Not the river but the watershed. In fact a river cares little about fish they just live there part time. That Chinook are important but more to humans than the other species in the stream. Streams that naturally had large Chum populations and Chum do poorly that has an negative impact on Coho which in turn effects Steelhead. Chinook in most watersheds are not in enough numbers to drive the interaction between species. Human values and natures are not the same at all.