Seafood Contamination by Airborne Mercury

Over the past century, mercury pollution in the surface ocean has more than doubled, as a result of past and present human activities such as coal burning, mining, and other industrial processes.  A project of Dartmouth College (New Hampshire, USA), C-MERC – the Coastal and Marine Mercury Ecosystem Research Collaborative, monitors mercury pollution in the marine environment.  The team presents a series of compelling scientific papers representing the culmination of two years of work that synthesizes the science on the sources, fate, and human exposure to mercury in marine systems by tracing the pathways and transformation of mercury to methylmercury from sources to seafood to consumers. Importantly, C-MERC reports that mercury released into the air and then deposited into oceans contaminates seafood commonly eaten by people in the United States and globally. Specifically, the team’s data suggests that mercury deposited from the atmosphere ranges from 56% of the mercury loading to several large gulfs to approximately 90% in the open ocean.  These deposits can find their way into the meat of fish such as tuna and swordfish, which together account for more than half of the mercury intake from seafood for the overall American population.