Q. 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:

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Solution:

Biomagnification, also known as bioamplification or biological magnification, is the increase in the concentration of a substance that occurs in a food chain.
This happens because a toxic substance accumulated by an organism cannot be metabolized or excreted, and is thus passed on to the next higher trophic level. This phenomenon is well-known for mercury and DDT. High concentration of DDT disturb calcium metabolism in birds, which causes thinning of egg shell and their premature breaking, eventually causing a decline in bird populations. This phenomenon is called biomagnification.