Ecological investigations of giant Phaeocystis colonies in Viet Nam : II. Photosynthesis-irradiance characteristics and nitrogen uptake
© 2024 The Author(s). Journal of Phycology published by Wiley Periodicals LLC on behalf of Phycological Society of America.
| Veröffentlicht in: | Journal of phycology. - 1966. - 60(2024), 5 vom: 16. Okt., Seite 1273-1284 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2024
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| Zugriff auf das übergeordnete Werk: | Journal of phycology |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Phaeocystis globosa bloom giant colony irradiance nitrogen uptake photosynthesis Nitrogen N762921K75 |
| Zusammenfassung: | © 2024 The Author(s). Journal of Phycology published by Wiley Periodicals LLC on behalf of Phycological Society of America. Phaeocystis globosa is a marine phytoplankton species that forms deleterious blooms in temperate and tropical waters. In some locations, "giant" colonies form, although the controls on its size are unknown. During a "giant" colony bloom, measurements were completed to characterize photosynthesis-irradiance relationships, nitrogen uptake kinetics, and nitrogen-irradiance relationships of P. globosa colonies to understand its growth characteristics and their relationship to colony size. The photosynthetic capacity (Fv/Fm) varied from 0.65 to 0.68 among colony sizes ranging from 3.0 to 11.0 mm, indicating that all colonial cells were physiologically robust. The maximum chl a-specific photosynthetic rates ( P max B ) ranged from 0.89 to 1.92 μg C · μg-1 chl · h-1, were maximal in the mid-sized colonies (5.5-6.5 mm) and decreased with size. The relatively low P max B values may be related to the high cellular chl a of colonial cells and their acclimation to in situ irradiance. Nitrate V max and K S values were greater than those of ammonium, although N affinity was greater for ammonium. No differences in light-limited rates in either nitrate or ammonium uptake among colony sizes were observed, and no dark uptake occurred. Both ammonium and nitrate uptake showed a saturation response as a function of irradiance. While the driving forces for the formation of giant colonies remain unknown, their impacts on coastal systems are substantial and a further assessment of their growth is warranted |
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| Beschreibung: | Date Completed 22.10.2024 Date Revised 24.10.2024 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1529-8817 |
| DOI: | 10.1111/jpy.13501 |