Only 7% of the Great Barrier Reef has avoided coral bleaching
Australians and the rest of the world will be shocked to discover what climate change actually means for the environment – and coral reefs in particular. Corals are sensitive to temperature, and have a threshold tolerance to maximum temperatures and other environmental stresses.
According to the James Cook University website, an extensive aerial and underwater survey reveals that 93% of the Great Barrier Reef (GBR) has been affected by unusually warm waters and resulting coral bleaching. The impacts on the GBR appear mixed, with significant areas of coral reef that are very severely impacted. Other areas have so far sustained moderate to little damage, with the greatest impacts in the northern stretches of the 2300 km long GBR. Researchers in Western Australia have also discovered large-scale bleaching caused by elevated temperatures.
“Of all the reefs we surveyed, only 7% (68 reefs) have escaped bleaching entirely. At the other end of the spectrum, between 60 and 100% of corals are severely bleached on 316 reefs, nearly all in the northern half of the Reef.”
– Professor Terry Hughes, convenor of the National Coral Bleaching Taskforce
A strong El Nino event and elevated seawater temperatures is consistent with Anthropogenic Global Warming (AGW). The AGW warming trend occurs as a ‘stairway’ of temperature jumps over decades, rather than as a smooth continuous rise in temperature.
For the people living in cities, and far from the GBR, what do they think about this? Can we simply ignore these abrupt changes to the natural world?
Map of the Great Barrier Reef showing results of aerial surveys of 911 reefs. Map: ARC Centre of Excellence for Coral Reef Studies / Tom Bridge and James Kerry