Biological Invaders How can foreign organisms successfully compete with naturally-occurring ones? How are biological invaders introduced? What can be done?
Asian Carp… 68D2eMhttp:// 68D2eM
Examples Round Goby fishPurple Loostrife Asian longhorn beetle Sea lamprey
Biological 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 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 Introduced? -sometimes, through natural migration MOSTLY carried by humans (not always intentionally!)
How are Biological Invaders 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? 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? 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)