The Mekong River has long been a source of food and water for millions, but according to the Mekong River Commission, an estimated 40 percent of fish have disappeared with many attributing the cause to China building eleven hydropower dams upstream. China insists these dams do not negatively impact the lower river and are willing to share water data. NBC News Keir Simmons speaks to some of those living and working along the river who have been impacted.