Chasing an Illusion? Successful Restoration of Okanagan River Sockeye Salmon in a Sea of Uncertainty
Kim D. Hyatt and Margot M. Stockwell
Abstract.—Since the mid-1800s, human activities have increasingly dominated ecosystems within the Okanagan River basin, which spans the Canada–United States border between British Columbia and Washington State. Over the past 50 years, fisheries for anadromous salmon in the Okanagan River basin virtually disappeared as once abundant stocks, such as Sockeye Salmon Oncorhynchus nerka, declined to fewer than 10,000 adults returning annually (on average) in the 1990s. Threat assessments suggested degradation of freshwater habitat in the Columbia River basin as the general cause for the decline. However, recent record returns (2008–2016 average >200,000 adults) indicated surprising resilience and recovery. Review of recent stock management and restoration efforts focused on Okanagan Sockeye Salmon indicated that management actions and fortuitous events facilitated the restoration of salmon to levels exceeding recorded, historic maxima. Actions and events identified include (1) assessment to determine whether large increases in escapement provided evidence of historic underuse of spawning (Okanagan River) and rearing environment (Osoyoos Lake) capacities; (2) development of a decision support system to facilitate fish-friendly water management, which reduced losses of eggs or fry to density-independent events (Okanagan River and Lake); (3) a small contribution (<10% of total production) of hatchery-origin fish; and (4) a coincidental return to favorable marine conditions for Okanagan Sockeye Salmon. Recovery success also involved development of an ecosystem-based sustainability strategy incorporating a shared vision for dealing with human and natural system impacts on salmon from local (Okanagan River basin) to global (North Pacific Ocean) scales. Key elements that characterized efforts to restore Okanagan Sockeye Salmon were the development of ecosystem-based management (including elevated levels of engagement, cooperation, and collaboration among responsible parties to support a common cause); the creation of new knowledge of complex cause-and-effect ecological, economic, and cultural associations; and the creation of new resource management tools (e.g., models and decision support systems). Science-based collaboration to restore aquatic ecosystems and Okanagan salmon is an example of positive outcomes resulting from implementation of Canada’s 2005 Wild Salmon Policy.