C. Savenkoff et al., DISTRIBUTIONS OF OXYGEN, CARBON, AND RESPIRATORY ACTIVITY IN THE DEEPLAYER OF THE GULF OF ST-LAWRENCE AND THEIR IMPLICATIONS FOR THE CARBON-CYCLE, Canadian journal of fisheries and aquatic sciences, 53(11), 1996, pp. 2451-2465
The Gulf of St. Lawrence (GSL) is a semi-enclosed sea with an estuarin
e circulation forced by runoff from the St. Lawrence and Great Lakes d
rainage systems and balanced by a deep inflow of oceanic waters throug
h the Laurentian Channel. Based on samples collected between July 1992
and June 1994 during Phase I of the CJGOFS program conducted in the G
ulf of St. Lawrence, we present new data on the carbon and nutrient ch
emistry as well as respiratory activity in the deep waters. Organic ca
rbon fluxes estimated from sediment tray, data, deepwater respiratory
activity, and benthic respiration measurements are consistent with tho
se obtained from the changes in the dissolved oxygen concentration of
the deep waters along the Laurentian Channel. These flux estimates sug
gest that approximately 10% of the local primary production reaches th
e deep layer (>200 m) and the sediments in the GSL. The vertical carbo
n budget is almost balanced in the eastern part of the gulf, but appro
ximately half of the carbon produced in the surface layer of the north
western gulf cannot be accounted for. The difference in hydrodynamic a
nd biological conditions prevailing in both areas may explain our obse
rvations.