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The authors sincerely thank the other experts who participated in the working group set up by the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) to prevent health risks associated with the consumption of shellfish contaminated with BTXs in France, that is to say: Katia Comte, Estelle Chaix, Nicolas Delcourt, César Mattei, Jordi Molgó and Raphaele Le Garrec.; International audience; In recent decades, more than 130 potentially toxic metabolites originating from dinoflagellate species belonging to the genus Karenia or metabolized by marine organisms have been described. These metabolites include the well-known and large group of brevetoxins (BTXs), responsible for foodborne neurotoxic shellfish poisoning (NSP) and airborne respiratory symptoms in humans. Karenia spp. also produce brevenal, brevisamide and metabolites belonging to the hemi-brevetoxin, brevisin, tamulamide, gymnocin, gymnodimine, brevisulcenal and brevisulcatic acid groups. In this review, we summarize the available knowledge in the literature since 1977 on these various identified metabolites, whether they are produced directly by the producer organisms or biotransformed in marine organisms. Their structures and physicochemical properties are presented and discussed. Among future avenues of research, we highlight the need for more toxin occurrence data with analytical techniques, which can specifically determine the analogs present in samples. New metabolites have yet to be fully described, especially the groups of metabolites discovered in the last two decades (e.g tamulamides). Lastly, this work clarifies the different nomenclatures used in the literature and should help to harmonize practices in the future.

To prevent health risks associated with the consumption of shellfish contaminated with BTXs in France, a working group was set up by the French Agency for Food, Environmental and Occupational Health & Safety (Anses). One of the aims of this working group was to propose a guidance level for the presence of BTXs in shellfish.; International audience; Brevetoxins (BTXs) are marine biotoxins responsible for neurotoxic shellfish poisoning (NSP) after ingestion of contaminated shellfish. NSP is characterized by neurological, gastrointestinal and/or cardiovascular symptoms. The main known producer of BTXs is the dinoflagellate Karenia brevis, but other microalgae are also suspected to synthesize BTX-like compounds. BTXs are currently not regulated in France and in Europe. In November 2018, they have been detected for the first time in France in mussels from a lagoon in the Corsica Island (Mediterranean Sea), as part of the network for monitoring the emergence of marine biotoxins in shellfish. To prevent health risks associated with the consumption of shellfish contaminated with BTXs in France, a working group was set up by the French Agency for Food, Environmental and Occupational Health & Safety (Anses). One of the aims of this working group was to propose a guidance level for the presence of BTXs in shellfish. Toxicological data were too limited to derive an acute oral reference dose (ARfD). Based on human case reports, we identified two lowest-observed-adverse-effect levels (LOAELs). A guidance level of 180 µg BTX-3 eq./kg shellfish meat is proposed, considering a protective default portion size of 400 g shellfish meat.

19th International Conference on Harmful Algae (ICHA 2021), 10-15 october 2021, La Paz, Baja California Sur, México, Ciguatera poisoning (CP) is a long-neglected foodborne disease affecting tropical regions of the Pacific and Indian Oceans and the Caribbean Sea. It was raised at the 32nd Session of the Codex Committee on Fisheries and Fishery Products (FAO) in 2016. In 2017, CP was an agenda item at the 11th Session of the Codex Committee on Contaminants in Food. The committee requested scientific advice, so late 2018 a group of experts met to advise FAO-WHO on the development of risk management options for CP. In parallel to this an interagency global ciguatera strategy was developed among FAO, IOC and IAEA. In this framework, an expert team is developing guidance for the implementation of CP Early Warning Systems (EWSs). The EWS approach includes monitoring Gambierdiscus species (benthic dinoflagellates) that produce the toxins responsible for CP. Advances in Gambierdiscus taxonomy, better understanding of their global distribution and toxicity and species-specific molecular identification and enumeration methods make this possible. Key to standardizing cell based EWS for Gambierdiscus are how, when and where to sample. Unlike planktonic species, no standardized sampling method for benthic species exists. Traditionally, macrophytes are collected and cells abundances normalized to grams wet weight of macrophyte. There are myriad arguments against this collection technique, including ignoring the use of more accurate, surface-area normalized cell densities. Artificial substrates, rather than macrophytes, are proposed so cell abundances can be normalized to surface areas. We hope to open a dialog among interested colleagues and invite them to develop proof of concept projects comparing traditional macrophyte sampling methods with artificial substrates

The first edition of this manual was first published in 2011 in Spanish. Pigmented phytoplankton is the main primary producer and constitutes the foundation of the marine food webs. Blooms, the explosive growth of phytoplankton, are natural phenomena that help to support the production of bivalves and small pelagic fish such as sardines and anchovies. Through photosynthesis, phytoplankton synthethizes organic material using solar energy, macronutrients — atmospheric CO2 and nitrates, phosphates and silicates dissolved in the water — and trace elements (e.g. trace metals and vitamins). In this way, phytoplankton growth acts like a “biological carbon pump” that helps to offset the greenhouse effect. In addition, phytoplankton populations excrete dimethyl sulphide (DMS) into the atmosphere, a gas that contributes to the formation of nuclei of condensed water, thus generating clouds and counteracting excessive solar radiation. Not all of these blooms are beneficial, however. Harmful algal blooms (HABs) is a term adopted by the Intergovernmental Oceanographic Commission (IOC) of UNESCO; it is internationally accepted to refer to any proliferation of microalgae (regardless of the concentration) perceived as harmful owing to its negative impact on public health, aquaculture, the environment and/or recreational activities. Published In Spanish and English. The first edition of this manual was first published in 2011 in Spanish. Refereed Current

2008/2009 Yessotoxins (YTXs) are ladder-shaped polycyclic ether toxins, structurally related to brevetoxins and ciguatoxins (Ciminiello and Fattorusso, 2008). The parent compound of this class, yessotoxin, has been initially isolated from the scallop Patinopecten yessoensis (Murata et al., 1987). Only later their natural source has been identified in the phytoplanktonic dinoflagellates Protoceratium reticulatum (= Gonyaulax grindley) (Satake et al., 1997), Lingulodinium polyedrum (= Gonyaulax polyedra) (Tubaro et al., 1998; Paz et al., 2004) and Gonyaulax spinifera (Rhodes et al., 2006). When environmental conditions promote the growth of these species, their toxins accumulate in edible tissues of filter feeding shellfish exposed to these dinoflagellates, thus entering in the food chain. No human toxicity has been reported for YTXs, although YTXs contaminated-shellfish were worldwide recorded, thus, yessotoxin toxicological potential is still unknown. Toxicological in vivo studies revealed high toxicity in mice after intraperitoneal administration (LD50~μg/Kg), whilst very low toxicity (no lethality) was found after acute or repeated oral administration. Both routes are associated with clear evidence of ultrastructural cardiac alteration in rodent cardiac muscle, soon after toxin administration (Aune et al., 2002; Tubaro et al., 2003). Notwithstanding many in vitro studies highlighted numerous intracellular targets, YTX mechanism of action is unclear and the effects on the cardiac functional properties remain unknown. This study was performed on neonatal rat cardiomyocytes to study toxin effects on various fundamental aspects of cardiac muscle cells activity: cell beating, intracellular Ca2+ and cAMP levels, cell vitality, mitochondrial membrane potential and type of cell death occurrence. Results showed a time- and concentration-dependent reduction in the beating frequency (0.3 μM YTX, 1 h; p