Columbia Basin Food Webs: Developing a Broader Scientific Foundation for Fish and Wildlife Restoration

Food webs fuel ecosystems and, as well, reveal insights into the basic properties of productive and resilient ecosystems.  Understanding, managing and restoring food web processes goes beyond simply addressing the impacts of the hydrosystem, habitat, hatcheries, and harvest – usually the main areas of focus for restoration activities. In 2011 the Independent Scientific Advisory Board of the Northwest Power and Conservation Council completed a two year investigation (ISAB 2011-1) addressing the role of aquatic food webs in the Columbia River basin and how they affect native fish restoration efforts.  The ISAB’s investigation indicates that changes to the Basin’s food webs are widespread and appear to be affecting the aggregate carrying capacity of the river to produce wild fish. The report identifies three highly important areas of concern: whether the system can produce enough of the right food at the right times to maintain thriving populations of native fishes (i.e., carrying capacity), the effects of hatchery releases and non-native species on food supplies (e.g., creation of ‘hybrid’ food webs), and the proliferation of contaminants and chemicals in the Basin. This presentation and the ones that follow provide a fundamental understanding of the Basin’s food webs, illustrating and summarizing their influences on native fish restoration efforts. The spatial scope addresses tributaries, impoundments, the free-flowing Columbia and Snake rivers, as well as the estuary and plume.  While the Council’s Fish and Wildlife Program strives to establish and maintain an ecosystem that sustains an abundant, productive, and diverse community of fish and wildlife, the ISAB suggests that achieving those goals is best accomplished through a time-prioritized action plan, one that complements other approaches while addressing important challenges and uncertainties related to the Basin’s food webs.