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Biological Amplification

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. Bioaccumulation.

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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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