Other low fat seafood  like cod, haddock, pacific halibut, ocean perch, pollock, sole, and cooked shellfish are also likely to be safe. Ditto for salmon and canned tuna. To avoid mercury, limit fresh tuna, swordfish and shark to once a week ( once a month if you are planning to become pregnant during the next year). Bluefish and lake trout may be contaminated with harmful PCBs.