FEATURED ACTION: 
Illustration: Wild Steelhead Status Today
Summary: In 1996, NOAA fisheries separated West Coast wild steelhead populations into 15 Evolutionary Significant Units (ESU), or regional population groups with similar genetic, evolutionary and reproductive traits. More recently these have been defined as Distinct Population Segments (DPS). These separate distinctions allowed evaluation and listing, as necessary, of each ESU under the Endangered Species Act (ESA).
