Optimizing Conservation and Habitat Restoration Portfolio Actions for Winter-run Chinook Salmon (Oncorhynchus tshawystscha) Based on Life Cycle Simulation

Abstract:

To stabilize and recover winter-run Chinook salmon populations, the National Marine Fisheries Service (NMFS) developed a recovery plan and a set of priority actions. It included an extensive set of restoration and management actions based on threats assessment, which targeted habitat quantity and quality requirements for each winter-run Chinook life stage. For instance, the reintroduction into historical spawning grounds upstream of Shasta Reservoir and along the North Fork of Battle Creek. However, these plans are only guidance and planning documents, without legal requirements to implement these actions by any public or private party. Optimization procedures have been used in conservation to structure, inform, and improve planning and management decisions. This presentation presents an optimization model developed to maximize winter-run Chinook salmon population and biomass, constrained by restoration costs and subject to suitable habitat quantity and quality, where restoration alternatives improve instream rearing, habitat capacity and survival conditions. The effect of changes in instream and habitat conditions on winter-run juvenile population dynamics is simulated using a life cycle and bioenergetics model for the Sacramento River Valley, i.e. the Winter-Run Habitat-based Population model (WRHAP).