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

In France, REPHY (Observation and Surveillance Network for Phytoplankton Hydrology in coastal waters) REPHYTOX (Monitoring Phycotoxins marine organisms) have been contributing to long-term time series on ocean health more than 30 years. The aim of this paper is describe these networks highlight their key results. Over the last 20 years, phytoplankton flora analysis French coasts from Channel Mediterranean has shown that five “emblematic” taxa are Chaetoceros, Skeletonema, Cryptophyceae, Leptocylindrus Pseudo-nitzschia. latter, together with interest Dinophysis + Phalacroma, Alexandrium, Karenia, consistently recorded along entire coastline. However, when taking into account frequency occurrence some exhibit distinct geographical distributions. particular, Phaeocystis appeared be strongly specific northern Channel. regularly affected since 1980s by presence toxins bivalve molluscs, leading bans fishing sale shellfish during periods varying duration. Three categories were involved. PST AST absent coasts, respectively before 1988 2000. DST (Diarrheic Shellfish Toxins) many areas whole coast every year 1987. For (Paralytic Toxins), only a few affected, sometimes sporadically, Channel, 1993 Atlantic, 1998 Mediterranean. Many impacted 2000 (Amnesic episodes, mainly affecting scallops Atlantic coasts. patterns change toxicity episodes showed no real trend any province over period 1987–2018.