Hydrodynamics affect predator controls through physical and sensory stressors

Area of Science:

• Ecology
• Marine Biology
• Trophic Interactions

Background:

• Predators control ecosystems via consumption (CEs) and trait alteration (NCEs), with cascading effects.
• Consumptive effects decrease in stressful environments, while non-consumptive effects can be reduced by sensory stress impacting prey detection.

Purpose of the Study:

• To investigate how physical and sensory stressors from tidal flow influence predator controls in a tritrophic system.
• To understand the distinct roles of physical and sensory stress on predator-prey interactions and their effects on lower trophic levels.

Main Methods:

• Examined mud crab reactive ranges to blue crab non-consumptive effects by assessing mud crab consumptive effects on oysters at varying distances from blue crabs under different flow conditions.
• Quantified the impact of physical (current speed) and sensory (turbulence) stressors on predator-prey interactions and oyster survival.

Main Results:

• Mud crab reactive ranges were larger under lower physical and sensory stress, leading to positive cascading effects of blue crabs on oyster survival.
• Higher flow conditions reduced blue crab non-consumptive effects. Physical stress enhanced oyster survival by limiting mud crab consumptive effects, while sensory stress disrupted predator detection, increasing mud crab consumptive effects and negatively impacting oysters.

Conclusions:

• Environmental factors like fluid flow create physical and sensory stressors that differentially affect predator-prey dynamics.
• These stressors impact basal prey performance by influencing consumptive and non-consumptive predator effects in distinct ways, highlighting the complexity of ecological regulation.