Topic 4-Introduced Species and the Australian Environment

This is the final topic of the HSCTopic 4-Introduced Species and the Australian EnvironmentTopic OverviewThere are 5 parts to this topic:Introduced Species in AustraliaThe Vulnerable Australian EnvironmentCase Study: Becoming a PestBiological ControlQuarantine Methods-Keeping Them OutTopic OutcomesDefine the term introduced speciesExplain how an organism is classified as introducedDescribe the variety of reasons exotic species are introduced into AustraliaIdentify the reasons why the Australian environment is particularly vulnerable to the effect of introduced speciesDescribe the features of the environment that contribute to an introduced species becoming a pestDescribe the natural history, history of introduction, ecological impact and control of several named introduced speciesDiscuss methods of biological control of introduced speciesDescribe the rehabilitation of ecosystems damaged by introduced speciesDescribe how quarantine is used to prevent further introductionsIdentify the aspects of your local environment tha have been affected by introduced speciesIntroduced Species in AustraliaPart 1-Lesson 1IntroductionAustralia 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.

IntroductionBecause 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.

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.

IntroductionLarge 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.

IntroductionIn order for an organism to be classified as introduced, its:Immigration history must be knownFeatures would not suit the environment in which it livesFood source would not be indigenous to the area Distribution would not appear to be limited by any physical feature of the environment. Colonising new areasSpecies 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.

Colonising new areasBirds, 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.

Colonising new areasAn 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.

Colonising new areasInsects, 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.

ColonisationAustralia has several non-native animal and plant species that colonised the continent. For example:RatsBatsSealsMany species of birds

ColonisationThe 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 its only believed to have been in Australia for the last 3500 years. They may have been brought here as domesticated species with Indigenous peoples.

ProjectSee Assessment Task #4 Introduced Species ReportDue: Aug 25thHomeworkRead pages 179 HSC Spotlight TextStart new electronic vocabularyComplete DOT Points 1.1-1.2Start research projectIntroduced Species in Australia

Part 1-Lesson 2Reasons for species being introducedThere are a number of reasons why humans have deliberately introduced new exotic species into Australia.FoodTransport Wool/fur/fibreLeisure activities (hunting and fishing)To make Australia more like home to immigrantsFor gardensPetsBiological controlMedical reasonsReasons for species being introducedThere are also a number of accidental ways exotic species have been introduced into Australia.In cargo or food transported by ships and airplanesIn soil on shoes, plants or machineryIn letters and parcels arriving by postIn the ballast dumped by ships

Deliberate IntroductionEarly Europeans brought a number of domesticated animals into Australia to meet a number of needs. For example:SheepPigsCattlePoultryDucksGeese

Deliberate IntroductionMany 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.

Deliberate IntroductionSome, 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.

Deliberate IntroductionMany 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.

Deliberate IntroductionMany 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.

Deliberate IntroductionSome 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.

Deliberate IntroductionGardeners are also responsible for brining in exotic plants which are now some of Australias worst weeds. Plants escaped garden areas by various reasons and explores also distributed seeds as they travelled. Examples of these include:HorehoundCastor-oilPennyroyal St. Johns wort

Accidental IntroductionThis 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.

Accidental IntroductionAs travel improved, the importation of unwelcome visitors also improved. Its 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.

Accidental IntroductionAn 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.

Accidental IntroductionAnother 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.

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.

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.

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?

ReviewThere 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.HomeworkRead pages 180-184 HSC Spotlight TextUpdate electronic vocabularyComplete DOT Points 1.4, 1.5Complete To Think About pg 186-188 HSC Spotlight Text