Freshwater and Saltwater ecosystems are the focus of this Earth Science PowerPoint. Presentation is full of interesting facts, photographs, and maps. A slide with review questions appears at the end of the presentation. Very nice!

Students assemble a classroom river model as an example of a lotic system. They control and measure biotic and abiotic information for the in-class system and compare data with a lotic system in a natural environment.

Students examine water samples from a local stream. They identify various types of macroinvertebrates found in that water ecosystem and perform a quantitative macroinvertebrate survey to determine the stream's water quality.

How would you define an ecosystem? Check out this educational resource to learn more about the living and nonliving parts of different ecosystems.