Predator-Prey Interactions: Rocky Subtidal

Our predation studies in the marine rocky subtidal of the southern New England coast have focused on the predators of new recruits and juveniles. These are generally the smallest and least-defended life stages of benthic invertebrates and, as such, suffer the highest mortalities. We have found that several species of small snails 4 -15 mm in length can completely eliminate recruitment of most species of sea squirts causing communities to shift from dominance by these species to dominance by bryozoans, hydroids, and barnacles. Other taxa such as recruiting and juvenile crabs, sea stars, and fish were also found to alter communities by preying on recruits.

Results of field experiments showing the dominance of the colonial sea squirts Botrylloides violaceus and Botryllus schlosseri when recruit predators are excluded and the dominance of colonial bryozoans when the predators are present.