Role Reversal on the Colorado

What is good for the humpback chub? If you have to ask, you won't comprehend the answer, which is this: It is good not because it is beautiful, not because it is interesting, not because it reaches 18 inches and is every bit as exciting to catch on a dry fly or nymph as any trout, not because it is anything, only because it is. And it needs to be saved because, to borrow the words of naturalist/explorer William Beebe, "when the last individual of a race of living things breathes no more, another heaven and another earth must pass before such a one can be again." The framers of the Endangered Species Act understood this.

So do Gunn and Foster, despite their grave reservations about the current experiment. Both stress that they want to see humpback chubs do well. And both have it right when they say that trout should not get all or even most of the blame for the chub's predicament. But trout are one of the few things adaptive managers can do something about.

Everyone who loves the wild, self-sustaining trout of the Colorado had better hope that the current experiment works. If it doesn't, the next experiment the Interior Dept. is almost sure to try is warming the river by releasing water from higher up on the dam. This could, as Walters puts it, "unleash vampires from the basement," bringing more alien predators such as stripers, largemouths, brown trout and channel cats up from Lake Mead and the lower river. On the other hand, the enormous amount of restored habitat in the main river might bring on an explosion of humpbacks sufficient to overwhelm the increased predation.

The vampire that frightens Walters most is the brown trout. "They wouldn't just eat chubs," he says. "Right now the brown population is small and mostly restricted to Bright Angel Creek. We think that the reason browns haven't been able to spread out very far is that the water's too cold. If they move up to Lees Ferry, they're going to eat the rainbows and ruin the fishing. And the brown-trout fishery would never replace it. Big rivers and brown trout fishing don't go together very well."

That doesn't mean that Walters—or anyone else with an ecological conscience—will fight temperature control on the Colorado if it really has to come to that. It means only that the current rainbow fishery is a nationally important mitigation resource that should be retained if it doesn't mean sacrificing the humpback chub.

Much of the environmental community doesn't agree. It is pushing hard for temperature control right now. The Grand Canyon Trust—which has announced that it will sue the Fish and Wildlife Service over a humpback recovery goal that's "a feel-good fairy tale based not on sound science, but political expediency and the desires of powerful special interests"--proclaims that "the Colorado River must be warmed in order to improve recruitment of the humpback chub." Eight other groups, including the frenetically litigious Center for Biological Diversity, have sent a letter to BuRec charging that one of the goals of its strategic plan—maintaining naturally reproducing rainbows around Lees Ferry "to the extent practicable and consistent with the maintenance of viable populations of native fish"—is not supported by law, contrary to the needs of native fish, and should be eliminated. Maybe they're right.

But maybe the adaptive managers will prove that humpbacks can be saved just with flow fluctuations and localized trout removal. And maybe the Lees Ferry reach will again produce big rainbows. Meanwhile, sportsmen need to support the professionals they've trained and hired with their tax and license dollars, forget everything their grandfathers taught them about "trash fish," and remember how they reacted most everywhere else—where the natives harmed by aliens are trout.