Simulated juvenile salmon growth and phenology respond to altered thermal regimes and stream network shape

• DOI: 10.1002/ecs2.2052
• Publication Date: 2017-12-24T09:33:00Z
• Authors: Aimee H. Fullerton; Brian J. Burke; Joshua J. Lawler; Christian E. Torg...; Joseph L. Ebersole; Scott G. Leibowitz
• Keywords: 0106 biological sciences; 13. Climate action; 14. Life underwater; 15. Life on land; 01 natural sciences

Abstract It is generally accepted that climate change will stress coldwater species such as Pacific salmon. However, it unclear what aspect of altered thermal regimes (e.g., warmer winters, springs, summers, or increased variability) have the greatest effect, and role spatial properties river networks play. Thermally diverse habitats may afford protection from by providing opportunities for aquatic organisms to find use with optimal conditions growth. We hypothesized climate‐altered growth timing life history events emergence migration but changes be moderated in topologically complex stream where thermoregulate are more readily available mobile animals. Because effects on populations spatially variable contingent upon physiological optima, assessments risk must take a explicit approach. developed structured individual‐based model Chinook Salmon ( Oncorhynchus tshawytscha ) which movement decisions were governed water temperature conspecific density. evaluated phenology (timing egg smolting) under variety (each having different minimum, rate warming, maximum, three network shapes increasing complexity. Across networks, fish grew faster capable smolting earlier scenarios temperatures experienced closer optimal; however, decreased some fish. found salmon size smolt date responded strongly springs summers than winters variability. Fish least ready contemporary regime; patterns similar less clear regimes. Our results demonstrate topology influence how respond landscapes, this information useful incorporating spatiotemporal context into conservation promote long‐term viability changing climate.