HYPOTHESES
(which we feel describe the essential elements that contribute to the high productivity of Georges Bank)
1. The flux of new nutrients into the tidal front in spring
and early summer is due primarily to tidally driven upwelling on the north flank
and northeast peak.
2. A major factor causing interannual variability of the
nutrient flux is the changes in deep-water inflow in the Northeast Channel, i.e., nutrient-poorer Labrador Slope
Water vs. comparatively
nutrient-richer Warm Slope Water from the south.
3.
The productivity over the crest of Georges Bank, primarily a recycling regime,
is maintained by a lateral flux of plankton (particulate and dissolved organic
nitrogen) produced in the tidal mixing front.
4. The most productive region of Georges Bank can be characterized as a donut-shaped domain situated at the tidal front with nutrient injections greatest along the north flank, a clockwise advected plume of elevated phytoplankton and zooplankton production resulting from these injections, and larval retention along the south flank.