more sensitive to those conditions -- and that's not likely. More likely the cause is the four dams, he said.
The same tags, inserted into some salmon, that show most salmon survive the trip down the river, also seem to show that more untagged fish are returning from the ocean. And that seems to suggest that fish that are handled to be loaded into transport barges may survive the trip downriver, but they may be less likely to survive in the ocean.
Jim Anderson, University of Washington fisheries biologist, said that sometimes the Snake River fish do better than the downriver fish. He supported a more regional look, rather than comparing specific fish runs in specific rivers. But he acknowledged that he did not have a good answer for the difference.
The recent decline of salmon numbers, however, correlates not only with dam construction, Anderson said, but also with a period of weather patterns less favorable to fish survival. He noted that natural fluctuations in weather patterns and the effects of human activities -- including hydroelectric dams, logging, agriculture and other increasing land uses -- have combined to reduce the survival of salmon. It's a combination he calls "the ratchet of extinction."
He noted, however, that many conclusions held today are based on data that in some cases is 10 years old. Numbers from 1997 are better that in past years and may signal a change. And that may give the region a little more breathing room as it struggles with the question of how best to recover the endangered fish.
Ted Koch, president of the Idaho chapter of the American Fisheries Society, said the region can't afford to wait for something that might happen to maybe benefit the salmon.
Koch, an endangered species biologist who works for the U.S. Fish and Wildlife Service, agreed that scientists should listen to other theories and should be willing to change their minds when new data becomes available. But salmon managers can't wait forever with a decision in hope that new information comes in that will make a difficult decision easier.
Like Petrosky and most other northwest fisheries biologists, Koch thinks the best way to restore declining Snake River salmon is to take out the earthen portion of the four federal dams on the lower Snake River in southeastern Washington.
Christine Moffit, president of the American Fisheries Society and University of Idaho research scientist, said she is concerned that too much focus is placed on finding the solution to the salmon problems in the hydroelectric system on the Snake River, letting others off the hook. And that's exactly what got the Northwest into the situation it is in today.
Earlier this century, fish managers decided to build hatcheries and raise lots of fish rather than deal with the problems caused by overfishing, agriculture and logging, she said.
But it is that attitude of relying on a simple solution that needs to change before the salmon issue, and other natural resource issues like it, can be effectively solved, said James Lichatowich, fisheries scientist and consultant, and the author of the book "Salmon Without Rivers."
Lichatowich spoke at the university's Borah Symposium on Natural Resource Conflict in the 21st Century also going on at the university.
Like the end of the frontier a little more than 100 years ago, the time of abundance of natural resources -- the era of extraction of free wealth -- has come to an end. For 100 years, our society has stripped the ecosystem of its economically valuable resources -- clean water, trees, grass and fish, he said.
People once thought the bounty was the result of human management; meanwhile extraction was destroying the foundation of the ecosystem that produced those resources.
Unless that attitude changes, Lichatowich predicts more natural resource conflicts like the salmon issue. Society needs to reach a balance between natural and industrial economies.
"It has to start with honest discussion from our politicians about the choices we have to make," Lichatowich said.
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