1. Pesticide, Bioaccumulation and Biomagnification

2. Brainstorm the pros and cons of pesticide on whiteboard

3. Pesticides- Pros and Cons?
1. Protect, thus protecting industries’ and farmers’ profits
2. Prevent epidemic outbreak
Cons
1. Mutation randomly occur allows pest to develop resistance to pesticides
2. Costs lots of time and resources to constantly develop new poisons
3. They are often toxic substances and can accumulate and magnify in the food chain

4. What are pesticides? - are chemicals that kill pests
- 2.3 million tonnes of pesticides used yearly
- 75% used in agriculture

5. Bioaccumulation vs Biomagnification (of toxin e.g. pesticides)
refers to an increase in the concentration of a chemical in an organism over time.
Biomagnification (also bioamplification) is the increase concentration of toxic chemicals, such as pesticides as it is passed upwards and maximized to the top predator of the food chain

6. DDT- a dangerous pesticide
DDT:(stands for Dichlorodiphenyltrichloroethane) 
- First produced in 1939
a highly potent,
fat soluble insecticides
Tobacco extract (i.e. nicotine sulfate) as insecticides
Plants themselves developed chemicals that can kill animals that graze on them
a DDT molecule

7. Case study 1: DDT and the bald eagle
Bald eagles feed on fish
They disappear for many reasons:
- Loss of habitat (industrialization, deforestation)
- Hunting
- Toxins in lake
in lake

8. DDT in the Great Lakes How DDT enter the Great Lakes?
- In this food chain, what type of consumer is the bald eagle?
- tertiary (top) consumer
- How could DDT end up in the bald eagle with highest concentration?

9. Impacts of DDT on birds double-crested cormorant
DDT was banned in Canada in 1971
Egg shell thinning

10. Discussion
There still countries haven’t banned DDT. Why would this be of concern to Canadians?
Breast milk contains fat. How breast-feeding might affect the concentration of DDT in a mother and in her baby?
Throw in questions of scavenger (vulture)

11. Mercury Poisoning- Minamata disease
Choose the most correct statement(s)
The residents of Minamata have bioaccummulated mercury in their body
The residents of Minamata have biomagnified mercury in their body
The residents of Minamata display both bioaccummulation and biomagnification
The residents of Minamata have also suffered from lead poisoning

12. Mercury Poisoning- Minamata disease
Choose the most correct statement(s)
The residents of Minamata have bioaccummulated mercury in their body
The residents of Minamata have biomagnified mercury in their body
The residents of Minamata display both bioaccummulation and biomagnification
The residents of Minamata have also suffered from lead poisoning

13. Activity
You are what you eat