Spatial Distribution of Zooplankton and Phytoplankton in British Columbian Coastal Waters

Abstract

An automated sampling system was used to obtain continuous transects of near-surface temperature, chlorophyll fluorescence, and zooplankton abundance in Georgia Strait and off the southwest coast of Vancouver Island. At length scales shorter than ~10 km, correlation between phytoplankton and zooplankton was weak, while the strength and the sign of the larger scale correlation varied between sampling regions. In both regions, the large scale zooplankton patchiness could be contoured unambiguously and appeared to be oriented parallel to bathymetric contours. We also found evidence for smaller scale zooplankton concentrations over and near several shallow banks. Dissolved nutrient supply to the Continental Shelf off southwest Vancouver Island appears to be dominated by entrainment in the Georgia Strait/Juan de Fuca Strait estuarine system. The high nutrient supply allows a zone of high phytoplankton and zooplankton standing stock to develop along the outer coast of Vancouver Island.Key words: plankton, spatial distribution, British Columbian Shelf, inorganic nutrients