Session B4 - An Exploratory Evaluation of the Swim Path Selection of Western Blacknose Dace in a Modified Flow Field

The goal of this study was to observe the response of Western Blacknose Dace (R. obtusus) to a turbulent flow field by comparing their swim paths to selected flow metrics in the hopes of garnering relationships between the two that could improve future research project designs. Experiments were carried out in a hydraulic flume populated with baffle-like obstructions under various flow conditions into which the dace were released. Fish movement was tracked with video cameras to catalog swim-paths, and acoustic Doppler velocimeter measurements were taken to characterize the hydraulic conditions encountered by the swimming dace. The motivation for this study was the need for biologically-based criteria to compare against results obtained from computational fluids dynamics (CFD) models. The ability to compare CFD model outputs to species-specific behavioral and performance-based criteria can facilitate more accurate evaluations from a fish passage perspective, increasing the likelihood of enhanced passage efficiencies at hydraulic structures such as recessed or baffled culverts and bypass channels. Preliminary results indicate that multiple flow parameters or metrics will be required to predict fish paths given the character of the flow measurements obtained here and the lack of a priori behavioral knowledge of this species. It is hypothesize that fairly sophisticated analyses, that incorporate considerations for fish behavior and physiology, will be required to understand and explain afish\u27s ability and desire to navigate a particular flow field in this type of study. In this presentation a brief explanation of the motivation, experimental set-up, preliminary results and initial conclusions will be delivered in conjunction with experimental images and videos