Elwha Watershed Information Resource

The USGS is studying the patterns of habitat utilization by Chinook salmon in the lower Elwha River, estuary, and nearshore using otolith analysis. This image is a cross section of a Chinook salmon otolith which are small stones found in the head and used for orientation and balance. By examining microstructural patterns, biologists can glean information about how individual fish grow prior to and during their seaward migration.

Credit: Jeff Duda, United States Geological Survey