RSSAll Entries Tagged With: "Reef Health"

Coral Bleaching Occurring at Shallow Depths

Coral Bleaching at Ko Haa

Coral bleaching is occurring at shallow depths in dive sites throughout the Andaman Sea. According to the Bangkok Post, coral reefs off Phuket, Krabi and Phang-Nga, including popular scuba diving sites such as the Similan, Surin and Phi Phi islands, have been damaged by the phenomenon.

The bleaching could get worse if sea temperatures continue to rise, says Niphon Phongsuwan, a marine biologist at the Phuket Marine Biological Centre (PMBC). The bleached corals may die if they cannot tolerate the stress, but if we’re lucky – and the monsoon winds come soon, those corals that are bleached already might survive and recover as was the case in 2003.

Temperatures in the Andaman Sea have stood as high as 31-32C for a long period this year and we are seeing temperatures as high as 33C in the shallow areas at Ko Haa, Hin Daeng & Hin Muang, Ko Rok and Ko Phi Phi.

Coral reefs in shallow waters at depths of up to 10m will take three to four years to recover. Coral at greater depths will take more time.

Coral bleaching is the whitening of corals, due to stress-induced expulsion or the death of zooxanthellae – symbiotic, algae-like micro-organisms. Under stress, corals may expel their zooxanthellae, which leads to a lighter or completely white appearance, hence the term ‘bleached’. Coral bleaching occurs when the conditions necessary to sustain the coral’s zooxanthellae cannot be maintained. If the coral colony survives the stress period, zooxanthellae often require weeks, or even months, to return to normal density.

You can report instances of coral bleaching to the NOAA Global Coral Reef Watch Project. Please follow this link to submit data: http://www.reefbase.org/contribute/bleachingreport.aspx

Other organisations that support coral bleaching monitoring include: