Consumers should have easy access to information about fish species with elevated mercury content. (NIH)

A new report has some not-so-great news for those who love to eat fish. Mercury is turning up in fish from all over the world—and coal is one of the main culprits.

Coal burned in power plants releases mercury, basically dissolved in smoke, that later settles out over the land. It typically falls out of the atmosphere within 30 miles or so of where it was burned and then finds its way into soil and runoff that eventually end in the oceans.

In July of 2011, Earthjustice filed a petition on behalf of Dr. Jane Hightower, the Mercury Policy Project and the Center for Science in the Public Interest, asking the Food and Drug Administration to post signs near market seafood counters and on seafood labels to warn consumers about mercury in fish.

Consumers should have easy access to information about fish species with elevated mercury content and to consumption limits for fish and shellfish. This should help consumers make quick, informed decisions about what to buy and what to steer clear of.

The new report, Mercury in the Global Environment, will be used in talks next year on a proposed United Nations global treaty to reduce mercury use and pollution.

The report shows that mercury contamination of seafood is global in scope, and that negative health effects from methylmercury in seafood are occurring at levels below what was considered to be safe a few years ago.

Cod, salmon and flounder are “low mercury” fish, especially when compared to marlin, tuna, mackerel, swordfish and grouper, which all typically contain higher levels of mercury. However, this information is not readily available to consumers at fresh fish counters or on seafood packaging.

The U.S. Geological Survey says that mercury:

…affects the immune system, alters genetic and enzyme systems, and damages the nervous system, including coordination and the senses of touch, taste and sight. Methylmercury is particularly damaging to developing embryos, which are five to ten times more sensitive than adults. It’s also known to affect the way that children think, talk and walk.