Environmental Toxins: Methylmercury Moves Up The Food Chain

Research by Dartmouth scientists suggests that animals who are fed nutritious, high-quality food have lower concentrations of methylmercury in their tissues. This suggests that methylmercury can be slowed when it passes up the food chain to fish. Lead author of the study, Roxanne Karimi, a graduate student at the Dartmouth Department of Biological Sciences, says that "this research provides evidence that by eating high-quality food, organisms may reduce their bodily concentration of a contaminant."

More nutritious, less toxic high-quality food helps reduce toxins in the food chain

Karimi and other researchers looked at the translucent water flea Daphnia pulex, which is a type of zooplankton that is one of the main food sources for freshwater fish. Methylmercury is a neurotoxin that is found in all bodies of water. Although methylmercury normally is only present in small amounts, methylmercury poses a serious health hazard because of biomagnification. Biomagnification is the process by which a toxin occurs in higher and higher concentrations as food chain ranking rises. The same effect also could be possibly observed for other environmental toxins such as PCBs and DDT.