The Mekong River is at its lowest level in Cambodia in a decade and could affect the country’s crucial fish catches, officials at the Mekong River Commission, the inter-governmental body that monitors the health of the river through Laos, Thailand, Cambodia and Vietnam, said Thursday.
The river’s low level is being blamed on a lack of rainfall during last year’s rainy season, but suspicion has also fallen on the massive dam projects on the upper reaches of the Mekong, particularly in China.
“We understand that the fish have been reduced quite a bit this year,” Ian Campbell, senior specialist for the environment division of MRC said in an interview Thursday.
“But there is a real problem monitoring fish throughout the region,” Campbell cautioned.
Fish larvae float down the Mekong and grow in the flooded areas during the wet season, Campbell said. The bigger the flood area, the more fish larvae survive, he said.
“We presume that there are not so many larvae surviving,” he said.
Another reason for the drop in fish stocks could be that a decrease in the Mekong’s water levels may lead to crowding of food sources making it harder for fish to survive, Campbell added.
The low level of the Mekong and its effects was one of the topics Wednesday and Thursday at MRC’s 19th Joint Committee meeting in Ho Chi Minh City.
May Sam Oeun, secretary of state for the Ministry of Agriculture, said Mekong’s low level was hurting the country’s fishing industry.
“People are catching less fish,” he said.
Nao Thuok, director of the Department of Fisheries at the Ministry of Agriculture, raised concerns last month over the country’s diminished fish hauls because flooding was not as widespread as normal and fish populations were denied much of their feeding and breeding grounds.
Nao Thuok said only about 1,000 tons of fish had been caught by early February, compared to some 7,000 tons collected during the same time period in 2003.
There have been long-standing concerns that dams upstream of the Mekong in China and on tributaries of the Mekong in Thailand, Laos and Vietnam have adversely affected river’s water levels and its fish stock.
China has reportedly plans to build more than a dozens dams on the upper portion of the Mekong in Yunnan province. Two dams have already been completed, Dachaoshan and Manwan, and have begun to store water for hydroelectricity production.
The dams in China could contribute to the low water levels, Campbell said, but cautioned they were not the sole problem.
“Chinese dams do have some affect. The way they operate causes daily fluctuations and changes the amount of sediment floating in the water,” he said.
Long Saravuth, deputy director of Hydrology and River Work at the Ministry of Resource and Meteorology, said on Thursday that the river levels were at the lowest recorded levels since 1998.
He denied that dams, particularly those in China, should be held solely responsible for the river’s low levels as only 12 percent of the Mekong’s water flows from China.
“Most of the water flows from the lower region such as Thailand, Laos and Burma—so we can not blame China alone for this,” he said Thursday.
“The biggest cause is low rainfall in the whole region,” he said.