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Biological Amplification

Learn about bioaccumulation, biomagnification, and their effects on the environment. Discover how pollutants enter food chains, the sources of pollutants, and the risks they pose to wildlife and human health.

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Biological Amplification

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  1. Biological Amplification What is it? • Toxic pollutants enter the ecosystem that are absorbed or ingested by organisms. Some substances accumulate in organism’s tissue over time.

  2. Bioaccumulation • An increase in the concentration of a pollutant in a biological organism compared to its concentration in the environment • It is how pollutants enter a food chain

  3. Biomagnification • Increase in the concentration of a pollutant as it passes from one trophic level to the next http://www.tutorvista.com/content/biology/biology-iv/ecosystem/biological-magnification.php

  4. Biomagnification • Small amount in environment → Large concentration at top of food chain http://www.tutorvista.com/content/biology/biology-iv/ecosystem/biological-magnification.php

  5. Why should we care? • Because the two processes together mean that when we release even small amounts of pollutants into the environment, eventually they build-up in organisms to toxic dosages http://oceanservice.noaa.gov/education/kits/estuaries/media/supp_estuar09a.html

  6. Where do pollutants come from? • Coal burning power plants • Factories • Farms, lawns, and gardens.

  7. Characteristics of pollutants: • In order for biomagnification to happen, substance must be: • Long lived • Soluble in fat • Mobile • Biologically active

  8. Characteristics of pollutants: Putting it into perspective: • Only some substances biomagnify • Most substances are water soluble and are excreted into the water • Many breakdown quickly • Many are not biologically active

  9. Ex. Biomagnification • Water • Phytoplankton • Zooplankton • Small fish • Large fish • Top Predator: • Human, osprey, eagle, otter – highest amount of toxic chemical http://www.dc.peachnet.edu/~ccarter/Millerlec-12/sld053.htm

  10. Follow link to video • http://happylibrarianblogs.blogspot.com/2008/01/biomagnification-video.html It can happen in terrestrial systems too!

  11. Pollutants that undergo biomagnification • Mercury • Persistent organic pollutants (POPs)

  12. Mercury • Source: Emissions from coal-burning power plants, metal processing, medical and other waste • Refer to notes on deposition xx/xx • Made bioavailable by bacteria • Inorganic mercury → Organic form of mercury that is biologically active

  13. Mercury • Elementary Mercury (Hg) • Methylmercury (CH3Hg) – most toxic form • Form ingested by consuming fish • Concentrated in muscle tissue • More in older fish than younger fish • Note – changed from Hg to this form by bacteria

  14. Where in the US is it a problem? • Low pH (acidic) lakes in Northeast and and Northcentral US • Everglades (FL) • Certain Wetlands • Coastal wetlands along San Francisco Bay, Gulf of Mexico and Atlantic Coast http://sofia.usgs.gov/sfrsf/rooms/mercury/food_chain/

  15. Impacts of Wildlife • Loons – diet of fish • Decrease in chicks in areas of high mercury • Large concentration of mercury in eggs • Great Egrets – study in Everglades indicates behavior of juveniles is effected • Deformities in developing animals http://www.usgs.gov/themes/factsheet/146-00/

  16. Risk to People • Exposed by eating contaminated fish • Pregnant women and children most at risk • 60,000 children born annually suffering from neurodevelopmental problems due to in utero exposure to mercury http://img.alibaba.com/photo/11388452/Frozen_Sushi.jpg

  17. Fish Advisories • 13 states have state wide advisories for fish from rivers and lakes • 40 states have advisories on selected bodies of water • Parts of Eastern Coast and Gulf of Mexico have advisories

  18. Concerned about the fish you eat? Recommendations per the FDA • Avoid shark, swordfish, king mackerel and tilefish = all are high in Mercury • 12 oz can be consumed a week of a variety of fish and shellfish that are lower in mercury. • Fish that are low in mercury are shrimp, canned light tuna, salmon, pollock, and catfish. • Note, albacore tuna has more mercury than canned light tuna. You may eat up to 6 oz of it in a week.

  19. Concerned about the fish you eat? • Check out the Mercury calculator athttp://gotmercury.org/article.php?id=1034 • For information on Sustainable Seafood Choices check out Monterey Bay Aquarium and print out a pocket sized cardhttp://www.mbayaq.org/cr/seafoodwatch.asp

  20. Origins of the term “Mad as a Hatter” • Hg(NO3)2 Mercury is a compound that was used to soften fur in the making of felt hats. • The phrase “Mad as a Hatter”, and the Mad Hatter of Alice in Wonderland -- both refer to thetoxic effect of mercury on the central nervous system of the hat makers, producing mental effects and "hatter's shakes". http://www.ci.springfield.or.us/Museum/Mad%20Hatter%20Tea%20Party.jpg

  21. Persistent Organic Pollutants (POPs) • Also called organochlorines • Synthetic organic chemicals that persist in the environment and biomagnify through the food web • Poses a risk to human health and the environment Sources: • Pesticides, some plastics, paints, industrial chemicals, bleaching, burning garbage • Examples: DDT, PCBs, dioxin

  22. Ban on POPs • 1995 UN estimated 20,000+ substances with properties of POPs • Stockholm Convention 2004, banned 12 worst • “The Dirty Dozen” • U.S. signatory in 2001 • Congress has not ratified • Signed by http://www.nature.com/nrmicro/journal/v4/n9/images/nrmicro1498-i3.jpg

  23. DDT - pesticide PCBs - Industrial Dioxin - waste Furans - waste Aldrin - pesticide Chlordane - pesticide Dieldrin - pesticide Endrin - pesticide HCB – pest/ waste Heptachlor - pesticide Mirex - pesticide Toxaphane - pesticide Stockholm Convention Treaty The Dirty Dozen

  24. Exposure • Environmental exposure – many will stay in soil or water for decades • Slow to breakdown • Humans consume toxins via fish, meat and dairy

  25. DDT (dichloro-diphenyl-trichloroethane) • Insecticide used to control malaria and typhus by killing mosquitoes and lice. • Commonly used after WWII • Inventor received Noble Prize • Overused on crops as a pesticide http://commons.wikimedia.org/wiki/Image:DDT_WWII_soldier.jpg http://www.flahumforms.org/FloridaDream/images/Thumbnails/1948-Spraying-DDT-in-war-ag.jpg

  26. Ex. DDT • Concentration of DDT increased 10 million times! http://www.cfkeep.org/html/stitch.php?s=98965698293378&id=34347859802049

  27. DDT problems Eggshell thinning • DDT interferes with metabolism of calcium • Result - thin shells in predator birds such as osprey, bald eagles, brown pelicans • Birds unable to brood (aka sit on) their eggs without breaking them www.ctaudubon.org/action/osprey.htm animals.nationalgeographic.com

  28. DDT problems (cont’d) Feminization • Acts as a hormone disrupter, mimics estrogen • Has impacted sex ratio in some birds

  29. DDT - it’s a long term problem • It has a half life of 15 year; it takes 15yrs for its quantity to be ½ its original

  30. DDT - it’s a long term problem • It has a half life of 15 year; it takes 15yrs for its quantity to be ½ its original • Ex. If we start with 100 kg, we will still have ~ 1 kg after 100 yrs

  31. DDT current use • Banned in US in 1972 • Still used overseas to prevent malaria • Estimated it save millions of lives annually in Africa

  32. POPs are everywhere! • Even Polar Bears have POPs in their system • Top predator • All toxins in prey is transferred to them, stored in fat • Concentration increases 5 – 10x each trophic level http://www.smh.com.au/ffximage/2006/12/28/polar_bear_narrowweb__300x387,0.jpg

  33. Health Impact of POPs • Some cause cancer, damage nervous system • Some act like hormones (estrogens) leads to: • Developmental changes, birth defects • Reproductive and Behavioral problems • Toxins can be passed to young

  34. Thought to ponder • Even pollutants in small quantities can build up to toxic/lethal doses

  35. Solutions to Toxic Pollution • Worst ones are banned or no longer used in U.S. • Still need to eliminate/reduce the processes that create toxins (i.e. burning coal)

  36. Question of the Day Which group of pollutants is suspected to act like hormones (estrogens)? • Heavy metals • Persistent organic pollutants (POPs) • Inorganic plant nutrients • Organic oxygen-demanding wastes

  37. http://gotmercury.org/article.php?id=1034 • http://www.seaturtles.org/article.php?list=type&type=75 • http://www.ec.gc.ca/Science/sandemay00/article4_e.html

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