Increased heavy metal contamination of border rivers threatening fish

Samples of the Bagarius fish, a catfish species caught in the Mekong River in Thailand’s northeastern province of Loei, have been found with blisters or lumps similar to samples caught and tested in rivers in the northern province Chiang Rai.

This is raising serious concerns over increased heavy metal contamination of the watercourses by mostly illegal mining activities in Laos and Myanmar, according to the findings of the Living River Association.

Somkiat Khuanchiangsa, president of Living River Siam Association, an environment advocacy organisation in the northern region, said that the blisters, lumps on and increased parasites found in the bodies of Bagarius fish are a clear sign of the weakening of fish exposed to heavy meals in rivers such as the Mekong, Kok, Ruak and Salween.

He noted that, even though the Mekong River is larger and holds more water than the other rivers and tributaries in the border areas adjoining Laos and Myanmar, the amount of heavy metals detected has increased alarmingly. He is urging authorities concerned to investigate.

Meanwhile, Dr. Suebsakun Kidnukorn, lecturer of the Mae Fah Luang University in Chiang Rai, said parasites found in the fish are an indicator that the environment in which the fish is living is badly contaminated and poses a threat to the health of the fish.

He said that fish samples caught in the rivers in Chiang Rai, Mae Hong Son and Loei and tested between November last year and February this year were found to contain high levels of arsenic, mercury, lead and cadmium.

He suggested that the Provincial Waterworks Authority and community-based tap water producers, who rely on raw water from the Mekong River, conduct tests of water samples for heavy metals to ensure the water is safe for consumption.

Dr. Suebsakun urged the government to call an urgent meeting with all relevant agencies to address the problem which, he says, is a matter of public safety.