Microalgae at two pearl oyster farms in the Abrolhos Islands, Australia, and implications for an adductor muscle industry
Cropp, D.A.; Helleren, S.; Boschetti, P.; Davidson, M. (2025). Microalgae at two pearl oyster farms in the Abrolhos Islands, Australia, and implications for an adductor muscle industry. Asian Fish. Sci. 38(4): 223–235. https://dx.doi.org/10.33997/j.afs.2025.38.4.002
In: De Silva, S.S. Asian Fisheries Science. Asian Fisheries Society: Makati, Metro Manila. ISSN 0116-6514; e-ISSN 2073-3720, more
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| Keywords |
Aquatic communities > Plankton > Phytoplankton
Biotoxins
Monitoring
Sampling
Shellfish
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| Authors | | Top |
- Cropp, D.A.
- Helleren, S.
- Boschetti, P.
- Davidson, M.
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| Abstract |
The shellfish industry in Western Australia (WA) is expanding and, as part of the WA Shellfish Quality Assurance Program (WASQAP), microalgal populations need to be sampled. This is detailed in the WA Marine Biotoxin Monitoring and Management Plan (MBMMP) where alert levels for potentially toxic algae species have been set. The current research conducted water sampling over a 4-year period, from two pearl farms at the Abrolhos Islands, one near Rat Island and one near Pelsaert Island. Samples were Lugol preserved on-site and then analysed by Dalcon Environmental, Australia. Phytoplankton results included abundance data and percentage of the sample on all taxa, with mention of any potentially toxic microalgae. Only one sample revealed numbers of a potential toxin producer - (PTP, Pseudo-nitzschia “seriata” group H. Peragallo, 1900), above the alert level. Subsequent toxin analysis of frozen, flesh samples, taken on the same day, from cultured penguin pearl oysters, Pteria penguin (Röding, 1798), grown at the same site, were found to be negative for paralytic shellfish toxin (PST), amnesic shellfish toxin (AST), diarrhetic shellfish toxin (DST) and pectenotoxin-2 (PTX-2) by Symbio Labs in Sydney, NSW, Australia. Other phytoplankton sampling during this study, found very low levels of several other PTP’s but with no incidences exceeding the MBMMP alert levels. The difficulty in identifying PTP’s fully to species level and the variability in toxin production by closely related species poses significant challenges. Overall, there was some presence of potentially toxic microalgae in the Abrolhos Islands, with one incidence above alert levels. However, there was no evidence that biotoxins were present in the algae detected. |
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