Sea lamprey display context-dependent attraction to specific types of turbulence within a laboratory flume

The development of stimuli to guide fish can both conserve native species and prevent the spread of invasive species. The manipulation of hydrodynamic features (e.g., velocity, turbulence intensity, eddy size and orientation) is a promising stimulus that can either attract or repel fishes. Management of anguilliform fishes, such as eels and lamprey, could benefit from strategies that direct upstream-swimming behavior to targeted areas, however the hydrological cues that either attract or repel anguilliform fishes have not been identified. Our study sought to define whether features of turbulent flow (specific velocity, turbulent kinetic energy or eddy time scale) could attract or repel upstream-swimming Great Lakes sea lamprey ( Petromyzon marinus ) for the purposes of redirection. We used a two-choice laboratory flume outfitted with structures of varying sizes and orientations to generate different turbulent environments, and quantified the preference for each feature by upstream swimming Great Lakes sea lamprey. Data showed that sea lamprey choices are not based on preference for a single, specific velocity, turbulent kinetic energy or eddy time scale. Rather, lamprey have context-dependent attraction to the turbulent features generated, showing a complex decision framework dependent on competing flow conditions. Results can be used to enhance trap efficiency for upstream migrating Great Lakes sea lamprey.