Oceanography of the Pacific Northwest Coastal Ocean and Estuaries with Application to Coastal Ecosystems Barbara M. Hickey1 and Neil S. Banas School of Oceanography Box 355351 University of Washington, Seattle, WA 98195-7940 Tel.: 206 543 4737 e-mail:
[email protected] Submitted to Estuaries May 2002 1Corresponding author. Hickey and Banas 2 Abstract This paper reviews and synthesizes recent results on both the coastal zone of the U.S. Pacific Northwest (PNW) and several of its estuaries, as well as presenting new data from the PNCERS program on links between the inner shelf and the estuaries, and smaller-scale estuarine processes. In general ocean processes are large-scale on this coast: this is true of both seasonal variations and event-scale upwelling-downwelling fluctuations, which are highly energetic. Upwelling supplies most of the nutrients available for production, although the intensity of upwelling increases southward while primary production is higher in the north, off the Washington coast. This discrepancy is attributable to mesoscale features: variations in shelf width and shape, submarine canyons, and the Columbia River plume. These and other mesoscale features (banks, the Juan de Fuca eddy) are important as well in transport and retention of planktonic larvae and harmful algae blooms. The coastal-plain estuaries, with the exception of the Columbia River, are relatively small, with large tidal forcing and highly seasonal direct river inputs that are low-to-negligible during the growing season. As a result primary production in the estuaries is controlled principally not by river-driven stratification but by coastal upwelling and bulk exchange with the ocean.