Late Holocene variability in pelagic fish scales and dinoflagellate cysts along the west coast of Vancouver Island, NE Pacific Ocean

Principal components analysis (PCA), and trend, wavelet and spectral analyses were used to identify relationships, cycles and trends in sediment grey-scale values, and the abundances of fish scales and dinoflagellate cysts on centennial to millennial time scales. Most observed cycles fluctuated in intensity over time, particularly following transition of the regional climate to a higher rainfall phase that impacted coastal oceanic dynamics ∼3400 ± 150 years ago. Correlation of the marine paleoproductivity records observed in Effingham Inlet with solar influenced climate proxy cycles observed in the North Atlantic region indicates that solar forcing at different scales might have influenced the climate in the northeast Pacific as well. In particular an 1100- to 1400-year cycle in regional climate is well represented in the fish productivity proxy and sedimentological record. It was also observed that colder water, high-productivity, Selenopemphix nephroides and anchovy-dominated “Anchovy Regime” ecosystems alternate with warmer water, herring-dominated “Herring Regime” ecosystems at millennial time scales. The fish scale record preserved in Effingham Inlet indicates that the NE Pacific is now in transition from an 'anchovy-' to a 'herring'-dominated regime.