To save the salmon, scientists will have to choose between the biologically questionable solution of barging the endangered fish up the river and the once-unthinkable idea of removing still operable dams.
A new report says the eight hydroelectric dams between Idaho and the Pacific are the greatest reason the fish are dying off. And if the fish are to survive, the river corridor has to be fixed, scientists say, and there are two ways to do it.Collect juvenile salmon at the Snake River dams and move them via barge and truck to the estuary below Bonneville Dam or breach one or more of the dams on the Snake and Columbia to allow longer stretches of the river to run naturally. That removes from the debate the seasonal river drawdowns that were once the cornerstone of Idaho's salmon recovery proposals.
Steelhead fishing brings $90 million into Idaho's economy.
Scientists remain sharply divided over whether barging really helps the fish. Supporters have long argued poor conditions in the ocean mask its effectiveness. But the new report, by scientists from environmental agencies and universities in the Pacific Northwest, says that hypothesis has not been proven.
"The hydroelectric system is the key problem, barging hasn't fixed it and obviously something else has to be done," said Ed Bowles, Idaho Department of Fish and Game's salmon and steelhead coordinator.
Another study appears to show that wild chinook salmon may benefit from barging.
The other option, breaching three or four dams on the lower Snake River in Washington, should allow 50 to 70 percent of migrating salmon to survive, the report says, but the scientists do not know whether that would be enough to recover the seriously depressed populations.
"That analysis has not been done," said Al Georgi, a fisheries consultant from Redmond, Wash., who is on the technical team that wrote the report.