Adult Winter Steelhead Monitoring and Abundance in the Lewis and Clark River

The Oregon Department of Fish and Wildlife has been comprehensively monitoring adult winter Steelhead (Oncorhnchus mykiss) populations on the Oregon Coast since 2003. However, monitoring Oregon tributaries of the Lower Columbia River has been sporadic over that period.  A dam site on the Lewis and Clark River has provided some indication of abundance in that basin since 2000.  Two different counting methods have been used during this effort.  From 2000-2013, a VAKI^© fish imaging counter was operated at the top of the dam’s fish ladder.  Starting in 2014, ODFW’s Oregon Adult Salmonid Inventory & Sampling project began operating a complete barrier trap at the site. The Lewis and Clark basin acts as somewhat of a wild fish sanctuary within the otherwise hatchery influenced Young’s Bay population, and current trap operations serve as a filter to this end. By performing steelhead redd surveys above the dam the trap also serves as a redd calibration site, aiding in long term population monitoring of Oregon Coastal and Lower Columbia Steelhead.  This poster summarizes the patterns of adult winter steelhead abundance within this basin, as well as compares the different monitoring methods.