Tag: the effects of human activities on ecosystems

Biomagnification is defined as the process by which a compound (such as a pollutant or pesticide) increases its concentration in the tissues of organisms as it moves up the trophic levels

The biotic components of an ecosystem are arranged in several trophic levels which are interdependent on each other. The energy produced at one level is passed to another level. Biomagnification refers to increase in concentration of the toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, and is thus passed on to the next higher trophic level. This phenomenon is well known for mercury and DDT. 

The different trophic level of an ecosystem interacts with each other and they are interdependent on each other. Biological magnification is a process where pollutants such as pesticides or heavy metals move up the food chain, passes into rivers or lakes and consumed by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. It occurs when the concentration of a substance, such as DDT or mercury, in an organism, exceeds the background concentration of the substance in its diet. 

Biomagnification refers to increase in concentration of the toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, and is thus passed on to the next higher trophic level. Thus, the correct answer is option A.

Biomagnification (or bioaccumulation) refers to the increase in the concentration of non-degradable pollutants as they pass through the food chains. It is the process whereby certain substances such as pesticides or heavy metals move up the food chain, work their way into rivers or lakes, and are eaten by aquatic organisms such as fish, which in turn are eaten by large birds, animals or humans. 

A few toxic substances, often present in industrial wastewaters, can undergo biological magnification (biomagnification) in the aquatic food chain. Biomagnification refers to an increase in the concentration of the toxicant at successive trophic levels. This happens because a toxic substance accumulated by an organism cannot be metabolised or excreted, and is thus passed on to the next higher trophic level in a food chain.

Biomagnification is the accumulation or increasing concentration of lipophilic pesticides in the top members of the food chain. During biomagnification, the concentration of non-degradable pesticide like DDT goes on increasing along the food chain and highest values occur in the consumers of the top trophic level. So, the value of pesticide will go on increasing at each trophic level.