HABs (Harmful Algal Blooms) are outbreaks of microalgae toxic to humans, as well as microalgae having a negative impact on the ecosystem through production of ichthyotoxins or causing conditions noxious to the habitat, such as hypoxia to anoxia.
Two groups of organisms can be distincted among HAB species: 1) toxin producers, that may contaminate seafood and cause problems to the public health or fish kills and 2) organisms responsible for events known as red tides or discoloured waters, with following ecologic damages due to water hypoxia/anoxia, thus threatening marine life and causing problems in recreational waters.
HAB events may thus represent a serious risk for public health, marine ecosystems, fish farming, recreational activities, tourism and, in general, economic industry. Many factors, natural or anthropic, can contribute to the spreading worldwide of HAB species. Such phenomena are amplified by human activities, such as the wrong management of the coastal area leading to increased amounts of nutrients in the waters and eutrophy, lack of seawage treatments, use of fertilizers in agriculture, the increase of confined waters (harbours, protected beaches), the sea discharge of ship's ballast water favouring the introduction of non-indigenous organisms, the so-called "alien species". Therefore, areas previously free by harmful species can later become subject to HABs, if "aliens" find in the waters environmental conditions favouring cell growth.
As regards to the health problems, the most important syndromes caused by toxic dinoflagellates are PSP - Paralythic Shellfish Poisoning, and DSP - Diarrhetic Shellfish Poisoning.
Health, ecology, economy implications arising from harmful phytoplankton blooms have attracted the research interest of the Istituto per l'Ambiente Marino Costiero (Sezione di Messina), addressing particular attention to the coastal zone with productive/ricreational activity, such as touristic and mariculture areas. National Research Projects coordinated by IAMC of Messina - a contractor of European Projects on HAB topics as well, allowed: the detection along the sicilian coastline of "critical areas", particularly sensitive to HABs; isolation and culturing of key-species (e.g. Alexandrium spp.), characterization of toxin profiles from clonal cultures (PSP) and, for the first time, from mussels farmed in our target sites (PSP and DSP). Looking at the improvement of the HAB detection tools, genus and species-specific primers for Alexandrium and Dinophysis were also developed and used for the PCR analysis of culture and field seawater samples.
The above issues will find an useful application both in the HAB control and mitigation in shellfish areas. Thus, future researches will give priority to the advancement in prevention strategies, as safeguard of the coastal marine environment and public health, and development of advanced technologies for the rapid detection and mitigation of HAB events through laboratory experiments and in situ application.
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