THE BIOLOGICAL CO_2 PUMP IN SEASONALLY ICE-COVERED WATERS (17th Symposium on Polar Biology)
Pools of biogenic carbon in oceans have been defined by reference to the time elapsed between the photosynthetic uptake of carbon and its return as carbon dioxide to surface waters or the atmosphere (i.e. turnover time). The three pools are: short-lived organic carbon (<10^2 years), long-lived or...
| Main Author: | |
|---|---|
| Format: | Report |
| Language: | English |
| Published: |
Proceeding
1996
|
| Subjects: | |
| Online Access: | https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=5304 http://id.nii.ac.jp/1291/00005304/ https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=5304&item_no=1&attribute_id=18&file_no=1 |
| Summary: | Pools of biogenic carbon in oceans have been defined by reference to the time elapsed between the photosynthetic uptake of carbon and its return as carbon dioxide to surface waters or the atmosphere (i.e. turnover time). The three pools are: short-lived organic carbon (<10^2 years), long-lived organic carbon (10^2 to 10^2 years) and sequestered biogenic carbon (>10^2 years). In seasonally ice-covered waters, as in other aquatic environments, primary production occurs over a large range of sizes, which can be partitioned into three classes, i.e. large cells (>5 μm), small cells (<5 μm), and dissolved organic carbon. In these waters, there is a wide array of pathways that channel the three size classes of primary production into long-lived and sequestered biogenic carbon. Biogenic carbon is often actively transferred from (large) ice algae to large metazoans (long-lived organic carbon). Small biogenic particles can escape the short-lived carbon pool through grazing by microphagous zooplankton such as pteropods, doliolids, appendicularians and Antarctic krill, or through incorporation into organic aggregates (e.g. marine snow). In addition, there are direct and indirect sedimentation pathways for ice-related algae. Finally, the alternation between biological pumping of CO_2, during the ice-free season, and algal carbon uptake, during the ice-covered period, creates unique conditions for the potential sequestration of atmospheric CO_2. |
|---|