Question

Differentiate between the Following:

Biological magnification and Eutrophication

Answer 1

Basis of Difference	Biological magnification	Eutrophication
Meaning	Biological magnification is the increase in the concentration of a non-biodegradable pollutant at successive levels of a food chain.	Eutrophication is the enrichment of a water body with nutrients such as nitrates and phosphates.
Main cause	It is mainly caused by persistent pesticides such as DDT entering the food chain.	It is mainly caused by excess fertilisers washing into water bodies.
Main effect	The pollutant accumulates in the greatest concentration in top consumers.	Excess nutrients cause rapid algal growth, and decomposition of the algae reduces dissolved oxygen in the water.
Example	DDT concentration may increase as it passes from aquatic organisms to fish and then to humans.	Fertiliser runoff may cause an algal bloom in a lake.