Relationships between Larval Fish Drift and Abiotic Factors in the Missouri River

ABSTRACT

We estimated the relative importance of key abiotic variables to predict the drift of larval fishes in the Missouri River. A multi-year database of spring drift sampling was used to examine relationships between larval freshwater drum (Aplodinotus grunniens) and catostomid drift and variables representing discharge, temperature, and turbidity in the Missouri River from Fort Randall Dam in South Dakota to Rulo, Nebraska. Two statistical modeling approaches were used to estimate the relative importance of the predictor variables. Temperature-related variables were consistently the most important predictors of the presence and density of larval freshwater drum and three species of catostomids.