Cooperative Fish and Wildlife Research Units Program: Colorado
Education, Research and Technical Assistance for Managing Our Natural Resources

Several fish species of interest to federal and state managers occupy the Colorado River within the Grand Canyon, including humpback chub (Gila cypha), flannel mouth suckers (Catostomus latipinnis), and rainbow trout (Oncorhynchus mykiss). A better understanding of how environmental variation and various management actions affect population and ecosystem dynamics requires development of new models that integrate disparate data informing both population and food web processes. Therefore an integrated ecosystem model for the Grand Canyon that includes the dynamics of humpback chub, flannelmouth sucker, and rainbow trout, combined with the dynamics of invertebrates and primary productivity, and assesses the transfer energy efficiency among trophic levels, is needed. This project is a collaboration with USGS Grand Canyon Monitoring and Research Center. The model and its results can be used by federal and state managers to better understand the ecosystem and fish populations, to evaluate which flows are best for meeting multiple management goals.