Marine hydrokinetic (MHK) turbines offer a robust renewable energy solution to address the challenges of energy scarcity and environmental degradation. However, owing to the potential impact of MHK turbines on the aquatic ecosystem, evaluating the implications of deploying such devices on fish life is essential. Herein, we conducted large eddy simulation (LES) of a vertical axis turbine (VAT) using the turbine geometry-resolving model to gain insights into the relationship between turbulent flow dynamics and fish trajectory. The LES results were validated using experimental data obtained at the Hydro-environmental Research Centre's hydraulic laboratory, Cardiff University, UK. The LES results of the turbulent wake flow field demonstrate meaningful alignment with fish behavioral experimental data, thus serving as a reliable turbulence map for elucidating the trajectories of fish movement within the flow.