This series of five lessons begins by introducing the concepts of aquatic food chains and food webs. Activities demonstrate that all living organisms in an ecosystem are connected and that this structure is sensitive to change. Lessons then discuss the problem of nonindigenous species and why some of these are invasive. Invasive species disrupt Great Lakes food webs and cause long-term ecological changes.

Lesson 1: Make the Connection
Demonstrates that all organisms are linked and emphasizes the importance of these connections. Discusses herbivores, carnivores, and producers.
See: Lesson 1

Lesson 2: Who's Eating Whom?
Explains that some animals eat multiple species, forming complex food webs that transfer energy. Discusses producers, consumers and top predators.
See: Lesson 2

Lesson 3: Great Lakes' Most Unwanted
Discusses the concept of nonindigenous species—how they’re introduced into an ecosystem and why some become invasive. Presents 10 invasive species and their impacts.
See: Lesson 3

Lesson 4: Beat the Barriers
Focuses on the invasive sea lamprey, its impact on the Great Lakes ecosystem, and various control methods used to manage the population. See: Lesson 4

Lesson 5: Ruffe Musical Chairs
Emphasizes the importance of meeting basic needs for food, water, and habitat. Demonstrates how invasive species can cause dramatic food web changes that impact native species.
See: Lesson 5