Puget Sound Steelhead Foundations: A Primer for Recovery Planning

Purpose of the Puget Sound Steelhead Foundations Project

The Steelhead Foundations project is a cooperative agreement among the Washington Department of Fish and Wildlife, National Marine Fisheries Service (NOAA Fisheries), Puget Sound Partnership, Recreation and Conservation Office, Governor’s Salmon Recovery Office, and Northwest Indian Fisheries Commission. The goal of the project is to form the basis (‘foundation’) for a steelhead recovery plan in Puget Sound.

This report provides information on Puget Sound steelhead taxonomy, natural life history strategies, and general habitat use. To provide a context for status evaluation and recovery of steelhead, a description of individual watersheds within the Puget Sound basin is included. We summarize habitat factors contributing to the depressed status of steelhead in Puget Sound and review current threats and stressors within each basin. To build on previous recovery work targeted at Chinook salmon, chum salmon, and bull trout, an information gap analysis is also provided to address the most important elements of steelhead recovery that are not covered in these existing plans. This report does not address environmental pollution challenges, such as potentially harmful chemical mixtures found in stormwater runoff, endocrine disruptors, pharmaceuticals or other forms of chemical pollution entering receiving waters of Puget Sound, and their potential adverse impacts on steelhead. In addition, harvest management, and current hatchery practices are not specifically addressed by this report; such a review is beyond the scope of this effort, but is anticipated to be addressed in the final steelhead recovery plan.

Introduction

Puget Sound steelhead (Oncorhynchus mykiss) were designated as an evolutionarily significant unit (ESU) in 1996 following a status review of west coast steelhead (Busby et al. 1996). Steelhead (the anadromous form of O. mykiss) occurring downstream of natural migration barriers in rivers draining to Puget Sound, Hood Canal, and Strait of Juan de Fuca (on the Olympic Peninsula west to the Elwha River) were included in the ESU. In 2004 the National Marine Fisheries Service (NMFS) was petitioned to list Puget Sound steelhead under the Endangered Species Act (ESA) as threatened or endangered. The petition engendered a new status review (Hard et al. 2007) and based on its findings, Puget Sound steelhead were ESA-listed as a threatened species effective 11 June 2007. Due to the shared jurisdiction over O. mykiss between NMFS and the U.S. Fish and Wildlife Service (USFWS), the ESU designations for west coast steelhead were re-described as distinct population segments (DPS) (National Marine Fisheries Service 2006), which are the ESA ‘species’ designations used by the USFWS. Thus, the Puget Sound steelhead ESU became a DPS, with no changes to geographic boundaries, and subsequent federal documents use the DPS language.

Factors that supported the threatened status of the Puget Sound steelhead DPS were widespread declines in abundance and productivity, steeply declining abundance of some populations, releases of hatchery stocks not included in the DPS, reduced habitat quality, habitat fragmentation, urbanization, and declining marine survival rates (Hard et al. 2007). Three years after the listing decision, the status of Puget Sound steelhead regarding risk of extinction had not changed (Ford et al. 2010), although estimated abundance of most populations within the DPS continued to exhibit downward trends (Ford et al. 2010.).

Various activities are underway to begin reducing extinction risks and plan recovery efforts. For example, a Puget Sound steelhead harvest management plan is being developed by WDFW and western Washington treaty tribes. Hatchery production and management have been altered to address risks to wild steelhead by actions such as reducing the number of hatchery smolts released in some watersheds. NMFS convened the Puget Sound steelhead Technical Recovery Team (TRT) that will delineate historical, demographically independent populations. After Puget Sound steelhead stocks are delineated recovery targets will be developed, and viability assessments will be conducted.

There are numerous �"stressors” that can adversely affect ecosystem processes, habitats, and fish species such as steelhead. Stressors can be grouped into three general categories that include chemical, biological, or physical habitat perturbations. Chemical stressors can range from agricultural runoff, stormwater pollutants, sewer overflow, or pharmaceutical chemicals that can mimic hormones (endocrine disrupting chemicals). Examples of biological stressors to steelhead are bacterial or viral infections, parasites, competition, or predation, including those fostered by invasive species. Habitat stressors can range from low in-stream flows, elevated temperature regimes, elevated sediment loads, fish passage barriers caused by improperly designed or installed culverts, dikes and levees that cut off access to historical flood plains and habitat.

Success in Puget Sound steelhead recovery will require the ability to identify, reduce and eliminate the various stressors adversely impacting steelhead. Table 1 provides general steelhead life history stages, functional requirements and types of stressors that can adversely affect those life stages. In addition, tables that identify habitat viability stressors on a watershed-by-watershed basis can be found in the Puget Sound Habitat Stressors section of this report.

Planning habitat restoration and protection actions directed at steelhead requires knowledge of habitat use and existing conditions that may be limiting productivity in Puget Sound watersheds and marine areas. Using a watershed focus, we have compiled in this document biological, ecological and environmental information that will serve as a foundation for developing a formal recovery plan for Puget Sound steelhead.