Mercury contamination of seafood is a widespread public health concern. In fact, the Food and Drug Administration warns pregnant women, children and women who might become pregnant to avoid the consumption of swordfish, shark, tilefish and king mackerel because of their high methyl- mercury content. In addition to being toxic for humans, swordfish and many other species of fish are being caught in ways that are devastating ocean habitats and fisheries. Longline fishing, the fishing method used to catch swordfish, kills thousands of sea turtles per year. Our organization is fighting for a world that is sustainable and just for both people and for wildlife.
Facts for Fish Eaters
Why isn't my fish listed in the calculator? This list of fish species comes from the FDA's 1991 data. The list contains some of the most commonly eaten species of fish but is in no way comprehensive. You should not assume that omission of a fish species indicates that fish is safe. Some fish species in this list may be low in mercury but are high in other contaminants such as PCB's, etc. – Farmed salmon is one such species.
How do I know if my tuna is chunk light or albacore? Most tuna cans are labeled as either albacore or chunk light. Albacore tuna, according to recent testing by the FDA, contains 3 times as much mercury as does chunk light. You should avoid albacore tuna if you wish to keep your blood mercury level low. There are exceptions, however. Some companies sell albacore that is troll-caught. These species are younger fish and therefore contain lower levels of mercury. According to a recent study from Oregon State University, troll-caught albacore mercury levels are similar to chunk light levels (on average. 0.14 parts per million). Data for troll-caught data in the mercury calculator above is from the OSU study. Cans of chunk light tuna typically contain skipjack tuna which is a smaller species of fish and therefore contains lower mercury levels (on average. 0.123 parts per million). You can compare the mercury levels between the two in the mercury calculator above.
What about salmon? Salmon has average mercury levels that are not detectable by the FDA. However, some salmon have been found by the FDA to have mercury levels as high as 0.18 ppm (which is still relatively low compared with many other fish species).
* Mercury concentration values used for this calculator come from the United States Food and Drug Administration website. Two exceptions are the troll-caught albacore data which comes from an Oregon State University study and canned albacore data, which comes from an FDA dataset that is not yet published on their site. Please be aware that these values are averages. The concentration of mercury in seafood can be significantly higher or lower than what is represented here. As a precautionary approach, we recommend that women, (especially of child-bearing age) avoid seafood species that contain higher average levels of mercury. Mercury information for many shellfish species is currently unavailable.