Nasty urban streams can be vital salmon habitat, at least during stormy weather.
Overturning conventional wisdom, baby salmon were found living in streams once thought to be too ruined by development in Ashland, Oregon. The trick for salmon is to use these streams selectively, as shelter from the rushing water of winter storms.
When the water is raging, juvenile salmon look for shelter wherever they can find it, and that can include tiny garbage-strewn streams that you could step across, flowing next to a big highway. A few days of shelter during winter floods can make a life-or-death difference for a salmon.