Cyclone damage to the Great Barrier Reef 'a warning on climate'

Sydney Morning Herald 20 Aug 09;

It could take 15 years for a quarter of the Great Barrier Reef to recover from the effects of Cyclone Hamish which tracked along the Queensland coast in March, researchers say.

Cyclone Hamish was part of a "triple whammy" - stifling heat, heavy rainfall and destructive winds - to the reef and a foretaste of the possible effects of climate change, scientists say.

The severe tropical cyclone, responsible for the ship Pacific Adventurer spilling oil along southeast Queensland beaches, has caused far more widespread damage, it has emerged.

Bureau of Meteorology reef weather stations recorded wind speeds of over 200km per hour as the eye of the cyclone passed over about a quarter of the length of the reef.

Preliminary results of research by scientists from the Australian Institute of Marine Science (AIMS) will be released on Thursday, a statement from the organisation said.

"Most cyclones track fairly directly from the Coral Sea to the coast and so only relatively small areas of the Great Barrier Reef are affected," the statement said.

"By running parallel to the coast for about 500km, Hamish damaged much more of the (reef) than most recent cyclones."

AIMS scientist Dr Ray Berkelmans said the damage was patchy.

"Reefs within 30km of the cyclone eye sustained most damage, with around half of the 500 reefs in this area exposed to destructive waves and suffering significant damage," he said.

Based on past experience with similar reefs, the researchers estimate that coral should recover in eight to 15 years, if there are no further major disturbances such as cyclones, coral bleaching or declines in water quality that might reduce the resilience of these reefs.

Dr David Wachenfeld of the Great Barrier Reef Marine Park Authority said the summer of extreme weather brought a triple whammy of pressures to the Great Barrier Reef and was a stark reminder of the potential impacts of climate change.

"We saw stifling heat, heavy rainfall causing significant flooding, and destructive winds from cyclone Hamish, all compounding to have a hard hitting impact on the Great Barrier Reef," Dr Wachenfeld said.

"The research results from the AIMS surveys continue to remind us of the remarkable nature of this extraordinary ecosystem and the importance of ensuring that it is as healthy as possible to withstand the impacts of more extreme weather events in the future."