Great Barrier Reef suffers 89% decline in coral reproduction rate after bleaching

The Great Barrier Reef is losing its ability to recover after coral bleaching.

The report, published in the journal Nature, found that coral reproduction on the Great Barrier Reef (GBR) has fallen to 89 per cent after repeated bleaching.

The study measured how many adult corals survived along the length of the world’s largest reef system. The report found that there has been a notable decline in ‘coral babies’.

“Dead corals don’t make babies,” said lead author Professor Terry Hughes of 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,” he added.

The Great Barrier Reef has experienced four mass coral bleaching events so far due to climate change. Declines in rates of coral recruitment were greatest in the northern parts of the reef, where bleaching was most pronounced in 2016 and 2017.

Despite southern parts of the GBR being in good condition after escaping bleaching, they are too far away to replenish reefs further north.

The study says that it is hard to know how long it will take for coral assemblages to recover from the recent mass bleaching, but they are certain that “low levels of coral recruitment will constrain coral recovery and greatly increase the recovery time”.

“There’s only one way to fix this problem,” says Professor Hughes, “and that’s to tackle the root cause of global heating by reducing net greenhouse gas emissions to zero as quickly as possible.”

Read the full report here.