Biomagnification is defined as the accumulation of a particular substance in the body of the organisms at different trophic levels of a food chain. One example of biomagnification is the accumulation of insecticide DDT which gets accumulated in zooplanktons. Small fishes consume these zooplanktons. Small fishes are consumed by large fish which are finally consumed by fish-eating bird present at the highest position in tropic level. Hence, the organism at the highest trophic level has the maximum accumulation of toxic substances.