Multiscale phytoplankton dynamics in a coastal system of the eastern English Channel: the Boulogne-sur-Mer coastal area
<p>To study changes in phytoplankton community composition on different timescales, an automated flow cytometer (CytoSub, CytoBuoy b.v.) was deployed at the MAREL Carnot automated monitoring station in Boulogne-sur-Mer (eastern English Channel, France) during spring (2021 and 2022) and summer ...
Saved in:
| Main Authors: | , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-08-01
|
| Series: | Ocean Science |
| Online Access: | https://os.copernicus.org/articles/21/1787/2025/os-21-1787-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <p>To study changes in phytoplankton community composition on different timescales, an automated flow cytometer (CytoSub, CytoBuoy b.v.) was deployed at the MAREL Carnot automated monitoring station in Boulogne-sur-Mer (eastern English Channel, France) during spring (2021 and 2022) and summer (2022), following an Eulerian approach. Phytoplankton dynamics were recorded every 2 h, distinguishing 11 phytoplankton functional groups (PFGs) based on optical and fluorescence properties. This enabled detailed characterization of PFG successions, including MicroRED (mostly diatoms) and NanoRED (mostly haptophytes of the species <i>Phaeocystis globosa</i>) transitions in spring, as well as a summer dominance by PicoORG (picocyanobacteria, mostly of the genus <i>Synechococcus</i>) and PicoRED. Four rare events, including a salinity drop (April 2021), strong winds (May 2021 and April 2022), and a marine heat wave (July 2022), caused rapid shifts in phytoplankton community assemblage. Empirical mode decomposition (EMD) and Lomb–Scargle periodogram (LSP) analyses revealed that <span class="inline-formula">85±10</span> % of variability in total phytoplankton abundance, red fluorescence (a proxy of chlorophyll <span class="inline-formula"><i>a</i></span>), and Shannon diversity occurred on relatively short timescales (9 h to 11 d) for time series of several months, highlighting the value of high-frequency monitoring in capturing ecological dynamics under macrotidal conditions in the eastern English Channel.</p> |
|---|---|
| ISSN: | 1812-0784 1812-0792 |