Question

Explain bioaccumulation and biomagnification with examples.

Answer 1

Bioaccumulation refers to the entry of a pollutant or toxic substance in the food chain whereas biomagnification refers to the increase in concentration of a toxic substance at each successive trophic level after entering into food chain. In bioaccumulation, the concentration of the toxic substance increases in the organism of same type as the toxic substance is retained in the body of the organism while in biomagnification, the toxic substance gets accumulated in the body of organisms at successive trophic levels at a higher concentration than the previous trophic level.

For example, pesticides such as DDT, is non biodegradable. It gets incorporated in the food chain and gets deposited the tissues of the organisms.

When DDT enters aquatic bodies, it gets build up in the body of fishes and this is known as bioaccumulation. When fishes are eaten by animals of higher trophic levels, concentration of DDT is increased at each successive trophic level and this is known as biomagnification.