To get the most benefit from omega-3 fatty acids with minimal danger of mercury and to best support sustainable fisheries, choose these kinds of seafood in stores and restaurants.
Wild Caught Alaskan Salmon--It's more expensive than farmed salmon but wild-caught fish have better flavor, less mercury and other toxins and are most environmentally friendly. Look for this stuff cheaper in cans and use it for salmon cakes, burgers and in quiches.
Trap-Caught Shrimp--Trap-caught is best but even farmed shrimp provide a good amount of omega-3 and little mercury.
Trout--Most trout tend to be bug-eaters not fish eaters and so have relatively low levels of mercury. In New Mexico waterways, most trout are stocked, meaning the populations are sustainable.
Farmed Oysters--Buy these zinc-rich shellfish in stores and restaurants you trust, follow recommended safe-handling precautions and the nutritional boost will be well worth it.
In March the EPA and the Food and Drug Administration (FDA) released advice for women of childbearing age, pregnant women, nursing mothers and young children. They recommended against eating:
Shark--Sharks, like swordfish, king mackerel, tilefish and tuna, eat a lot of smaller fish, concentrating toxins in their flesh.
Swordfish--Though they can grow to over 600 pounds, overfishing has reduced the average size considerably. Their diet of fish, squid and octopus contributes to high mercury levels.
King Mackerel--This tuna relative is common in the Gulf of Mexico and feeds mostly on small fish and squid. It carries very high levels of mercury.
Tilefish--Also known as golden bass or golden snapper, tilefish has the highest reported levels of mercury.
Tuna--Reports vary on tuna. The FDA and EPA recommend against eating more than one serving of albacore tuna per week. Though troll or pole-caught tuna is safely responsibly harvested and high in omega-3 fatty acids it is also relatively high in mercury. Men may more safely eat tuna.