Coral Reefs

While scleractinian coral populations continue to diminish throughout the Caribbean, gorgonian corals are showing signs of resilience and in some areas are thriving. Despite their prominence on reefs, gorgonian species are notoriously difficult to field identify and as such have been underrepresented in most monitoring efforts. However, with reports of increased resistance to elevated temperatures, ocean acidification, and nutrient enrichment, there is now a growing interest in the ecological and physiological mechanisms that contribute to their success in changing environmental conditions. Here, we compile widely scattered taxonomical, biological, and ecological research on shallow-water symbiotic gorgonians in the wider Caribbean into a comprehensive resource document that can be used by researchers and managers to inform and promote future studies. Each section provides a brief summary of past research, accessible bibliography, and suggestions for future work.

Given the severity of the 2016 global bleaching event, there are major questions about how quickly reef communities will recover. Here, we explore the ecological and physical structural changes that occurred across five atoll interior reefs in the southern Maldives using data collected at 6 and 12 months post-bleaching. Following initial severe coral mortality, further minor coral mortality had occurred by 12 months post-bleaching, and coral cover is now low (<6%). In contrast, reef rugosity has continued to decline over time, and our observations suggest transitions to rubble-dominated states will occur in the near future. Juvenile coral densities in shallow fore-reef habitats are also exceptionally low (<6 individuals m−2), well below those measured 9–12 months following the 1998 bleaching event, and below recovery thresholds identified on other Indian Ocean reefs. Our findings suggest that the physical structure of these reefs will need to decline further before effective recruitment and recovery can begin.