Assessing Thermal Habitat Variability to Identify Refugia in SE Alaska Subsistence Salmon Watersheds

Water temperature affects salmon growth, behavior, and survival across freshwater life stages. This project will assess the sensitivity of stream temperatures in Southeast Alaska to climate change by analyzing long-term water temperature data and by mapping the “thermal habitat” for salmon within several key subsistence watersheds. This project will also identify watersheds that are expected to remain productive into the future and important thermal refugia within watersheds that should be protected.

Understanding current and future thermal conditions in Southeast Alaska’s salmon streams is critical for making informed decisions about which watersheds are likely to continue to be (or may become increasingly) suitable for salmon productivity and should therefore be the focus of future restoration and protection actions. This project will produce a regionally-relevant assessment that provides insights into the types of watersheds likely to be resilient (or resistant) to climate change with respect to water temperatures, and will identify specific locations within eight salmon watersheds (833 km2), including four important subsistence watersheds (582 km2), that may provide thermal refugia and should be considered priorities for restoration and/or protection actions.