Climate Change and Vulnerability of Bull Trout in a Fire-Prone Landscape

Linked atmospheric and wildfire changes will complicate future management of native coldwater fishes in fire-prone landscapes and new approaches to management that incorporate uncertainty are needed to address this challenge. We used a Bayesian network (BN) approach to evaluate population vulnerability of Bull Trout (Salvelinus confluentus) in the Wenatchee River basin, Washington, USA under current and future climate and fire scenarios. The BN was based on modeled estimates of wildfire, water temperature, and physical habitat prior to, and following, simulated fires throughout the basin. We found that Bull Trout population vulnerability depended on the extent to which climate effects can be at least partially offset by managing factors such as habitat connectivity and fire size. Moreover, our analysis showed that local management can significantly reduce the vulnerability of Bull Trout to climate change given appropriate management actions. Tools such as our BN that explicitly integrate the linked nature of climate and wildfire, and incorporate uncertainty in both input data and vulnerability estimates will be vital in effective future management to conserve native coldwater fishes.