Guam Coral bleaching becoming prominent

Guampdm 13 Oct 13;

Biologists at the University of Guam Marine Lab are looking into a phenomenon that is affecting the coral around the island.

According to Laurie Raymundo, associate professor of biology at the University of Guam, coral bleaching occurs when the animal is under extreme stress, using up its energy resources, much like humans do when under duress. This causes the animal to change color from a vibrant hue to white.

Raymundo said if it occurs, she usually sees bleaching around late August. But she and other colleagues noticed the event occurring about six weeks ago and only getting worse in the last three weeks.

And to Raymundo's surprise, the event spanned the entire 108 square kilometers of coral around the island, not just isolated areas.

"Every place we've gone to, we've seen it," she said. "That's why we're so concerned."

Raymundo said she received a notice from the National Oceanic and Atmospheric Administration informing her the event had reached bleaching alert level two, one of the most dangerous threat levels, according to the agency, that could possibly lead to mortality.

The cause of the bleaching is the extreme warm waters Guam has been experiencing due to the overall climate change of the planet, Raymundo said. With the lack of cloud coverage and decreased wave action, corals as far down as 50 feet are slowly being affected.

But corals closer to the surface of the water might have a better chance of surviving, Raymundo said, because they are used to the warmer temperatures. Biologists can't be sure at this point, however.

Some of the corals living around Guam are also part of a list of Indo-Pacific species proposed for protection, Raymundo said, and this bleaching event is affecting them as well.

The long-term effects of an intense coral bleaching event like this are the unlikely survival rate of the coral and the decrease in habitats for local fish.

Raymundo said, depending on the severity, it could take anywhere from weeks to years for the coral to recover or, in more extreme cases, reproduce if they do at all.

She also said that if the coral dies, local fish won't have the habitats necessary to thrive and protection from large storms such as typhoons could be put in jeopardy as well.

Raymundo said her team and others from the Guam Environmental Protection Agency are planning to dive on 50 sites around the island to assess the extent of the event and damage to the coral.

Usually, the university's Marine Lab would have the resources and help of the National Parks Service and the National Oceanic and Atmospheric Administration, but because of the federal government shutdown, these agencies aren't able to support any research efforts, causing a bigger burden on the remaining divers, Raymundo said.

Raymundo is hoping that the ocean nursery in Piti can be used to possibly breed more coral to replace the dead species around the island.