Zebra Mussel
Introduction
and Extinction
of Species in an
Eco System
Species Introduction
“Introduced species are species that have
become able to survive and reproduce
outside the habitat where they evolved or
spread naturally.”
-United States Environmental Protection
Agency
Example of an
ecosystem
Introduced Species
 Species
can be classified in two classes
1)Invasive
2)Non-invasive
 Both types of introduced species are
brought to a new environment by human
activity, either accidentally or
deliberately.
Example of an
invasive species
:Zebra Mussels
Definition of Non-Invasive
Species
A
non-invasive species is an organism that
is not native to the ecosystem, but doesn't
have any negative effects on the
ecosystem.
 Examples include peaches and
tomatoes.
Definition of Invasive Species
 An
invasive species is an organism that is
not native to the ecosystem, and has
negative effects on the ecosystem.
 Examples include the zebra mussel which
originated in Russia, and are now found in
rivers worldwide, and cause damage by
clogging pipes and contaminating the
water.
A colony of Zebra
mussels that are
attached to a
larger mussel
What do invasive species do,
anyway, and why do they
pose such a threat
 Invasive
species cause harm to wildlife
that is foreign to it. These species are new
which causes them to be more
aggressive. The new species may not
have any predators, and their numbers
will spread rapidly and uncontrollably,
along with taking over an area. Native
wildlife wont be able to protect it’s self
against the new invasive species
New Zealand
Invasive species videos!
 https://www.youtube.com/watch?v=k3N
5t70aJ2A
 https://www.youtube.com/watch?v=oYcl
0xxU5_s
 http://www.jfindlay.ca/?go=flowplayer&r
esid=977
Extinction Definition
 The
death of a species. It is considered to
be the death of the last member of the
species.
 The two types of extinction are:
Global Extinction
Local Extinction
Global Extinction
 Defined
species
as the total disappearance of a
Examples include the Dinosaurs and
the Dodo, both of which are extinct
worldwide.
Dodo Bird
Extinct dinosaur
Local Extinction



Defined as the disappearance of a species in
a certain ecosystem, but the species lives in a
different ecosystem.
Local extinction can be fixed by replacing
the missing organisms with the same species
from other locations.
An example of local extinction is that
saltwater crocodiles used to live in Vietnam,
but are now extinct in that specific location.
Salt water crocodile
Effects of the Extinction of a
Species
 If
a species is eliminated, it will cause
many problems with the other trophic
levels. Everything that this species feeds
on will become overpopulated and begin
to die out, affecting the next trophic level,
and so on.
 This is called the cascade effect.
Practice
Questions
 1)
What is the definition of extinction?
 The
death of a species
 What
are the two types of Extinction
 Global
and local extinction
 What
are two examples of global
extinction
 Dinosaur
and Dodo Birds
 What
is an example of local extinction
 Salt
water crocodiles
 What
are the two types of introduced
species
 Invasive
and non-invasive species