Developing new approaches for the harmful dinoflagellate diversity studies and management of their toxic blooms

The huge and complex biodiversity of dinoflagellates stimulated for many years interesting genetic and molecular studies mainly aimed at harmful species worldwide. Their toxic blooms cause serious impacts to human health, marine environment and economic maritime activities at many coastal sites. Therefore, there is a urgent need for new methods not only for rapid and accurate detection and count of HAB species, but also for species-specific identification and reliable quantification of cell densities, the ultimate goal being the development of early warning and forecasting systems for HABs. Phylogenetic relationships and genetic population studies proved the identity of new species (i.e. in Alexandrium or Ostreopsis genera) and allowed to gain new insights into phytoplankton assemblage structure in the Mediterranean Sea. Genus- and species-specific primers and probes designed on rDNA ribosomal and saxitoxin genes allowed to develop and apply new identification and counting qPCR and microarray based assays, which proved to be more rapid, sensitive and specific when applied in various substrates, such as the water column, hard and soft bottoms and aerosol. In the recent aquaculture system investigated for the PSP toxin producing species, the sxtA1 gene qPCR assay can support the analytical methods for STX determination in seawater and shellfish especially at early warning stage of toxic blooms. Further, predictive models can play an important role in managing and forecasting HABs. Models based on Machine Learning techniques and principally those based on Random Forests are very promising both at regional and at wider scale.