This one may seem like a bit of a surprise, as tuna is notorious for high mercury levels. But the Seafood Watch isn't just referring to any old albacore tuna. They're quite specific in their recommendation, as is often the case. Look for troll- or pole-caught albacore tuna (fresh, not canned) from the United States or British Columbia, whose populations are in fairly good shape, and fishing method results in little bycatch. In light of its high levels of omega-3s and reasonable sustainability levels, the Seafood Watch placed it on the list despite its moderate mercury levels.
Kids 6 years old and younger should eat no more than two servings per month, kids 6 to 12 years old no more than three, and adults should limit themselves to four servings per month.
Famous for its high levels of omega-3 fatty acids (particularly in wild-caught species), salmon is an American favorite. And thankfully, levels of mercury are very low in this fish, at just 22 parts per billion. Seafood Watch recommends looking for either wild-caught salmon from Alaska, where the fisheries and population are extensively managed, or for freshwater coho salmon farmed in tank systems in the United States.
According to the Seafood Watch, farmed oysters actually make up about 95 percent of the world's supply, surprisingly. Generally, oyster farms have environmentally sensitive practices and are a sustainable source of oysters. And, according to the FDA, oysters contain only about 12 parts per billion mercury. So grill some oysters up, or just split them in half and slurp away!
Sardines are low on the food chain, and so one would expect them to have lower levels of mercury on average. Indeed, they do: just 13 parts per billion. Seafood Watch recommends opting for wild-caught Pacific sardines. They're an acquired taste, but once you've had fresh sardines, you'll probably wonder what took you so long to try them.
The concentration of mercury in this freshwater fish is relatively low, at just 71 parts per billion. The Seafood Watch recommends looking for farmed rainbow trout, which may also be sold as "golden trout" or "steelhead trout." Avoid wild-caught lake trout from Lake Michigan, whose population is still in recovery.
Arctic char's raw flesh is comparable in appearance (and when cooked, some say, comparable in flavor) to salmon. This fish is a relative newcomer to market, so much so that the FDA doesn't have any measurable level of mercury yet for it. But since it made the list, it's safe to assume that it's below 216 parts per billion. If you've never had arctic char before, here's your chance to try some.
Here's another fish that hasn't been seen often until recently. Barramundi is a firm, white-fleshed fish with a mild flavor. The FDA doesn't have any statistics on the fish yet, but the Seafood Watch says that U.S.-farmed barramundi is raised in an environmentally responsible manner, putting it on its list.
Wild-caught Dungeness crab from the West Coast (California, Oregon, or Washington) is caught using traps and practices that are sound. Fisheries take only male crabs of a certain size and close during molting season, giving populations a chance to recover and reach a certain size. And with just 65 parts per billion mercury, it's easy to see why it made the list.
Seafood Watch recommends wild-caught longfin squid from the U.S. Atlantic. With its relatively attractive market price (even cleaned), versatility of preparation, and a generally quick cooking time, squid is something more Americans may want to consider putting on their dinner plates. Furthermore, it is relatively low on the food chain, resulting in a mere 23 parts per billion mercury concentration.
Mussels are high in zinc, iron, and protein, and relatively low in mercury. Seafood Watch recommends farmed mussels, which are sustainably farmed in an environmentally responsible manner. They are generally available year-round.