This document discusses invasive species, which are introduced species that spread rapidly and negatively impact the environment. It provides examples of invasive species in Canada like zebra mussels, European earwigs, and carp. Introduced species often lack natural predators and can outcompete native species, allowing their populations to grow unchecked. This can significantly damage ecosystems and cost the economy billions. The document outlines different methods to control invasive species populations, including pesticides, physical removal, and biological controls like introducing predators. However, prevention of accidental introductions is the most effective approach.

1. Invasive SpeciesInvasive Species

2. Non-Native SpeciesNon-Native Species
Can you name a species that lives in
Ontario but is not native to Ontario?
Do you think that species has an impact
on the natural environment?
How and why did the species get here?

3. Non-Native SpeciesNon-Native Species
The introduction of non-native or exotic
species to an ecosystem by humans is a
major cause of species loss.

4. Non-Native SpeciesNon-Native Species
Introductions of non-
native species usually
fail because so few
species can tolerate
an entirely new
environment.

5. Non-Native SpeciesNon-Native Species
Remember that for a species to survive it
must be within its tolerance range for all
abiotic factors.

6. Non-Native SpeciesNon-Native Species
Even if a species is adapted to the abiotic
environment, it may have difficulty finding
food or may be unable to compete with
native species.

7. Occasionally, an introduced species is
successful in its new environment…
zebra mussels

8. The new ecosystem may lack population
controls for the new species, such as predators
and diseases. Native species may not be able to
compete with the introduced species.

9. When a population is unchecked, it gains
an advantage over native species. It can
increase rapidly and become invasive.

10. Invasive species are introduced species
with growing populations that spread and
have a negative effect on their environment.

11. Non-Native SpeciesNon-Native Species
There are well over
3000 invasive species
in Canada. In the Great
Lakes, there are over
185 invasive species.

12. European Earwig

13. European Starling

14. Carp

15. Non-Native SpeciesNon-Native Species
Invasive species have significant
environmental and economic impacts.
These species change natural
ecosystems and cost Canadians
billions of dollars annually just
to control their population size.

16. It is impossible to predict which
introduced species will become invasive.
Preventing the accidental introduction of a
non-native species is ideal but difficult.

17. Insects can arrive as adults, larvae, or
eggs in imported foods and containers
from around the world.
fruit infested with citrus codling moth

19. Small seeds are equally difficult to detect…

20. Controlling Introduced SpeciesControlling Introduced Species
Once an introduced species is
established, it may be difficult to control.
Elimination is unlikely, however there are
three types of control measures.

21. Perhaps the most
widely used control
method is the use
of pesticides.

22. Chemical ControlChemical Control
Pesticides are used mostly on forest and
agricultural pests because trees and
crops have significant economic value.

23. Pesticides
dramatically reduce
crop damage, but
there are
environmental risks.
They may kill non-
target native species
and pollute the air,
water and soil.

24. Mechanical ControlMechanical Control
Some invasive
species may be
controlled with
physical barriers
or removal.

25. Mechanical ControlMechanical Control
Invasive plants can be cut down, burned,
or even removed by hand.

26. Mechanical ControlMechanical Control
Invasive animals can be hunted or trapped.

27. For example, in Hamilton harbour, barriers
were constructed to protect valuable wetland
from carp, an invasive fish species.

28. Biological ControlBiological Control
Biological control is a challenging but effective
method of controlling invasive species.

29. Biological control uses intentionally
introduced organisms to control the
invasive species.

30. For example, three insect species were released
in Ontario to control purple loosestrife, an
invasive plant that grows in wetlands.