Mercury can only be found in fish through laboratory analysis. Mercury contamination is dangerous. Mercury cannot be "cooked out" of the fish.
Fish and shellfish contain omega-3 fatty acids that can improve the health of people of all ages. Pregnant women who eat fish will pass these nutrients to her baby supporting healthy brain and eye development.
Fish are generally good to eat, but some have higher levels of toxins than others. Mercury and other pollutants can build up in the bodies of living things, especially the larger types of fish we eat. These pollutants can harm brain development at relatively low levels and can be toxic to adults at high levels.
Women of childbearing age should eat two to three servings each week and children older than age two should try to eat one to two servings of seafood from the "best choices" list each week.