Proximal and distal factors associated with the decline in secondary invertebrate prey production in the Colorado River, Glen Canyon, Arizona.

Using a bioenergetic model, demographic data for the Rainbow Trout (Oncorhynchus mykiss) population were compiled and used to estimate total prey consumption in the Colorado River, Glen Canyon , AZ. Additionally, other data including invertebrate diet, drift, and benthic measurements were used to make generalized estimates of daily production rates for the most common benthic invertebrate taxa. The primary objectives were to test a set of hypotheses regarding proximate and distal drivers that were regualating secondary production of invertebrate prey in Glen Canyon. These production estimates represent an estimate of aggregate prey items that include Chironomidae and Simulium arcticum [complex]), as well as amphipods (Gammarus lacustris); [...]