Publication Date:
2013-11-24
Description:
Suspended biogenic particles were examined across subarctic and arctic seas during the Canada-Three-Oceans (C3O) program in the summers of 2007 and 2008. Particulate organic carbon (POC) and nitrogen (PON), biogenic silica (bSiO 2 ) and size-fractionated chlorophyll a (chl a ) concentrations were measured within the euphotic zone throughout five domains: Eastern Subarctic North Pacific (ESNP), Bering and Chukchi Seas (BE-CH), Southern Beaufort Sea & Canada Basin (BS-CB), Canadian Arctic Archipelago (CAA) and Baffin Bay & Labrador Sea (BB-LS). Despite large variability along the sampling transect and vertically throughout the euphotic zone, domain averages of depth-integrated POC and PON were relatively invariant across the ESNP, BE-CH, CAA and BB-LS, ranging from 546–670 mmol m -2 (POC) and 101–154 mmol m -2 (PON), but were much lower in BS-CB (199 and 78 mmol m -2 , respectively). In contrast, depth-integrated bSiO 2 averages were highest in BE-CH and CAA (〉100 mmol m -2 ), intermediate in ESNP and BB-LS (34–48 mmol m -2 ), and low in BS-CB (6 mmol m -2 ). Similarly to the bSiO 2 distribution, the biomass of the 〉5 µm chl a size-fraction averaged 68-69% of total chl a in BE-CH and CAA, 56% in BB-LS, and 22-23% in ESNP and BS-CB. Ratios of bSiO 2 :PON averaged 1.10-1.30 in BE-CH and CAA, 0.30-0.34 in ESNP and BB-LS, and 0.08 in BS-CB. This study highlights the relative importance of siliceous phytoplankton such as diatoms in BE-CH and CAA, smaller non-siliceous cells in BS-CB and ESNP, and a mixed assemblage of variably-sized phytoplankton with a less siliceous component in BB-LS.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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