30% Ocean Mercury Rise Linked to Asian Coal Plants
World wide, 75 percent of human exposure to mercury is from the consumption of marine fish and shell fish. In the U.S., about 40 percent of all human exposure to mercury is from tuna harvested in the Pacific Ocean, according to Elsie Sunderland, a coauthor of the recent US Geologic Survey study.
Data used in this study comes from one of 15 (so far) research cruises that are part of a much larger, international project called CLIVAR; the Climate Variability (CLIVAR) Repeat Hydrography/CO2 research program.
Data analysis of the water samples indicated that total mercury levels in the North Pacific Ocean water have risen about 30 percent over the last 20 years.

