Dam Fixes, Barging Won’t Help, Biologist Says Expensive Measures Won’t Help Salmon, Steelhead Runs On Snake River, Says Expert

Scientific evidence strongly suggests gold-plating Snake River dams with expensive fish bypass projects or expanding the fleet of barges with the latest technology will not save dwindling salmon and steelhead runs, a state expert says.

Steve Pettit, a Lewiston-based Idaho Fish and Game Department fisheries staff biologist, points out that about 80 percent of the young fish migrating through the dams perish and a fifth of the larger, stronger adults returning to spawning streams are claimed by the four lower Snake River dams.

During a forum in Lewiston on Monday, Pettit said the role of the dams in the demise of the runs was long foreseen, and today all of the river’s salmon and steelhead runs are protected under the Endangered Species Act.

While the lower Snake River dams were being built in the 1960s, some biologists openly predicted the fish would last about 30 years, he said.

A comparison of the Snake’s salmon runs with those downstream in the Columbia River basin more clearly illustrates the dams’ effects, Pettit maintained.

The 2,000 or so fall chinook in the Snake are a shadow of the 60,000-fish run from the 1960s. Yet the fall chinook of the Columbia’s Hanford Reach, fish that must migrate across only four dams on the lower Columbia, have remained one of the brightest successes in the Northwest, he said.

“They have to go through the same gauntlet of pinnipeds or sea lions and seals, squawfish and birds that the Snake River fish have to go through,” Pettit said.

A comparison of spring chinook from the Snake and the John Day River downstream along the Columbia proves the point again, Pettit said.

The Snake runs are struggling while the John Day’s remain strong.

“It looks to me like those stocks with two, or only one dam to cross are much healthier and doing much better than our stocks,” Pettit said.

Even with better barging methods, experts predict returns would barely top 1 percent, he said.

The biggest detractions to barging range from greater exposure to bacterial kidney disease among the fish when they are packed into barges together to the overall cumulative stress the fish face in handling, Pettit said.