Some of the man’s activities like hunting of various animals disrupt the food chains in which there animals normally take parts. The shortening of food chains due to man’s activities leads to an imbalance in the functioning of an ecosystem and ultimately in the functioning of the whole biosphere.
Modern agricultural activities use a large number of toxic chemicals like pesticides, weedicides and rodenticides, to protect the crop plants from pests and diseases. Some of these poisonous chemicals mix-up with soil and water and are absorbed by the plants from the soil along with water with other minerals. In this way, the poisonous chemical substances enter the food chain right from the producer level. When man and other animals eat these plants or their products, the poisonous chemical substances are transformed to their bodies.
During the process of food transfer through tropic levels, there harmful chemicals get concentrated at each successive level. The increase in concentration of harmful chemical substances like pesticides in the body of living organisms at each tropic level of a food chain is called biological magnification. To consume ecosystem, such activities should be minimized.