Massive coral bleaching events associated with high sea surface temperatures are forecast to become more frequent and severe in the future due to climate change. Monitoring colony recovery from bleaching disturbances over multiyear time frames is important for improving predictions of future coral community changes. However, there are currently few multiyear studies describing long-term outcomes for coral colonies following acute bleaching events. We recorded colony pigmentation and size for bleached and unbleached groups of co-located conspecifics of three major reef-building scleractinian corals (Orbicella franksi, Siderastrea siderea, and Stephanocoenia michelini; n = 198 total) in Bocas del Toro, Panama, during the major 2005 bleaching event and then monitored pigmentation status and changes live tissue colony size for 8 years (2005–2013). Corals that were bleached in 2005 demonstrated markedly different response trajectories compared to unbleached colony groups, with extensive live tissue loss for bleached corals of all species following bleaching, with mean live tissue losses per colony 9 months postbleaching of 26.2% (±5.4 SE) for O. franksi, 35.7% (±4.7 SE) for S. michelini, and 11.2% (±3.9 SE) for S. siderea. Two species, O. franksi and S. michelini, later recovered to net positive growth, which continued until a second thermal stress event in 2010. Following this event, all species again lost tissue, with previously unbleached colony species groups experiencing greater declines than conspecific sample groups, which were previously bleached, indicating a possible positive acclimative response. However, despite this beneficial effect for previously bleached corals, all groups experienced substantial net tissue loss between 2005 and 2013, indicating that many important Caribbean reef-building corals will likely suffer continued tissue loss and may be unable to maintain current benthic coverage when faced with future thermal stress forecast for the region, even with potential benefits from bleaching-related acclimation.
Bibliographical noteFunding Information:
This project supported by NSF Awards OCE 09-41760 (B.G. Mitchell ? PI) and OCE-09-26822 (M. Coffroth ? PI). In-country Panama support provided to M.A. Coffroth and D.I. Kline by E. Bermingham and the Smithsonian Tropical Research Institute (STRI). Thanks to M. Medina, D.A. Hamilton, P. Bongaerts, D. A. Al-Abdulrazzak, L. McClenachan, M. Stevens, and L. Cummings for field and laboratory assistance. Thanks to Rachael Silverstein for helpful manuscript comments.
© 2017 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.
- Coral reefs
- Orbicella franksi
- Siderastrea siderea
- Stephanocoenia michelini
- climate change
- coral bleaching
- resilience and recovery
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Nature and Landscape Conservation