After recently reading an Alaska Dispatch News headline with a preposterous claim, "Manager says increasingly expensive Susitna dam could help salmon," (Dec. 18) I must protest with due respect. As a freshwater ecologist who has worked on salmon rivers for 40 years, I want to make it clear: Without question, a dam the size of Susitna-Watana will kill the Susitna as a salmon river.
The Alaska Energy Authority vastly oversimplifies the impacts of this megadam on Alaska's fourth-largest king salmon river by stating that sediment trapped in the reservoir behind the dam would improve water clarity and food resources for fish. Perhaps the statement is based on dammed Lower 48 rivers, where hydroelectric dams often cool water and reduce sediment discharge, allowing trout food to proliferate in previously warmer, more turbid rivers where trout were never native. But in the case of northern rivers like the Susitna, wild salmon are adapted to and depend on ecological interactions between seasonal flooding, sediment flux, streamside vegetation, cold temperatures, ice and a suite of other biophysical conditions. Development of the 735-foot-tall Susitna Dam would completely change -- and in many cases destroy -- these in-stream processes that Susitna salmon depend upon.
Hydroelectric operations like Susitna-Watana release water according to electricity demand, thereby eliminating natural river flow and temperature patterns. If built, the Susitna dam will decrease summer flows by more than half, and winter flows will vary by more than 400 pecent over the course of just one day. Rather than freezing over downstream of the dam, anchor ice will form under water. When anchor ice jams, it will scour the river bottom and the floodplain habitats that the juvenile salmon depend upon. High, clear water flows in winter will degrade the river bottom and disconnect channel environments essential for salmon spawning and rearing.
Flows regulated by hydropower dams always vastly reduce salmon productivity because they destroy natural patterns salmon require. Salmon cannot hatch and grow to properly time their out-migration to sea or their return to natal habitats to spawn. The proposed dam cannot improve conditions but, conversely, will very negatively impact native Susitna salmon. Moreover, keep in mind that the reservoir will trap vast quantities of sediments, filling the reservoir basin sooner than later in this case, shortening the life of hydropower production.
The truth is that Susitna salmon are uniquely adapted to and thrive in a cold, sediment laden river fed by glaciers. AEA completely misses -- or more likely purposefully ignores -- the essential point that removing the conditions to which the salmon are adapted has no other outcome than vastly reducing or eliminating salmon runs.
AEA's claim that a dam can improve salmon runs simply and blatantly fails the test of common sense. One need look no further than the Lower 48, where salmon are at just 7 percent of their historic abundance. In the Columbia River alone -- formerly the world's largest king salmon producer -- more than half of salmon habitat was eliminated by dam construction. Despite our best efforts and billions of dollars, we have failed to engineer or mitigate development projects to produce more than a small fraction of pre-dam salmon numbers. Now 80 percent of the salmon returning to the Columbia basin are spawned and reared in hatcheries, a process that is not only extremely expensive but is very harmful to wild salmon. And to add insult to injury, nearly all Columbia River salmon are trapped during their migration to sea so they can be transported around dams by barge or truck. Due to dams and other development, remaining Lower 48 salmon depend on factory-like production in aquatic zoos and "swim" to the ocean in trucks. Do we want that kind of salmon management in Alaska?
Indeed, Alaska remains home to some of the last, best, free-flowing, wild salmon-sustaining rivers in the world. Wild king salmon are declining all around the Pacific Rim, owing to fishing pressure, climate warming and changing ocean conditions, among other anthropogenic influences. The point is simply that we must preserve systems like the Susitna where king salmon still thrive.
Alaska has a reputation for stellar salmon management, and the Susitna is one of the success stories. So rather than wrongfully claiming that man can improve on nature -- as we've unsuccessfully tried time and again with Lower 48 salmon rivers -- it will cost nothing to just leave the Susitna alone. Here's hoping the state's new leadership can see through the lies purported by AEA and abandon this project in the name of common sense, if not simply for the preservation of uniquely adapted wild Alaska salmon.
Jack Stanford, Ph.D., is the Jessie M. Bierman Professor of Ecology at the Flathead Lake Biological Station of The University of Montana. He has worked for much of his career on salmon rivers impacted by dams.
The views expressed here are the writer's own and are not necessarily endorsed by Alaska Dispatch News, which welcomes a broad range of viewpoints. To submit a piece for consideration, email commentary(at)alaskadispatch.com.