Coral Disease Linked To Ocean Warming

An international team of scientists working on Australia’s Great Barrier Reef (GBR) have found a clear link between coral disease and wanner ocean temperatures. Research conducted at 48 reefs spread along 1,500 kilometers of the GBR, combined with six years of satellite data on sea temperatures, have revealed a highly significant relationship between ocean warming and the emergence of numerous unexplained coral diseases, such as white syndrome.

"Coral reefs have been decimated over the last several decades on a global scale," said Dr. Bette Willis of the Australian Research Council’s Centre of Excellence for Coral Reef Studies, one of the research team leaders. "Infectious diseases are thought to contribute to this mass coral mortality in reef regions like the Caribbean, and many reef ecologists suspected that high ocean temperatures were a key factor in the increased incidence and severity of disease outbreaks. Our results indicate that major outbreaks of the coral disease white syndrome only occurred on reefs with high coral cover after especially warm years."

In 2002, when sea temperatures were especially warm and a major bleaching event affected up to half the area of the GBR, there was a 20-fold upsurge in coral disease, notably on reefs with high coral cover. The researchers speculate that the disease may be due to a combination of the corals becoming stressed by high temperatures and an increase in the virulence of the attacking organisms.

"Our results suggest that climate change could be increasing the severity of disease in the ocean, leading to a decline in the health of marine ecosystems and the loss of the resources and services humans derive from them," the team’s report said.

Copyright Compass Publications, Inc. Jun 2007