Dark fixation of 14 C: Variations related to biomass and productivity of phytoplankton and bacteria
In various North Atlantic sites, the rate of dark 14 C fixation by microbial plankton was significantly correlated with the rate of light 14 C fixation, with the rate of bacterial [ 3 H]thymidine incorporation, and with chlorophyll biomass. For plankton sampled near the sea surface (<5 m) and at...
| Published in: | Limnology and Oceanography |
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| Main Authors: | , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Wiley
1993
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.4319/lo.1993.38.3.0483 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.4319%2Flo.1993.38.3.0483 https://aslopubs.onlinelibrary.wiley.com/doi/pdf/10.4319/lo.1993.38.3.0483 |
| Summary: | In various North Atlantic sites, the rate of dark 14 C fixation by microbial plankton was significantly correlated with the rate of light 14 C fixation, with the rate of bacterial [ 3 H]thymidine incorporation, and with chlorophyll biomass. For plankton sampled near the sea surface (<5 m) and at the depth of the maximum light 14 C 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 14 C fixation is high in relation to light fixation only at depths where photosynthesis is severely limited by light. We infer that direct 14 C fixation by both bacteria and phytoplankton are significant processes that contribute to measured 14 C fixation in opaque bottles during 12 h dawn‐to‐dusk incubations. |
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