Mass bleaching events have devastated coral reefs globally. While management organizations assume reducing local stressors like overfishing will increase coral resilience to climate-induced warming recent large-scale studies suggest local conservation actions do not protect corals. We conducted a global survey of managers and found that removing coral-eating organisms (i.e. corallivores) is a common but untested strategy intended to increase coral resilience. Removal of a common corallivorous snail before a widespread coral bleaching in Florida in 2014 showed that this strategy increases both coral resistance to and recovery from heat-induced bleaching (i.e. resilience). At natural-high and average snail densities corals experienced 89% and 71% bleaching levels respectively with tissue mortality of 36% and 17% respectively. Almost 20% of corals with snails died from heat-induced bleaching while no corals died from bleaching if snails had been removed. Removing snails reduced bleaching to 57% and tissue mortality to 7%. This study is the first to track corals through the entirety of a high stress event and demonstrate that reducing local biological stressors can increase coral resilience to a changing climate.
