Biological InvadersBiological Invaders• How can foreign organisms successfully

compete with naturally-occurring ones?• How are biological invaders introduced?• What can be done?

Asian Carp…Asian Carp…

• http://www.youtube.com/watch?v=mUssO68D2eM

ExamplesExamples

Round Goby fish Purple Loostrife

Asian longhorn beetleSea lamprey

Biological InvadersBiological Invaders• Any foreign species that is introduced to an

ecosystem. • Can have devastating effects on the naturally-

occurring plant and animal life.

Why are some Invaders so Why are some Invaders so Successful?Successful?

• 1) NO Predators - they have evolved elsewhere; no predators

are present• 2) NO Competition – similar species, with similar niches, have

not evolved to compete with invaders

How are Biological Invaders How are Biological Invaders Introduced?Introduced?

• -sometimes, through natural migration

• MOSTLY carried by humans (not always intentionally!)

How are Biological Invaders How are Biological Invaders Introduced?Introduced?

• Ballast water from ocean going ships– Water is picked up in ship’s home port and

then dumped when it reaches the Great Lakes

• Human transport– Boat picks up species in one lake; boat is

then trailered to a neighbouring lake (zebra mussels)

Who cares?Who cares?

• Native species dying out (negatively impacts ecological balance)

• Huge costs (Ontario sportfishing – lamprey; water intake – zebra mussels)

• Pain in the butt (feet) – zebra mussels cut up your feet when you swim

How can they be Stopped?How can they be Stopped?

• Natural competition of the ecosystem (eg. exotic fish)

• By physical or chemical means (eg. lamprey eel, weeds)

• Tighter controls in the shipping industry

• BIOLOGICAL CONTROLS (other foreign species) are also introduced to prey on invader (purple loosestrife)