Hood Canal

Hood Canal Action Area mapHood Canal is a natural fjord separating the Olympic and Kitsap peninsulas. It stretches 68 miles from the northern tip of the Kitsap peninsula to Lynch Cove, forming an L shape that remains narrow, only one and a half to two miles across. The Action Area includes the Canal, streams and upland areas draining into it, and all the land north to Point Wilson, in Port Townsend. Major rivers entering Hood Canal from the Olympics, on the west side, include the Skokomish, Dosewallips, and Big Quilcene. Precipitation is variable – Port Townsend receives only 19 inches per year, while 90 inches annually fall at Skokomish.

Water circulation in the Canal is a serious issue. The average depth is only 177 feet, but it reaches a maximum depth of 600 feet, and circulation is poor, especially in the southern portion. Water from the Strait of Juan de Fuca mixes poorly due to an underwater sill south of the Hood Canal Bridge, and freshwater entering the canal often forms a layer at the surface. Algal blooms reduce dissolved oxygen, providing a poor habitat for marine species. However, fisheries and aquaculture are economically important to the region, and the Canal is famous for its oysters and other shellfish species. Many salmon populations, including an evolutionarily significant unit of summer chum, spawn in the streams of Hood Canal and migrate through on their way to other waters.

The Hood Canal region is less developed than other Puget Sound basins, and around 90 percent of the drainage area is forested. The shoreline is the most utilized, with an estimated 33 percent modified by human activity.



Figure 1. Map of study area. Map depicts the four receiver arrays: Hood Canal Bridge (HCB), Mid Canal (MCL), Admiralty Inlet (ADM), and Strait of Juan de Fuca (JDF). Lower insets show single receiver locations for each year.

Paper: A floating bridge disrupts seaward migration and increases mortality of Steelhead smolts in Hood Canal, Washington State

A new study provides strong evidence of substantial migration interference and increased mortality risk associated with the Hood Canal Bridge for aquatic animals, and may partially explain low early marine survival rates observed in Hood Canal steelhead populations.

Map of the Hood Canal Action Area; courtesy Puget Sound Partnership

PSI review finds minimal evidence for human impacts on Hood Canal hypoxia

An independent review conducted by the Puget Sound Institute (PSI) is featured in findings by the Environmental Protection Agency and the Washington State Department of Ecology that there is currently “no compelling evidence” that humans are the cause for recent trends in declines in dissolved oxygen in Hood Canal.