POSTER SESSION 2
10:30–12:30, Tuesday, September 15
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1181 | POSTER 126
SEASONAL DYNAMICS OF PHYTOPLANKTON IN THE SEINE ESTUARY AND BAY
Phytoplankton phenology in coastal ecosystems is driven by both natural variability and anthropogenic pressures, particularly in highly dynamic land–sea interfaces such as the Seine Estuary and Bay (SEB) in France. As part of the LandSeaLot project, this region is being investigated through an integrated observation strategy that combines satellite remote sensing, numerical modelling and in-situ measurements. Here, we used daily ocean colour observations from the European Space Agency’s Sentinel-3 OLCI sensor (300 m spatial resolution) to monitor inter- and intra-annual phytoplankton bloom dynamics. Surface chlorophyll a concentration, derived from OLCI imagery, was used as a proxy for phytoplankton biomass and analysed as a time series to characterise phenological patterns. A dynamic linear model was applied to extract key features of the seasonal cycle, including the time of minimum and maximum chlorophyll values, providing a robust framework for describing bloom timing and intensity. In addition, based on identified bloom dynamics, clustering techniques were used to identify phenoregions within the SEB, enabling an explicit mapping of phytoplankton phenology. This approach represents a first step towards a common observational framework aimed at understanding how riverine inputs and human pressures may drive bloom dynamics. Finally, some identified bloom episodes can be further isolated and investigated by combining satellite observations with in-situ data and modelling, to better characterise the physical drivers of intense phytoplankton events in the Seine estuary.
Enora Lecordier, Nantes Université, Institut des Substances et Organismes de la Mer, France, [email protected], https://orcid.org/0009-0002-2920-5387
Pierre Gernez, Nantes Université, Institut des Substances et Organismes de la Mer, France, [email protected], https://orcid.org/0000-0003-2055-410X
Dominique Soudant, Ifremer, COAST, France, [email protected]
Pascal Claquin, Univ. de Caen-Normandie, UPMC Univ., France, [email protected], https://orcid.org/0000-0002-5183-203X
Tania Hernández-Fariñas, Ifremer, COAST, France, [email protected], https://orcid.org/0000-0002-8453-7096
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
