Many people are worried about high mercury counts in fish, so they're swearing off seafood. The thing is, many types of fish are low in saturated fat, are an excellent source of lean protein, and are high in essential heart-healthy omega-3 fatty acids. I'm not saying that mercury is something to overlook, since this toxin can cause brain damage, and possibly cancer, but it doesn't mean you need to give up fish entirely.
It's safe to eat fish twice a week (up to 12 ounces), but you should choose two different types of fish to get a variety of nutrients. Good sources of low-mercury fish are shrimp, oysters, scallops, canned light tuna, salmon, pollock, flounder, sole, halibut, and catfish. Young children, women trying to get pregnant, those already pregnant, and nursing moms are considered "high risk," since too much mercury can affect developing brains. So for those people, the EPA recommends limiting intake of seafood that's high in mercury such as swordfish, golden bass, golden snapper, and shark.