By Chris Hunter, The New York Times, September 3, 2015
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| Pallid sturgeon |
HELENA, Mont. — FROM an evolutionary perspective, the pallid sturgeon is a thing of beauty.
Its eyes are a bit beady, it’s true, but good vision is not a prerequisite for living on the bottom of the Missouri River. And its toothless mouth, with its protruding, whiskerlike barbels, is creepy. But these barbels are perfect for sensing food, which it sucks in like a vacuum cleaner.
No, these fish are not sleek and beautiful like trout. But this species of sturgeon, which can grow to a length of six feet and weigh as much as 80 pounds, has managed to survive since the time of the dinosaurs, with fossils dating back some 70 million years.
For all of the adaptations that have enabled this fish to have such a long run, however, the pallid sturgeon is in serious trouble. Twenty-five years ago, the federal government concluded the fish was in imminent danger of extinction and placed it on the endangered species list, where it remains today.
Despite government efforts to expand the population, only perhaps 200 or fewer wild-born pallid sturgeons are thought to inhabit one of its last strongholds — the Montana stretches of the Missouri and Yellowstone Rivers.
And now, paradoxically, a federal agency, the Army Corps of Engineers, is pursuing a project that threatens this population, perhaps the most genetically robust of the groups still surviving in the Missouri and Mississippi Rivers. These fish in the upper Missouri River basin can live upward of 50 years, but they are old and their chances of reproducing are diminishing.
Dams along the Missouri River have contributed to the sturgeon’s undoing, blocking spawning runs and altering hundreds of miles of river habitat in ways that have been harmful not only to the pallid sturgeon but also to other species, like the least tern and piping plover. Fifty-one of the river’s 67 native fish species are now rare, uncommon or decreasing, according to the government.
The mostly free-flowing Yellowstone River, which converges with the Missouri River near the border of Montana and North Dakota, offers the most cost-effective chance in the region for pallid sturgeon recovery. But the Intake Dam, an irrigation diversion impoundment on the Yellowstone, is a major obstacle for fish attempting to swim upstream to spawn.
The dam, in operation since the early 1900s, is a collection of boulders that straddle the river and cause it to rise so water can flow into an irrigation ditch that sustains tens of thousands of acres of sugar beets and other crops. On occasion, when the water is high enough, sturgeon have been able to make it around the dam by swimming up a naturally occurring side channel to reach the spawning habitat on the lower Yellowstone and tributaries like the Powder River. Last year, only five pallid sturgeon were known to have made it up the natural bypass. One of them, a tagged female, was later recaptured and it was determined that she had spawned.
Now the corps wants to spend some $60 million to build a concrete dam to upgrade the existing rock weir. The dam will block the river entirely, as well as the natural channel sturgeon have used in the past. In its place, the corps proposes to build a canal around the concrete dam as a bypass for the fish. Many biologists who have studied the pallid sturgeon believe these fish are unlikely to use this bypass. But the dam will, according to the corps, continue to provide water for irrigation.
The corps is seeking to move forward with construction. Two environmental groups, Defenders of Wildlife and the Natural Resources Defense Council, have asked a federal judge for an injunction blocking construction of this new dam.
The corps should return to the drawing board. Otherwise, this remnant wild population, whose ancestors were around when dinosaurs walked the landscape, is doomed.
Chris Hunter is the former chief of fisheries for the Montana Department of Fish, Wildlife and Parks.
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