As plankton strongly relies on environmental conditions, its abundance, composition and dynamics often reflect short term and local scale environmental variability. However, in the Gulf of Lion (GoL, northern most part of the western Mediterranean basin), plankton dynamic is still poorly understood particularly regarding its seasonal variations. In addition, major anthropogenic forcing involving heavy fishing pressure in the area have given rise to numerous management plans aimed at protecting the GoL's exploited species, and led to a growing need for knowledge about the overall functioning of this complex ecosystem. A research project aimed at surveying the GoL demersal and pelagic seasonal dynamics (GOLDYS project, 2021-2023) was undertaken to attempt filling this knowledge gap (Jacob, Salvado et al., 2023).