Does Farm-Raised Fish Contain Mercury?

If you go to a good fishmonger, you'll soon find out that there's no shortage of options for your next lemon and herb fish skillet. There's a ton of different fish on the market waiting to be enjoyed, but it can be hard to make distinctions. One division you can make right off the cuff is the difference in mercury levels of farm-raised and wild-caught fish.

Recently, Chowhound spoke with Matt Ranieri, the VP of Technical Services at Acme Smoked Fish, to shoot the breeze about all things related to fish farming. Among these topics was the mercury level in farmed fish, which Ranieri assured is less than that of its wild counterpart. "Farm-raised fish generally contain the lowest levels of mercury," he said. "They are often raised under strict environmental programs that include testing for mercury, and the feed can be controlled." So when you're contemplating the differences between farm-raised and wild-caught fish, you can safely chalk mercury up as one of the distinguishing factors.

It's no secret that mercury isn't exactly a good thing for us humans to eat, and there are a number of reasons why you want to watch your mercury intake. But on the whole, most of the fish you eat has a level of mercury safe for consumption. Mercury in fish isn't usually a prohibitive factor, but there are still scenarios where you'd have to be careful depending on what type you're eating.

Matt Ranieri touched on the fact that pregnant people especially should avoid mercury-rich fish. "If you are pregnant, mercury in the diet can lead to birth defects. It is important to check with your doctor if you have concerns about high mercury," he stated. He also brought up a specific type of fish that you should avoid, since "larger fish, like swordfish, are typically higher in mercury content." Indeed, larger, predatory fish tend to have higher mercury levels. According to the U.S. Food and Drug Administration, this also includes shark, king mackerel, and tilefish.

If you still want to scratch that fish itch, you can check out common fish with the lowest mercury levels, which tend to be safe to eat in moderation regardless of your situation. Of course, you can also buy farm-raised fish to lower those mercury levels even more.