This is the final topic of the HSC Topic 4-Introduced Species
and the Australian Environment
Slide 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
Slide 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
Slide 4
Introduced Species in Australia Part 1-Lesson 1
Slide 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.
Slide 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.
Slide 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 18 th Century.
Slide 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.
Slide 9
Introduction In order for an organism to be classified as
introduced, its: 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.
Slide 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.
Slide 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.
Slide 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.
Slide 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.
Slide 14
Colonisation Australia has several non-native animal and plant
species that colonised the continent. For example: Rats Bats Seals
Many species of birds
Slide 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 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.
Slide 16
Project See Assessment Task #4 Introduced Species Report Due:
Aug 25th
Slide 17
Homework Read pages 179 HSC Spotlight Text Start new electronic
vocabulary Complete DOT Points 1.1-1.2 Start research project
Slide 18
Introduced Species in Australia Part 1-Lesson 2
Slide 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
Slide 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
Slide 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
Slide 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.
Slide 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.
Slide 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.
Slide 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.
Slide 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.
Slide 27
Deliberate Introduction Gardeners 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: Horehound Castor-oil Pennyroyal St. Johns wort
Slide 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.
Slide 29
Accidental Introduction As 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.
Slide 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.
Slide 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.
Slide 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.
Slide 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.
Slide 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?
Slide 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.
Slide 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