Great Barrier Reef more robust than was thought, say scientists

Great Barrier Reef, Australia [image credit:BBC]

This makes a change from the more usual climate-related doom-and-gloom reef scenarios often served up by the media.

Researchers have identified a series of robust reefs that may act as sources to replenish areas of the Great Barrier Reef (GBR) damaged by severe disturbances such as bleaching events and cyclones, reports ABC News.

The “robust source reefs” typically lie on the outer shelf fringes of the GBR where ocean currents push deeper, cooler water toward the surface, reducing the severity of heat stress.

It is hoped that these reefs may temper the decline of the GBR as climate change pressures continue to mount, according to Scott Condie from the CSIRO’s Oceans and Atmosphere department in Hobart.

“They’re the bank for the future of the reef,” Dr Condie said.

“Even though they represent a small percentage of the total reefs, they have the ability to actually replenish probably almost half the reefs within a given season, which is very encouraging.”

Robust reefs most common in southern GBR
In the paper published today in PLoS Biology, the researchers identified 112 reefs which met the robust source reef criteria.

These reefs are identified as being less vulnerable to bleaching. They are also exposed to currents that would convey coral larvae across a significant area of the GBR.

Importantly, they also have a “lower risk of conveying a crown of thorns starfish outbreak”.

Spread by larvae carried on ocean currents, similar to coral, crown of thorns starfish has been responsible for 50 per cent of the total GBR decline between 1985 and 2012, according to the Australian Institute for Marine Science.

Although robust source reefs were identified across the length of the reef, from just north of Gladstone to Cape York, they were only sporadically distributed north of Townsville.

Continued here.