Pacific Salmon Environmental and Life History Models: Advancing Science for Sustainable Salmon in the Future

Restoring Habitat Could Recover Chinook Populations in the Dungeness and Dosewallips Watersheds

Brad E. Thompson, Lawrence C. Lestelle, Gregory R. Blair, Lars E. Mobrand, and James B. Scott

doi: https://doi.org/10.47886/9781934874097.ch16

Abstract.—The Washington Department of Fish and Wildlife and Tribal co-managers are using the Ecosystem Diagnosis and Treatment (EDT) model to identify the spatial and temporal habitat limits of salmon populations and predict the effects of proposed habitat restoration projects for ESA-listed Chinook salmon Oncorhynchus tshawytscha in two Puget Sound watersheds. The collaborative, iterative process focused on habitat-based population models for the Dungeness and Dosewallips watersheds. Workshops were held to develop quantitative characteristics of current, historic, hypothetical properly functioning, and future habitat conditions. The model predicted salmon populations in the watersheds for each set of habitat conditions. Recovery targets were based on the predicted populations for historic and hypothetical properly functioning conditions. Future populations were modeled using projected habitat conditions with individual habitat restoration and protection actions already proposed and combinations of these actions. Populations resulting from further habitat degradation were estimated using the effects of projected human population growth on habitat.