Innovative technologies applied to monitoring of benthic HAB Ostreopsis: an overview of molecular and analytical tool development for in situ characterization of harmful benthic blooms

Since the summer 2005, in the Mediterranean Sea, growing concerns regarding exposure to harmful benthic blooms and associated toxic aerosol of the benthic dinoflagellate Ostreopsis spp. have been reported, as they represent major health and economic risks to human populations, and animal biota. In fact, the genus Ostreopsis produces non protein palytoxin (PLTX) and PLTX analogs, such as ovatoxins (OVTXs). Among the OVTXs, ovatoxin-a is the major toxin produced by O. cf. ovata. Advanced technologies based on molecular quantitative PCR have greatly improved the identification and quantification of Ostreopsis species on/in different substrates, seawater and marine aerosol, thus providing a more accurate and specific alternative detection assay. The molecular methods were always applied in combination with the advanced liquid chromatography HR MS or FLD techniques for the determination of palytoxin profile of various Mediterranean toxic O. cf. ovata populations. Recently, an improved monitoring for in situ detection of the Mediterranean Ostreopsis occurrence was developed. A qPCR monitoring of seawater quality affected by Ostreopsis spp. blooms at various Mediterranean beaches was carried out during summer periods. This molecular approach was performed by developing specific geographical site and environmental standard curves to quantify cell abundance and determine the species-specific identification of Ostreopsis in field samples. Improved monitoring based on molecular and analytical advanced technologies to be implemented in HAB event management programs will be our effort for the future in order to minimize societal impacts.