In an ongoing effort to protect indigenous fish populations, the U.S. Bureau of Reclamation is taking strategic action against an invasive predator in the waters of the Grand Canyon. As the environmental review wraps up, the agency has the clear to use colder water releases from Glen Canyon Dam to specifically target and impede the smallmouth bass, as reported by the AZPM. This invasive fish has been known to wreak havoc on native species, including the humpback chub, a fish under federal protection.
The technique of releasing cooler water from Lake Powell is intended to disrupt the invasive smallmouth bass’ spawning process. The Bureau explained, having now completed the necessary environmental review, that they can proceed to strategically use the dam to adjust the river's temperature regimes and reduce the bass' chances to firmly establish themselves in the ecosystem. The bass has been increasingly migrating downstream as dropping water levels have led to warmer waters below the dam—a condition that favors the smallmouth bass.
According to the AZPM, the strategy is the latest in a series of attempts to control the population of these predatory fish, which also includes the green sunfish. The smallmouth bass, a species used to warmer waters, preys on native fish, leading to a decline of local species integral to the river’s ecosystem.
