The Mae Klong River (not to be confused with the Mekong River), is heavily polluted with toxic waste from factories upstream along the river, and this is believed to be the culprit in the deaths of the endangered giant stingrays as well as many other fish species.
The die-off is particularly alarming because there are so few of the giant rays left in the river. More alarming is that these magnificent fish were only discovered by scientists in the 1990s, and now they are already on the endangered species list. The World Wildlife Fund (WWF) says the giant stingray has declined dramatically in Thailand due to serious pollution, overfishing and dam building.
The stingray deaths began in September when a few of the giants began turning up dead along the river. On October 14, the Bangkok Post reported that the Industry Ministry was preparing to press charges on an ethanol-producing factory in Ratchaburi because their wastewater flowing into the river exceeded safe levels for pollutants and this was suspected to be the cause of the stingray deaths.
A total of 45 stingrays were found dead from Sept 29-Oct 10 in Samut Songkhram. The factory admitted that one of their wastewater pipes had broken on Sept. 29, and the discharge of polluted water into the river was accidental. They also said the company was in the process of repairing the leak.
Nantarika Chansue, a veterinarian from Chulalongkorn University said the deaths were not normal. A by-product in the making of ethanol is ammonia. Some stingray autopsies showed the internal organs were destroyed. Many of the stingrays had 20 times the safe level of ammonia.
“One thing is clear: a reduction of pollution from surrounding factories is needed to improve the health of the river and save the stingrays in the long term,” a biology professor tells National Geographic.
