Cetaceans ( whales and dolphins) also bioaccumulate mercury and other pollutants, so populations that eat whale meat, such as the Japanese, Icelanders, Norwegians and the Faroese, are also vulnerable to mercury ingestion. Species of fish that are long-lived and high on the food chain, such as marlin, tuna, shark, swordfish, king mackerel and tilefish contain higher concentrations of mercury than others. įish products have been shown to contain varying amounts of heavy metals, particularly mercury and fat-soluble pollutants from water pollution. In human-controlled ecosystems of fish, usually done for market production of wanted seafood species, mercury clearly rises through the food chain via fish consuming small plankton, as well as through non-food sources such as underwater sediment. Mercury is dangerous to both natural ecosystems and humans because it is a metal known to be highly toxic, especially due to its neurotoxic ability to damage the central nervous system.

This element is known to bioaccumulate in humans, so bioaccumulation in seafood carries over into human populations, where it can result in mercury poisoning. Fish and shellfish concentrate mercury in their bodies, often in the form of methylmercury, a highly toxic organomercury compound. The presence of mercury in fish is a health concern for people who eat them, especially for women who are or may become pregnant, nursing mothers, and young children. Through the process of biomagnification, mercury levels in each successive predatory stage increase. Nearby anthropogenic sources, such as coal burning and iron mining, can contaminate water sources with methylmercury, which is efficiently absorbed in the bodies of fish.

What is mercury poisoning