•Hypothesis:
The occurrence of large populations of Calanus
finmarchicus in the coupled GB/GoM system REQUIRES (1) high seed stocks (supply) of
diapausing C.finmarchicus in the deeper
ocean regions nearby (GOM basins and the Slope Sea), (2) that the deep C. finmarchicus stocks terminate
diapause at the appropriate time to be synchronous with continental shelf
spring blooms, and (3) a
nutrient enriched, highly productive ecosystem in the GB/GoM to sustain high growth and survival rates of Calanus that
will provide seed for the subsequent year.
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•Prediction A:
Overwintering Calanus finmarchicus seed stocks are LOW and GB/GoM productivity is HIGH when the water masses of the Slope
Sea have little influence (input) from Labrador-Irminger Gyre (Labrador Slope Water) water
masses (due to the relatively nutrient replete bottom waters and low Calanus supply
in Warm Slope Waters), but C.
finmarchicus recruitment is good because of a near-perfect match
between the time of diapause awakening and the time of the spring bloom, the latter of which is
large because of the higher concentration of nutrients in deep warm slope waters.
•Prediction B:
Overwintering C. finmarchicus seed stocks are HIGH and GB/GoM productivity is LOW when the water masses of the Slope Sea have a large
proportion of Labrador Sea water (due
to the relatively nutrient-depleted bottom waters and high C. finmarchicus supply in cold Labrador
Slope Water), but recruitment and
productivity are poor because of the generally low springtime productivity (low nutrients) and a timing
mismatch between diapause awakening, ascent
and reproduction and the NW Atlantic spring bloom.