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Hokkaido University Collection of Scholarly and Academic Papers >
Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences >
Peer-reviewed Journal Articles, etc >
Seasonal phosphorus depletion and microbial responses to the change in phosphorus availability in a subarctic coastal environment
| Title: | Seasonal phosphorus depletion and microbial responses to the change in phosphorus availability in a subarctic coastal environment |
| Authors: | Yoshimura, Takeshi Browse this author | | Kudo, Isao Browse this author →KAKEN DB |
| Keywords: | Phosphorus | | Orthophosphate | | Phosphatase | | Phytoplankton | | Bacteria | | Coastal zone |
| Issue Date: | 20-Sep-2011 |
| Publisher: | Elsevier B.V. |
| Journal Title: | Marine Chemistry |
| Volume: | 126 |
| Issue: | 1-4 |
| Start Page: | 182 |
| End Page: | 192 |
| Publisher DOI: | 10.1016/j.marchem.2011.06.003 |
| Abstract: | Temporal variations of phosphorus (P) pools (soluble reactive P (SRP), dissolved organic P (DOP), and particulate P (PP)), alkaline phosphatase activity (APA), and orthophosphate uptake were measured in Funka Bay to describe the annual P cycle in the bay and determine the phytoplankton and bacterial responses to the change in P availability. Observations over four years demonstrated that SRP concentrations in the surface waters decreased from the winter maximum of 1.0 μmol L^[-1] to 0.3 μmol L^[-1] at the end of the spring phytoplankton bloom, and then to under the detection limit by around August. The DOP concentration was relatively constant at 0.1 μmol L^[-1] throughout the year with higher concentrations up to 0.3 μmol L^[-1] just after the peak of the spring bloom. PP concentrations varied around 0.1 μmol L^[-1] with higher concentrations up to 0.6 μmol L^[-1] during the high chlorophyll a concentration period. SRP comprised 85% of the total P pool prior to the spring bloom, but the contribution decreased to less than 30% in the post-bloom period and DOP dominated the P pool in the surface. Most of the measured APA was less than 0.1 nmol L^[-1] min^[-1] in the whole water column, but exceptionally high values up to 1.4 nmol L^[-1] min^[-1] were observed in low SRP surface waters during summer. When SRP decreased from 0.3 μmol L^[-1] in spring to under the detection limit in summer, turnover time for orthophosphate at 10 m depth decreased from 61 days to 4.2 hours. The high APA and short turnover time for orthophosphate suggested that microbes in the surface mixed layer experienced severe P stress in summer. Under severely P stressed conditions, APA was detected mostly in the >10 μm fraction, suggesting that large phytoplankton would acquire P from DOP to overcome the P stress. This was supported by the result that large phytoplankton were outcompeted by the 0.2-1 μm sized microbes for orthophosphate uptake. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/47275 |
| Appears in Collections: | 水産科学院・水産科学研究院 (Graduate School of Fisheries Sciences / Faculty of Fisheries Sciences) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 工藤 勲
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