title: Caribbean massive corals not recovering from repeated thermal stress events during 2005-2013.
abstract: 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% (±5.4SE) forO. franksi,35.7% (±4.7SE) forS. michelini, and 11.2% (±3.9SE) forS. siderea. Two species,O. franksiandS. 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.
authors.affiliation: The Bigelow Laboratory for Ocean Sciences East Boothbay ME USA.
authors.forename: Benjamin Paul
authors.initials: BP
authors.lastname: Neal
authors.affiliation: The Scripps Institution for Oceanography University of California San Diego La Jolla CA USA.
authors.forename: Adi
authors.initials: A
authors.lastname: Khen
authors.affiliation: Marine Imaging Lab Leon H. Charney School of Marine Sciences University of Haifa Haifa Israel.
authors.forename: Tali
authors.initials: T
authors.lastname: Treibitz
authors.affiliation: Berkeley Vision and Learning Center Electrical Engineering and Computer Sciences University of California Berkeley Berkeley CA USA.
authors.forename: Oscar
authors.initials: O
authors.lastname: Beijbom
authors.affiliation: Environmental Studies Department Colby College Waterville ME USA.
authors.forename: Grace
authors.initials: G
authors.lastname: O'Connor
authors.affiliation: Department of Geology State University of New York at Buffalo Buffalo NY USA.
authors.forename: Mary Alice
authors.initials: MA
authors.lastname: Coffroth
authors.affiliation: National Museum of Natural History Smithsonian Institution Washington DC USA.
authors.forename: Nancy
authors.initials: N
authors.lastname: Knowlton
authors.affiliation: Computer Science and Engineering University of California, San Diego La Jolla CA USA.
authors.forename: David
authors.initials: D
authors.lastname: Kriegman
authors.affiliation: The Scripps Institution for Oceanography University of California San Diego La Jolla CA USA.
authors.forename: B Greg
authors.initials: BG
authors.lastname: Mitchell
authors.affiliation: The Scripps Institution for Oceanography University of California San Diego La Jolla CA USA; Smithsonian Tropical Research Institute Ancon Republic of Panama.
authors.forename: David I
authors.initials: DI
authors.lastname: Kline
keywords: Coral reefs; Orbicella franksi; Siderastrea siderea; Stephanocoenia michelini; climate change; coral bleaching; resilience and recovery