Gargett, A. E.. Institute of Ocean Sciences, gargettA@pac.dfo-mpo.gc.ca
Li, M. E.. Institute of Ocean Sciences, mli@ios.bc.ca
Denman, K. Institute of Ocean Sciences, denmank@pac.dfo-mpo.gc.ca

 
MECHANISMS OF PHYSICAL "CONTROL" OF ZOOPLANKTON PRODUCTION IN A STRONGLY ESTUARINE SYSTEM
 
This talk will consider various mechanisms by which physical processes might "control" the success of zooplankton stocks in an estuarine coastal environment characterized by a simple food chain. Potential physical "control" may be exerted (i) from below, if physical processes set the level of primary production available to support higher trophic levels, (ii) from within, if physical processes determine the feeding success of zooplankton, or (iii) from above, if physical processes affect the rate at which zooplankton are themselves cropped. These possibilities will be explored using a simple N-P-Z biological model embedded in a physical box model of the Strait of Georgia / Haro Strait / Strait of Juan de Fuca system of southern British Columbia. Model results indicate that while observed levels of interannual variation in the physical forcing of this system produce reasonable variation in the annual cycles of characteristic physical parameters (such as salinity, stratification etc.), there is very little associated variation in the embedded biological system. However major changes in the annual cycles of biological variables can be produced by relatively minor changes in biological rate parameters (phytoplankton growth rate, zooplankton feeding and/or mortality rate) which may themselves be "controlled" by characteristics of the physical environment, notably wind-driven turbulence and turbidity.
 
Day: Monday, Feb. 1
Time: 02:00 - 02:15pm
Location: Sweeney Center
 
Code: SS01MO0200S