"The mercury found in marine animals often originates from coal-fired power plants. These plants emit mercury into the atmosphere and it later deposits into surface waters and oceans, where bacteria turn it into methylmercury. Methylmercury ingested by smaller marine organisms makes its way up through the sea's food chain, resulting in bioaccumulation throughout the ecosystem, most noticeably in aquatic apex predators. This study aims to shed light on the impact of mercury on the oceans, which humans rely on for food."
Dolphin study could yield insight into how mercury influences health. Hub. Phil Sneiderman. April 1 , 2015. http://hub.jhu.edu/2015/04/01/mercury-levels-dolphins-singapore

