http://dsc.discovery.com/news/afp/20020923/reef.html
Sep. 26 — A potentially devastating coral disease is threatening the Great Barrier Reef, one of Australia's greatest natural wonders and biggest tourist attractions, experts revealed Wednesday.
The Australian Institute of Marine Science (AIMS), based in the north Queensland coastal city of Townsville, said the condition had spread from seven to 33 reefs within four years.
AIMS ecologist Cathie Page said little was known about the condition, known as white syndrome, which had killed entire coral colonies.
Page said in a statement: "In areas where white syndrome is most prevalent, the disease can kill a colony two meters in diameter in about two weeks. In other cases, it can take months to kill a large colony. Some colonies are spared and only parts of them are infected."
Page said the disease was not as threatening to the reef as the crown of thorns starfish, coral bleaching or cyclone damage, and its impact was still relatively minor. But on outer reefs off the far northern town of Cooktown and the Capricorn (central Queensland) coast, it had taken hold and was the main contributor to coral death, she said.
Scientists did not know what caused the disease, where it came from, or how it killed.
Affected colonies were partly colorful and partly white. Behind the white area was found dead coral covered with algae. The problem could be a virus, bacteria, or something totally different, Page said.
"All we can see is there is live coral, and then there's an area of dead coral," she said. "We don't know how it's actually killing the coral."
The new threat has appeared after last summer's coral bleaching, which affected 60 per cent of the Barrier Reef marine park.
"Corals are under stress already and this is another stress on top of that," Page said. "It is possible that the increases in disease we're seeing are because the corals are already stressed. Hence the disease is able to spread more quickly throughout the coral community."
White syndrome was considered rare until 1999, when the AIMS long-term monitoring program began surveying reefs for the disease.
Infected coral samples are being examined by AIMS microbiologists. Other samples have been sent to the United States for pathology tests, the AIMS statement said.
