DDT content in the water of a lake that supplies drinking water to the nearby villages is found to be 0.033 ppm. The kingfishers of that area reported to have 2 ppm of DDT. This phenomenon is known as:

DDT content is 0.033 ppm is water and 2 ppm in kingfisher which means the concentration of toxicant has increased in successive trophic levels. It is referred to as biomagnification. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, and is thus passed on to the next higher trophic level.