Corals in trouble

an epidemic of coral bleaching has adversely affected Australia's Great Barrier Reef for the second time in four years. This was revealed during a survey recently carried out by the Australian Institute of Marine Science. The epidemic is also fast spreading to the islands of the South Pacific. Coral bleaching occurs when higher sea temperatures force algae out of the coral polyps. These algae have a symbiotic relation with the corals and they lend them their brilliant colours. Usually, bleached coral recovers in the next cool season, but if all the algae are lost, the corals die and the reefs crumble.

According to the Great Barrier Reef marine park authority, bleaching around Keppel island is extreme, with almost all the species suffering there. Other places badly hit include Whitsunday island and Magnetic island. The bleaching follows record sea temperatures since the beginning of the year. "Almost the entire reef's temperature was 2