Published In

Journal of Environmental Management

Document Type

Article

Publication Date

5-21-2025

Subjects

Climate change, Salmon -- Habitat -- North America, Salmon -- Habitat -- Pacific Northwest

Abstract

Rising stream temperatures pose significant challenges to aquatic ecosystems, particularly for coldwater-adapted organisms like salmonids. This study examines the effects of climate change on stream temperatures and salmonid habitats in the Clackamas River Basin, Oregon, USA. Using spatial stream network models and CMIP6 climate projections under SSP2-4.5 and SSP5-8.5 scenarios, we project mid- (2045-2074) and late-century (2075-2100) stream temperature changes. These projections are then integrated with thermal tolerances and intrinsic habitat metrics to assess future habitat suitability for key species, including steelhead, coho, Chinook, and bull trout. Stream temperature trends from 1991 to 2023 reveal basin-wide warming, with high-elevation tributaries demonstrating more resilience to climate impacts while lower-elevation subwatersheds face greater vulnerability. Future projections indicate a basinwide maximum 7-day average of daily maximum stream temperature increases of 1.42 °C-2.04 °C for the midcentury, and 1.84 °C-3.24 °C by the end of the 21st century. These increases reduce the most thermally suitable habitats for steelhead, coho, Chinook, and bull trout by an average of 27 %-36 % during the mid-century time period, and 35 %-51 % by the end-of-century time period. By linking climate-driven temperature projections with habitat metrics, we identify priority subwatersheds based on projected thermal suitability where conservation efforts can maximize impact.

Rights

Copyright (c) 2025 The Authors

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.

DOI

10.1016/j.jenvman.2025.125843

Persistent Identifier

https://archives.pdx.edu/ds/psu/43677

Publisher

Elsevier BV

Included in

Geography Commons

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