The 2005 Bleaching Legacy: Q4 2006 and Reef Recovery After the Caribbean’s Worst Event

Briefing

• Reef surveys documented high post-bleaching coral mortality at multiple north coast sites.
• 2005 Caribbean bleaching event identified as most severe on record by NOAA and regional scientists.
• Recovery prospects at stress-affected sites complicated by ongoing water quality deterioration.
• Scientists urged reduction of local stressors to give thermally damaged reefs recovery chance.
• Tourism ministry expressed concern about implications for dive and snorkel product quality.

The 2005 Atlantic hurricane season had been the most active on record, and it had coincided with a Caribbean-wide coral bleaching event that NOAA’s Coral Reef Watch programme identified as the most severe ever recorded. The combination of extremely high sea surface temperatures and the accumulated thermal stress of preceding years had triggered mass bleaching across the Caribbean basin, and Jamaica’s reefs had been among those most severely affected. By the time the water temperatures returned to normal in the autumn of 2005, significant proportions of the coral cover at multiple Jamaican reef survey sites had bleached, and the mortality that followed bleaching — which typically becomes visible weeks to months after the thermal event — was being documented through 2006.

The fourth-quarter 2006 surveys were providing the first comprehensive picture of the bleaching event’s full ecological cost at Jamaican sites. The mortality rates were high — at some sites, a significant proportion of the coral colonies that had been alive before the bleaching event were now dead. This represented, in ecological terms, the erasure of growth that had taken decades to accumulate, and it set back the recovery trajectories that scientists had been tracking since the disease and bleaching events of the late 1990s. Jamaica’s reefs had been recovering, tentatively and unevenly, for almost a decade. The 2005 event had interrupted that recovery comprehensively.

Recovery Conditions

The scientists who were assessing recovery prospects in late 2006 were explicit about the conditions required. Reef recovery after a thermal bleaching event is possible, but it requires conditions that are favourable for coral recruitment — the settlement and growth of new coral larvae. Those conditions include adequate larval supply from surviving parent colonies; suitable substrate that is not dominated by algae; and water quality that is not excessively loaded with the nutrients that promote algal growth at the expense of coral recruitment. All three conditions were compromised at the north coast reef sites most affected by both the 2005 bleaching and the ongoing resort development. The scientists’ message was that addressing the local stressors — reducing nutrient loading, managing fisheries to maintain herbivore populations — was the most effective intervention available to Jamaican reef managers, since the global emissions trajectory that had caused the bleaching was beyond their control.

Tourism’s Stake

The tourism ministry’s concern about dive and snorkel product quality was commercially understandable. Jamaica was actively marketing its marine environment as part of its tourism offer, and the visual degradation of reef systems that were prominent dive destinations — the brown, algae-dominated, rubble-strewn appearance of reefs that had previously had living coral cover — was a quality problem that tour operators and travel writers were beginning to document. The irony that the development boom that was the primary driver of Jamaica’s tourism growth was also the primary controllable threat to the reef ecosystems that sustained part of the tourism offer was not lost on the scientists, even if it was politically inconvenient in the context of 2006’s investment climate.

Related: Property Market Analysis | NOAA Coral Reef Watch | NEPA Jamaica

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