Evolution of PSP Toxicity in Shellfish from the Beagle Channel (Tierra del Fuego, Argentina): An Overview

Abstract

The Beagle Channel (Tierra del Fuego, Argentina) is the southernmost area of the world for commercial shellfish harvest. Since 1985, Paralytic Shellfish Poison (PSP) monitoring activities have been performed in samples of shellfish taken from different places from the Channel. Up to 1992, there were no outbreaks of toxicity in shellfish, and no detectable PSP levels were recorded in most of the samples. In mid-January, 1992, a toxicity increase was detected in mussels Aulacomya ater sampled at Upú Island (∼54°53′S–67°30′W), which reached levels of 365 μg STX eq.100 g⁻¹. A few days later, molluscs reached high PSP levels in other points of the channel and in February levels of 120,440 μg STX eq.100 g⁻¹ were detected by us in the mussels Mytilus edulis chilensis. The species identified in this toxic bloom was Alexandrium catenella. Since this exceptional outbreak, PSP toxin levels exceeding the safety limit have been detected every year, generally being recorded in spring and summer. In October, 2009, PSP levels increased in some harvesting areas, and in December, 2009 shellfish harvesting was banned along the entire Beagle Channel. Unlike previous years, many areas had to remain closed until winter 2010 due to an unusual persistence of toxicity in shellfish. A similar pattern was recorded the following year. Our findings suggest that the distribution pattern and seasonality of PSP toxicity of shellfish in the Beagle Channel are changing. The potential sanitary consequences call for a closer monitoring of this phenomenon.