Field Validation of the Southern Rock Lobster Paralytic Shellfish Toxin Monitoring Program in Tasmania, Australia

Abstract

Paralytic shellfish toxins (PST) are found in the hepatopancreas of Southern Rock Lobster Jasus edwardsii from the east coast of Tasmania in association with blooms of the toxic dinoflagellate Alexandrium catenella. Tasmania’s rock lobster fishery is one of the state’s most important wild capture fisheries, supporting a significant commercial industry (AUD 97M) and recreational fishing sector. A comprehensive 8 years of field data collected across multiple sites has allowed continued improvements to the risk management program protecting public health and market access for the Tasmanian lobster fishery. High variability was seen in toxin levels between individuals, sites, months, and years. The highest risk sites were those on the central east coast, with July to January identified as the most at-risk months. Relatively high uptake rates were observed (exponential rate of 2% per day), similar to filter-feeding mussels, and meant that lobster accumulated toxins quickly. Similarly, lobsters were relatively fast detoxifiers, losing up to 3% PST per day, following bloom demise. Mussel sentinel lines were effective in indicating a risk of elevated PST in lobster hepatopancreas, with annual baseline monitoring costing approximately 0.06% of the industry value. In addition, it was determined that if the mean hepatopancreas PST levels in five individual lobsters from a site were <0.22 mg STX equiv. kg−1, there is a 97.5% probability that any lobster from that site would be below the bivalve maximum level of 0.8 mg STX equiv. kg−1. The combination of using a sentinel species to identify risk areas and sampling five individual lobsters at a particular site, provides a cost-effective strategy for managing PST risk in the Tasmanian commercial lobster fishery.

Contamination Status and Risk Assessment of Paralytic Shellfish Toxins in Shellfish along the Coastal Areas of China

“…Furthermore, differences in the rate of filter-feeding and the uptake of toxic algal cells by different shellfish can also lead to variations in the toxicity of PSTs in different shellfish. Mussels accumulate toxins quickly as a result of their high filtration rate during feeding [48]. Clams (80 µg per 100 g) have been reported to present a significantly lower rate of accumulation and maximum load of PSTs following exposure to A. tamarense when compared with mussels (1100 µg per 100 g), and the main toxin detected was C1/2 [49].…”