Zebra Mussels, an Invasive Species

Have students find where the deer graph levels off before they answer questions about carrying capacity. After the zebra mussel sheet, ask students to name the change that started the chain of effects.

Read how zebra mussels reached the Great Lakes in ballast water and complete a chain of effects. The directions on the page read: Read the passage and study the table. Then answer the questions on page 2. An answer key is included.

Yes, both. We made it for 6th Grade ecosystems, and the page works the same whether it lands on a kitchen table or a center rotation. At home, most families go through it together and talk the answers out loud, and that talking is where most of the learning happens with populations and invasive species. In class it runs well as independent work while you pull a small group. Print one copy or thirty, whichever the day needs.

On the island deer sheet, food, water and space limit the herd before any predators arrive. Predators can also be a limiting factor, and a drought that kills plants lowers the number of deer the island can support.

An invasive species is a living thing that is brought to a new place, where it spreads and causes harm. Zebra mussels, native near the Black Sea and Caspian Sea, were first found in the Great Lakes in 1988.

Boaters are asked to clean, drain and dry their boats before moving them to another lake, because tiny young mussels can travel in the water left inside a boat.