1. Activity 4
Invasive Species

2. The Threat of Invasive Species
Watch the video & answer these questions:
What is an invasive species?
List examples
What problems do these invasive species cause?

3. Read the introduction and discuss the following as a class:
What is the difference between non- native species & invasive species?
What determines if a species is considered an invasive species?
What are some examples of the effect an invasive species might have on a community?
This class discussion should take approximately 10 minutes.

4. A nonnative species is a species introduced to an area where it is not normally found.
A habitat is the specific location where an organism lives within an ecosystem.

5. An invasive species is a nonnative species that causes harm to the economy, the environment, or human health.

6. Within an ecosystem, the population of a native species may decline when a non-native species begins to take over the same role in a habitat.
Kudzu is known to uproot native trees and shrubs, and also essentially smother them by covering them up and preventing access to resources such as sunlight and carbon dioxide (Bergman & Swearingen, 2005)
KUDZU VIDEO

7. How do certain characteristics increase the likelihood that a nonnative species becomes an invasive species?
Another way to think of this question is: What features of a species make it more likely to become an invasive species?

8. Part A
Form groups of 3-4. Each person should chose one case study to read.
Share information about your case study with your group
make a list of similarities you note in all the case studies
Begin creating a list of traits your group thinks increase the potential for a non native species to become invasive

9. What conditions and characteristics would increase the likelihood that a nonnative species would become an invasive species?
Be sure to think about the following:
Characteristics of the organism
Environmental conditions
Other native organisms being affected
Effects on the economy or health of the local human community

10. TRAITS THAT INCREASE LIKELIHOOD OF NON-NATIVE SPECIES BECOMING INVASIVE
Rapid reproduction
Ample nourishment (plentiful food supply; or organism can feed on variety of food)
Traits well suited for environment
Adequate defense against potential predators or absence of predators

11. Part B
In this section you will read about the benefits and risks of the possible introduction of a nonnative species to try to replenish a fishery. The balance between these benefits and risks is known as a trade-off.
If appropriate, introduce the concepts of evidence and trade-offs here. See your Teacher’s Edition for more information on how to do this.

12. PAPER OR PLASTIC? Why choose PLASTIC?
Conserve water & energy usage…reduce CO2 emissions…all result of making paper…also to reduce the amount of solid paper waste
Why choose PAPER?
Avoid generating plastic waste or using up petroleum resources

13. TRADE OFF… an exchange of one thing in return for another,
giving up something that is a benefit or an advantage,
in exchange for something that ay be more desirable

14. Should nonnative oysters be introduced into the Chesapeake Bay in order to sustain the oyster fishing industry?
Read the summary report
Use the “read…think…take note” procedure

15. Chesapeake Bay
Discuss your notes with your group
Create a “discussion web” to analyze this question
Consider two opposing viewpoints:
FISHERMEN:
make their living off the oysters in the bay
CONSERVATIONISTS; want to protect the bay…keep it at its original state

16. Discussion Web
In the center box, write the question being considered: Should nonnative oysters be introduced?
In the box at the top of each column write one of the viewpoints being presented. Record the evidence supporting each viewpoint in the appropriate column.
The graphic is from Literacy Student Sheet 4, Discussion Web, found in the Teacher Resources.

17. How likely could the oysters spread outside the bay?
What other questions need to be answered in order to fully justify one side or the other?
What is the likelihood of the nonnative species bringing disease into the ecosystem?
How likely could the oysters spread outside the bay?
Would the nonnative oysters crowd out the native species?
If appropriate, introduce the ET assessment variable here. See your Teacher’s Edition for more information on how to do this.

18. Analysis
Describe some characteristics that increase the likelihood of nonnative species becoming invasive
Discuss the trade-off in introducing a predator into an ecosystem to prevent a specific species that has become a “pest” from spreading
Take either the side of the fishermen or the conservationists and make a recommendation for or against the introduction of the nonnative oysters into Chesapeake Bay. Include at least two trade- offs associated with your recommendation.
If appropriate, introduce Evidence and Trade-offs (ET) assessment variable here. It can be used to score Analysis Question 4. More information on how to introduce and use this assessment variable, as well as a sample student response, is available in your Teacher’s Edition for this Activity and in Teacher Resources IV: Assessment.

19. ecosystem evidence habitat invasive species nonnative species
trade-off
See Teacher Resources III: Literacy for more information on key vocabulary and the most effective strategies to enhance student vocabulary learning.
Note that bold words are formally defined in this activity. Words in regular font are used in the activity, but not formally defined. The definition of a key vocabulary word should not be discussed as a class prior to the formal definition being introduced.