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Alexandrium tamarense Group I as the cause of PST on the east coast of Tasmania, Australia


Bolch, C and Harwood, T and Untari, L and Murray, S and Hallegraeff, G and Turnbull, A, Alexandrium tamarense Group I as the cause of PST on the east coast of Tasmania, Australia, The 16th International Conference on Harmful Algae Book of Abstracts, 27-31 October, Wellington, New Zealand, pp. 29. (2014) [Conference Extract]

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In October 2012 paralytic shellfish toxins (PST) were detected in shellfish on Tasmania's east coast resulting in widespread harvest closures of mussels, oysters, scallops, rock lobster and abalone over a period of six months along 350 km of coastline with total economic losses estimated at $23M. Phytoplankton sampling indicated Alexandrium tamarense as the likely source, a species not previously linked to PST in Australia because past recorded blooms were low-toxicity A. tamarense Group 5. More than 20 cultures were established from inshore and the continental shelf-edge locations. DNA sequence analysis (LSU-rDNA, rONA-ITS, STX synthetase SxtA1/A4) confirmed all isolates as toxic A. tamarense Group I, not previously known from Australasia. HPLC fluorescence analysis of PST showed a consistent profile dominated by C1/2 and GTX1/4, low proportions of NEO, C3/4, and traces of GTX2/3 and dcGTX2/3, with an 8-fold variation in STX content (8-65 fmol cell -1) among strains. Sequences of A. catenella Group IV were also recovered from seawater and shellfish samples indicating that multiple toxic Alexandrium genotypes may have contributed to the 2012 event. Cells of A. tamarense were detected again in early July 2013 resulting in widespread PST from Flinders Island (Bass Strait) and south to the Tasman Peninsula during winter-spring. The presence of G. catenatum and now at least three A. tamarense genotypes extend PST risk in Tasmania to year-round, presenting a major challenge for Tasmanian seafood assurance and HAB monitoring.

Item Details

Item Type:Conference Extract
Keywords:Alexandrium tamarense, biotoxin, PSP, DNA, Tasmania
Research Division:Biological Sciences
Research Group:Plant biology
Research Field:Phycology (incl. marine grasses)
Objective Division:Animal Production and Animal Primary Products
Objective Group:Fisheries - aquaculture
Objective Field:Fisheries - aquaculture not elsewhere classified
UTAS Author:Bolch, C (Associate Professor Christopher Bolch)
UTAS Author:Untari, L (Mrs Ludmilla Untari)
UTAS Author:Hallegraeff, G (Professor Gustaaf Hallegraeff)
ID Code:106251
Year Published:2014
Deposited By:IMAS Research and Education Centre
Deposited On:2016-02-03
Last Modified:2016-02-03
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