A large-scale bleaching event due to high ocean temperatures appears to be underway off the coast of Sumatra, an Indonesian island, reports the Wildlife Conservation Society (WCS).
An initial survey by the conservation group’s “Rapid Response Unit” of marine biologists found that 60 percent of corals were bleached. Follow up assessments “revealed one of the most rapid and severe coral mortality events ever recorded” with 80 percent of some species dying.
“It’s a disappointing development particularly in light of the fact that these same corals proved resilient to other disruptions to this ecosystem, including the Indian Ocean Tsunami of 2004,” WCS Indonesia Marine Program Director Dr. Stuart Campbell said in a statement.
The banner reads: “The entire Sungai Tohor community rejects the presence of P.T. LUM.”
Campbell, and other members of the research team, linked the event to a sharp rise in sea surface temperatures in the Andaman Sea. Temperatures reached 34 degrees Celsius (93°F)—4 degrees Celsius higher than long term averages for the area—in May 2010.
“If a similar degree of mortality is apparent at other sites in the Andaman Sea this will be the worst bleaching event ever recorded in the region,” according to Dr. Andrew Baird of the ARC Centre of Excellence for Coral Reef Studies at James Cook University. “The destruction of these upstream reefs means recovery is likely to take much longer than before”.
“This is a tragedy not only for some of the world’s most biodiverse coral reefs, but also for people in the region, many of whom are extremely impoverished and depend on these reefs for their food and livelihoods,” said WCS Marine Program Director Dr. Caleb McClennen. “Immediate and intensive management will be required to try and help these reefs, their fisheries and the entire ecosystem recover and adapt. However, coral reefs cannot be protected from the warming ocean temperatures brought on by a changing climate by local actions alone. This is another unfortunate reminder that international efforts to curb the causes and effects of climate change must be made if these sensitive ecosystems and the vulnerable human communities around the world that depend on them are to adapt and endure.”
Coral reefs are also at risk from ocean acidification, a product of rising carbon dioxide concentrations in the atmosphere. Some researchers say acidification could prove more devastating in the long-run to coral ecosystems than elevated sea temperatures.