M

arine scientists from several NGOs are conducting joint efforts with dive operators to recover coral reefs in some areas in Indonesia affected by mass bleaching due to global warming.

At a workshop on coral bleaching held in Denpasar on Friday, they discussed the impact of coral bleaching, which occurred at an alarming rate in 2009 and 2010, and attempted to learn from the episode to anticipate more bleaching in the future.

It was predicted that future coral bleaching could be more severe and frequent as sea temperatures continued to rise significantly, said Scott Heron, marine physicist from NOAA Coral Reef Watch.

'€œWe'€™re looking back at the 2010 bleaching event to see what we can learn and do. Ocean acidification has been more severe due to higher carbon emissions, which have weakened coral exposed it to stressful conditions due to pollution and irresponsible human activities in the ocean,'€ Heron said.

Coral bleaching occurs when coral loses its alga symbionts called zooxanthellae due to stressful conditions. The coral tissue becomes transparent, bleaching it white. Without the zooxanthellae, the coral not only lose their color, but also slowly starve to death.

In 1998, the worst coral bleaching in 700 years occurred, hitting the Great Barrier Reef. The Caribbean area suffered a similar fate in 2005.

In 2009, mass bleaching was recorded in Bali and a year later many famous dive sites in the Maldives, Thailand and Malaysia reported severe bleaching affecting all coral areas there.

'€œIn Indonesia, about 20 locations also reported mass bleaching. In Sabang and East Aceh up to 90 percent of coral were reported to be bleaching and have gradually recovered,'€ said Naneng Setiasih from the Coral Reef Alliance.

Heidi Schuttenberg from the Centre for Sustainable International Development at the University of Aberdeen, said bleaching had a negative impact on tourism, particularly divers'€™ satisfaction with reef conditions and marine life.

'€œHowever, there are factors that operators can control to maintain diver satisfaction, price and information. Divers are supportive of such management and prefer operators that are engaged in reef management and who are environmentally-friendly,'€ she said.

She explained what could be done to respond to coral bleaching and climate change, including implementing effective responses by raising awareness, supporting coral survival and collecting information to improve management, as well as identifying naturally resilient areas and incorporating these into management priorities.

Amar Doshi from Queensland University of Technology'€™s School of Economics and Finance conducted research on the economic value of scuba diving and the impact of bleaching in Indonesia, Malaysia and Thailand.

He found that coral bleaching in 2010 probably resulted in a loss of about Rp 1.1 billion (US$96,800) to 1.7 billion.

'€œDiving brings substantial economic benefits to economies '€” as much as Rp 14.5 billion a year, but the total cost of bleaching to the region is likely to have been over Rp 1.1 billion,'€ he said.

Representatives from the diving industry said they would actively report to the authorities and NGOs that were responsible or monitoring coral. NGOs also provided an easy guide on recognizing bleached coral and reporting it.