Physiological and behavioral responses of phytoplankton communities to nutrient availability in a disturbed Mediterranean coastal lagoon
Leruste, A.; Pasqualini, V.; Garrido, M.; Malet, N.; De Wit, R.; Bec, B. (2019). Physiological and behavioral responses of phytoplankton communities to nutrient availability in a disturbed Mediterranean coastal lagoon. Est., Coast. and Shelf Sci. 219: 176-188. https://dx.doi.org/10.1016/j.ecss.2019.02.014
In: Estuarine, Coastal and Shelf Science. Academic Press: London; New York. ISSN 0272-7714; e-ISSN 1096-0015, meer
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| Trefwoorden |
Eutrophication
Growth rate
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| Author keywords |
Dilution experiment; Functional traits |
| Auteurs | | Top |
- Leruste, A.
- Pasqualini, V.
- Garrido, M.
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- Malet, N.
- De Wit, R.
- Bec, B.
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| Abstract |
Short-term bioassays were conducted in Biguglia lagoon (Corsica) to study the physiological and behavioral responses of phytoplankton to N- and P-availability. Natural communities were collected in two stations representative of the two sub-basins, at three periods with contrasting environmental characteristics to address the impact of seasonal variability. These samples were separately enriched with a full N and P enrichment, and with enrichments minus N or minus P. Phytoplankton size structuration, diversity, and growth of the total phytoplankton, the micro-, nano- and ultraphytoplankton were evaluated using spectrofluorimetry, and optical microscopy. Results showed that the communities were fueled by NO3− in the wet periods (autumn and spring) and NH4+ in summer. The phytoplankton communities displayed highest cell size in autumn, with high abundances of nanoflagellates, and smallest cell size in summer with a large dominance of phycocyanin-rich picocyanobacteria. Blooms of dinoflagellates also occurred during the wet periods, coinciding with high N:P ratios. The full enrichment has not stimulated phytoplankton growth in autumn, suggesting the importance of other controlling factors such as light, a possible NH4+ inhibition or the use of mixotrophic abilities. In spring, communities have displayed single P-limitation in the northern basin and different N and P co-limitations in the southern basin. In summer, the full enrichment consistently stimulated the growth of all cell sizes. The communities showed high N and P co-limitations, which is consistent with growing observations in aquatic ecosystems, and reflects the different functional responses of phytoplankton communities to the nutrient availability. |
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