¥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.