Bio-Accumulation: A Case Study

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Bio-Accumulation A Case Study
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Bibliography
Fisheries and Oceans Canada.(June 7, 2007).
Bioaccumulation A Case Study of British
Columbias Killer Whales. Retrieved on September
6, 2007 from http//www-heb.pac.dfo-mpo.gc.ca/com
munity/education/lessonplans/orca-bioacc/orca_bioa
cc_e.htm
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What is bioaccumulation?

• Many of the chemicals we use in our daily lives
  are toxic. Some of these toxins are persistant.
• This means that they do not break down in the
  body and are stored in the fat of an organism.
  This is because the chemicals are fat soluble.
• These toxins are called Persistant Organic
  Pollutants (ie. DDT or PCBs)

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• The build up of these toxins in the food chain is
  known as bioaccumulation.
• This can cause
• Reproductive failure
• Birth defects
• Immune system disorders
• Death
• The more toxins in the organism, the greater the
  problem is.

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Persistant Toxins in British Columbias Killer
Whales

• The amount of toxins have been tested in resident
  and transient killer whales

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Resident Killer Whale Food Chain

• Phyto/ zooplankton
• Herring
• Salmon
• Resident Killer Whale

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Transient Killer Whale Food Chain

• Phyto/ zooplankton
• Herring
• Salmon
• Seal
• Transient Killer Whale

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Killer Whale Food Chain Game

• The squares around the room represent plankton
• Students in lab coats represent salmon
• Students in safety glasses represent resident
  killer whales
• Herring will carry around a styrofoam cup
  (stomach) and are ONLY allowed to feed on
  plankton (by gathering markers).

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• Salmon are ONLY allowed to feed on (tag) herring
  and resident killer whales are ONLY allowed to
  feed on (tag) salmon.
• When you get tagged hand over your cup(s) to your
  successful predator and go have a seat
• All move to their seats when I call the end of
  the game

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Data Collection
Organism Surviving Amt of Food En Total of marked food pieces Survived(s), died (d), or reproduction and immune system problems (RI)
Resident killer whales
Seals NA NA NA NA
Salmon
Herring
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How did we let this happen?

• Chemicals such as DDT and PCBs were never tested
  for their long-term effects before they were put
  to use
• DDT kills mosquitoes
• PCBs were used in everything from electrical
  lights to paint and printed ink because of their
  properties (conduct electricity, insulate, dont
  burn and dont corrode).

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So, we have learned our lesson right?

• WRONG
• Many countries still use the chemicals that have
  been proven to bioaccumulate
• Canada and the US do not have laws that insist on
  the testing of new chemicals that are not used in
  food. In fact, of 85, 000 chemicals used in North
  American only 10 are tested for their
  environmental effects
• There is a new group of chemicals (PBDEs) that
  have already proven to accumulate. Europe has
  banned these, but North America has not.

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The DDT Story Pg. 30