Habitat studies have focused on the effects of various flow regimes on habitat suitability. Availability of preferred mesohabitats (pools, eddies, backwaters, etc.) vary depending on flow stage. Additionally, such habitats are generally formed during large spring-flow events. The quality of the substrata (river bottom sediments) that produce algae and benthic invertebrates, the base of the food chain, are affected by flows.

Seasonal water temperatures that affect feeding rates and timing of spawning are also affected by flows and river regulation. Hence, assessing the suitability of the environment for the endangered fishes requires linking our knowledge of their biological requirements with our understanding of how flows affect the quality of their physical habitat. Equally important is understanding how the endangered fish interact with other members of the biological community, i.e., the foods they feed on and the predators that feed on them. Hence, research is a critical prerequisite to devising effective management actions.



Image of an endangered razorback sucker
Ouray National Fish Hatchery - Randlett Unit was established in 1996 as a fish refugia and technology development facility to assist in the recovery of razorback sucker, Colorado pikeminnow, bonytail, and humpback chub.
Horsethief Canyon Native Fish Facility in Fruita Colorado
The Grand Junction Fish and Wildlife Conservation Office works with the Ouray National Fish Hatchery-Grand Valley Unit to recover four endangered fish species of the upper Colorado River basin: Razorback Sucker, Colorado Pikeminnow, Humpback Chub, and Bonytail.