Introduced and Invasive Species

Why would humans introduce a species? 1. Organisms are purposely released for

establishment in the wild. 2. Species transported into a new region may

escape and establish in the wild.

Introduced Species

An introduced species is an organism that is not native and has been accidentally or deliberately transported by human activity.

Introduced species can often be damaging to the ecosystem it is introduced to.

Examples of Introduced/Invasive species

Rabbits, cats, frogs and foxes in Australia Cats on the Galapagos Islands Red squirrels and snowshoe hares on the

island of Newfoundland Plants like Kentucky Bluegrass, periwinkle,

lily of the valley and the dandelion Many of Canada’s exotic species are

beneficial, but a great number of them are not when they become Invasive species.

Introduced species Kudzu Ivy

Rabbits introduced into Australia

Look what happens when there are no natural predators

Why Introduce an Organism?

Economic gain. Recreational activities (fish and game animals) Aesthetic reasons (flowers)

Invasive Species

An invasive species means the species causes economic or environmental harm or harm to human health.

When species compete to survive, invasive species have traits that allow them to out-compete native species.

This could be the ability to grow and reproduce more rapidly than native species

How Introduced and Invasive Species Relate

An introduced species becomes invasive if it can out compete native species

Or some species lack the competition and natural predators freeing them to flourish quickly.

Why are we concerned with Invasive Species?

Invasive species can cause the extinction of native species

Ecosystem destruction, habitat loss Biodiversity loss, crop loss Threats to human health Costs of the removal of invasive species (in

the billions)

Methods of Removal

Physical control: physically removing the species from its environment (pulling out unwanted plants, burning an area, snaring and trapping, and shooting unwanted animals).

Chemical control: pesticides, herbicides, fungicides, and other chemicals used to kill the target invasive species. Ex. poison to kill rats.

Biological control: parasites and disease are used to control the growth of invasive species.

Effectiveness of Methods of Removal

It is usually difficult to trace the places that species have been introduced accidentally. Accidental arrivals are rarely discovered until they become invasive.

Controlling invasive species is very difficult, sometimes impossible

Canadian Laws are in place to prohibit some species from entering the country.

What can we do to prevent invasive species?(write 2-3)

Do not release exotic plants or animals into the wild Do not bring fruit, vegetables, plants or animals with you

across international borders Do not transport over long distances, firewood or other wood

with bark attached Learn which plant species are invasive and remove them from

your gardens Volunteer with local environmental organizations that work to

maintain healthy ecosystems Know where consumer products come from and buy from

local sources whenever possible.

Key Questions

1. How and why are plant and animal species introduced into new areas (give at least 3 reasons)?

2. What are the three of the methods for removal of introduced/invasive species?

3. Consider some future problems that some removal methods might cause and discuss one of them.

4. List three of the things we can do to prevent introducing species to Canada.