Marine & Environmental Sciences Faculty Proceedings, Presentations, Speeches, Lectures


Ecological and Framebuilding Consequences of the 1996 Coral Mass Mortality Event in the Arabian Gulf (Dubai, UAE)

Event Name/Location

9th International Coral Reef Symposium, Bali, Indonesia, October 23-27, 2000

Document Type

Conference Proceeding

Publication Date



Between May and August 1996, sea-surface temperatures in the southern Arabian Gulf were elevated by 2 degrees above average and led to widespread coral death. The consequences for coral fauna, frame-building potential, coral diseases and coral regeneration were studied between Jebel Ali and Ras Hasyan. In the study area, all 6 Acropora species suffered total mortality, thus the coral fauna was reduced from 34 species to 28. The nearest areas with surviving Acropora were 30 km to the east (Deira) and 20 km to the west (Al Jazira). The Acropora overkill turned 7.8 km2 (19.7% of total coral covered area) of previously lush coral gardens into a dead framework that was increasingly bioeroded. Acropora recruitment only started in 1998, average recruit size in 1999 was 7±3 cm, and recruits were rare. Presently, bioerosion is faster than recruitment, and the coral framework will likely be eroded before a new generation of frame builders is present. Since historical data suggests that such mortality events are recurrent, the observed destruction of the framework and slow regeneration explains the absence of lasting coral frameworks, i.e. reefs. Massive coral species suffered negligible mortality, and slowly increased in space cover. Prior to the mass mortality event, coral diseases were common and seasonal (14±5% of corals, mainly Acropora, affected in summer, in winter 7±6%, mainly massives), after the mortality event seasonality was lost and infection remained on winter-levels (6±5%, only massives infected).


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