18 January 2008

Lower than average sea temperatures projected for the summer could provide a reprieve for corals on the Great Barrier Reef.

Great Barrier Reef Marine Park Authority (GBRMPA) Climate Change Group Director Dr Paul Marshall said the best weather and climate information currently available indicated that it was unlikely the Great Barrier Reef would suffer this year from the type of widespread bleaching experienced in 1998 and 2002, the two hottest summers on record.

“Australia is now in a La-Niña cycle so we are currently experiencing lower than average ocean temperatures which are a welcome relief.

“There are a few localised warm patches in northern areas which have lead to some minor bleaching, but nothing too worrying. We will be keeping a close eye on conditions up north over the coming weeks,” Dr Marshall said.

The risk of sea temperatures increasing to levels which are stressful for corals depends on a complex interaction of regional water temperatures, local air temperatures, cloud cover, winds and rainfall.

Increasing summer temperatures associated with climate change remain a concern for corals in the future.

While the threat of mass bleaching this year is low, the GBRMPA will continue to closely monitor sea surface temperatures and weather conditions using state-of-the art technology including climate models, reef-based weather stations, and a satellite-based monitoring tool called ReefTemp designed to assess the risk of bleaching on a daily basis.

Coral bleaching is also monitored throughout the summer by a network of observers participating in the GBRMPA’s community-based ‘BleachWatch’ programme where volunteer observers report signs coral bleaching.

“BleachWatch is an integral part of the Great Barrier Reef Marine Park Authority’s Coral Bleaching Early Warning System,” Dr Marshall said.

“We have 120 participants this summer including tourism operators, commercial fishers, scientists, community groups like ReefCheck and other visitors to the Marine Park.

“This wide network of observers provides information on coral conditions throughout the Great Barrier Reef and works to alert us of any signs of coral bleaching,” he said.

“So far this summer, BleachWatch observers have reported some slight paling of corals in the central Great Barrier Reef which the Climate Change Group will continue to monitor as the summer progresses.”

Dr Marshall said BleachWatch was an excellent example of a successful partnership between reef managers and the broader community.

The Great Barrier Reef Marine Park Authority welcomes reports on reef condition over the bleaching season.

If you have seen bleaching on the reef you can download and submit BleachWatch Monitoring forms.