As smallmouth bass move into the Colorado River, a humpback chub stronghold is threatened

By Ron Dungan
Published: Thursday, October 12, 2023 - 8:05am
Updated: Thursday, October 12, 2023 - 9:49am

humpback chub
U.S. Fish and Wildlife Service
The humpback chub.

The Bureau of Reclamation recently announced a new comment period for a Supplemental Environmental Impact Statement that will guide management of Glen Canyon Dam operations.

The agency is looking for ways to keep smallmouth bass out of the Colorado River.

Smallmouth bass are predators, and can wipe out populations of native fish, such as the endangered humpback chub.

As the water from Lake Powell has warmed due to climate change, the smallmouth have made their way into the Colorado River, and efforts to eradicate them have fallen short.

Taylor McKinnon, of the Center for Biological Diversity, says that the stream is a stronghold for the chub.

"The last large source population for the humpback chub on earth is at the confluence of the Colorado River and the Little Colorado River in Grand Canyon," McKinnon said. "As goes that population, so goes the species. It’s that important."

He says one way to prevent smallmouth from entering the river is to build a fish barrier where water leaves the dam.

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