Management of the production and harvesting in Greek mussel culture areas, according to the occurrence of lipophilic toxic episodes

Toxic episodes due to lipophilic biotoxins, mainly Diarrhetic Shellfish Poisoning (DSP) toxins, constitute one of the major problems in Greek mussel culture, leading to significant economic losses per year. The present study aimed at establishing occurrence trends of lipophilic toxic episodes throughout the year, in order to serve as a tool for better scheduling and management of production and harvesting, and involved five major mussel culture areas of Greece, representing ca. 95% of Greek production (Saronikos, Thermaikos, Maliakos, Gulf of Kavala and Amvrakikos Gulf). Data were obtained during the years 2003-2008 and included closure time periods due to both presence of lipophilic biotoxins in shellfish and increased abundance of Dinophysis spp. populations, the main phytoplankton genus responsible for the occurrence of DSP lipophilic biotoxins in mussels, as well as respective climatological parameters (wind direction and intensity, rain precipitation and temperature). Statistical analysis of the data confirmed the empirically evident yearly periodicity of DSP toxic episodes occurrence, presenting significant differences between specific production areas. For instance, closures in production areas of Saronikos and Thermaikos Gulfs occurred mostly during winter/spring, whereas spring/autumn was the common occurrence time for areas in Maliakos and Kavala Gulfs. The suggested approach of evaluating past data regarding time period, duration and factors affecting the occurrence of DSP toxic episodes, can significantly contribute towards a more efficient financial management of mussel cultures.