The Mekong River ecosystem has been devastated from rising water levels during the dry season, as upstream dams in China discharge water to facilitate navigation in the river.
An activist from Chiang Rai’s Chiang Khong district, Jirasak Inthayot, yesterday raised concerns over the mass extinction of bird and fish species in the Mekong and the grave impacts on the livelihoods of local people from the unnatural rise in water levels during the dry season.
Jirasak said that the water level in the Mekong has been increasing since March 15 and, as of yesterday, all the sandy beaches, islets, and rocks in the river that are normally exposed at this time of year were submerged.
“These sandy beaches and rocky areas are the major nesting ground for many bird species, while the shallow and clear water of the Mekong River in the dry season allows gai (river algae) to bloom and become a food source for fish and local people,” he said.
“However, the unnatural water-level rising has already damaged almost all the nests along the river, threatening the survival of many bird species and destroying gai. The water discharged from Chinese dams has both deepened the river and made the water too turbid for the growth of gai.”
According to information provided by Mekong River Commission, the water level at Chiang Rai’s Chiang Saen district increased rapidly by up to 0.6 metres during the past week. The water level on Thursday was 2.7 metres, compared to 2.1 metres on March 12.
Jirasak said this was not the first time that a water discharge from dams in China had devastated bird-nesting areas and harmed the river ecosystem. China had previously released water to facilitate a survey of the Mekong River navigation channel improvement project, causing the water level to remain high throughout the last dry season.
“We have noticed a significant decrease in the bird population this year, as an entire generation of many bird species was killed last dry season. The nests of the remaining birds were destroyed by the unseasonable rising of the water level. I fear that many bird species will be extinct soon,” he said.
Philip Round, an expert from Bird Conservation Society of Thailand, said that at least 13 rare bird species are endangered by the loss of habitats and nesting grounds from the dry season water discharge and blasting of river rapids. Two species of critically endangered birds – Sterna aurantia (river tern) and Esacus recurvirostris (great stone-curlew) – may face extinction.
Adding to the grave impacts on Mekong River fauna and flora, the livelihood of local people has also been threatened by activity at the upstream dams. Jirasak said that people were now unable to gather gai from the river, and that deprived them of income of up to Bt2,000 per day.
“Farmland along the riverbank, which provides another way of life for local people, is going to be the next victim, as the water level is still rising and some of the low-lying farms have already been flooded,” he said.
It was reported earlier this month that the low water level in the Mekong River during dry season had disrupted the navigation of big vessels and stranded many transport boats. The Marine Department asked Chinese authorities to discharge more water to support river navigation, and to share water-discharge information from Jinghong Dam with Thailand.