1. Perturbation of Ecological Systems
Dr. Debrah Fine

2. Ecology
The study of how living things interact with each other and their non-living environment
From Greek “oikos,” meaning “home,” and “logy,” meaning “knowledge.”

3. Lesson Overview I. Types of ecological interactions
II. Examples of human perturbation of ecological systems
Australia
Hawaii
New Zealand
III. What are humans doing now to perturb the ecosystem?

4. Types of Social Actions
Effect on organism 1
Effect on organism 2
Benefit
Harm
No Effect
Mutualism
Predation or parasitism
Commensalism
Competition
Amensalism -

5. Lesson Overview I. Types of ecological interactions
II. Examples of human perturbation of ecological systems
Australia
Hawaii
New Zealand
III. What are humans doing now to perturb the ecosystem?

6. Rabbits in Australia
In 1859, Thomas Austin imported and released 24 rabbits in Australia
"The introduction of a few rabbits could do little harm and might provide a touch of home, in addition to a spot of hunting."

7. Population Surge
Since there were few natural predators to rabbits in Australia, their population soared to an estimated 20 billion by the 1920’s
Foxes and feral cats are predators of rabbits in Australia

8. Why are rabbits such a nuisance?
Rabbits threaten native mammalian populations
Support fox and feral cat populations
Compete with similar sized native mammals for shelter and food
Rabbits threaten native plants
Rabbits feed on seedlings and prevent regeneration of native trees and shrubs
Australia has had more native mammalian extinctions than any other country (22 as of 2007).
In 2007, 17 bird species, 13 mammal species, 4 reptile species, 1 fish species and 1 insect species that are considered to be vulnerable, endangered or critically endangered native species were threatened by rabbits.
In 2007, 121 vulnerable, endangered or critically endangered native plant species were considered to be threatened by rabbits.

9. An Early Attempt at Containment
Early 20th century, attempted to contain rabbits with a fence. Since rabbits can jump quite high and also burrow quite deep, this was unsuccessful and costly.

10. Myxoma Virus
PIC: Wardang Island, myxomatosis trial site: In 1950, myxoma virus was introduced into the rabbit population and killed about 99.8% of the rabbit population (from an estimated 600 million). Shortly after myxomatosis was introduced into the rabbit population, a human encephalitis epidemic began in Australia. This led to a pnic, with the public thinking that the myxomavirus was the cause of the encephalitis. Two Australian scientists injected themselves with myxoma virus to show that it was harmless and the public was satisfied that the virus didn’t cause human disease.

11. Development of Resistance to Myxoma Virus
Resistant
In March 1995, a quarantine station was set up on tiny Wardang Island off the coast of South Australia to test Rabbit calicivirus, which had kept down rabbit populations in Europe. It was due for release in 1998, but, after only 6 months, it escaped from the island, most likely carried by insects. Calicvirus has been somewhat successful in reducing rabbit population numbers in the drier more arid regions of Australia. Scientists have found that rabbits living in the wetter areas of Australia have antibodies to a virus that is very similar to rabbit calcivirus and they think that this is causing these rabbits to be resistant to infection.
Resistant

12. Hawaii: Mongoose
Sugar cane farmers brought the mongoose to control the rat population
Only the islands of Lana'i and Kaua'i are (thought to be) free of mongooses. There are two conflicting stories of why Kaua'i was spared. The first is that the residents of Kaua'i were opposed to having the animals on the island and when the ship carrying the offspring reached Kaua'i, the animals were thrown overboard and drowned. A second story tells that on arriving on Kaua'i one of the mongooses bit a dockworker who, in a fit of anger, threw the caged animals into the harbor to drown.

13. Hawaii: Mongoose No natural predators in Hawaii
Only the islands of Lana'i and Kaua'i are (thought to be) free of mongooses. There are two conflicting stories of why Kaua'i was spared. The first is that the residents of Kaua'i were opposed to having the animals on the island and when the ship carrying the offspring reached Kaua'i, the animals were thrown overboard and drowned. A second story tells that on arriving on Kaua'i one of the mongooses bit a dockworker who, in a fit of anger, threw the caged animals into the harbor to drown.

14. Hawaii: Mongoose
The mongoose did not control the rat population, but instead preys on native birds and bird eggs
Only the islands of Lana'i and Kaua'i are (thought to be) free of mongooses. There are two conflicting stories of why Kaua'i was spared. The first is that the residents of Kaua'i were opposed to having the animals on the island and when the ship carrying the offspring reached Kaua'i, the animals were thrown overboard and drowned. A second story tells that on arriving on Kaua'i one of the mongooses bit a dockworker who, in a fit of anger, threw the caged animals into the harbor to drown.

15. New Zealand: Possum
Possums were introduced in New Zealand to establish a fur trade

16. New Zealand: Possum
No natural predators

17. New Zealand: Possum Spread bovine tuberculosis
Damage crops and orchards

18. Lesson Overview I. Types of ecological interactions
II. Examples of human perturbation of ecological systems
Australia
Hawaii
New Zealand
III. What are humans doing now to perturb the ecosystem?

19. Humans and the Earth’s Ecosystem

20. Climate Change

21. Climate Change: What is a Greenhouse Gas?

22. A Map of the World

23. Population

24. Energy Consumption

25. Greenhouse Gas Emissions

26. What is a Carbon Footprint?
Your carbon footprint is the sum of all emissions of CO2 (carbon dioxide), which were induced by your activities in a given time frame

27. Ways to Reduce Our Carbon Footprints
Take public transportation, walk, ride a bicycle, carpool
Switch to bio-diesel or a hybrid car
Less air travel
Use energy efficient lightbulbs and appliances
Recycle and reuse stuff
Don’t be wasteful
Eat food grown locally
Eat less meat
If your four-person family skips steak 1 day a week [for a year], it’s like taking your car off the road for almost 3 months
Lamb and beef are the worst
Methane gas from their digestive systems (ruminants) and nitrous oxide from the fertilizer used to grow their feed. Both methane and nitrous oxide are more potent greenhouse gases than Co2.
Reduce air travel
Reduce energy consumption in the home (turn off lights, etc)
Turn down heat