DOI: 10.1111/gcb.14896
论文题名: Unnatural selection of salmon life histories in a modified riverscape
作者: Sturrock A.M. ; Carlson S.M. ; Wikert J.D. ; Heyne T. ; Nusslé S. ; Merz J.E. ; Sturrock H.J.W. ; Johnson R.C.
刊名: Global Change Biology
ISSN: 13541013
出版年: 2020
卷: 26, 期: 3 语种: 英语
英文关键词: biocomplexity
; dam operation
; flow alteration
; hydrology
; juvenile salmon emigration
; life-history diversity
; migration phenology
; otolith strontium isotopes
; portfolio effect
Scopus关键词: Oncorhynchus tshawytscha
; Pisces
英文摘要: Altered river flows and fragmented habitats often simplify riverine communities and favor non-native fishes, but their influence on life-history expression and survival is less clear. Here, we quantified the expression and ultimate success of diverse salmon emigration behaviors in an anthropogenically altered California river system. We analyzed two decades of Chinook salmon monitoring data to explore the influence of regulated flows on juvenile emigration phenology, abundance, and recruitment. We then followed seven cohorts into adulthood using otolith (ear stone) chemical archives to identify patterns in time- and size-selective mortality along the migratory corridor. Suppressed winter flow cues were associated with delayed emigration timing, particularly in warm, dry years, which was also when selection against late migrants was the most extreme. Lower, less variable flows were also associated with reduced juvenile and adult production, highlighting the importance of streamflow for cohort success in these southernmost populations. While most juveniles emigrated from the natal stream as fry or smolts, the survivors were dominated by the rare few that left at intermediate sizes and times, coinciding with managed flows released before extreme summer temperatures. The consistent selection against early (small) and late (large) migrants counters prevailing ecological theory that predicts different traits to be favored under varying environmental conditions. Yet, even with this weakened portfolio, maintaining a broad distribution in migration traits still increased adult production and reduced variance. In years exhibiting large fry pulses, even marginal increases in their survival would have significantly boosted recruitment. However, management actions favoring any single phenotype could have negative evolutionary and demographic consequences, potentially reducing adaptability and population stability. To recover fish populations and support viable fisheries in a warming and increasingly unpredictable climate, coordinating flow and habitat management within and among watersheds will be critical to balance trait optimization versus diversification. © 2019 The Authors. Global Change Biology published by John Wiley & Sons Ltd
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/159057
Appears in Collections: 气候变化与战略
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作者单位: Center for Watershed Sciences, University of California, Davis, Davis, CA, United States; Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, CA, United States; US Fish and Wildlife Service, Lodi, CA, United States; California Department of Fish and Wildlife, La Grange, CA, United States; Institute of Marine Sciences, University of California Santa Cruz, Santa Cruz, CA, United States; Cramer Fish Sciences, West Sacramento, CA, United States; Department of Epidemiology & Biostatistics, University of California, San Francisco, San Francisco, CA, United States; Fisheries Ecology Division, Southwest Fisheries Science Center, National Marine Fisheries Service, Santa Cruz, CA, United States
Recommended Citation:
Sturrock A.M.,Carlson S.M.,Wikert J.D.,et al. Unnatural selection of salmon life histories in a modified riverscape[J]. Global Change Biology,2020-01-01,26(3)