Activity: Great Lakes Most Unwanted

Summary: Students work in small groups to organize invasive species cards, featuring facts and photos. Each group presents a different invasive species in a poster or fact sheet to the class.

You Need:


  • Copy photo cards onto white card stock.
  • Copy characteristics cards onto colored card stock.
  • Assemble all cards by cutting, folding in half, and taping to make 2-sided cards.
  • Each group of 3-4 students should get one set of the cards.


Introduce the topic of invasive species to the class. Explain key points made in the background section and define difficult vocabulary words, such as non-native, invasive, ballast water, etc.

  • Have the students work in groups of three to four people, each with a complete set of 16 shuffled cards — 8 photo cards and 8 characteristics cards.
  • Beginning with the photo cards, match each invader to its corresponding characteristics and impacts.
  • When group members agree that they have matched the cards to the best of their ability, they may review their answers on the answer sheets.
  • Each group selects an invader to present to the class, and constructs a poster about the invader or develops a fact sheet. Be sure to include the impact of the invader on the ecosystem. Brainstorm ways to prevent new species from entering the Great Lakes.
  • After all the groups have presented and discussed their species, review with students the importance of human behavior in preventing the introduction and spread of invasive species.

Activity Extension

  • Draw an invasive species, paying special attention to distinguishing characteristics.
  • Create a humorous cartoon depicting some of the impacts of invasive species (example: purple loosestrife choking other plants, etc.)
  • Learn about ways to prevent the introduction of new invasive species and slow the spread of existing populations using the Great Lakes Most Unwanted (poster series).


Adapted for the Great Lakes Education Program with permission from “What do scientists know about invader species of the Great Lakes?” in Earth Systems—Educational Activities for Great Lakes Schools: Life in the Great Lakes. Modified by Anne Williamson and Mike Klepinger.