Biological Magnification can simply be described as increasing a substance's concentration as the substance moves up a food chain, pyramid, or web. This is often detrimental because the substance is usually toxic.
How does it occur?
Well, it starts at the very bottom with the producers who, by mistake, bring the substance into their bodies. Later, a primary consumer, squirrel or rabbit, will eat the plant and ingest the substance. Because of the flow of energy (remember that only about 10% of energy is actually available for the next trophic level), the consumer will need to eat more plants and, in turn, ingest more of the substance. The substance is now somewhat concentrated within the primary consumer. The next levels, the secondary and tertiary consumers, eat the primary consumers and will eventually have a build up of the substance. Certain conditions need to be met in order for a pollutant to bio magnify:
1) Pollutant must be long- lived.
2) Pollutant must be concentrated by the producers - the plants.
2) Pollutant must fat-soluble.
Fat soluble, you ask? Once the producer is eaten, the substances move into the consumers fat storage. Once that consumer is eaten, the next consumer will have the substance in their fat tissues. Hence, this causes a build up in the fat tissues. Since fat is not water soluble, it does not leave the bodies of the consumers or the cells of the producers naturally to the environment and build up can occur.
How can us, the humans, solve this growing problem?
We can help prevent and possibly stop biological magnification by stopping the production of man-made synthetics like pesticides. It may seem like a ridiculously easy thing to do but imagine how many pesticides are used daily on our crops and local farms. The first step is to reduce the amount used and then move onto a more natural solution that is easily broken down by the environment and water soluble.
DDT
DDT was a long lived insecticide that improved the health of humans and was not easily broken down by the environment. It improved human health by killing off bugs that contained diseases of all sorts. A significant negative effect of DDT was the interference it caused with calcium in bird eggs. The eggs would be laid soft and often break early in development, causing their numbers to decline. Rachel Carson published her book called Silent Spring in the early 1960's explaining the detrimental effects of DDT and was key in the banning of the substance.
http://www.youtube.com/watch?v=-UiCSvQvVys
References:
- http://www.marietta.edu/~biol/102/ecosystem.html
- http://marinediscovery.arizona.edu/lessonsF99/chautran/index.html
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