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Biology Decision Case

Biology Decision Case. Bi o m a g n i f i cati on. The Problem:. Peregrine Falcons Extirpated from much of U.S. http://www.iowaccess.org/main/news/newsimages/peregrine.jpg. Osprey and Bald Eagles were declining, as well. http://www.state.tn.us/twra/graphics/BLDEAGLE.jpg.

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Biology Decision Case

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  1. Biology Decision Case Biomagnification

  2. The Problem: Peregrine Falcons Extirpated from much of U.S. http://www.iowaccess.org/main/news/newsimages/peregrine.jpg

  3. Osprey andBald Eagles were declining,as well. http://www.state.tn.us/twra/graphics/BLDEAGLE.jpg http://www.state.tn.us/twra/graphics/OSPREY.jpg

  4. Meanwhile, in Borneo: • Roofs began to fall • Gecko-eating cats began to die, • and thriving rats brought plague and typhus • The World Health Organization began to parachute cats into Borneo, but what was causing these problems? http://www.herpafauna.com/pics/geckos/a-felinus.jpg

  5. Finding the cause: Roof collapse traced to disappearance of parasitic wasp which had controlled thatch-eating caterpillars. http://www.life.umd.edu/classroom/bsci124/img/parisitoid.jpg

  6. It seemed to be a chain: Wasps disappeared because DDT had been sprayed to kill mosquitos, which carried malaria - number one killer of humans worldwide

  7. The data suggested DDT: • Measurements of DDT levels seemed to multiply as the compound moved up the food chain: • Water to zooplankton: 800x • Zooplankton  to fish #1 = 31x • Fish #1 to fish #2 = 1.7x • Fish #2 to gull = 4.8x • Overall = 202,368x

  8. More evidence against DDT: Eggshells from Peregrines with high DDT levels showed significant thinning http://www.kodak.com/US/images/en/corp/features/birdcam2000/gallery/04_03/13_32__2000_04_03_fullcam2.jpg

  9. How does biomagnification work? • DDT, a synthetic molecule, cannot be broken down or excreted – Life doesn't have enzymes that "know" how. • Thus, it concentrates as animals higher on the food chain eat more and more food.

  10. Solutions: • Ban DDT • "Hack out" captive-bred peregrine chicks • Build nest platforms for Osprey

  11. How effective were these solutions? • Peregrines, Osprey, and Bald Eagles recovered However, • Other countries still use DDT and • DDT isn't the only chemical that biomagnifies!

  12. The problem magnifies: • MethylMercury concentrates just like DDT and damages human Nervous Systems • A person who eats one meal of lake trout from Lake Michigan will be exposed to more PCBs in one meal than in a lifetime of drinking water from the lake!

  13. PCBs (polychlorinated biphenyls) PAHs (polynuclear aromatic hydrocarbons) Heavy metals: mercury copper cadmium chromium lead nickel zinc tin TBT (tributyltin) mercury from gold mining cyanide selenium The number of new molecules we introduce into our environment continues to increase. The Problem is ongoing:

  14. The Ultimate Solution? • Models are being developed to predict toxicity of new chemicals • Pollution control must be intensified: Zero Tolerance in the Great Lakes? • Education: Increase awareness so everyone will decrease use and dispose of chemicals properly.

  15. "This we know: The earth does not belong to man; man belongs to the earth. Whatever befalls the earth befalls the sons of the earth. Man did not weave the web of life; he is merely a strand in it. Whatever he does to the web he does to himself." - Chief Seattle

  16. Bibliography… • "ToxFAQsTM for DDT, DDE, and DDD," ATSDRIC Information Center Division of Toxicology, Agency for Toxic Substances and Disease Registry, Atlanta, GA, June 11, 2001. <http://www.atsdr.cdc.gov/tfacts35.html> 2/21/02 • Mader, Sylvia S. 1996. Biology - 5th Ed. WCB and Cox, G.W. 1997. Conservation Biology - 2nd ed. WCB < http://www.marietta.edu/~biol/102/2bioma95.html> 2/21/02 • "Chapter 4: The Great Lakes Today – Concerns" Government of Canada (Toronto, Ontario) and United States Environmental Protection Agency, Great Lakes National Program Office (Chicago, Illinois) The Great Lakes: An Environmental Atlas and Resource Book, Third Edition, 1994, http://www.epa.gov/glnpo/atlas/glat-ch4.html> 2/20/02 • "Mercury: In Your Community and the Environment." PUB-CE-239 98 Wisconsin Department of Natural Resources and the Pollution Prevention Partnership; Last Modified: November 29, 1999 Environment Canada : http://www.on.ec.gc.ca/glimr/classroom/millennium/mercury/mystery-e.html • "Great Lakes Initiatie," Wisconsin Sea Grant, 2001 http://seagrant.wisc.edu/Communications/Publications/One-pagers/CriticalPollutants.html 2/20/02

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