productivity of phytoplankton and bacteria
Number 3 In various North Atlantic sites, the rate of dark 14C fixation by microbial plankton was significantly correlated with the rate of light 14C fixation, with the rate of bacterial [7H]thymidine incorporation, and with chlorophyll biomass. For plankton sampled near the sea surface (~5 m) and a...
| Main Authors: | , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
1993
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.509.8521 http://www.aslo.org/lo/toc/vol_38/issue_3/0483.pdf |
| Summary: | Number 3 In various North Atlantic sites, the rate of dark 14C fixation by microbial plankton was significantly correlated with the rate of light 14C fixation, with the rate of bacterial [7H]thymidine incorporation, and with chlorophyll biomass. For plankton sampled near the sea surface (~5 m) and at the depth of the maximum light 14C fixation, the median value for the ratio of dark to light fixation was only 1%. At the depth of the subsurface chlorophyll maximum where less light was available, the median value for this ratio was still quite low at 7%. Our results confirm early claims that generally in the oceans, including oligotrophic regions where plankton biomass is low, dark 14C fixation is high in relation to light fixation only at depths where photosynthesis is severely limited by light. We infer that direct 14C fixation by both bacteria and phytoplankton are significant processes that contribute to measured 14C fixation in opaque bottles during 12 h dawn-to-dusk incubations. In a bottle containing ocean plankton to which H14C0,- has been introduced, the amount of radiolabel fixed by the microbial |
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