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If Dams Don't Kill Them, What Does? by Tracy Warner Wenatchee World, June 12, 2012

You spend a lot for salmon, or perhaps we should say, your investment is great. If you live in the Northwest and use electricity, which is most of us, the bill came to $644 million in 2012 alone, according to the Northwest Power Planning and Conservation Council. That is what the Bonneville Power Administration paid for "fish and wildlife enhancement," almost all for salmon. That is nearly a third of what BPA charges utilities for power from federal dams.

That's just one year. The bill comes to $13.1 billion since 1978, which makes the effort to resuscitate the Columbia's suffering salmon runs "the world's most expensive effort in ecological management and restoration," wrote Ray Hilborn, University of Washington fisheries biologist, in an April commentary in the Proceedings of the National Academy of Sciences. I first saw it linked in a commentary by Bill Rudolph of Northwest Fishletter.

Several millions of that massive spending helped scientists devise sophisticated salmon tracking systems that, ironically, make you ask how much of this investment is worth it. Now they can see where young salmon go, count how many survive, and get a general idea where they meet their fate. The results can let heretical thoughts seep in to once cooperative minds, and bring widely held beliefs into question. Spending hundreds of millions more to improve salmon passage at dams and improve the lot of young salmon in fresh water, may be less beneficial than we hope. That's because the biggest problem isn't the dams. It's something else, still mysterious, out there in the deep blue of the North Pacific.

Hilborn made the point that in the last century mankind has made a mess of what were the greatest salmon runs on earth. Industrial harvest, impassable dams like Grand Coulee, the destruction of spawning habitat, and much more brought Columbia chinook salmon runs to 10 percent of historical levels by 1960. Further declines in returning adults came in the 1960s and 1970s, coinciding with construction of the Snake River dams. Now billions have been spent to improve salmon passage, and still fewer salmon from the Snake River survive, compared with their downstream brethren, said Hilborn. The assumption was, blame the dams. They kill salmon migrating downstream, and cause such stress that the salmon lucky enough to survive to the ocean soon succumb.

Then came the trackers, with acoustic tags in the fish and sensors at sea. First, scientists at Kintama Research of Nanaimo, B.C., compared the downstream survival of Snake River salmon, passing many dams, to salmon in British Columbia's Fraser River, passing no dams. They came out about the same. Dams apparently made no difference. Then, in results released this April, scientists compared the survival of hatchery fish released far up the Snake, passing the dreaded Snake River dams, with hatchery smolts from the Yakima, passing few dams. Their survival in the lower Columbia and 300 miles out to sea was compared, and again, came out about the same.

The researchers said the common assumption that the stress of passing the Snake River dams leads to "delayed mortality" of salmon at sea is questionable. That in turn leads to them to ask whether large investments in the rivers, for small effect, are enough to overcome the large and still unknown calamities of life in the sea. Spending $1 billion to breach the Snake River dams and giving up enough hydropower to light Seattle may be money wasted.

There are still disputes and questions. The tags don't track all salmon. Some might wander away from the detectors. There's still a lot to learn. "Those arguing that dams are the major problem with Snake River chinook salmon will remain unconvinced by this study," wrote Hilborn. ... "Overall, chinook salmon are doing poorly throughout their range, from the Yukon River to the Sacramento. Although here are more salmon in the ocean now than any time in the past, the boom in salmon has been in pink, chum and sockeye, while the freshwater river-rearing coho and chinook have declined. It may be that with current ocean conditions many stocks of chinook salmon cannot survive ..."