Occurrence and seasonal variations of algal toxins in water, phytoplankton and shellfish from North Stradbroke Island, Queensland, Australia

Abstract

A number of marine microalgae are known to produce toxins that can accumulate in shellfish and when eaten, lead to toxic and potentially fatal reactions in humans. This paper reports on the occurrence and seasonal variations of algal toxins in the waters, phytoplankton and shellfish of Southeast Queensland, Australia. These algal toxins include okadaic acid (OA), domoic acid (DA), gymnodimine (GD), pectenotoxin-2 (PTX-2) and pectenotoxin-2-seco acid (PTX-2-SA), which were detected in the sampled shellfish and phytoplankton, via HPLC-MS/MS. Dissolved OA, PTX-2 and GD were also detected in the samples collected from the water column. This was the first occasion that DA and GD have been reported in shellfish, phytoplankton and the water column in Queensland waters. Phytoplankton tows contained both the toxic Dinophysis and Pseudo-nitzschia algae species, and are suspected of being the most likely producers of the OA, PTX-2s and DA found in shellfish of this area. The number of cells, however, did not correlate with the amount of toxins present in either shellfish or phytoplankton. This indicates that toxin production by algae varies with time and the species present and that number of cells alone cannot be used as an indicator for the presence of toxins. The presence of OA and PTX-2s were more frequently seen in the summer, while DA and GD were detected throughout the year and without any obvious seasonal patterns.

Application of Solid Phase Adsorption Toxin Tracking (SPATT) for field detection of the hydrophilic phycotoxins domoic acid and saxitoxin in coastal California

“…We have demonstrated the successful application of HP20 for detection of the hydrophilic toxins DA and PST in the field, and previous studies have demonstrated its applicability for lipophilic toxins (Fux et al 2009;Fux et al 2008;Mackenzie et al 2004;Pizarro et al 2008aPizarro et al , 2008bRundberget et al 2007Rundberget et al , 2009Takahashi et al 2007;Turrell et al 2007). HP20 demonstrates characteristics that perhaps most closely imitate those of a mussel, i.e., a relatively low rate of accumulation (19% over 7 d) and a relatively higher rate of desorption.…”

“…Extraction of a field SPATT sample is comparatively lower in time and labor requirements. The SPATT extraction described here includes a three-step series of column elutions that can be completed within 10-30 min, yielding extracts that are available for immediate analysis of a single toxin or of multiple toxins, as demonstrated (e.g., DA or DA plus PST), We note that others have already demonstrated the ability to use HP20 for a suite of marine toxins (Fux et al 2008(Fux et al , 2009Mackenzie et al 2004;Pizarro et al 2008aPizarro et al , 2008bRundberget et al 2007Rundberget et al , 2009Takahashi et al 2007). The resin and extract are reasonably stable when stored at -80°C, providing the ability to archive samples for further analysis at a later time.…”

“…Here, as in preceding studies, SPATT is prescribed and evaluated as a monitoring technology for time-integrative detection of dissolved toxin (Mackenzie et al 2004;Mackenzie 2010;Pizarro et al 2008aPizarro et al , 2008bRundberget et al 2009;Takahashi et al 2007;Turrell et al 2007) and is assessed for its potential to provide "reliable, sensitive, time-integrated sampling to monitor the occurrence of toxic algal bloom events" (Mackenzie 2010). We evaluate the applicability of SPATT for the detection of DA in seawater, in both controlled-condition laboratory trials and coastal site field deployments.…”

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“…It is reported that correlation between Pseudonitzschia abundance and pDA concentration is not significant when the study area does not have sufficient water circulations (Takahashi et al, 2007;Schnetzer et al, 2007;Bargu et al, 2012). In the sampling area, if we consider the water circulations at stations FD5 and FD6, it is possible to say that unsuitable environmental conditions at the section UE may limit the growth of Pseudo-nitzschia species and also their toxin production.…”

Feasibility of gymnodimine and 13-desmethyl C spirolide detection by fluorescence polarization using a receptor-based assay in shellfish matrixes

“…Since their discovery in the early 1990s in New Zealand [2] and Canada [5], gymnodimines and spirolides have been demonstrated to have a global distribution. GYMs have been also detected in Tunisia [6] and Australia [7] Abbreviations: nAChR, nicotinic acetylcholine receptor; BSA, bovine serum albumin; ␣-BTX, ␣-bungarotoxin; FP, fluorescence polarization; GYM, gymnodimine; PBS, phosphate buffered saline; SPX, spirolide.…”