A new study by a team of biologists from the Australian Institute of Marine Science and the ARC Centre of Excellence for Coral Reef Studies has shown that isolated coral reefs can recover from catastrophic damage.  The study challenges conventional wisdom that suggested isolated reefs were more vulnerable to disturbance, because they were thought to depend on recolonisation from other reefs. Instead, the scientists found that the isolation of reefs allowed surviving corals to rapidly grow and propagate in the absence of human interference.

Scott Reef, a remote coral system in the Indian Ocean, has largely recovered from a catastrophic mass bleaching event in 1998, according to the study published in Science today.

Australia’s largest oceanic reef system, Scott Reef, is relatively isolated, sitting out in the Indian Ocean some 250 km from the remote coastline of north Western Australia (WA). Prospects for the reef looked gloomy when in 1998 it suffered catastrophic mass bleaching, losing around 80% of its coral cover. The study shows that it took just 12 years to recover.

We know from other studies that the resilience of reefs can be improved by addressing human pressures such as water quality and overfishing,” says Dr.  Gilmour,  the lead author. “So it is likely that a key factor in the rapid recovery at Scott Reef was the high water clarity and quality in this remote and offshore location.”

Dr. Andrew Heyward, Principal Research Scientist at AIMS, highlights another conclusion from their findings. “Previously we’ve tended to factor proximity to other reefs as a key attribute when estimating the resilience of a reef following a major disturbance, but our data suggests that given the right conditions, reefs might do much of the recovery by themselves.”  This finding could have implications for the management of marine protected areas.

In their publication the team also draws attention to the important role played by climate change in the longer-term prospects for coral reefs, as Prof Morgan Pratchett of CoECRS explains:

“While it is encouraging to see such clear recovery, we need to be mindful of the fact that the coral recovery at Scott Reef still took over a decade. If, as the climate change trend suggests, we start to see coral bleaching and other related disturbances occurring more frequently, then reefs may experience a ratcheting down effect, never fully recovering before they suffer another major disturbance.

Source article can be found here