CORAL BLEACHING THREAT.

The article reports that a bout of coral bleaching is affecting the Great Barrier Reef in Queensland as of April 2006. Scientists have warned that the problem could be as bad as the worst case on record in 2001-2002, when 60 percent of the reef was affected. An international team studying the world's reef explained that for the past four months water temperatures off Australia's northeastern coast have exceeded long-term averages. Bleaching occurs when the zooxanthellae microscopic plants which live in coral tissue and provide it with colour and food stop working due to stress, often as a result of rising temperatures.