In the past, we thought it was a good idea to clean up the log jams that “choked up” steam channels. As a matter of fact, Oregon used to have employees whose primary role was dynamiting log jams in rivers. Today, things have changed. We now understand that pulling logs and other wood out of streams really limits the creation of pools and hiding habitat for fish.
Logs and tangles of woody debris in a stream play important roles in creating several different habitats that are important to steelhead, migratory salmon, and other fish.
- Large wood provides overhead shade that helps keep water temperature down and at the same time provides the cover young fish need to escape from predators.
- By partially blocking stream flow large logs can create pools upstream or encourage the downstream development of gravel bars, used by adult fish for spawning.
- The logs themselves are habitat for some of the aquatic insects that are an important food source.
So, log jams are vital for maintaining fish habitat. Now that you know it, do a fish a favor and let those (sleeping) logs lie.