Of course no one believes that pushing salmon smolts through a turbine is helping them. But as billions of dollars generated by the dams are invested in structural improvements, fish production, habitat improvements, and control of natural predators, the possibility emerges that all these efforts have generated a river system that, on balance, is more survivable for fish than a natural river system.
Last week, Northwest Fishletter obtained an internal memorandum from the National Marine Fisheries Service summarizing recent studies addressing that question. The memorandum presents estimates of smolt survival in the Columbia and Snake Rivers as compared with the unregulated, unimpounded Fraser River in British Columbia, and the regulated but unimpounded Sacramento River in California.
So on first appearances, survival down the
One can certainly quibble
with the details. The measurements for
the other rivers are taken further downstream.
Predator densities are highest below Bonneville Dam, so the Columbia and
Snake River numbers above need a downward adjustment—perhaps 10% more mortality,
perhaps more. The
A more exact analysis could easily show adverse effects from the dams, as compared to a more natural, dam-free river, but those effects would be small, and probably not enough to make much difference at all to adult returns. Here is a recent graph of the relationship between downstream steelhead survival and adult returns:
Juvenile survival through the
The NMFS memo is careful to say that the data from other
rivers are “preliminary” and “it is not appropriate to imply their meaning
regarding policy issues at this time”. But
one wonders when it will be time for Northwesterners
to wake up and realize that the massive and continuing campaign against the
dams is based on very significant misrepresentations. Powerful interests (investor-owned utilities)
have earned hundreds of millions of dollars annually from reducing power
production at the publicly-owned dams on the
Pretending that the dams are killing most of the fish (rather than Mother Nature) saddles us all with billions in increased electric rates, and funnels millions of tons of additional carbon dioxide into the atmosphere annually. Even if fish advocates don’t care about that, they ought to be wondering whether all this focus on dams distracts sportsfishing interests from what is really needed: sensible harvest and hatchery management. Why on earth do we take money from every taxpayer to release hatchery fish that aren’t fin-clipped, so only the Tribes can keep them? Why does a small Northwest minority with rights to “fish in common with all citizens” get to take the vast majority of salmon and steelhead out of the river? Why do sportsfishing interests get thrown off the river with paltry allocations while gillnets continue to decimate salmon and steelhead runs? In large part, it is because sportsfishing interests are distracted with constant fraudulent attacks on dams and landowners that have no reasonable prospect of putting more fish in the river to catch.
© James Buchal, November 7, 2007
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