1. Identify examples of invasive species common to our region.

What are some examples of invasive species threatening biodiversity in our region? If students are not already familiar with invasive species, explain they are species that are not native to our region. They can cause ecological, economic, or human heath problems. Ask students to brainstorm some reasons people should be aware of invasive species and the problems they cause. List student ideas on the board.

Explain to students that they will each receive a picture card representing an example of an invasive species found in the Great Lakes region. (Note: Several cards depict species not currently established in the region but are considered potential threats.) As the cards are passed out, have the class discuss whether or not they have previously heard of that species. Form two groups (“well known” and “not wellknown”) as the cards are passed out. This will help provide an indication of which species students may have heard of previously. Each student should wear a Picture Card around his/ her neck.

2. Classify the invasive species according to various characteristics.

What are some other ways to classify or group the different invasive species? Students should refer to the information on the backs of their cards to learn more about “who they are” and then suggest different ways of classifying the organisms. Have students physically walk (quietly) into groups based on each of the various classification systems. Refer to the suggested ideas and related discussion points.

• Plant, animal, or disease-causing microbe. Plants make up the largest group of invasive species in Michigan. Out of 2600 species of plants in the state, 800 of them are nonnative. Of these, only some are considered to be problematic and are labeled as invasive.

• Terrestrial or aquatic habitat. Make sure students understand these terms.

• Where they originated (Europe, Asia, Africa, or other parts of the United States). Optional: Locate the areas on a large world map.

• Dates of introduction. Students form a human timeline, showing the order of arrival into the region. Discuss what events may have contributed to increases in the number of invasions (opening of canals, roadbuilding, airplanes, etc.). Optional: Have students create a timeline related to invasive species in the Great Lakes region. 

• Method of introduction. Discuss the ways species were introduced to the region and then classify them according to the four main categories of introduction:

a. Accidental (or unintentional) release (includes release of aquarium pets and plants, escape of cultivated plants or animals from gardens or ponds, and release of unused live bait). [Answers: curly-leafed pond-weed, Eurasian watermilfoil, flowering rush, hydrilla, Asian carp, northern snakehead, rusty crayfish, gypsy moth, common periwinkle, glossy buckthorn, and autumn olive.]

b. Ship-related introductions (attachment to boat or ship hulls, solid ballast, or ballast water). [Answers: purple loosestrife, Eurasian ruffe, round goby, spiny and fishhook waterfleas, zebra mussel, leafy spurge, Asian long-horned beetle, emerald ash borer, house mouse, Norway rat, Dutch elm disease, and spotted knapweed.]

c. Deliberate releases (stocking of fish or animals, especially game species). [Answers: European starling and house sparrow.]

d. Movement through or along canals, railways, or highways. [Answers: alewife, sea lamprey, and white perch.]

3. Tying it all together.

How can we prevent new introductions of invasive species or the spread of current invasive species? Ask students to think of activities that may contribute to the introduction and/or spread of invasive species. Provide groups of two to four students with a Problem- Solver Role Play Card that gives a description of what they could do to prevent the spread of invasives. Each group should read their card and then decide how to teach the rest of the class about the actions that could be taken to prevent the spread of invasives. Students could perform a quick skit or create a poster.