Abstract Summary
Invertebrate corallivores can negatively impact the survival of coral species through direct predation and by serving as a vector for diseases. While outbreaks of Acanthaster and Drupella are known to rapidly devastate entire reef systems, other corallivores such as Culcita, Coralliophila and Hermodice also degrade resilience and prevent recovery of coral populations following disturbance from bleaching, hurricanes and disease outbreaks as they tend to form feeding aggregations on remnant wild colonies. Furthermore, chronic predation on nursery-propagated corals has been shown to cause partial and total colony mortality, reduced growth rates and increased algal colonization. Predator control efforts for Acanthaster were first initiated in the early 1960s, with intensive removal efforts undertaken to date in 48 countries, resulting in the elimination of 18 million starfish. Although large scale, multi-year efforts have been considered inefficient and unsuccessful, smaller scale programs have successfully eradicated starfish, prevented declines in coral cover, and improved recovery prospects, especially when control efforts are implemented after first detection and outbreaks are confined to a restricted area. Furthermore, removal efforts for Acanthaster and other Pacific corallivores are being recommended to improve survival, growth and recovery of remnant coral populations following the catastrophic bleaching between 2014-2017. In the Caribbean, removal of Coralliophila abbreviata has mitigated losses to endangered acroporids and has reduced bleaching severity in boulder corals. Extensive mortality among outplanted and wild acroporids during recent hurricanes and increased prevalence of aggregations of C. abbreviata on surviving storm generated fragments and colony remnants, along with recent emergence of coral diseases, emphasizes the need for direct efforts to control corallivore predators, as this will prevent further decline, enhance recovery, and improve coral restoration outplanting success.
