No dam(n) difference?

Dams are bad for salmon. That's been the conclusion of thousands of biologists, environmentalists and fishermen after years of watching rapidly declining salmon runs on the Northwest's dammed rivers. We've written many stories about the topic (here are a few: Salmon Justice, Another chance emerges for salmon, Fishermen blamed for salmon troubles, Dams will stand - salmon be damned,  The latest salmon plan heads for a train wreck, Salmon plan grows a few teeth).

Now, a controversial new study claims that salmon on an undammed river in British Columbia survive the downstream journey at rates roughly comparable to those for salmon on the Snake and Columbia rivers. The Seattle Times reports:

... a number of scientists — including several co-authors of the study — are questioning the results and cautioning about what conclusions can really be drawn. There have even been charges that it's little more than a promotion for fish-tracking technology in which the lead author has a financial stake.

"There's a huge mass of scientific literature that documents the impacts of dams. It's just huge," said Michele DeHart, manager of the Fish Passage Center, a government-funded agency that tracks and studies Columbia River fish. "It's like saying, 'Gosh, I just did this comparison and smoking does not cause cancer.' Would you change your mind?"

The answer to DeHart's question is No, of course -- but with a caveat. Maybe the study does indicate that dams aren't quite as bad for fish as they used to be, says the Oregonian's editorial board:

It's considered bad form in the Northwest salmon debate to say anything positive about the Bonneville Power Administration and the Army Corps of Engineers, but it does appear that the fish-friendly improvements at their dams have helped counter the harm of the power-generation structures. It also appears that efforts to control squawfish and other predators in the Columbia system, which isn't done on the Fraser, might be helping the salmon.

No doubt irrigators and hydropower operators will seize on the study. But the research says nothing about how salmon fare when returning upstream to spawn in dammed vs. undammed rivers -- and those numbers are much more telling.