A. Last year, the FDA did advise "pregnant women and women of childbearing age who may become pregnant on the hazard of consuming certain kinds of fish that may contain high levels of methyl mercury. The FDA is advising these women not to eat shark, swordfish, king mackerel, and tilefish. As a matter of prudent public health advice, the FDA is also recommending that nursing mothers and young children not eat these fish as well."
The FDA advisory also stated that "seafood can be an important part of a balanced diet for pregnant women and those of childbearing age who may become pregnant. FDA advises these women to select a variety of other kinds of fish -- including shellfish, canned fish, smaller ocean fish or farm-raised fish -- and that these women can safely eat 12 ounces per week of cooked fish. A typical serving size of fish is from 3 to 6 ounces."
According to the FDA, "consumption advice is unnecessary for the top 10 seafood species, making up about 80 percent of the seafood market--canned tuna, shrimp, pollock, salmon, cod, catfish, clams, flatfish, crabs, and scallops. This is because the methyl mercury levels in these species are all less than 0.2 ppm and few people eat more than the suggested weekly limit of fish (2.2 pounds) for this level of methyl mercury contamination.?
What about tuna fish? This is actually controversial. The original FDA advisory did not specifically say to avoid tuna fish, which might also become contaminated with mercury, and many critics have come out against the FDA saying that they should have included tuna on the original list. Still, the FDA did give a general recommendation to avoid eating more than 12 ounces of fish each week, which would also include tuna. To be safe, many professionals recommend limiting yourself (if you are pregnant) and younger children to just one tuna fish sandwich each week.
You can view the latest FDA recommendations here, which includes new warnings about fish and mercury, including tuna fish.
What about fresh fish that you catch on your own? These fish may also put you at risk and you should check your local advisories from your local health department for offical warnings and recommendations about eating freshly caught fish.