The role of the sensory environment and predator chemical signal properties in determining NCE strength in cascading interactions on oyster reefs

Georgia Tech Research Corporation, Atlanta GA

Investigators

Abstract

In this project, the investigators will examine the ability of top blue crab predators to indirectly benefit the abundance of basal oyster prey by reducing the density (consumptive effects, CEs) and suppressing foraging (non-consumptive effects, NCEs) of intermediate mud crab predators. These NCEs are mediated by chemical perception of aversive cues in blue crab urine and produce a behaviorally mediated trophic cascade. Through a series of manipulative experiments, the investigators will examine how the strength of this behaviorally-mediated trophic cascade is modulated and factors that influence perceptive range such as predator diet and intake rate, and the flow environment. The investigators will also determine the chemical identity, concentration and release rate of chemical cues. Identifying the quantitative and molecular aspects of aversive cues, and linking them to behavioral responses that produce trophic cascades establishes the chemical basis of risk perception by prey and how this translates into cascading ecological effects. The use of perceptive range as a framework for evaluating the effects of both chemistry and environment provides an integrated view of processes affecting chemically-mediated NCEs. The use of a water borne predator-prey signaling system to test ideas on the strength of NCEs should have broad applications. The broader impacts include interdisciplinary training and support for three graduate students, undergraduate training, and collaborations with Georgia Department of Natural Resources to translate research results into improved techniques for fisheries management and oyster aquaculture. Graduate students funded will be encouraged to participate in Georgia Tech's "Tech for Teaching" program, which supports K-12 teaching efforts. Teaching fellows will be trained in classroom management, pedagogical theory, and strategies for teaching a summer course.