Has there been research into the feeding habits of Rainbow trout? Is there a preferred color, shape, movement, feeding location (top, bottom or mid water), temperature range, light level, habitat structure, water flow and quality ad infinitum.

I ask because there are several small streams in my area with native fish which seem to be in slow decline. Many of these creeks had heavy steelhead and salmon runs over a half century ago but have declined in recent years.