A severe drought(干旱) that has caused water levels in Southeast Asia's Mekong River to drop to their lowest in more than 100 years could have devastating(毁灭性的) consequences for fish, as well as the tens of millions of people living and working along the river, experts warn.
This year, the dry conditions in the Mekong region persisted(持续) due to warm Pacific Ocean currents(洋流)known as the EI Nino effect. But climate change is also a driving factor, experts say, causing the rainy season to shorten considerably. The situation was made worse by hydropower (水力力电)dam operators upstream, in China and Laos , withholding water for their own purposes.
Many rice farmers in the region have been unable to plant their main crop, raising fears 'of a heavily diminished harvest this fall. Less water flow could also have a devastating impact on fish reproduction in the Mekong River basin. Perhaps even more alarming, experts expect that droughts and disruptions(中断)to the water flow of the Mekong will become more common, and they warn that it could eventually lead to the ruin of the entire ecosystem.
Originating in the Tibetan highlands, the Mekong River flows through six Asian counties before emptying into the South China Sea. The river basin is home to the largest inland fishery in the world and more than 60 million people depend on it for their livelihoods.
Few rivers in the world rise and fall with the seasons as much as the Mekong, which can drop Few rivers in the world rise and fall with the seasons as much as the Mekong, which can drop up to40 feet in some places at the end of the dry season. When the rainy season arrives, they normally produce a flood pulse that brings with it sediment(沉淀) important to agriculture as well as huge amounts of tiny fish, including many critically endangered species such as the Mekong giant catfish, that are swept into the Tonle Sap Lake and other floodplains where they can mature.