Mark-recapture and environmental data used to predict humpback chub (Gila cypha) growth rates within the Colorado River in the Grand Canyon from April 2012 to October 2022

These are the data used for growth modeling in the paper ‘Growth of a threatened desert fish becomes resource dependent when released from temperature limitation in a regulated river’. Growth of ectotherms is strongly tied to temperature but can vary with other factors, especially food acquisition rates. River regulation is widespread globally and often significantly alters both environmental conditions (e.g., flow, turbidity, and temperature) and aquatic food webs, modifying the quality and quantity of resources available to consumers. To understand how food availability, water temperature, and other environmental factors are associated with fish growth (defined here as a change in length) in a large, regulated desert river, we fit Bayesian state-space growth models to data collected for federally listed humpback chub (Gila cypha; 'HBC') at two different reaches located ~240 river kilometers apart in the Colorado River within the Grand Canyon, Arizona, USA. Hypolimnetic water releases from Glen Canyon Dam, upriver of both reaches, results in colder summertime water temperatures than existed in the river pre-dam. Glen Canyon Dam also traps >95% of the sediment that previously moved through the Grand Canyon, as well as much of the allochthonous carbon.