1. Ecosystem Threats Ecosystems Unit, March 21 st 2005

2. **Major (man-made) Threats to our Ecosystems: 1. Habitat Loss 2. Chemical Pollution 3. Introduced Species 4. Acid Rain 5. Climate Change

3. 1. Habitat Loss As the human population grows, humans use more and more of the world’s ecosystems for their use (homes, farms, factories, malls etc.). This leaves less habitat for wildlife.

4. Losing Habitat Housing Development has taken over the mountain in Coquitlam, B.C.

5. Across Canada Comparison of Protected Areas (2001 data) World Wide, 12% of the terrestrial landscape is protected. Only 4% total is protected (land and marine)

6. Habitats must be large and connected in order to protect wildlife

7. Connections between habitats are called corridors

8. 2. Chemical Pollution Humans use chemicals to: – Kill unwanted pests (e.g. insects & weeds) – To clean items (e.g. laundry soap) – To manufacture items (e.g. paint) Why do Humans Use Chemicals?

9. DDT (dichloro-diphenyl-trichloro-ethane) In 1939 a Swiss Scientist invented a chemical (DDT) that could kill insects but was safe for mammals. DDT was used to kill insects that ate crops and those that caused diseases like Malaria (transmitted by mosquitoes) and Typhus (transmitted by lice). Müller won the Nobel Prize in 1948 for his work on DDT.

10. Spraying DDT, Florida, 1948

11. Still spraying after all these years. This 1950s photo shows a flight attendant dispensing the now banned pesticide DDT in an aircraft cabin.

12. Rachel Carson Silent Spring 1962 “Can anyone believe it is possible to lay down such a barrage of poisons on the surface of the earth without making it unfit for all life? They should not be called insecticides but Biocides.”

13. DDT (dichloro-diphenyl-trichloro-ethane) DDT poisoned the insects. Animals such as birds and mice continued to eat the poisoned insects. Rain washed the DDT from the fields into the rivers where fish also became poisoned. The DDT spread through the food chain and accumulated in the animals at the top of the food chain (e.g. Ospreys, Peregrine Falcons).DDT spread through the food chain

14. Biomagnification Biomagnification: The process of gathering higher and higher amounts of a toxin in the bodies of animals at the top of the food chain.

15. Birds were dieing... Egg Shell Thinning Ospreys Pesticides such as DDT deformed cormorants.

16. What harmful effects can DDT have on us? Probable human carcinogen Damages the liver Temporarily damages the nervous system Reduces reproductive success Can cause liver cancer Damages reproductive system Arctic Contaminents Arctic Contaminents

17. Pollution Solution: Do not use pesticides on your lawn or gardens. Use biodegradable or “environmentally friendly” soaps & detergents. Dispose of toxic chemicals at a proper facility. NEVER pour them down your sink or down a road drain!