biomagnification 10-2
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- Lillyana Georgieva Rumyana Nikolova Georgi Rusinov 10/2 Biomagnification
- What is bioaccumulation?
- Definition: Increase in concentration of a pollutant from the environment to the first organism in a food chain. (1)
- When a pollutant enters a food chain (1)
- Occurs when the rate of absorption of a pollutant is greater than the rate of excretion. (1)
- What is biomagnification?
- Definition: I ncrease in concentration of a pollutant from one link in a food chain to another . (1)
- Transfer of a pollutant from one trophic level to another. (1)
- How does biomagnification look like? http://web.bryant.edu/~dlm1/sc372/readings/toxicology/biomagnification.jpg
- What causes biomagnification and bioaccumulation?
- Presence of food chains in which higher trophic levels depend heavily on large number of organisms from lower trophic levels
- (in the last picture, the osprey gets energy fixed in the form of food by a vast number of zooplankton organisms) (2)
- The Rule of 10: 10 % of the energy of one trophic level passes to the next trophic level in a food chain (4)
- The rate of absorption of a pollutant should be greater than the rate of excretion (depends on the physiology of organisms in the system) (1)
- http://mff.dsisd.net/Environment/PICS/Trophics.jpg
- What are some substances that bioaccumulate?
- Bioaccumulating substances should meet the following criteria:
- long-lived
- mobile
- soluble in fats
- biologically active (1).
- Examples: metals (mercury, cadmium, arsenic), pesticides (DDT, HCB), radioactive materials (2).
- DDT
- A chlorinated hydrocarbon with a half-life of 15years (1).
- Comes into ecosystems as a synthetic pesticide. (1)
- Almost non-toxic to humans but damaging to the nervous systems of insects. (1)
- Exemplary Case: Long Island Estuary, U.S.A., 1967
- - extensive use of the pesticide over the years
- - biomagnification factor of DDT: 800x
- - effects: DDT was absorbed by zooplankton and was biomagnified as it moved through crustaceans and fish -> hell-thinning in birds, the last trophic level (ospreys, eagles, etc.) -> inability to brood
- - solution: banning of DDT in the U.S.A. in 1972 -> birds gradually recovered. The bold eagle came back (1)
- Radioactive Materials
- Unstable substances that emit energy
- Damage all kinds of living tissue
- Exemplary Case: The Chernobyl Accident,
- Ukraine, 1986
- - large amounts of caesium-137 released in the air and brought around northern Europe
- - resulted in genetic damage in fish species and bird species that feed on them in the Baltic Sea
- - in Bulgaria, there was a ban on milk products because there were biomagnified as cows consumed contaminated grass
- - solution: the Chernobyl NPP plant was sealed, and milk and meat consumption was restricted over Europe to prevent human casualties. (5)
- Works Cited
- Bioaccumulation & Biomagnification. The Department of Biology and Environmental Science . N.p., 3 Apr. 2002. Web. 15 Dec. 2010. .(1)
- Biomagnification. Wikipedia . N.p., n.d. Web. 15 Dec. 2010. . (2)
- Bioaccumulation. Wikipedia . N.p., n.d. Web. 15 Dec. 2010. .(3)
- The Rule of 10. The Leading from the Heart Workshop . N.p., n.d. Web. 15 Dec. 2010. . (4)
- Types of Pollution (I). ChemgaPedia . N.p., n.d. Web. 15 Dec. 2010. . (5)
- "What Does It Mean When a Substance Is Said to Bioaccumulate?" WiseGEEK: Clear Answers for Common Questions . Web. 16 Dec. 2010. .
- Works Cited (pictures)
- http://www.tc.umn.edu/~allch001/1815/pestcide/sim/background.htm
- http://mff.dsisd.net/Environment/PICS/Trophics.jpg
- http://marine.usgs.gov/fact-sheets/fs41-98/
- http://atomwatch.blogspot.com/2007_09_01_archive.html
- http://web.bryant.edu/~dlm1/sc372/readings/toxicology/biomagnification.jpg