Longitudinal Study on Seasonal Variation of Marine Biotoxins and Related Harmful Algae in Bivalve Mollusks Bred in Sardinia (Italy, W Mediterranean Sea) from 2015 to 2020 and Assessment of Potential Public Health Risks

Abstract

Annual and interannual dynamics of shellfish toxins and associated harmful algal species (HAS) were analyzed from 2015 to 2020 in Tortolì Lagoon (Sardinia, west Mediterranean Sea). Analysis of seasonal occurrence of different harmful algae, such as Dinophysis spp., Prorocentrum spp., Pseudo-nitzschia spp. and Alexandrium minutum, was performed. The species Dinophysis acuminata and Dinophysis sacculus were responsible for the accumulation of lipophilic toxins belonging to the okadaic acid group (OAs) and pectenotoxins2 (PTX2) in bivalve mollusks. The highest HAS detection was recorded in the winter months; in particular, Dinophysis spp. was mostly present in January–February. Out of 1090 analyzed mollusk samples, 39 were non-compliant, exceeding the legal limits (160 μg OA eq/kg e.p.) reported in Regulation 853/2004 of the European Commission. A statistical analysis related to the presence of OA and PTX2 in mollusks with various environmental parameters (pH, water temperature, dissolved oxygen, algal density) was implemented, proving a clear winter seasonality. The present study highlights the necessity to better understand the different factors able to influence the production and accumulation of toxins in bivalve mollusks bred in an important Sardinian production area. The contribution of this research is important not only from an environmental and productive point of view but also from the view of implementing management in order to mitigate any harm to human health.

Determination of phytoplankton in water samples, algal biotoxins, microbiological parameters and microplastics in Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) from an experimental pilot farm in the Calich Lagoon (Sardinia, Italy)

“…Finally, the DO acid was detected according to the Standard Operating Procedure AESAN, 2008. The description of the methods has been previously described in Mudadu et al , 2021 .…”

Development of harmful algal blooms species responsible for lipophilic and amnesic shellfish poisoning intoxications in southwestern Mediterranean coastal waters

“…OA was also detected in Sardinia, Italy (Mudadu et al, 2021) and in the Thermaikos Gulf in Greece (Ciminiello et al, 2006;Reizopoulou et al, 2008) (Table 1). An important amount (1.1 µg g -1 meat) of OA was recorded in Mytilus galloprovincialis in the Northern Adriatic Sea (Ciminiello et al, 1997).…”

“…Dinophysis is also responsible for the production of pectenotoxins (PTXs) in the Mediterranean Sea. PTX-2 was recorded for the first time in France in 2005 in the oysters with a maximum of 22 µg Kg -1 and in mussels with a maximum of 26 µg kg -1 in Thau Lagoon (Amzil et al, 2007), as well as found in oysters in Sardinia (Italy) during 2019 (Mudadu et al, 2021) and in mussels in Catalonia (Spain) in 2012 (Garcia Altares et al, 2016). Belin et al (2021) revealed frequent detection of high levels of PTX2-seco-acid in various sites of shellfish aquaculture in the French Mediterranean lagoons.…”

Marine natural products

“…625 Synthesis of the proposed structures of bathymodiolamides A and B, originally isolated from the deep-sea hydrothermal vent mussel Bathymodiolus thermophilus, gave products that exhibited discrepancies in NMR data and in vitro cytotoxicity proles. 626 The seasonal and location variations of levels of cyclic imine toxins in northern Adriatic Sea mussels, oysters, scallops and edible ascidians, 627 gymnodimine A in Spanish molluscs, 628 lipophilic toxins in shellsh from SE China, 629 and Southern Gulf of California, 630 and okadaic acids and pectenotoxin-2 toxins and associated algal species in a lagoon in Sardinia, 631 have been reported. The distribution of other mollusc/bivalve…”

“…The seasonal and location variations of levels of cyclic imine toxins in northern Adriatic Sea mussels, oysters, scallops and edible ascidians, 627 gymnodimine A in Spanish molluscs, 628 lipophilic toxins in shellfish from SE China, 629 and Southern Gulf of California, 630 and okadaic acids and pectenotoxin-2 toxins and associated algal species in a lagoon in Sardinia, 631 have been reported. The distribution of other mollusc/bivalve related toxins including tetrodotoxin in shellfish in southern England, 632 and Central and Northern Adriatic Sea, 633,634 and domoic acid in mussels (Turkey), 635 and bivalves (NW Spain), 636 have also been described.…”