New coral growth collapses


Growth of new coral in the Great Barrier Reef has collapsed by over 80% following two major bleaching events in 2016 and 2017.

In a report published by the ARC Centre of Excellence for Coral Reef Studies, researchers found that new coral growth has collapsed by an alarming 89% since the two climate-change driven bleaching events.

Published in the journal Nature, the report not only details an overall collapse in new coral recruitment, but an overall precipitous decline in coral bio-diversity.

“Dead corals don’t make babies,” said lead author Professor Terry Hughes, Director of the ARC Centre of Excellence for Coral Reef Studies at James Cook University (JCU). “The number of new corals settling on the Great Barrier Reef declined by 89 percent following the unprecedented loss of adult corals from global warming in 2016 and 2017.”

So far, the Great Barrier Reef has experienced four mass bleaching events due to global warming, in 1998, 2002, and back-to-back in 2016 and 2017. Scientists predict that the gap between pairs of coral bleaching events will continue to shrink as global warming intensifies.

“It’s highly unlikely that we could escape a fifth or sixth event in the coming decade,” said co-author Professor Morgan Pratchett.

“We used to think that the Great Barrier Reef was too big to fail – until now,” he said.

“For example, when one part was damaged by a cyclone, the surrounding reefs provided the larvae for recovery. But now, the scale of severe damage from heat extremes in 2016 and 2017 was nearly 1500km—vastly larger than a cyclone track.”

The report concludes that the reef will need a full decade free of bleaching events if it is to stand any chance to recover from the damage.

The full report can be found here