Spatiotemporal distribution of paralytic shellfish poisoning (PSP) toxins in shellfish from Argentine Patagonian coast

Leilén Gracia Villalobos,Norma H Santinelli,Alicia V Sastre,Germán Marino,Gastón O Almandoz

doi:10.1016/j.heliyon.2019.e01979

Abstract

Harmful algal blooms (HABs) have been recorded in the Chubut Province, Argentina, since 1980, mainly associated with the occurrence of paralytic shellfish poisoning (PSP) toxins produced by dinoflagellates of the genus Alexandrium. PSP events in this area impact on fisheries management and are also responsible for severe human intoxications by contaminated shellfish. Within the framework of a HAB monitoring program carried out at several coastal sites along the Chubut Province, we analyzed spatiotemporal patterns of PSP toxicity in shellfish during 2000–2011. The highest frequency of mouse bioassays exceeding the regulatory limit for human consumption was detected in spring and summer, with average values of up to ≈70% and 50%, respectively. By contrast, a lower percentage of positive bioassays (2–8%) or no toxicity at all was usually detected during autumn and winter. The most intense PSP events were usually observed between November and January, with values of up to 4,000 μg STX eq 100 g−1, and showed a marked interannual variability both in their magnitude and location. In addition, a severe PSP outbreak was recorded during autumn, 2009, at Camarones Bay, with toxicity values of up to 14,000 μg STX eq 100 g−1. The scallop Aequipecten tehuelchus showed significantly higher toxicity values compared to other shellfish species in SJG and SMG, suggesting a lower detoxification capacity. Our results contribute to the understanding of HABs dynamics on the Argentine Patagonian coast.

Highlights

Public health problems arising directly or indirectly as a result of harmful algal blooms (HABs) are of widespread occurrence
Only a low percentage of positive mouse bioassays (2–8%) or no toxicity at all were detected during autumn and winter, with the exception of high values observed in Camarones Bay (CB) (22% and 16%, respectively)
In CB and San Jorge Gulf (SJgeG), mean toxicity values were higher in summer than in spring, contrary to that observed in San Matías Gulf (SMG) and Nuevo Gulf (NG), whereas means values in San Jose Gulf (SJG) and Engan~o Bay (EB) were similar in both seasons

Summary

Introduction

Public health problems arising directly or indirectly as a result of harmful algal blooms (HABs) are of widespread occurrence. Respiratory distress may occur, as a consequence of muscular paralysis progressing through the whole body, and death may be the outcome of PSP by respiratory paralysis (Rossini and Hess, 2010). Marine bivalves, such as mussels, clams, oysters and scallops, accumulate PSP toxins in their tissues, which makes them potentially toxic to vertebrates, including humans (Estrada et al, 2007). The bioaccumulation in filter-feeding bivalves and the subsequent transfer through the food web results in potentially fatal human illnesses, which have become a widespread public health problem especially along the Pacific and Atlantic coasts of North America, in Central and South

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