Studies have shown 2010 was not a good year for South East Asian reefs, as unusually high or prolonged summer sea temperatures caused mass bleaching. So what exactly is bleaching? Corals have a single-cell algae called zooxanthellae that lives with in their tissue. Through photosynthesis,zooxanthellae produces sugars to feed the coralls, sugars make ars to feed the coral's food. Zooxanthellae with their brilliant reds, oranges and browns give corals their color.
Blencing occurs when corals lose their zooxanthellae. The coral's tissue becomes transparent, a white skeleton can be seen, making the corals look bleached white. Without zooxanthellae, corals will not only lose their color, but also slowly starve to death. Zooxanthellae are expelled from the tissue when water temperature increases. It could take days to weeks for corals to turn from a to weeks for corals to turn from a "health"state to a"bleached"one.
Mass bleanching has been recorded in 20 location across the archipelago, including Aceh and Padang In Sumatera, The thousand Island National Park and Karimun Jawa National Park in Java, Gili Indah Island In Lombok, Wakatobi and Tomini Bay in Sulawesi, Maluku, and Raja Ampat, West Papua. Roughly 50 different organization and individuals, rangingfromsurfers, anglers, divers,dive operators and scientist, have reported bleaching from mid-March to mind-July 2010. Severe bleaching was reported in Sumatera and Sulawesi (more than 75 percent of coral were said to be bleanced), while reports of coral bleanching in Java, Bali Lombok, Maluku and west papua ranged from miled to medium.
Up to 90 percent of bleaching was reported in sabang and East Aceh and up to 40 percent of corals in Lypah Bay in Amed, Karangasem regency were reported as bleached. Other mass bleaching was also reported in Bali's Menjangan Island and Labuhan Lalang, Lovina, Tejakula and Tulamben. Although temperatures are already decreasing in many areas in Indonesia, many experts fear that recovery will be a struggle.
A resilience survey in Gili Indah by Reff Check Foundation Indonesia showed that some corals found bleached a month ago was already dead and covered by algae, while other coral had been affected by diseases.