Explain the following : (i) Eutrophication; (ii) Biomagnification.

i) Eutrophication is a phenomenon that occurs in water bodies. Fertilizers run of from crop fields lead to accumulation of the chemicals in water bodies which results in algal blooms. These alagal blooms thus block the sunlight from penetrating into the aquatic bodies. The aquatic plants thus do not get sunlight to synthesize food and oxygen, thus causing Eutrophication.

ii) Chemicals, pesticides and heavy metals move up the food chain, get into aquatic bodies and are eaten by organisms like fishes which are in turn eaten by hawks/eagles. This process where the chemical enters the food chain and gets concentrated at each trophic level is known as Biological Magnification.