Occurrence and seasonal variations of algal toxins in water, phytoplankton and shellfish from North Stradbroke Island, Queensland, Australia
Introduction
Toxic shellfish poisonings occur when algal toxins are transferred through the food chain to higher trophic levels, including humans. Diarrhetic shellfish poisoning (DSP), named after the human symptom of gastroenteritis, is one such example (Yasumoto et al., 1987, Carmody, 1996, Fernandez et al., 2006). Within DSP, there are lipophilic group of toxins: okadaic acid (OA), dinophysis toxins (DTXs) and pectenotoxins (PTXs), which are produced by dinoflagellates (Yasumoto et al., 1987, Yasumoto and Murata, 1990, Draisci et al., 1996, James et al., 1999, Fernandez et al., 2006). These toxins are harmful to humans and pose a serious threat to aquaculture industries (Fernandez, 2000). The OA group is responsible for causing diarrhoea, inhibiting protein-phosphatase enzymes and has the potential to be a tumour promoter (Fujiki, 1990, Creppy et al., 2002). Although, PTXs do not cause such diarrhoea related illnesses, they were formally placed into this group since they are commonly found with the OA (Fernandez, 2000, Creppy et al., 2002, Miles et al., 2004). To date, no records of OA have been recorded in the waters around Southeast Queensland.
Domoic acid (DA) is a toxin produced by diatoms from the genus Pseudo-nitzschia, and is known to cause amnesic shellfish poisoning (ASP) (Van Dolah, 2000, Jeffery et al., 2004). Toxic reactions to DA in humans include abdominal cramps, vomiting, diarrhoea, disorientation, short term memory loss and even death (Perl et al., 1990). It has been documented to affect, not only humans, but marine organisms such as marine mammals and sea birds (Lefebvre et al., 1999, Gulland et al., 2002, Shumway et al., 2003). Although, DA has been detected in Australia, there has not been any reported incidences of ASP in Australia (Lapworth et al., 2000).
Gymnodimine (GD) was first detected in New Zealand in 1994 (Seki et al., 1995, Stirling, 2001). This toxin is a compound produced by dinoflagellates from the genus Karenia, with Karenia selliforme being associated with the toxin in New Zealand (Seki et al., 1995, Mackenzie and Beuzenberg, 2003). Although, this compound has low toxicity when introduced orally, it is a fast acting toxin when it is injected intraperitoneally (ip) into mice (Stirling, 2001). Due to its high potency when injected into mice, GD can cause Type I errors (false positive) during mouse bioassays designed to test for paralytic and neurotoxic shellfish poisoning (Seki et al., 1995).
This study assesses the occurrence and seasonal variations of marine algal toxins in shellfish and phytoplankton collected from waters around North Stradbroke Island, located in Moreton Bay, southeastern Queensland. The waters around the island yield a variety of shellfish, some of which are consumed by the locals and sold to the public by oyster lease owners. Although, there have been no reported incidences of algal toxin poisoning around the study sites, algal blooms have been observed around the island (Osborne et al., 2001). The work presented here provides information in qualifying and quantifying the potential hazard posed by endemic forms of marine algal toxin to the consumers of the shellfish caught in these waters. In this study, OA, DA, PTX-2s and GD were detected from the sampling sites, and their exposure to the consumers was estimated.
Section snippets
Sample collection
Sampling for this study was conducted monthly for 24 consecutive months from July 2003 to June 2005, in Moreton Bay, on the east-coast of Australia (27°15 S, 153°15E) (Fig. 1). Moreton Bay is a sub-tropical, shallow coastal embayment (1.5 × 103 km2) bordered by sand barrier islands to the east (Moreton Island and North and South Stradbroke Islands). A total of six sampling sites were selected for shellfish collection and phytoplankton tows, three within Moreton Bay and three along the exposed beach
Species identification
The occurrence of Dinophysis and Pseudo-nitzschia are plotted in Fig. 2a and b. These plots indicate that Dinophysis genus was present during the warmer months and was more prominent in the open beaches than in the bay. D. caudata was more abundant in November and January 2004, with the highest concentration of 15 cells l−1 recorded from the open beaches. D. acuminata was also present between November 2004 and January 2005, and only seen on the open beaches (data not shown).
Pseudo-nitzschia, was
Discussion
The Dinophysis detected around the North Stradbroke Island were most abundant during the warmer months and thereby, displayed similar trends to other members of this genus found in other geographical locations (Hallegraeff, 2002). In this study, D. acuminata was only detected in the second year of sampling, and they were only found in late spring and summer. Similar trends were seen in Portugal, where, the presence of D. acuminata are assumed to be related to organic nutrients (Vale and
Acknowledgements
National Research Centre for Environmental Studies is funded by State of Queensland – Queensland Health, Griffith University, The University of Queensland and Queensland University of Technology. We thank the staff at Centre for Microscopy and Microanalysis at UQ and Dr. Gustaaf Hallegraeff for the TEM analysis. The DNA probe analysis for Karenia selliformis were conducted by Cawthron Institute. We also thank Lincoln MacKenzie at Cawthron Institute for kindly providing the SPATT bags.
References (53)
- et al.
Recent advances in the study of epigenetic effects induced by the phycotoxin okadaic acid
Toxicology
(2002) - et al.
First report of pectenotoxin-2 (PTX-2) in algae (Dinophysis fortii) related to seafood poisoning in Europe
Toxicon
(1996) - et al.
Ecological characterization of toxic phytoplankton species (Dinophysis spp., Dinophyceae) in Slovenian mariculture areas (Gulf of Trieste, Adriatic Sea) and the implications for monitoring
Marine Poll. Bull.
(2006) Harmful algal blooms in the Australian region
Marine Poll. Bull.
(1992)- et al.
Efficient isolation of the rate diarrhoeic shellfish toxin, dinophysistoxin-2, from marine phytoplankton
Toxicon
(1999) - et al.
Amnesic shellfish poison – Review
Food Chem. Toxicol.
(2004) - et al.
Occurrence of okadaic acid-producing Prorocentrum lima on the Sanriku coast, northern Japan
Toxicon
(1998) - et al.
Solid phase adsorption toxin tsracking (SPATT): a new monitoring tool that simulates the biotoxin contamination of filter feeding bivalves
Toxicon
(2004) - et al.
Complex toxin profiles in phytoplankton and Greenshell mussels (Perna canaliculus), revealed by LC-MS/MS analysis
Toxicon
(2002) - et al.
Diarrhetic shellfish poisoning (DSP) toxins in South Australian shellfish
Harmful Algae
(2006)
Isolation of pectenotoxin-2 from Dinophysis acuta and its conversion to pectenotoxin-2 seco acid and preliminary assessment of their acute toxicities
Toxicon
Domoic acid: a fascinating marine toxin
Environ. Toxicol. Pharmacol.
The toxins of Lyngbya majuscula and their human and ecological health effects
Environ. Int.
Gymnodimine, a new marine toxin of unprecendented structure isolated from New Zealand oysters and the dinoflagellate, Gymnodinium sp
Tetrahedron Lett.
Marine birds and harmful algal blooms: sporadic victims or under-reported events?
Harmful Algae
Okadaic acid production from the marine benthic dinoflagellate Prorocentrum arenarium Faust (Dinophyceae) isolated from Europa Island coral reef ecosystem (SW Indian Ocean)
Toxicon
Joint FAO/WHO/IOC activities to provide scientific advice on marine biotoxins (Research Report)
Marine Poll. Bull.
Differential dynamics of dinophysistoxins and pectenotoxins, part II: offshore bivalve species
Toxicon
Seasonality of diarrhetic shellfish poisoning at a coastal lagoon in Portugal: rainfall patterns and folk wisdom
Toxicon
Controls of domoic acid production by the diatom Nitzschia pungens f. multiseries in culture: Nutrients and irradiance
Can. J. Fish Aquat. Sci.
Dinophysistoxin-2: The predominant diarrhoetic shellfish toxin in Ireland
Toxicon
Domoic acid production by Pseudo-nitzschia seriata (Bacillariophyceae) in Scottish waters
J. Phycol.
Pectenotoxin-2 in single-cell isolates of Dinophysis caudata and Dinophysis acuta from the Galician Rias (NW Spain)
Toxicon
Regulations for marine microalgal toxins: Towards harmonization of methods and limits
S. Afr. J. Marine Sci.
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Present address: National Research Centre for Environmental Toxicology, 39 Kessels Road, Coopers Plains, QLD 4108, Australia.