Seasonal dynamics of Dinophysis in coastal waters of the NW Adriatic Sea (1990-1996)

This paper provides time series data (1990-1996) on the distribution of dinoflagellates of the genus Dinophysis in NW Adriatic waters. The aims of this paper are: 1) to describe seasonal patterns of the main species of Dinophysis; 2) to determine oceanographic conditions triggering or preventing their growth. The most abundant species were first D. sacculus Stein, followed by D. rotundata Claparede et Lachmann in spring and summer, and D. caudata Saville-Kent and D. fortii Pavillard in summer and autumn. Relationships between Dinophysis abundances and temperature, salinity and wind speed indicate these parameters as the main factors forcing the spatial and temporal distribution of the species. Thus, stratification and low turbulence induced by hydrodynamic calm are favourable conditions for Dinophysis growth and, consequently, for the risk of diarrhetic shellfish poisoning (DSP) in Adriatic coastal waters.