Environmentalists have expressed grave concerns over an alleged plan by Laos to remove some islets on the Mekong River by blowing them up to allow larger cargo ships to navigate the waterway more safely.
The environmentalists, led by Chirasak Inthayot, coordinator of the Hong Hien Mekong River Network (Network of School for Mekong River), submitted a letter on Friday to Thailand's Marine Department asking it to look into the matter as they fear the plan would cause significant damage to the environment.
Mr Chirasak said he also wanted the department to assess how Thailand would be effected by the alleged plan.
He said he was forced to act after receiving information from Lao environmentalists who claimed China was behind the plan.
He said China has sent three vessels to the lower Mekong River to help Laos conduct a survey of islets which needed to be removed. The first islets likely to be targeted were at Kaeng Paew, located between Huay Xai and Pak Beng in Laos. He said the islets are around 100 kilometres away from Chiang Rai's Wiang Kaen district.
"The Marine Department should provide us with more information. We also want the Mekong River Commission to intervene as the Mekong is an international river. Any action taken along the river must be approved by all the MRC's members," he said.
Mr Chirasak said islets in the Mekong River are known breeding areas for various species of freshwater fish, including the rare giant catfish.
China in 2003 destroyed all islets along the Mekong River located in its territory to clear the way for shipping heading to the Lower Mekong Region.
Mr Chirasak said the ecological systems and people's food security and livelihoods would be put at serious risk if all the islets in Lao territory are destroyed for trade purposes.
Dam construction projects along the river have already badly effected people whose lives depend on the river, and that situation could further deteriorate if those islets are removed, he said.
He said he suspects China might be putting pressure on Thailand to remove Khon Phi Long, the country's biggest river islet in Chiang Rai's Chiang Khong district to allow access for bigger vessels.
All islets have been cleared, except the ones in Thailand, which means we have to defend them to protect the environment and people's livelihoods, he said.