Copepod abundance and distribution in San Juan Channel, Washington: Tidal effects

Abstract

Copepods are a highly important group of organisms to local and global ecosystems and carbon cycles. By linking trophic levels and exporting production, copepods have great cumulative effect on the fate of biogenic carbon and energy. Copepod abundance across fall 2012 was measured at two stations in the San Juan archipelago, WA, a highly productive and tidally complex region. Using these data and past measurements from the University of Washington’s Pelagic Ecosystem Function research apprenticeship, a pattern was shown linking higher-than-average copepod abundance with sampling that followed a flood tide. Tidal currents seem to interact with complex shallow bathymetric features near stations in the north and south end of San Juan Channel to create areas of high copepod abundance following flooding tides. These patterns suggest mechanisms influencing aggregations of animals in higher trophic levels (fish, seabirds, mammals).