Mercury Levels in Fish

The health benefits of including fish in our diets have been repeatedly advertised and are true to a great extent. Fish is rich in protein, omega 3 fatty acids and a variety of other vital nutrients. Balanced and thoughtful consumption of sea food is associated with proper growth and development of children and improved health of the heart.

These reasons might be sufficient for quite a number of people to include fish in their regular diets. However, it may not be as healthy as we think. The reason behind this is mercury. Most fishes contain traces of mercury. The biomagnification process increases the concentration of mercury in each successive predatory stage. Mercury is a highly toxic metal and has the potential to get accumulated in our bodies. It has been found that heavy accumulation of mercury may lead to a condition called mercury poisoning. It is particularly harmful to pregnant ladies and young children.

Not all fishes have high concentration of mercury. A careful selection and placement of fish on the menu is mostly sufficient to keep the mercury intake under check. As mentioned earlier, successive predation is one of the major causes for elevated mercury levels in fish. Therefore, avoid consuming predatory fishes like shark, swordfish and king mackerel. Including fishes, with low mercury levels, in our diet is suggested but it is still recommended to restrict fish intake to twice a week.

Fishes with the highest concentration of mercury are king mackerel, shark, tile fish and swordfish. Fishes with moderate levels of mercury are tuna (except skipjack), lobster, halibut, bluefish, grouper and sablefish. The safest method of regulating mercury intake is to include fishes and seafood with low mercury levels. These would include skate, light tuna, jacksmelt, croaker, whitefish, crab and squid.