Even altered streams still provide some habitat for native freshwater species. In this light, we can still take positive steps toward restoring and improving these habitats for Hawai'i's native freshwater species. Since native stream animals need to migrate to and from the ocean to complete their life cycles, an almost continuous flow into the ocean is the utmost priority. Native stream animals thrive best when the water is as clear and clean as possible. Riparian vegetation also creates a canopy over the stream which provides shaded areas and the cooler water which native stream animals prefer.
Stream channelization removes the riparian vegetation which provide shade for the stream.
The combination of direct sunlight and absorption of heat by the concrete channel increases water temperatures which favor the proliferation of alien species and is adverse to native species. In addition, the rocks and boulders needed to provide shelter and protection for native stream animals are removed. Preventing the release of any additional alien species into any stream system is also very important. Alien species compete with native stream animals for food and habitat, prey on native species, and harbor parasites and diseases that can harm native species. We cannot do everything needed to restore all the streams to the pristine conditions they once had been.