Within the Bay of Biscay, the Basque coast offers particularly favourable ecological conditions for the development of Gelidium resources. The canopy formed by its fields is of great functional value in maintaining the biodiversity of coastal communities. In addition to its ecological value, this species is an important economic resource. Numerous works are available but only on the Spanish Basque coast, very few have been done on the French part. The originality of this project “Gelidium64” is based on the synthesis of data collected in 2022 on the French Basque coast, focusing on four main axes: (1) characterization of Gelidium fields through a dedicated sampling campaign by scuba divers; (2) a broader visualization of their distribution using underwater images taken by drone and scuba diving; (3) an assessment of the resource  regarding biochemical composition; (4) an analysis of the Gelidium exploitation by industry and its historical context. This work represents, for the first time in 2022, an overview of the qualitative situation (biochemistry, plant height, yellowing, etc.) and quantitative aspects (percentage of coverage, biomass, landings) of the Gelidium resource on the French Basque coast. Considering a decline in onshore and offshore collection by the professionals, results particularly highlight the effect of bathymetry on the resource and the yellowing impact on the Gelidium quality on the Basque coast. Changes in available environmental conditions partly explain observed trends but require additional environmental data acquisition to properly understand (qualitatively and quantitatively) the evolution of this resource in an increasing human pressure context coupled with global change.