WASHINGTON, Oct. 1 (Xinhua) -- The Great Barrier Reef has lost half of its coral cover in the past 27 years due to storm damage, crown-of-thorns starfish and bleaching, according to a new study published on Monday in the Proceedings of the National Academy of Sciences.
The study clearly shows that three factors are overwhelmingly responsible for this severe loss of coral cover. Intense tropical cyclones have caused massive damage, primarily to reefs in the central and southern parts of the Reef, while population explosions of the coral-consuming crown-of-thorns starfish have affected coral populations along the length of the Reef. Two severe coral bleaching events have also had major detrimental impacts on the northern and central parts of the Reef.
"This finding is based on the most comprehensive reef monitoring program in the world. The program started broad-scale surveillance of more than 100 reefs in 1985 and from 1993 it has incorporated more detailed annual surveys of 47 reefs," said Peter Doherty, a research fellow at the Australian Institute of Marine Science.
Doherty said that if the trend continued, coral cover could halve again by 2022.
Interestingly, the pattern of decline varies among regions. In the northern Great Barrier Reef, coral cover has remained relatively stable, whereas in the southern regions the researchers see the most dramatic loss of coral, particularly over the last decade when storms have devastated many reefs.