title: Potential responses to climate change in organisms with complex life histories: evolution and plasticity in Pacific salmon.
abstract: Salmon life histories are finely tuned to local environmental conditions, which are intimately linked to climate. We summarize the likely impacts of climate change on the physical environment of salmon in the Pacific Northwest and discuss the potential evolutionary consequences of these changes, with particular reference to Columbia River Basin spring/summer Chinook (Oncorhynchus tshawytscha) and sockeye (Oncorhynchus nerka) salmon. We discuss the possible evolutionary responses in migration and spawning date egg and juvenile growth and development rates, thermal tolerance, and disease resistance. We know little about ocean migration pathways, so cannot confidently suggest the potential changes in this life stage. Climate change might produce conflicting selection pressures in different life stages, which will interact with plastic (i.e. nongenetic) changes in various ways. To clarify these interactions, we present a conceptual model of how changing environmental conditions shift phenotypic optima and, through plastic responses, phenotype distributions, affecting the force of selection. Our predictions are tentative because we lack data on the strength of selection, heritability, and ecological and genetic linkages among many of the traits discussed here. Despite the challenges involved in experimental manipulation of species with complex life histories, such research is essential for full appreciation of the biological effects of climate change.
authors.affiliation: Northwest Fisheries Science Center, NOAA-Fisheries Seattle, WA, USA.
authors.forename: L G
authors.initials: LG
authors.lastname: Crozier
authors.affiliation: Redpath Museum and Department of Biology, McGill University, Montréal Québec, Canada.
authors.forename: A P
authors.initials: AP
authors.lastname: Hendry
authors.affiliation: Northwest Fisheries Science Center, NOAA-Fisheries Newport, OR, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Lawson
authors.affiliation: School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA.
authors.forename: T P
authors.initials: TP
authors.lastname: Quinn
authors.affiliation: School of Aquatic and Fishery Sciences, University of Washington Seattle, WA, USA.
authors.forename: N J
authors.initials: NJ
authors.lastname: Mantua
authors.affiliation: Northwest Fisheries Science Center, NOAA-Fisheries Seattle, WA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Battin
authors.affiliation: Department of Ecology, Evolution and Behavior, and Minnesota Center for Community Genetics, University of Minnesota St Paul, MN, USA.
authors.forename: R G
authors.initials: RG
authors.lastname: Shaw
authors.affiliation: Department of Biology, University of Washington Seattle, WA, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Huey
keywords: genetic correlation; global warming; phenological change; smolt timing