High-frequency monitoring of phytoplankton functional groups using an automated flow cytometer during two deployments (2021, 2022) at the MAREL CARNOT station (Boulogne-sur-Mer, France) in the eastern English Channel

An automated flow cytometer, CytoSub (Cytobuoy b.v., Netherlands), was deployed twice in conjunction with the MAREL Carnot station (COAST-HF network, IR ILICO) during spring 2021 and the spring-summer period of 2022. This high-frequency instrument continuously sampled the surface coastal waters of Boulogne-sur-Mer every two hours, enabling the identification of eleven phytoplankton functional groups, along with their abundances and associated optical properties, including red, yellow, and orange fluorescence, as well as forward and sideward light scatter.