If industrial emissions of mercury continue at their current rate, the Pacific Ocean’s mercury levels in 2050 will have increased by 50 percent. Those findings are part of a study led by Harvard University and U.S Geological Survey researchers and published in Global Biogeochemical Cycles journal.
The study also found that total mercury levels in the Pacific Ocean have already risen about 30 percent in the past 20 years, which the authors attribute to increases in mercury atmospheric emissions, particularly from Asia.
That said, the authors also note that it is “plausible that reductions in ocean mercury levels would follow if mercury emissions were decreased.”
Consumption of ocean fish and shellfish accounts for more than 90 percent of human methylmercury—a highly toxic form of mercury—exposure in the United States, the study reports. Forty percent of that is from Pacific Ocean tuna. As methylmercury is a neurotoxin that can alter brain development of fetuses, the U.S. Food and Drug Administration advises women who are pregnant, nursing or expecting to become pregnant to limit their consumption of fish and seafood to two, 6-ounce servings per week. The FDA also says they should not eat any shark, swordfish, king mackerel or tilefish and no more than one of their weekly servings should be albacore or white tuna.