August 19th, 2010 by Tom Schueneman
Record die-off of coral in Southeast Asia will likely continue for months
Researchers from the Wildlife Conservation Society (WCS), supported by scientists at Cook University in Australia and Syiah University in Indonesia, released a report earlier this week revealing one of the most sudden and severe coral bleaching and die-off events ever recorded.
In May, temperatures in the Andamann Sea off the coast of Indonesia spiked up to as high as 93 degrees Fahrenheit, bleaching and killing some 60 percent of coral off the coast of Indonesia near the Aceh province.
Extent of coral bleaching “unexpected”
Coral bleaching occurs when algae that typically lives within the coral is ejected as a response to environmental stress, such as rising ocean temperatures. It is the algae within that gives healthy coral their vibrant colors.
The initial survey was done in May, when researchers recorded the abnormally high spike in ocean temperatures that lasted for about a month. Subsequent monitoring done by the WCS team in early August revealed bleaching and die-off of some coral species as high as 80 percent. Caleb McClennen, the director of marine conservation for WCS, said that more colonies of coral are expected to bleach and die in the coming months.
“The mortality rate is incredibly high for this type of bleaching,” said McClennen. “Frequently, corals will bleach and recover, but that is not happening here.”
The extent and speed of the bleaching of these coral is a surprise to researchers, since these same colonies have survived significant environmental stresses, including the 2004 tsunami in the Indian Ocean.
“When we went and did surveys in early 2005, it turned out the corals were resilient to the impacts of the tsunami,” McClennen said. “Local fishing, river runoff and poor management were greater causes of localized coral decline. So the region has quite robust coral reef populations. We thought they would be quite resilient to these types of impacts.”
The WCS report comes just as the NOAA’s National Climatic Data Center released their monthly global analysis report showing 2010 year-to-date as the warmest on record (with last July as the second warmest on record).
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