Predators influence communities through either consuming prey (consumptive effects, CEs) or altering prey traits (non-consumptive effects, NCEs), which has cascading effects on lower trophic levels. CEs are well known to decrease in physically stressful environments, but NCEs may be reduced at physically benign levels that affect the ability of prey to detect and respond to predators (i.e., sensory stress). We investigated the influence of physical and sensory stressors created by spatial and temporal differences in tidal flow on predator controls in a tritrophic system. We estimated mud crab reactive ranges to blue crab NCEs by evaluating mud crab CEs on juvenile oysters at different distances away from caged blue crabs across flow conditions. Mud crab reactive ranges were large at lower physical and sensory stress levels and blue crabs had a positive cascading effect on oyster survival. Blue crab NCEs were not important at higher flow conditions. Oyster survival was a complicated function of both types of stressors. Physical stress (i.e., current speed) had a positive effect on oyster survival by physically limiting mud crab CEs at high current speeds. Sensory stress (i.e., turbulence) interfered with the propagation of blue crab chemical cues used by mud crabs for predator detection, which removed blue crab NCEs. Mud crab CEs increased as a result and had a negative effect on oyster survival in turbulent conditions. Thus, environmental properties, such as fluid flow, can inflict physical and sensory stressors that have distinct effects on basal prey performance through impacts on different predator effects.

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Predation is fundamentally important in the structure and function of ecosystems (Ripple et al., 2014). Top predators in a tritrophic food chain can indirectly impact lower trophic levels by reducing intermediate prey density through consumption (i.e., consumptive effects). Density-mediated indirect effects (DMIEs) affecting the prey of these intermediate consumers have been well-documented to influence diverse ecological communities (Carpenter et al., 1987; Estes

Student-generated concept maps in an undergraduate ecology laboratory course were used to examine the benefit of community-engaged fieldwork on sustainability learning. This short-term service-learning experience led to conceptual changes in sustainability knowledge and is a promising pedagogical approach in sustainability education.

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