Reccurent blooms of <i>Alexandrium catenella</i> in Mediterranean confined waters

Paralytic Shellfish Poisoning (PSP) events related to phytoplankton blooms have increased worldwide. In the Mediterranean Sea, species belonging to the genus Alexandrium are chiey associated with PSP events, and A. catenella is one of its most toxic. Before A. catenella had been detected in the Mediterranean Sea, that species was related to productive, cold upwelling regimes. However, in the MediterraneanSea, A. catenella blooms are often localised phenomena that occur in enriched and confined coastal waters (harbours, bays). An intensive study was carried out during a huge bloom of this species in the Tarragona harbour in 2002