Feds Tout Improved Odds for Survival of Colorado River Fish

(CN) – Touting successful conservation efforts in recent decades, the U.S. Fish and Wildlife Service said Tuesday it will reclassify a Colorado River fish from endangered to threatened.

The agency said the humpback chub, a dorsal-finned fish that primarily resides in the Colorado River, no longer meets the required criteria to be classified as a federally endangered species. Conservation efforts have helped the humpback chub population recover significantly so that a downgrade from “endangered” to “threatened” is ecologically appropriate under the language of the Endangered Species Act of 1973, according to the agency.

“We believe the humpback chub no longer meets the act’s definition of an endangered species, but does meet the act’s definition of a threatened species. The actions of multiple conservation partners over the past 30 years have improved the condition of humpback chub and reduced the threats to the species,” the agency said in its proposal.

Young humpback chub (Gila cypha) swimming in Shinumo Creek, inside Grand Canyon National Park soon after release. (Melissa Trammell / National Park Service)

Humpback chub were first placed on a federal recovery plan in 1979, when it became apparent the species faced mounting threats within their local environments. One of the primary threats came from dam construction on and around the Colorado River that was severely interrupting their migration patterns and damaging their natural habitats.

While the construction of these dams, such as the Glen Canyon and Hoover Dams, are frequently cited as critical contributors to the weakening of humpback chub populations, Fish and Wildlife said the species was also being threatened by the introduction of around 50 non-native fish species into humpback chub habitats. These new species, some of which were predatory, made it increasingly difficult for the humpback chub to thrive in their environment and contributed to their increasingly endangered status.

Fish and Wildlife said many of these threats have been properly countered in recent years. The agency’s proposal suggests that environmental efforts to protect the species have helped the humpback chub population stabilize, and that better water and dam management policies have allowed the population to partially recover.

The proposal also points out the humpback chub is surprisingly resilient naturally, and that the species is far more adaptable than many would assume.

“The humpback chub has many traits that enable individuals to be resilient in the face of environmental or demographic stochasticity, including a long life span, high reproductive potential, use of habitats and water quality that are arduous to other species, adaptation to a wide variety of flow and thermal regimes, and a variable omnivorous diet,” according to the proposal.

The reclassification allows for some “incidental take” of humpback chub as well as some catch-and-release angling in designated areas and provided it is carefully implemented.

While these changes could result in some small harm to individual humpback chub, the value that actions would bring to the entire population would far outweigh any potential consequences and would allow humpback chubs to continue their positive population trends.

“We believe the actions and activities that would be allowed under this proposed 4(d) rule, while they may cause some level of harm to individual humpback chub, would not negatively affect efforts to conserve and recover humpback chub, and would facilitate these efforts by increasing educational opportunities and public support for the conservation of humpback chub and by providing more efficient implementation of recovery actions,” the agency said.

Representatives from the Fish and Wildlife Service did not immediately respond to a request for comment by press time.

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