Whole season net community production in the Weddell Sea
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Depletions of total CO2, nitrate, phosphate and silicate in the surface layer were calculated for cruise ANT XXII/3 with FS Polarstern in March 2005 for estimating the annual net community production. East-west across the Weddell Sea the variation of all depletions is similar, but this holds to a lesser extent for silicate. Depletions in March 2005 are 2–3 times larger than those in January 1993 for the same transect. Very low N:P and C:P depletion ratios seem to point to dominance of diatoms, in the central Weddell Sea more than in the margin. Estimates of annual net community productions are about 1.8 and 3.5 mol C m−2 year−1 for the interior Weddell Sea and a near-margin region, respectively. The region does not comply with the classical view of a marginal ice zone with high productivity. Net community production is similar to annual export production, implying that remineralization in the ensuing winter be minor.
KeywordsPhytoplankton Southern Ocean Vegetative Season Conductivity Temperature Depth Depletion Ratio
We would like to thank captain and crew of FS Polarstern for their great support. This research was supported by the European Commission’s Sixth Framework Programme for Research and Technological Development, Integrated Project “CARBOOCEAN” (contract no.: 511176-2).
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