Abstract:
The San Juan Channel is one passageway linking the Strait of Georgia and the
Strait of Juan de Fuca. Thus, the physical oceanography of this region is complex and has
both estuarine and oceanic influences. We sampled a 5-station transect along the San
Juan Channel during fall 2011 as part of a multi-annual study started in 2004 and a
monthly study started in early 2011. We deployed a CTD to gather information on
temperature, salinity, and density structure in the water column. Temperature followed an
annual cycle with cooling in the winter and warming in the summer, while haloclines
were more tidally modulated. Short-term along-channel density structure was controlled
by both tides and wind. Density stratification increased at the south end increased during
flood tides, and at the north end and mid-channel during ebb tides. The depth and width
of the pycnocline at the southern end of the channel were correlated to tidal height. These
findings enhance our understanding of both short-term and long-term patterns in density
gradients of the San Juan Channel pelagic environment.
