Ecosystem Threats Ecosystems Unit, March 21 st 2005 Slide 2
**Major (man-made) Threats to our Ecosystems: 1. Habitat Loss 2.
Chemical Pollution 3. Introduced Species 4. Acid Rain 5. Climate
Change Slide 3 1. Habitat Loss As the human population grows,
humans use more and more of the worlds ecosystems for their use
(homes, farms, factories, malls etc.). This leaves less habitat for
wildlife. Slide 4 Losing Habitat Housing Development has taken over
the mountain in Coquitlam, B.C. Slide 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) Slide 6 Habitats must be large and connected in order to
protect wildlife Slide 7 Connections between habitats are called
corridors Slide 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? Slide 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). Mller won the Nobel
Prize in 1948 for his work on DDT. Slide 10 Spraying DDT, Florida,
1948 Slide 11 Still spraying after all these years. This 1950s
photo shows a flight attendant dispensing the now banned pesticide
DDT in an aircraft cabin. Slide 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. Slide 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 Slide
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. Slide 15 Birds were dieing... Egg Shell
Thinning Ospreys Pesticides such as DDT deformed cormorants. Slide
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 Slide
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!
