1. Lesson 9 – Invasive or Exotic Species

2. Non-Native Species
Non-native, or exotic, species are those species that do not naturally occur in an ecosystem
They arrive in ecosystems in a variety of ways:
Boats or travellers from other countries carry organisms unknowingly
People bring seeds or cuttings of exotic plants to grow in their gardens
Sometimes species are intentionally introduced to help solve a problem

3. Non-Native Species
Introduction of many non-native species fails because few species can tolerate the conditions (temperatures, precipitation, predators, disease) of an entirely new ecosystem
Once in a while, a species will thrive due to few predators or disease to limit reproduction
The intentional introduction of a species must be carefully monitored to ensure it does not disrupt the existing ecosystem

4. Invasive Species
In some cases, native species might not be able to compete with an introduced species, which will allow the new species to increase quickly and become invasive
Invasive species are non-native species that have a negative impact on the natural environment
Invasive species populations often grow out of control which can lead to the extinction of native species

5. Introduction Fail!
South America introduced the Canadian beaver in the 1940s for its fur; the fur did not grow thick enough in the warmer climate; beavers were not trapped or hunted and populations exploded causing lots of damage; foxes were introduced to prey on beavers; foxes fed on native rabbits instead; lack of rabbit droppings affected soil conditions and entire ecosystem was out of balance; the beavers have continued to spread and cause damage

6. Invasive Species in Canada
More than 3000 invasive species in Canada
More than 185 of those are in the Great Lakes region
Invasive species have negative impacts on the ecology, economy, tourism, and health of a region
Canada spends millions of dollars each year to control invasive species
Damage by invasive species around the world is estimated to cost $1.4 trillion annually

7. Invasive Species in Canada
Zebra mussel
1988 from bilge water
Sea lamprey
Round Goby
Emerald ash borer beetle
Asian long-horned beetle
Toronto, Vaughn – trees removed
Purple Loosestrife
Kudzu Vine

8. Controlling Introduced Species
Chemical Control – use pesticides to protect trees, crops, fisheries, human health; may pollute or kill native species
Mechanical Control – human made barriers to prevent spread; pulling or digging up plants or trapping insects
Biological Control – predator or infectious agent is used to kill or harm the species

9. Keeping Asian Carp out of Great Lakes
Escaped into Mississippi River in 1990s during flooding
Have made their way north towards the Great Lakes
Chicago Ship and Sanitary Canal is the only connection from the Mississippi to the Great Lakes
Building a Barrier
Asian Carp Fishing