Native fish in the Colorado River evolved over hundreds of millions of years. They have developed biological features and life histories adapted to the river’s unique hydrology and environmental conditions. Changes in hydrology, water uses, introduced game fish, and habitat alterations have deteriorated conditions for many native fish. Four imperiled fish species have received threatened and endangered status under the Endangered Species Act: the Colorado pikeminnow, razorback sucker, humpback chub, and bonytail.

Join us February 21, when Middle Colorado Watershed Council will host the first of their Winter Speaker Series guests. David Graf, Instream Flow Coordinator for US Fish and Wildlife, will share information about the Fish Recovery Program and the 15 Mile Reach. The Recovery Program is managed by the U.S. Fish and Wildlife Service in partnership with the various nonfederal public and private partners to ensure compliance with the Endangered Species Act.

The Upper Colorado River Endangered Fish Recovery Program facilitates recovery of these four species while still allowing existing water uses and some additional water development. Partners from Federal and State agencies, Tribal organizations, water users, hydropower interests, and conservation groups collaborate in this recovery effort.

The 15-Mile Reach starts east of Grand Junction on the mainstem Colorado River below the last of the large Grand Valley water diversion structures and ends at the confluence with the Gunnison River. This river stretch contains critical habitat for the listed species. Multiple program partners came together to collaborate on a plan for using strategic reservoir releases to ensure water continuously flows year-round through this reach.

In 2018 the 15-Mile Reach would have been dry for approximately 12 days in late September and early October without the reservoir releases. Thanks to Colorado’s water rights system, ensuring water to this critical reach also ensures upstream water continues to flow through the Middle Colorado watershed and further augments baseflows below the Gunnison confluence to Lake Powell.

Providing habitat and connectivity for the multiple life stages of fish are important aspects of recovery. Using reservoir releases to connect the main channel to nursery flood plain habitat as fry are hatching has been successful in enhancing recruitment of the endangered species.

Ensuring that fish can pass successfully past diversion dams plays a vital part in maintaining connectivity for these species to access critical spawning habitat. Adding screens to water diversions helps prevent fish from becoming trapped in canals. Electronic tagging fish to track movement has proven hugely successful in determining migration routes and habitat preferences at different life stages.

Over the past 150 years, various fish species have been introduced into the Colorado river drainage. Invasive species compete for resources and can prey upon native fish species. Smallmouth bass, northern pike, and walleye are currently being removed because these invasive predators can adapt to reproduce in both flowing and stored water systems.

Providing information and education to the public about the importance of the 15-Mile Reach is vital to the program’s success and recovery of native fish. The program maintains a public website, develops a variety of educational materials, works with the media and partners to share news stories, supports classroom programs, and attends public outreach events.

Federal and State agencies operate native fish recovery hatcheries across the upper Colorado basin. Hatchery personnel work with geneticists to ensure captive brood stocks are as diverse as possible. Fish are raised to sizes that increase their chances of survival—at least ten inches and sometimes eighteen inches. Successful culturing of razorback sucker has brought them back from the brink of extinction.

Research is essential for providing the best information possible to aid in the Recovery Program’s efforts. Research areas include utilizing floodplain wetlands as fish nursery habitat, growth and movement monitoring, determining the most effective size to stock fish, and enhancing invasive species control methods.