Occurrence of Marine Biotoxins and Shellfish Poisoning Events and Their Causative Organisms in Argentine Marine Waters

Bernd Krock,Rut Akselman,Nora Montoya,Martha Ferrario

doi:10.5670/oceanog.2018.403

Abstract

In the Argentine Sea, marine phycotoxins of microalgal origin associated with five shellfish poisoning syndromes have been reported. The most problematic in terms of toxicity and geographic distribution is paralytic shellfish poisoning (PSP), followed by diarrhetic shellfish poisoning (DSP). In contrast, amnesic shellfish poisoning (ASP), spiroimine shellfish poisoning (SSP), and azaspiracid shellfish poisoning (AZP) have not been reported to cause human illness or closures of shellfish harvest sites in Argentina to date but pose a potential risk, as associated toxins and producing organisms are present in Southwest Atlantic waters and were detected at subregulatory levels in mollusks. Alexandrium catenella and Gymnodinium catenatum have been identified as producers of the PSP toxins C1/2, gonyautoxins (GTX1-4), saxitoxin (STX), and neosaxitoxin (NEO) in the Argentine Sea. Nine potentially toxigenic species of the diatom genus Pseudo-nitzschia have been reported for Argentinean coastal waters: P. australis, P. brasiliana, P. delicatissima, P. fraudulenta, P. multiseries, P. pseudodelicatissima, P. pungens, P. seriata, and P. turgidula, all of which are known to produce the neurotoxin domoic acid that causes ASP. Two genera have been identified as producers of DSP toxins in Argentina: the benthic dinoflagellate Prorocentrum lima and several species of the pelagic dinoflagellate genus Dinophysis: D. acuminata, D. caudata, D. fortii, D. norvegica, and D. tripos. The occurrence of these species in Argentine waters is associated with okadaic acid (OA), dinophysistoxin-1 (DTX-1), pectenotoxin-2 (PTX-2), and pectenotoxin-2 seco acid (PTX-2sa). Historically, yessotoxins (YTXs) were also included in DSP syndrome and all three known YTX-producers have been confirmed in Argentinean waters: Gonyaulax spinifera, Lingulodinium polyedra, and Protoceratium reticulatum, but of these only P. reticulatum could be associated with YTX production to date. Several species of the family Amphidomataceae, which cause AZP, have been reported for Argentina: Amphidoma languida, Azadinium dexteroporum, Az. luciferelloides, Az. poporum, and Az. spinosum. In Argentinean coastal waters, out of these species only Az. poporum has been identified as toxigenic to date, as it produces azaspiracid-2 (AZA-2) and its phosphorylated form. Currently in Argentina, seafood is monitored for the risk of ASP, AZP, DSP, and PSP.

Highlights

Toxic marine microalgae are usually responsible for human shellfish poisoning events
Not all types of shellfish poisoning syndromes have been reported to date in Argentine waters, several toxigenic microalgal species and their toxins have been identified in this region during the last four decades
Several species of amphidomataceans were identified in plankton samples collected across a geographic range from the San Jorge Gulf to Tierra del Fuego in autumn 2004 and spring 2005, along with a dinoflagellate whose morphology is similar to Azadinium in the Beagle Channel (Ferrario et al, 2017), records that are complemented by the detection of AZA-2 in plankton samples from the eastern mouth of Beagle Channel

Summary

INTRODUCTION

Toxic marine microalgae are usually responsible for human shellfish poisoning events. They produce secondary metabolites that may be taken up and concentrated to high levels by filter-feeding mollusks and cause severe illnesses or even death in vertebrates (including humans) after consumption of contaminated shellfish. These marine biotoxins usually trigger no or few adverse effects in primary consumers of toxic microalgae, such as crustaceans and mollusks. Not all types of shellfish poisoning syndromes have been reported to date in Argentine waters, several toxigenic microalgal species and their toxins have been identified in this region during the last four decades. Includes, in addition to the monitoring of toxic species, the control of toxins in

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Findings

CONCLUSION