Corallivorous snail removal: evaluation of impact on Acropora palmata

With the continuing decline of Acropora palmata throughout the Caribbean region, impacts of the gastropod corallivore, Coralliophila abbreviata, are becoming more noticeable. A snail removal experiment was performed in remnant A. palmata populations in the Florida Keys National Marine Sanctuary to quantify the area of coral tissue consumed by ambient snail aggregations and to assess the possible effectiveness of snail removal in conserving live coral tissue. Corals where ambient snail aggregations were removed maintained significantly more live tissue area during the 2-month experiment than those where feeding snail aggregations were left in place. The corals with feeding snails left in place lost more than 3 cm(2) tissue day(-1) on average. Thus, removal of C. abbreviata may be an effective measure for conserving depressed A. palmata populations, though secondary effects of such a manipulation remain to be carefully evaluated.