Corals are in fact a combination of animal, algae and “rock”. Colonies are made up of many identical individuals called polyps that secrete a stony skeleton. Polyps contain microscopic algae called zooxanthellae living within the coral animal tissue; the relationship is mutually beneficial, or symbiotic. Zooxanthellae use sunlight to provide energy and nutrients for the coral through photosynthesis, in return they are provided with shelter. In a reef, each colony acts as a building block, pieced together to form intricate structures that provide habitats for an abundance of reef fish and many other creatures.

Sea temperatures are at an all-time high. Major bleaching incidents are increasingly prevalent. The US National Oceanographic and Atmospheric Administration (NOAA) revealed that 2010 has been the hottest year in recorded history. Prior to this, 1998 was the hottest for 130 years, leading to unprecedented intense bleaching and coral mortality worldwide which wiped out more than 90 per cent of shallow water corals in the Indian Ocean. NOAA’s Coral Reef Watch monitors and predicts bleaching events using HotSpots, a measure which highlights areas where sea surface temperatures rise above levels that can lead to bleaching.

As predicted by NOAA, bleaching began this February in Mauritius and it has progressed throughout the Indian Ocean and South East Asia, including reefs off Thailand, Cambodia, Malaysia and Philippines. Florida and the Caribbean are next, with strong warming of the surrounding sea and severe bleaching expected for the coming months.

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