Last updated June 5, 2017 at 2:47 pm
Unless we reduce sea temperatures, which are rising due to global warming, we are committed to more frequent severe bleaching events of the Great Barrier Reef and other coral reefs around the world. The increased ocean temperatures also make it unlikely that the Great Barrier Reef will recover from bleaching events that have already occurred according to a paper published today in the journal Nature.
Terry Hughes, Director of the Australian Research Council’s Centre of Excellence for Coral Reef Studies at James Cook University and Bragg Member of The Royal Institution of Australia was part of a team that assessed three major bleaching events on the Great Barrier Reef that occurred in 1998, 2002 and 2016. They analysed individual reefs and were able to determine why some corals are more prone to bleaching than others.
Coral bleaching is the phenomenon where living coral ejects the algae that they depend on for processing food, thus removing the colour from the coral (hence ‘bleaching’). If the coral do not accept the algae back into their systems, the coral will die. It has long been known that corals eject their algae in response to warmer sea conditions.
The research team found that the distinctive pattern of bleaching across the reefs was primarily driven by patterns of sea temperatures where unbleached reefs were located towards the generally cooler waters at the southern end of the Great Barrier Reef.
They also found that local management of reef fisheries and measure to maintain water quality offered little to no protection against extreme heat but that these measures may help ecosystems to recover from bleaching events.
Further research suggests that it is unlikely that the Great Barrier Reef will ever fully recover from the severe bleaching that occurred in 2016 where over 90% of the corals were damaged by bleaching.
Terry and his colleagues argue that the security of coral reefs requires urgent and rapid global action to curb future warming.
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