Mercury concentration in seafood gets plenty of attention from researchers and consumers, since mercury poisoning is a very real short- and long-term threat to our wellness. A study by the National Centers for Coastal Ocean Science (NCCOS) has identified which edible fish has higher mercury levels than any other.

According to studies by the NCCOS and the Food and Drug Administration, tilefish from the Gulf of Mexico have the highest levels of mercury, ranking at 1.123 on the Mercury Concentration Mean (PPM). However, location matters; tilefish from the Atlantic carry less mercury, with a concentration of only 0.144 PPM.

Other mercury-laden fish include swordfish, shark, mackerel king, and bigeye tuna, but other tunas, such as albacore and yellowfin, have only about 0.35 PPM. In the mid-range are fish such as marlin, orange roughy, and grouper, while sardines, tilapia, salmon, anchovies, and catfish have relatively low mercury levels.