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pesticides and bioaccumulation.notebook December 06, 2015
Unit 1
• Review
• Pests
• Pesticides
• DDT
• Bioamplification
• conclusion
• Challenge!
Life Science: Sustaining Ecosystems
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pesticides and bioaccumulation.notebook December 06, 2015
Algae Blooms
• The nitrogen cycles can be changed by the actions of humans.
• Fertilizing farms results in runoff from rain being rich in phosphorous and Nitrogen.
• This water ends up in ponds and causes algae to grow.
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pesticides and bioaccumulation.notebook December 06, 2015
• When the algae die, bacteria break it down and grow faster than usual.
• This can happen natural, but humans make it happen faster
Also known at Eutrophication
Algae Blooms
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pesticides and bioaccumulation.notebook December 06, 2015
http://www.youtube.com/watch?v=UGqZsSuG7ao
http://www.youtube.com/watch?v=UGqZsSuG7ao
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pesticides and bioaccumulation.notebook December 06, 2015
Pesticides p.3437
• Pest – An organism that humans do not like.
• What a pest is depends on who you ask.
Which ones are pests?
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pesticides and bioaccumulation.notebook December 06, 2015
Pesticides p.3437
• If you are trying to grow carrots, a dandelion or even a cabbage are pests.
• Pests can include: plants, fungi, insects or mammals.
• Pesticide – A chemical that kills pests.
• Pesticides usually kill only one type of organism.E.g. insecticide kill insects.
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pesticides and bioaccumulation.notebook December 06, 2015
Pesticides• About 30% of the crops in Canada are destroyed by pests.
• Pesticides help us make more food and to prevent diseases like malaria.
• Malaria is a disease that damages blood and is spread by mosquitoes.
• Pesticides can kill the mosquitoes before they spread the disease.
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pesticides and bioaccumulation.notebook December 06, 2015
Pesticides
• Although some pesticides affect only a few species, others affect many different kinds.
• If these types of pesticides are used they can affect many parts of the ecosystem.
• This can be a serious problem if large areas of land are sprayed with pesticides, as is often done to kill insects.
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pesticides and bioaccumulation.notebook December 06, 2015
• E.g. DDT
• DDT was an insecticide used in Canada and the U.S. in the 1950s 1970s.
It was a good insecticide because it was cheap and killed a lot of insects.
Pesticides
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pesticides and bioaccumulation.notebook December 06, 2015
Pesticides DDT
• However people noticed that there were few birds in areas where DDT was used.
• Eventually they found out that the birds had high levels of DDT in their system.
• In birds DDT cause their eggs to have thin shells.
• Eggs with thin shells easily break, killing the baby birds.
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pesticides and bioaccumulation.notebook December 06, 2015
How did DDT get into the birds?
Question:
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pesticides and bioaccumulation.notebook December 06, 2015
Pesticides• Bioaccumulation – As you go up food chains, there is more and more poison in the organisms.
• Insects have only a little poison in them.
• But they are eaten by mice.
• The mice then get more poison in them.
• Then birds eat the mice and get even more poison them.
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pesticides and bioaccumulation.notebook December 06, 2015
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pesticides and bioaccumulation.notebook December 06, 2015
• There is an outbreak in Terrenceville of an insect that eats blueberries.• State a benefit and problem with doing each of the following:
1. Use an insecticide to kill the insect.2. Bring in another insect to eat the pest3. Do nothing
Which do you think is best?
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Attachments
1206Attendance.xlsx
Sheet1
5-Sep
Gustav Barbourp
Echo Henochp
Toni Lampep
Anthony Saksagiakp
Dwayne Williamsp
Kayla Wyattp
Sheet2
Sheet3
SMART Notebook
Page 1: Sep 8-9:31 AMPage 2: Nov 3-2:26 PMPage 3: Dec 2-7:40 AMPage 4: Dec 2-7:32 AMPage 5: Jan 29-5:33 PMPage 6: Jan 29-5:34 PMPage 7: Jan 29-5:35 PMPage 8: Jan 29-5:38 PMPage 9: Jan 29-5:41 PMPage 10: Jan 29-5:40 PMPage 11: Jan 29-5:43 PMPage 12: Jan 29-5:44 PMPage 13: Jan 29-5:47 PMPage 14: Sep 8-9:31 AMAttachments Page 1