Which Fish, Now?

This winter, a joint draft fish advisory from the FDA and EPA added tuna—America's most popular seafood—to its list of mercury-containing fish that should be restricted in the diets of pregnant women and young children, and a new study found unhealthy pollutants in far higher amounts in farmed salmon than in their wild kin.

Here's an update on toxins to avoid, fish that contain them and fish that are safer to eat.

Mercury

Fetuses, infants and young children are at greatest risk of harm from mercury, which can damage developing brains and nervous systems. Because mercury is stored in our bodies, just as it is in those of fish, women planning to have children should also avoid high-mercury fish well before they become pregnant. According to the Centers for Disease Control, 16 percent of American women of child-bearing age have levels of mercury in their blood high enough to indicate increased chance of harm to their fetuses. Symptoms of mercury poisoning include fatigue, headache, decreased memory and joint pain.

The FDA and EPA advise that young children, pregnant women, nursing mothers and women of childbearing age not eat more than two or three meals, or 12 ounces total, of fish and shellfish a week. They should limit high-mercury fish to one serving per week.

To be safest, however, The Green Guide and the Environmental Working Group (EWG) recommend limiting moderate-mercury fish to one meal a month, and bypassing high-mercury fish completely. In addition, our list of high-mercury fish is longer than the FDA's, which includes only king mackerel, shark, swordfish and tilefish (see fish lists below).

POPs

Polychlorinated biphenyls (PCBs)—neurotoxic, hormone-disrupting chemicals banned in the U.S. since 1977—were found at levels seven times higher in farmed salmon than in wild ones, according to a study published in Science in January 2004. PCBs are persistent organic pollutants (POPs), which accumulate in animal fats. Because most farmed salmon are raised on feed that includes ground-up fish—and sometimes other animals, such as cattle—their bodies collect POPs.

Fish to Avoid

High mercury: Atlantic halibut, king mackerel, oysters (Gulf Coast ) pike, sea bass, shark, swordfish, tilefish (golden snapper), tuna (steaks and canned albacore).

High POPs: Farmed salmon. Limit to once a month if pregnant/nursing. Check thegreenguide.com for updates on POPs in other farmed fish.

Fish to Eat

Moderate mercury (children and pregnant/nursing women can eat one from this list, once a month): Alaskan halibut, black cod, blue (Gulf Coast) crab, cod, dungeness crab, Eastern oysters, mahimahi, blue mussels, pollack, tuna (canned light).

Low mercury (above groups can safely eat 2-3 times a week, but check fish list at thegreenguide.com for environmental impacts): anchovies, Arctic char, crawfish, Pacific flounder, herring, king crab, sanddabs, scallops, Pacific sole; tilapia, wild Alaska and Pacific salmon; farmed catfish, clams, striped bass and sturgeon.

Note: low-mercury but overfished or destructively harvested species, such as Atlantic cod, shrimp, Atlantic flounder, and Atlantic sole should be avoided for the environment's sake.

Low POPs: Wild Alaska and California salmon (fresh or canned). Check with your state's department of health for POP advisories before eating fish from local waters. Also see map1.epa.gov.