Who Can Harvest a Walleye?

The Great Lakes are an example of a natural community. In this community the small organisms (living things) outnumber the large organisms. The smaller organisms may be eaten by the larger ones.In this activity, students will count all the organisms of one kind, then count all the things they eat and all the things that eat them, creating pyramid of numbers that will also show who eats what.


When you have completed this investigation you should be able to:

  • Apply the meaning of the following terms as they relate to a biomass pyramid: producer, herbivore, first-order carnivore, second-order carnivore.
  • Calculate the relative number of kilograms at each level of the biomass pyramid in a given environment.
  • Analyze how different conditions in the environment affect the pyramid

External Curriculum Materials


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