Culverts and Stream Ecology: Building Background Understanding

By the end of this Unit your students will have an introduction to the basics of stream ecology and habitat connectivity.

Unit Overview

Students need a general sense of the streams as systems. Walking the length of a stream you will find that it is not the same from start to end; and for every difference (many trees, no trees; gravelly bottom, muddy bottom; warm, cool; fast, slow) there is a different habitat for the organisms that live in the stream.  Streams are not only habitats but also habitat connectors. Understanding both will help students think about how changes in the system might result in different patterns of macroinvertebrates living in a stream.

Some ideas in ecology- movement of energy, habitats, communities- can be abstract, but in this Unit we are asking the students to put those ideas into the context of their local stream. What does a stream do? How does the stream work as a habitat? How do the stream organisms function, and what are their specific habitat requirements?


The Culverts and Stream Ecology project is about developing an understanding of a system, testing that understanding through experimentation, and then refining that understanding. Any research project with a hypothesis- a test of the understanding of a system- should grow out of some kind of a model of the system or mechanism under investigation.  A student ought to have some idea, based on their model, about why the outcome predicted by the hypothesis would happen.

We need to employ what students already know and build their background understanding of streams as systems to give them the framework for their own models.


  • Students understand the basics of stream ecology and habitat connectivity and how those pertain to their local stream.

Instructional Strategies

In the first two Units of this project we recommend starting each lesson asking students what they know about that Lesson’s topic.

There are many different ways to think about streams. We are most interested in streams as habitats for macroinvertebrates. It is important to keep students focused on macroinvertebrates as much as possible.