Occurrence of the toxic dinoflagellate Ostreopsis cf. ovata in relation with environmental factors in Monaco (NW Mediterranean)

► First multi-factorial ecological study on Ostreopsis in the NW Mediterranean Sea. ► One of the most important concentrations never observed in the NW Mediterranean Sea. ► High spatial and temporal variations observed at small scales. ► First hypothesize of a strong impact of annual hydroclimatic conditions on the bloom's occurrence and amplitude.