La Niña spikes sea surface temps in western Pacific
By Summit Voice
SUMMIT COUNTY — A rapid response team of marine biologists from the World Conservation Society is investigating what they say could be the most widespread incident of coral reef bleaching recorded in the past few decades.
Results of the initial May survey in May show that up to 60 percent of corals in near the northern tip of the island of Sumatra have bleached as water temperatures in the area climbed well above normal. The scientists found that 80 percent of some species have died since the initial assessment and more colonies are expected to die within the next few months.
That, in turn, will have huge impacts on the reef fishery, critical to residents of the area who depend on it for their livelihood.
“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. “It 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 “bleaching,” or whitening, occurs when algae living within coral tissues are expelled. The condition results from stress triggered by environmental factors such as sea surface temperature fluctuations. Some bleached corals may recover over time, while others die.
Sea surface temperatures in the Andaman Sea—an area that includes the coasts of Myanmar, Thailand, the Andaman and Nicobar Islands, and northwestern Indonesia—have been on the rise. According to the National Oceanic and Atmospheric Administration’s Coral Hotspots website, temperatures in the region peaked in late May, when the temperature reached 34 degrees Celsius. This represents a dramatic 4-degree rise over the long-term averages for the area.
The ocean around Indonesia is the warmest pool of water on the planet. Climate researchers say it’s very likely that global warming trends will exacerbate cycles like El Niño and La Niña, sending sea surface temperatures spiraling higher.
The World Conservation Society and Australia’s James Cook University have been working in the region since March 2005. Surveys conducted in the wake of the Indian Ocean tsunami in 2004 revealed that the many reefs of Aceh were largely unaffected by this massive disturbance. Indeed, reefs severely damaged by poor land use and destructive fishing prior to the tsunami had recovered dramatically in the intervening years due to improved management by local governments and communities.
But the recent bleaching and mortality will have a profound effect on reef fisheries. Of particular concern is the scale of the sea surface temperature anomaly, which the NOAA website indicates has affected the entire Andaman Sea and beyond. Similar mass bleaching events in 2010 have now been recorded in Sri Lanka, Thailand, Malaysia and many parts of Indonesia.