Topic 4-Introduced Species and the Australian Environment

1. Topic 4-Introduced Species and the Australian Environment This is the final topic of the HSC

2. Topic Overview • There are 5 parts to this topic: • Introduced Species in Australia • The Vulnerable Australian Environment • Case Study: Becoming a Pest • Biological Control • Quarantine Methods-Keeping Them Out

3. Topic Outcomes • Define the term introduced species • Explain how an organism is classified as introduced • Describe the variety of reasons exotic species are introduced into Australia • Identify the reasons why the Australian environment is particularly vulnerable to the effect of introduced species • Describe the features of the environment that contribute to an introduced species becoming a pest • Describe the natural history, history of introduction, ecological impact and control of several named introduced species • Discuss methods of biological control of introduced species • Describe the rehabilitation of ecosystems damaged by introduced species • Describe how quarantine is used to prevent further introductions • Identify the aspects of your local environment tha have been affected by introduced species

4. Part 1-Lesson 1 Introduced Species in Australia

5. Introduction • Australia separated from Antarctica in the final break up of Gondwana about 40 million years ago. Since then, the continent has been geographically isolated as an island.

6. Introduction • Because of its isolation, our flora and fauna have evolved into distinctive ecosystems which humans first invaded 60,000 years ago. The Indigenous peoples caused changes to the environment however did not deliberately introduce exotic plants and animals with an exception of possibly the dingo.

7. Introduction • Later visitors, Macassan fisherman from Indonesia, introduced some species of plants and possibly animals but this was very small scale. The major introduction of new species happened when Europeans settled in the late 18th Century.

8. Introduction • Large numbers of plants and animals both deliberately and accidentally were brought into the country by these early settlers. Some did not survive because of the harsh environments however those that did had an enormous impact on the countries ecosystems.

9. Introduction • In order for an organism to be classified as introduced, it’s: • Immigration history must be known • Features would not suit the environment in which it lives • Food source would not be indigenous to the area • Distribution would not appear to be limited by any physical feature of the environment.

10. Colonising new areas • Species that occur outside their native range in a given area as a result of human actions are called introduced species. Many animal and plant species will introduce themselves into new areas. This is called colonisation.

11. Colonising new areas • Birds, bats, insects, spiders and plants rapidly colonise new and suitable habitats that become available to them. Birds can fly to new areas and they can also carry seeds with them. Insects and small spiders can be carried thousands of kilometres by winds to new areas.

12. Colonising new areas • An example of such colonisation is the volcanic island of Surtsey (Iceland). This island was recently created from volcanic eruptions and within 6 months after the eruption bacteria, moulds, insects and birds inhabited the island. Within 30 years there were several hundred species living on the island.

13. Colonising new areas • Insects, reptiles and small mammals can also be washed down rivers during floods and carried by ocean currents to islands or new lands. The survival odds of such scenarios are low but it does happen.

14. Colonisation • Australia has several non-native animal and plant species that colonised the continent. For example: • Rats • Bats • Seals • Many species of birds

15. Colonisation • The dingo is believed to have originated from a variety of gray wolf in Southern Asia. Scientists are unable to classify it as native or introduced because it’s only believed to have been in Australia for the last 3500 years. They may have been brought here as domesticated species with Indigenous peoples.

16. Project • See Assessment Task #4 Introduced Species Report Due: Aug 25th

17. Homework Read pages 179 HSC Spotlight Text Start new electronic vocabulary Complete DOT Points 1.1-1.2 Start research project

18. Part 1-Lesson 2 Introduced Species in Australia

19. Reasons for species being introduced • There are a number of reasons why humans have deliberately introduced new exotic species into Australia. • Food • Transport • Wool/fur/fibre • Leisure activities (hunting and fishing) • To make Australia ‘more like home’ to immigrants • For gardens • Pets • Biological control • Medical reasons

20. Reasons for species being introduced • There are also a number of accidental ways exotic species have been introduced into Australia. • In cargo or food transported by ships and airplanes • In soil on shoes, plants or machinery • In letters and parcels arriving by post • In the ballast dumped by ships

21. Deliberate Introduction • Early Europeans brought a number of domesticated animals into Australia to meet a number of needs. For example: • Sheep • Pigs • Cattle • Poultry • Ducks • Geese

22. Deliberate Introduction • Many of these animals did not present a direct problem to the environment because they were incapable of fending for themselves in the wild. However the clearing of land to make pastures for them has had significant ecological impacts.

23. Deliberate Introduction • Some, like goats, rabbits and pigs, were able to survive on their own in the wild. These animals became feral as they escaped from farms and today are still a problem.

24. Deliberate Introduction • Many introduced food plants have also escaped and formed feral populations in Australia. Olives, coffee, melons, fennel and blackberry are now considered a noxious weed and a serious problem to agriculture in Australia.

25. Deliberate Introduction • Many animals have been imported into Australia for the use of sale as pets. Some of these animals escape or are released by their owners. A classic example of this is cats. Wild cats now inhabit a large area of the country.

26. Deliberate Introduction • Some organisms have been introduced in attempt to biologically control a pest species. Were do you think the pest species came from? Some have been successful while others have failed terribly. For example the Myxoma virus for rabbits was very successful the cane toad has been disastrous.

27. Deliberate Introduction • Gardeners are also responsible for brining in exotic plants which are now some of Australia’s worst weeds. Plants escaped garden areas by various reasons and explores also distributed seeds as they travelled. Examples of these include: • Horehound • Castor-oil • Pennyroyal • St. John’s wort

28. Accidental Introduction • This has been happening for hundreds of years but has dramatically increased as travel methods have improved. The very first settlers to Australia inevitably introduced insects, spiders, parasites, rats and mice as these are very common in cargos.

29. Accidental Introduction • As travel improved, the importation of unwelcome visitors also improved. It’s very easy for small insects and spiders to travel unnoticed in shipping containers or food or raw materials. Travellers can also bring in the seeds of foreign plants either on their shoes or in their clothing.

30. Accidental Introduction • An example of such introduction is the fire ant. This ant was believed to be introduced by a ship in Brisbane in 1966. This insect is native to South America and is establishing in parts of Brisbane. The Queensland government is planning the largest insect eradication program ever attempted in Australia which will cost over $100 million.

31. Accidental Introduction • Another way organisms have arrived is in the ballast of ships. Water is pumped in and out of ships to make them stable organisms included. Some animals like barnacles attach to the hull of ships which is another way ships can carry unwanted guests.

32. Are all introduced species pests? • Some introduced species which have a considerable impact on native species are not always universally condemned. For example trout are being bred and released into our streams with little concern because people enjoy catching them. Trout are thought to have driven several native species to near extinction.

33. Are all introduced species pests? • Some introduced species have advantaged people. For example feral camels are rounded up and used for tourism and sent back to the Middle East where they came from. Feral goats are used for meat and hides. Feral pigs are shipped to Europe for consumption. • Because of this is often a difference in opinion about the need to eradicate some introduced species.

34. Are all introduced species pests? • Many introduces species are pests only in certain areas. For example the prickly pear is a major problem in Queensland but not southern NSW as they do not grow in cooler areas. • How do you think the effects the issue of introduced species?

35. Review • There are a number of reasons why humans have deliberately and accidently introduced new exotic species into Australia. • As travel improved, the importation of unwelcome visitors increased. • Some introduced species have advantaged people. • There is often a difference in opinion about the need to eradicate some introduced species.

36. Homework Read pages 180-184 HSC Spotlight Text Update electronic vocabulary Complete DOT Points 1.4, 1.5 Complete ‘To Think About’ pg 186-188 HSC Spotlight Text