HOLOCENE SOLAR VARIABILITY AND PELAGIC FISH PRODUCTIVITY IN THE NE PACIFIC

ABSTRACT

Many cycles recognized in the ocean sedimentary record have been linked to variable solar irradiance. This conclusion can be extended to include the paleoproductivity of fish stocks in the northeastern Pacific Ocean. Predominantly anoxic sediments from Effingham Inlet, Vancouver Island, British Columbia, collected from a 693 cm segment of a 1125 cm piston core, archive a high-resolution late Holocene (1,800-4,700 years BP) record of climate-change and paleoproductivity in the North American Coastal Upwelling Domain (CUD). Fish-scale abundances of Northern Anchovy and Pacific Herring were measured in this core. Spectral analysis (SA) and continuous (Morlet) wavelet transform (CWT) analysis of the dataset were used to examine fish productivity cycles and their variability within the absolute time scale. Anchovy and herring populations cycle independently at decadal to centennial scales, with especially well-defined variability at the stationary Gleissberg solar cycle (75-90 years here). Several other cycles are non-stationary, changing frequency following transition of the regional climate to a higher rainfall phase that impacted coastal oceanic dynamics ~ 3,400 years ago.

R. Timothy Patterson. Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada, K1S 5B6.
Andreas Prokoph. SPEEDSTAT, 36 Corley Private, Ottawa, ON, K1V 8T7.
Cynthia Wright. Institute of Ocean Sciences, Department of Fisheries and Oceans, 9860 West Saanich Road, Sidney, BC V8M 4B2.
Alice. S. Chang. Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada, K1S 5B6
Richard E. Thomson. Institute of Ocean Sciences, Department of Fisheries and Oceans, 9860 West Saanich Road, Sidney, BC V8M 4B2.
Daniel M. Ware. Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, BC, V6T 1Z4.

KEY WORDS: Holocene, Effingham, British Columbia, anoxic basin, fish scales, paleoclimate, paleoproductivity