The Pacific decadal oscillation and changes in anchovy populations in the Northwest Pacific

Abstract

The Pacific decadal oscillation (PDO) has been identified as an important driver for fluctuation of fish populations on the eastern Pacific Ocean. However, the relationship between changes in fish population and climate oscillations on a decadal time scale in the Northwest Pacific is still unclear due to the lack of reliable long-term time series data. In the present study, a time series of Engraulis japonicus (Japanese anchovy) populations was reconstructed using the density of sedimentary fish scales in the Yellow Sea basin. E. japonicus populations and the PDO index showed similar patterns on a decadal time scale. Our results confirm that climate is a major driver of ecological changes on a decadal time scale, and indicate that suitable sea water temperature might be the main forcing of anchovy migration. This work also demonstrates the potential of predicting changes in fish population based on climate records.