Three decades of data on phytoplankton and phycotoxins on the French coast: Lessons from REPHY and REPHYTOX

•REPHY and REPHYTOX have been contributing to ocean survey for more than 30 years.•Five taxa are “emblematic” of phytoplankton flora from the Channel to Mediterranean.•Four harmful taxa have been consistently recorded along the entire French coastline.•Episodes of toxicity in shellfish mainly started in the 1980s and 90s.•Patterns of change of toxicity episodes have not shown a real trend for 30 years.