Biomagnification

Biological magnification or biomagnification is the increase in concentration of a substance. A pesticide, for example, may increase in the tissues of organisms. This increase can occur as a result of:
 Persistence – where the substance cannot be broken down by environmental processes
 Food chain energetics – where the substance's concentration increases progressively as it moves up a food chain 
 Low or non-existent rate of internal degradation or excretion of the substance.


Pesticides or heavy metals work their way into lakes, rivers and the ocean. They may move up the food chain in progressively greater concentrations as they are eaten by aquatic organisms such as zooplankton, which in turn are eaten perhaps by fish, which then may be eaten by bigger fish, large birds, animals, or humans. The substances become increasingly concentrated in tissues or internal organs as they move up the chain. Bioaccumulants are substances that increase in concentration in living organisms as they take in contaminated air, water, or food because the substances are very slowly metabolized or excreted.

 References 

Category:Ecology
Category:Pesticides