Coral predators such as the crown of thorns starfish (COTS) have the capability to damage the coral reefs and eventually lead to coral mortality. For instance, in 2015 the coral surveying team encountered crown of thorns starfish present within their long transects near the Nelson Island that resulted in the death of a large bed of corals. http://chagos-trust.org/blog/biot-mpa-survey-expedition-2015-day-10-nelson-island