3.8. Time-lag and unique responses of local populations to climatic regime shifts
Statistically significant changes in the regime shift index for the fish stocks examined did not always coincide with years of climatic regime shifts (Fig. 5, Fig. 7, Fig. 8, Fig. 9, Fig. 10 and Fig. 11). In some cases, fish stocks responded 1–2 years after the climatic regime shifts or showed no apparent link. Nor did the time-series of relative biomass of summer mesozooplankton always match with climatic regime shifts (Fig. 3). We discuss these issues from three aspects: the importance of (1) regional physical environments, (2) phenology of zooplankton, and (3) stochastic processes of fish recruitment.