Record heat over Great Barrier Reef raises fears of second summer of coral bleaching

Ocean temperatures over parts of the Great Barrier Reef have reached record levels this month, sparking fears of a second summer in a row of mass coral bleaching.

Data from the US government’s National Oceanic and Atmospheric Administration (Noaa) shows sea surface temperatures over the northern parts of the reef have been the highest for any November on a record going back to 1985.

With the peak period for accumulated heat over the reef not expected until February, cooler weather conditions and cyclone activity before then could stave off a mass bleaching event.

Prof Terry Hughes, a leading expert on coral bleaching at James Cook University, said he had never seen heat stress accumulating on the reef this early, but a “well timed cyclone” in December could reduce the risk of bleaching.

“It is certainly the case that temperature records are tumbling. The warning signs are clear,” he said.

Last summer’s mass bleaching, declared by the Great BarrierReef Marine Park Authority (GBRMPA), was the first outbreak during a La Niña – a climate pattern that historically has kept…