Harmful Algal Blooms were studied between 2000-2005 in a Mediterranean locality (Sicily, Italy) recurrently subject to outbreaks of toxic dinoflagellates, mostly Alexandrium minutum and Dinophysis spp., whose identity was confirmed by molecular tools (genus and species-specific PCR assays). Evidence for toxicity of phytoplankton natural assemblages was gained through HPLC analysis, indicating the occurrence of either Paralytic Shellfish Toxins (goyautoxins and saxitoxin) or Diarrhetic Shellfish Toxins (okadaic acid and dinophysistoxin-1) in bloom samples from various Sicilian areas. On some occasions, shellfish (Mytilus galloprovincialis) from Ionian and Tyrrhenian farming areas were also analysed for toxicity by mouse bioassay and HPLC, since no previous information on possible shellfish contamination by phycotoxins is available from the Sicilian coast. Gonyautoxins (mostly GTX4) were detected in 2001 in mussels, although their concentration was below the safety threshold for human consumption. In some cases (2000 and 2004), mouse assays gave positive results and HPLC analyses of farmed mussels indicated the presence of yessotoxins (2000), as well as spirolides and gymnodimine (2004), although at trace levels. These first records of phycotoxins both in Tyrrhenian and Ionian localities, suggest a high risk for future seafood contaminations, and the need for an intensive shellfish monitoring in target areas of Sicily particularly susceptible to Harmful Algal Blooms.
Plankton toxicity and shellfish contamination by phycotoxins in a new Mediterranean locality
2006
Abstract
Harmful Algal Blooms were studied between 2000-2005 in a Mediterranean locality (Sicily, Italy) recurrently subject to outbreaks of toxic dinoflagellates, mostly Alexandrium minutum and Dinophysis spp., whose identity was confirmed by molecular tools (genus and species-specific PCR assays). Evidence for toxicity of phytoplankton natural assemblages was gained through HPLC analysis, indicating the occurrence of either Paralytic Shellfish Toxins (goyautoxins and saxitoxin) or Diarrhetic Shellfish Toxins (okadaic acid and dinophysistoxin-1) in bloom samples from various Sicilian areas. On some occasions, shellfish (Mytilus galloprovincialis) from Ionian and Tyrrhenian farming areas were also analysed for toxicity by mouse bioassay and HPLC, since no previous information on possible shellfish contamination by phycotoxins is available from the Sicilian coast. Gonyautoxins (mostly GTX4) were detected in 2001 in mussels, although their concentration was below the safety threshold for human consumption. In some cases (2000 and 2004), mouse assays gave positive results and HPLC analyses of farmed mussels indicated the presence of yessotoxins (2000), as well as spirolides and gymnodimine (2004), although at trace levels. These first records of phycotoxins both in Tyrrhenian and Ionian localities, suggest a high risk for future seafood contaminations, and the need for an intensive shellfish monitoring in target areas of Sicily particularly susceptible to Harmful Algal Blooms.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
