Paleoclimate Variability in Ocean Conditions and the Production of North American Atlantic Salmon

• Main Authors: Alan Condron, Robert Deconto, Kevin Friedl
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Multidecadal climate cycles; thermohaline circulation; regime shifts; winter salmon mortality; Pacific; Atlantic salmon; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.598.2194; http://www.npafc.org/new/publications/Technical Report/TR4/page 53-55(Condron).pdf

Climate regime shifts related to changes in circulation variations, nutrient upwelling and productivity have been shown to influence the survival success of young salmon at sea in the North Pacific (Mantua et al. 1997; Beamish et al. 1999). A similar relationship to climate and salmon production in the North Atlantic is less clear. While the ecology of young European salmon appears to be correlated with climate (Friedland et al. 2000) the only climatic link to North American Atlantic salmon is shown between winter thermal habitat and catch (Friedland et al. 1993). However, the relationship between the season in which this climatic link occurs suggests that the precise mechanism controlling salmon survival remains unknown (Friedland et al. 1993). Principal Component Analysis of global multiproxy paleoclimate datasets and instrumental records reveal a 50– 75 year multidecadal climate oscillation centered over the North Atlantic (Mann et al. 1998). The original dataset examined in this reconstruction (Mann et al. 1998) was compiled from 1,082 nearly continuous land air/sea surface instrumental temperature grid points from 1902 onward. An extensive set of proxy data was then calibrated against the records, extending the reconstruction over the past millennium. The multidecadal oscillation is best described by the fifth eigenvector of reconstructed global climate and is observed back to 1650. Although observational data is lacking in spatial coverage, climate model simulations using two independent, naturally forced integrations of the Geophysical Fluid Dynamics Laboratory (GFDL) coupled ocean-atmosphere