Life Sciences Commons^™

Unintended Facilitation Between Marine Consumers Generates Enhanced Mortality For Their Shared Prey, F. Joel Fodrie, Matthew D. Kenworthy, Sean P. Powers

University Faculty and Staff Publications

We manipulated predator densities and prey vulnerability to explore how interactions between two predators affect overall mortality of their shared prey. Our threemember study system included eastern oysters (Crassostrea virginica) and two of its major consumers: southern oyster drills (Stramonita haemastoma) and stone crabs (Menippe adina). Field experiments demonstrated that drills and crabs foraging together generated higher than expected oyster mortality based on each species operating independently, even though crabs also killed some drills. In subsequent laboratory trials, we experimentally mimicked the handling of oysters by foraging crabs and confirmed that crabs facilitated drills by breeching oyster valves, thereby granting …