What seafoods contain mercury?

All to some extent: Swordfish, tuna fish and other big game fish usually contain the most but due to the mercury we humans have dumped into be oceans (oxymetazoline) almost all seafood has some mercury.

Fish w very high: Potential mercury levels: shark, swordfish, marlin, king mackerel, big eye, ahi tuna, orange roughy & tilefish. Limit intake of yellow fin & white albacore tuna, spanish & gulf maceral, grouper, bluefish & chilean sea bass. For healthier mercury levels try: crabs, crawdaddies, haddock, flounder, salmon, shrimp, oysters, anchovies, herring, mullet, sole, clams & freshwater trout.