| one publication added to basket [133377] | Spatial distribution of bacterioplankton production across the Weddell-Scotia Confluence during early austral summer 1988-1989
Kuparinen, J.; Bjørnsen, P.K. (1992). Spatial distribution of bacterioplankton production across the Weddell-Scotia Confluence during early austral summer 1988-1989. Polar Biol. 12(2): 197-204
In: Polar Biology. Springer-Verlag: Berlin; Heidelberg. ISSN 0722-4060; e-ISSN 1432-2056, more
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| Authors | | Top |
- Kuparinen, J.
- Bjørnsen, P.K.
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| Abstract |
We applied two methods to measure bacterio-plankton production, the [3H]-thymidine (TTI) and the [3H]-leucine (LEU) incorporation into cold trichloro-acetic acid precipitate. Both methods gave similar results of the distribution of production in time and space (r 2=0.82, n=66). Using empirically determined conversion factors the TTI gave production values from 21 to 125 mg Cm-2 day-1, which are within the range reported earlier from the Southern Ocean. Highest production rates were associated with the open water in the Confluence area (59°S-60°S) and with the Scotia Sea front. Low production rates were recorded from the ice covered areas in the Weddell Sea and in the open Scotia Sea waters. Good correlation on an areal basis was found between bacterioplankton production and other measures of heterotrophy, including ETS (r2=0.93, n=9) and NH4(r2=0.50, n=21). Good correlation was also found between bacterioplankton and phytoplankton production (r2=0.63, n=19). Bacterioplankton production seems to be driven by products from photosynthesis and heterotrophic processes, most likely grazing, which are tightly coupled to autotrophy. Quantitatively, bacterioplankton production was on an average 11 % of net primary production, which is clearly a lower value than the 30% based on a review from temperate freshwater and marine ecosystems, but is comparable with values reported from the spring period in subarctic ecosystems. In comparison with the measurements of ETS, bacterioplankton contribution to community respiration was also lower than predicted from results from temperate ecosystems. We concluded from these results and the results obtained from microcosm experiments (Bjørnsen and Kuparinen 1991b) that the flux of organic matter to eucaryote heterotrophs via bacterioplankton during spring and early summer periods in the Southern Ocean is of considerable, but not of equivalent importance as in temperate waters.Data presented here were collected during the European Polarstern Study (EPOS) sponsored by the European Science Foundation |
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