Biomagnification
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  • 1. Biomagnification Gunjan Mehta, VSC, Rajkot
  • 2. Biological AmplificationWhat is it? Toxic pollutants enter the ecosystem that are absorbed or ingested by organisms. Some substances accumulate in organism’s tissue over time.
  • 3. 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
  • 4. Biomagnification Increase in the concentration of a pollutant as it passes from one trophic level to the nexthttp://www.tutorvista.com/content/biology/biology-iv/ecosystem/biological-magnification.php
  • 5. Biomagnification Small amount in environment → Large concentration at top of food chainhttp://www.tutorvista.com/content/biology/biology-iv/ecosystem/biological-magnification.php
  • 6. 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/educat ion/kits/estuaries/media/supp_estu ar09a.html
  • 7. Where do pollutants come from? Coal burning power plants Factories Farms, lawns, and gardens.
  • 8. Characteristics of pollutants: In order for biomagnification to happen, substance must be:  Long lived  Soluble in fat  Mobile  Biologically active
  • 9. 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
  • 10. 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
  • 11. Follow link to video http://happylibrarianblogs.blogspot.com/2008/ 01/biomagnification-video.htmlIt can happen in terrestrial systems too!
  • 12. Pollutants that undergo biomagnification Mercury Persistent organic pollutants (POPs)
  • 13. 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
  • 14. 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
  • 15. 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/ro oms/mercury/food_chain/
  • 16. 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/
  • 17. 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
  • 18. 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
  • 19. 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.
  • 20. Concerned about the fish you eat? Check out the Mercury calculator at http://gotmercury.org/article.php?id=1034 For information on Sustainable Seafood Choices check out Monterey Bay Aquarium and print out a pocket sized card http://www.mbayaq.org/cr/seafoodwatch.asp
  • 21. 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 the toxic effect of mercury on the central nervous system of the hat makers, producing mental effects and "hatters shakes". http://www.ci.springfield.or.us/ Museum/Mad%20Hatter%20Tea %20Party.jpg
  • 22. 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
  • 23. 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/v 4/n9/images/nrmicro1498-i3.jpg
  • 24. Stockholm Convention TreatyThe Dirty Dozen1. DDT - pesticide 7. Dieldrin - pesticide2. PCBs - Industrial 8. Endrin - pesticide3. Dioxin - waste 9. HCB – pest/ waste4. Furans - waste 10. Heptachlor - pesticide5. Aldrin - pesticide 11. Mirex - pesticide6. Chlordane - pesticide 12. Toxaphane - pesticide
  • 25. Exposure Environmental exposure – many will stay in soil or water for decades  Slow to breakdown Humans consume toxins via fish, meat and dairy
  • 26. 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 pesticidehttp://commons.wikimedia.org/wiki/Image:DDT_WWII_soldier.jpg http://www.flahumforms.org/FloridaDream/images/Th umbnails/1948-Spraying-DDT-in-war-ag.jpg
  • 27. Ex. DDT Concentration of DDT increased 10 million times! http://www.cfkeep.org/html/stitch.php?s=98965698293378&id=34347859802049
  • 28. DDT problemsEggshell 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
  • 29. DDT problems (cont’d)Feminization Acts as a hormone disrupter, mimics estrogen Has impacted sex ratio in some birds
  • 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
  • 31. DDT - it’s a long term problem It has a half life of 15 Amount Year year; it takes 15yrs for Remaining its quantity to be ½ its 0 100 kg original 15 50 kg Ex. If we start with 30 25 kg 100 kg, we will still 45 12.5 kg have ~ 1 kg after 100 60 6.25 kg yrs 75 3.13 kg 90 1.56 kg 105 0.78 kg
  • 32. DDT current use Banned in US in 1972 Still used overseas to prevent malaria  Estimated it save millions of lives annually in Africa
  • 33. POPs are everywhere! Even Polar Bears have POPs in their system  Top predator  All toxins in prey is transferred to them, stored in fat http://www.smh.com.au/ffxi mage/2006/12/28/polar_bear Concentration increases 5 – _narrowweb__300x387,0.jpg 10x each trophic level
  • 34. 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
  • 35. Thought to ponder Even pollutants in small quantities can build up to toxic/lethal doses
  • 36. 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)
  • 37. Question of the DayWhich group of pollutants is suspected to act like hormones (estrogens)? Heavy metals Persistent organic pollutants (POPs) Inorganic plant nutrients Organic oxygen-demanding wastes
  • 38.  http://gotmercury.org/article.php?id=1034 http://www.seaturtles.org/article.php?list=type &type=75 http://www.ec.gc.ca/Science/sandemay00/artic le4_e.html