For many years, public health experts have warned against eating certain kinds of fish, including tuna, that tend to accumulate mercury. But recently, as industry cuts down on its mercury emissions (whether it be by new enforced standards or better business practices), research has found mercury concentrations in some fish are dropping!
Mercury levels in the atmosphere, oceans, streams, lakes, and rivers have been rising as a result of emissions from coal-fired industrial plants, which are still the world’s major source of power. Plumes of smoke carry mercury, a neuro-degenerative toxin (3), into the atmosphere, where it insidiously filters into all of our water supplies and even our organic foods.
Humans, all wildlife, birds, soil, plants and fish, particularly larger fish (like tuna, who are high on the food chain) have been the most affected, and recommendations from the FDA have suggested limited consumption of fish, particularly for pregnant women.
Good News! Mercury Levels Dropping in North Atlantic Tuna
The latest study, published in Environmental Science & Technology, reports that this is the case in prized Atlantic Bluefin tuna. (2)
Researchers at Harvard and the University of Massachusetts analyzed mercury levels in tissue samples from nearly 1,300 Atlantic Bluefin tuna caught between 2004 and 2012, and found that mercury levels in the fish fell an average of 19% during that period.
While coal burning is still on the rise in Asia and mercury contamination of the air and water are rising globally, in North America, mercury levels have fallen 2.8% a year from 1990 to 2007 according to a hopeful new study. (1)
During the same period, mercury in North Atlantic waters dropped 4.3% annually. Mercury in the air above the North Atlantic Ocean declined 20% from 2001 to 2009. (1)
While the researchers are quick to point out that these reductions do not prove the relationship between lower coal plant emissions and lower mercury levels in fish, this is good news for fish eaters!
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We’re Not Out of the Woods Yet…
An international team led by the U.S. Geological Survey (USGS) recently documented widespread mercury contamination in air, soil, sediment, plants, fish, and wildlife at various levels across the region. They evaluated potential risk from mercury to human, fish, and wildlife health.
“Mercury is widespread in the environment, and under certain conditions poses a substantial threat to environmental health and natural resource conservation,” says Collin Eagles-Smith, Ph.D., USGS ecologist and team lead.
- There is strong evidence that by reducing coal burning, we can, perhaps in short order, detoxify our oceans. To protect the earth, our environment, humankind, and wildlife, I highly recommend we promote the use of clean energy sources that do not burn coal.
- North Atlantic fish may have lower levels of mercury, but they still contain mercury. Thus, it would still be wise to choose fish that have shown to be lower in mercury levels. >>> See a list here
- Buying North Atlantic fish may be safer than fish from the Pacific. While the study only measured the mercury levels in North Atlantic fish, the notion is that this effect is due to lower coal burning in the United States. With coal burning in Asia still on the rise, and winds that generally blow from west to east, it might be wise to source your fish from the North Atlantic whenever possible.