Climate variability and ecosystem response in the NE Pacific: a case study using otoliths of Pacific Ocean perch (Sebastes alutus)

Temporally long datasets in the marine environment are an important tool for climate reconstruction and investigating the effects of environmental variability on marine species. Such time series are often lacking due to the... [ view full abstract ]

Temporally long datasets in the marine environment are an important tool for climate reconstruction and investigating the effects of environmental variability on marine species. Such time series are often lacking due to the substantial time and financial inputs required for data collection. Dendrochronology (tree ring science) techniques applied to annual increments deposited in otoliths of Pacific Ocean perch (Sebastes alutus) collected from the Bering Sea were used to produce multi-decadal growth and luminance (a measure of the optical density of increments) measurement time series. A chronology spanning 60 years was generated for Pacific Ocean perch in the Bering Sea, far exceeding previous biological time series of any kind for this region. Significant (p<0.01) correlations between growth increment and luminance chronologies and climate data (sea surface temperature, the Multivariate ENSO Index, and sea ice extent) were observed. Correlations with climate were particularly strong for the width chronology, although comparisons with the Pacific Decadal Oscillation Index indicate the luminance chronologies track low-frequency variability including the 1976/77 and 1988/89 regime shifts. These results reaffirm the potential for hard structures in marine species to provide long-term archives of climate influences on growth and illustrate the importance of climate variability to upper-trophic processes.