Alteration of sensory abilities regulates the spatial scale of non-lethal predator effects

Many studies have shown that nonlethal predator effects such as trait-mediated interactions (TMIs) can have significant impacts on the structure and function of communities, but the role environmental conditions play in modulating the scales and magnitude of these effects has not been carefully investigated. TMIs occur when prey exhibit behavioral or physiological responses to predators and may be more prevalent when abiotic conditions increase prey reactions consumers. The purpose of this study was to determine if changes in environmental conditions would alter the spatial scales over which prey respond to predators in a nature. Using hard clams and blue crabs as a model predator-prey system, we investigated the effects of turbulence on clam reactive distance to blue crab predators in the field. Results suggest that turbulence diminishes clam reactions to predators and that environmental context must be considered when predicting the extent of indirect effects in natural systems.