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 din oflagellates of the genus Dinophysis in NW Adriatic waters. The aims of thi s paper are: 1) to describe seasonal patterns of the main species of Dinoph ysis; 2) to determine oceanographic conditions triggering or preventing the ir 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 b etween Dinophysis abundances and temperature, salinity and wind speed indic ate these parameters as the main factors forcing the spatial and temporal d istribution 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 Adria tic coastal waters.