Quantitative observations of a major coral bleaching event in Barbados, Southeastern Caribbean

In late summer 2005 a mass coral bleaching event occurred in the Caribbean. Here we quantify coral bleaching in Barbados at six sites on the island's sheltered west and exposed southwest coasts, including nearshore fringing and patch reefs and offshore bank reef habitats. Onset of coral bleaching occurred in late August 2005 and persisted for many months after temperatures cooled. All reef habitats and virtually all coral taxa were affected, with an average of 70.6% of all colonies bleaching. Nearshore reefs (< 10 m depth) were affected more severely than offshore deeper reefs (> 15 m) with an average of 80.6% of all coral colonies bleaching compared with 60.5% on the latter. Inter-species variation in susceptibility to bleaching was marked with > 90% of colonies bleaching in some species whilst < 10% bleached in others. Follow-up surveys revealed low coral mortality, with an overall mean of 3.8% partial colony death across all species and reefs by February 2006. However, bleached condition has persisted with a mean of 37.7% of all coral colonies still bleached after 5 1/2 months, indicating that loss of live coral is likely to continue for some time. This event represents the most severe bleaching episode ever witnessed on Barbados' reefs and emphasises the vulnerability of small island states, with a high reliance on healthy coral reef ecosystem services, to elevated sea water temperatures associated with climate variability and global climate change.