(Chon Buri) The sky-blue sea evokes a postcard setting for tourists. But underwater, a mysterious disease destroys corals in the Gulf of Thailand, a headache for scientists short of means, and a threat to the local economy.
“I’ve never seen anything like this before,” breathes oceanologist Lalita Putchim, after a dive off the island of Samae San, southeast of Bangkok.
Large yellow spots cover sections of the coral reef, victims of a killer bacterium which until now had spared this corner appreciated by amateur divers.
The spread of the so-called “yellow bands” disease, spotted in the province of Chonburi (southeast) for the first time in 2021, reminded Thailand of the fragility of its marine biodiversity, exposed to climate change.
In this tourist region, between the island of Samae San and Pattaya, scientists have found traces of dead coral in an area of more than 2 km2explains Lalita Putchim, who works for the Department of Marine and Coastal Resources, under the authority of the Ministry of Natural Resources and Environment.
The rapid spread of the disease worries scientists all the more as no treatment is known to get rid of the bacteria, first observed in Florida in the 1990s.
Other questions remain about the arrival in Thailand of the disease, which could be linked to overfishing, pollution and the warming of sea water which weakens the structure of the coral, according to experts.
Environmental protectors have organized their response on the ground, via dives to spot and collect diseased corals, and in laboratories, where researchers are trying to unravel the mysteries of the bacteria.
“So far, we only know the name of the bacterium that causes the disease,” admits Sarawut Siriwong, a researcher specializing in aquatic environments at Boraphat University in neighboring Chanthaburi province.
It is necessary to accentuate the protection of coral reefs, by limiting the evacuation of waste water into the sea or to dissuade visitors from touching the corals, he assures.
Volunteer divers
But research comes up against a financial and human barrier, which restricts research and prevents any large-scale operation to contain the bacterium.
The authorities could decide to allocate special funds in 2023, Athapol Charoenshunsha, director general of the marine and coastal resources department, told AFP.
“This is a very important subject. This is the first time that Thailand has encountered this disease, so we have to be very careful,” he said.
In the meantime, the researchers are calling on volunteer divers to help them spot the destroyed reefs.
“I started helping… after seeing the abnormal color of the coral,” said Thanapon Chaivanichakul, 38, a business executive from Bangkok, one of four volunteers helping the scientists that day, in taking pictures of underwater flora and fauna.
It is an entire region that is watching the precious corals disappear, one of its assets that attract Thai and foreign tourists in search of idyllic beaches and turquoise waters and which sustains the local economy.
“It’s as if our own house was destroyed,” complained Choopan Sudjai, owner of a tourist boat offering tours of Samae San Island.
This 55-year-old man keeps his community up to date with the latest news on the disease.
“Everyone is more careful when they go to sea now,” he says. “But since the coral is infected, and will be destroyed, what are we going to do in five years? »