Biomagnification starts when toxic substances are introduced into the environment, usually through industrial discharge, agricultural runoff, or improper waste disposal. These toxins are absorbed by phytoplankton and other small organisms at the base of the food chain. As these organisms are consumed by larger zooplankton and fish, the toxins accumulate in higher concentrations. Each step up the food chain results in greater accumulation of the toxin, a process known as bioaccumulation.
