They form the base of the food chain by providing food for fish and other small creatures. These invertebrates are sensitive to water quality and to habitat quality, preferring a gravelly or stony bottom. They also are negatively affected by rapid changes in flow rates, which scour the bottom and then deposit sediment when the water slows down. Headwaters areas are generally of poorer quality than areas further downstream. This phenomenon has been observed in other parts of the country as well.
Streams integrate all aspects of the environment.
When the watershed is transformed, the first impacts are seen in the headwater streams. In summary, the Cannon River Watershed has been greatly affected by human activities that have degraded its water quality and biological integrity. But it still remains a haven for biological diversity, scenic beauty, and productivity. Threats to the resource in the future will primarily involve increased intensity of both agricultural and urban land uses. Many activities are already being undertaken to restore and improve the watershed's resources, but more effort will be needed.