What is biological magnification?

3. What is biological magnification? What is DDT? Explain how the use of DDT is an example of biological magnification?

Biological magnification is when a strong amount of chemicals enter an ecosystem and affects the different trophic levels of a food web. When a pollutant enters the base of a food web, basically the producer, all the other upper levels soon get affected after consuming those who already ate others containing the pollutant and are somehow negatively damaged in the tissues.
DDT (dichlorodiphenyltrichloroethane) is a pesticide made of chlorinated organic insecticides used in the USA to kill agricultural pets and mosquitoes carrying malaria. It is an example of such chemicals. It was abundantly used after WWII, but was eventually banned because of the insects growing immune to the pesticide and a large amount of fish being intoxicated. Although it does not grow fast in animals, it is stored in the fatty tissues. If ingested at a steady rate, the DDT will build up inside the animal.
The use of DDT is an example of biological magnificatio. It is a pollutant that became abundant in the trophic levels of a food web and affected other organisms. An example is the shells of bird eggs and making them softer, which resulted in fewer chicks surviving and a decrease on the bird’s population. The birds ate the fish that were infected with the pollutant, and so they themselves were affected in the tissues and passed it on to their young.

Sources:
www.3dchem.com/molecules.asp; Banned Insecticide; updated by Karl Harrison.
http://pmep.cce.cornell.edu/profiles/extoxnet/carbaryl-dicrotophos/ddt-ext.html