Adult steelhead abundance estimates are based on redd surveys conducted weekly from February through June. (Redds are gravel nests  where salmon and steelhead deposit and cover their eggs.)  Outmigrating juvenile salmonid abundance is monitored annually using rotary screw traps from late March through early June.

Genetic samples are collected from summer parr, smolts, resident rainbow trout, and hatchery-reared fish to determine if genetic changes occur as a result of supplementation. Scale samples are collected for age determination.

Oncorhynchus mykiss exist as resident rainbow trout and anadromous steelhead, and this project is measuring the proportion of the two forms in different streams. Supplemented and control populations are sampled to determine if changes in the proportion of resident and anadromous fish occur as a result of hatchery supplementation.

Using acoustic technology, steelhead early marine migration and survival is being investigated by NOAA Fisheries as part of the Hood Canal Steelhead Project. Over multiple years, acoustic transmitters were surgically implanted in steelhead smolts. Unique signals from the transmitters were detected by receivers located at river mouths, nearshore sites in Hood Canal, and transects in northern Hood Canal, Admiralty Inlet, and the Strait of Juan de Fuca. The information was analyzed to show migration patterns and survival rates.