Is phosphorus a limiting factor to regulate the growth of phytoplankton in Daya Bay, northern South China Sea : a mesocosm experiment
Previous field investigations implied a potential phosphorus (P)-limitation on the growth of phytoplankton in Daya Bay, a mesotrophic bay in the northern South China Sea. Using a total of 15 mesocosms (3 × 3 × 1.5 m, with ~10.8 m3 natural seawater containing phytoplankton assemblages for each), we f...
| Veröffentlicht in: | Ecotoxicology (London, England). - 1992. - 28(2019), 5 vom: 23. Juli, Seite 559-568 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , , , , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2019
|
| Zugriff auf das übergeordnete Werk: | Ecotoxicology (London, England) |
| Schlagworte: | Journal Article Daya Bay Growth Mesocosm N- or/and P-enrichments Photosynthetic performance Phytoplankton assemblages Water Pollutants, Chemical Phosphorus 27YLU75U4W |
| Zusammenfassung: | Previous field investigations implied a potential phosphorus (P)-limitation on the growth of phytoplankton in Daya Bay, a mesotrophic bay in the northern South China Sea. Using a total of 15 mesocosms (3 × 3 × 1.5 m, with ~10.8 m3 natural seawater containing phytoplankton assemblages for each), we found P-enrichment caused no obvious effect on phytoplankton (Chl a) growth across 8-day's cultivation in neither winter nor summer, while nitrogen (N)-enrichment greatly increased Chl a in both seasons. N plus P-enrichment further increased Chl a content. The N- or N plus P-enrichments increased the allocation of nano-Chl a but decreased micro-Chl a in most cases, with no obvious effect by P-alone. Coincided with nutrients effect on Chl a content, N- or N plus P-enrichments significantly enhanced the maximum photochemical quantum yield of Photosystem II (FV/FM) and maximum relative electron transport rate (rETRmax), but declined the non-photochemical quenching (NPQ), as well as the threshold for light saturation of electron transport (EK); again, P-enrichment had no significant effect. Moreover, the absorption cross section for PSII photochemistry (σPSII) and electron transport efficiency (α) increased due to N- or N plus P-enrichments, indicating the increased nutrients enhance the light utilization efficiency through promoting PSII light harvesting ability, and thus to enhance phytoplankton growth. Our findings indicate that N- or N plus P-enrichments rigorously fuel phytoplankton blooms regardless of N:P ratios, making a note of caution on the expected P-deficiency or P-limitation on the basis of Redfield N:P ratios in Daya Bay |
|---|---|
| Beschreibung: | Date Completed 29.10.2019 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1573-3017 |
| DOI: | 10.1007/s10646-019-02049-7 |