Mercury released to the environment from industrial sources ends up in our oceans, contaminating seafood. Because it builds up in wildlife through a process called bioaccumulation, animals high on the food chain carry the most mercury. Many of the fish we eat, such as tuna and swordfish, are close to the top of the marine food chain.

People exposed to high levels of mercury in fish can experience health effects such as delayed neurological development in children. Both the Food and Drug Administration and the Environmental Protection Agency have advised women of childbearing age and children not to eat certain types of fish due to high levels of mercury. Elevated mercury levels are also being found in wildlife, like polar bears, whales and sharks.