Ecological factors influencing lifetime productivity of pink salmon (Oncorhynchus gorbuscha) in an Alaskan stream

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 74; no. 9; pp. 1325 - 1336
• Main Authors: Manhard, Christopher V, Joyce, John E, Smoker, William W, Gharrett, Anthony J
• Format: Journal Article
• Language: English
• Published: Ottawa NRC Research Press 01.09.2017; Canadian Science Publishing NRC Research Press
• Subjects: Animal reproduction; Creeks & streams; Ecological effects; Ecology; Emigration; Environmental aspects; Fresh water; Freshwater; Freshwater ecology; Freshwater fish; Marine; Marine environment; Migration; Oncorhynchus gorbuscha; Physiological aspects; Pink salmon; Productivity; Recruitment; Salmon; Sea surface temperature; Spawning; Statistics; Stream discharge; Stream flow; Studies; Survival; Time series; Alaska; United States > US; USA, Alaska, Auke Creek
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/cjfas-2016-0335

Ecological factors underlying freshwater productivity and marine survival of pink salmon (Oncorhynchus gorbuscha) were evaluated by analyzing a 30 year time series of local environmental data and censuses of migrating adult and juvenile fish collected at Auke Creek, Alaska. Freshwater productivity was influenced primarily by spawning habitat limitation and less so by stream temperature and flow. Furthermore, a trend of declining freshwater productivity was detected over the time series, which may be related to observed declines in spawning substrate quality and in the duration of the adult migration. Marine survival was highly variable among brood years and was influenced by physical conditions in the nearshore marine environment; warm sea-surface temperatures during nearshore residency were associated with higher marine survival rates, whereas high stream flows late in the fry emigration period were associated with reduced marine survival. Simulations of adult recruitment, based on ecological factors in the freshwater and marine environments, indicated that the productivity of pink salmon in this stream is determined primarily by early marine survival.