Results of phytoplankton description by imaging flowcytometry (Cytosense from Cytobuoy). Water sampling were made during the "Objectif plancton" project from 2018 to 2021 (https://www.mnhn.fr/fr/objectif-plancton-observez-la-biodiversite-marine). At low water, a synoptic sampling throughout the bay was conducted by citizens (17+ sampling stations). Samples were then fixed (between 15 min and 1 h after sampling) and stored (liquid N). After the flowcytometry analysis, a manual clustering was performed and groups were labelled following Thyssen et al. (2022) https://doi.org/10.3389/fmars.2022.975877. Images of the largest cell were also taken during the analysis. Images can be cropped or uncropped acccording to the export file. A synthetic file (CSV) was made for an easy use. Raw and exported files are avaible in *tar archives.