Recent Trends in Marine Phycotoxins from Australian Coastal Waters

Phycotoxins, which are produced by harmful microalgae and bioaccumulate in the marine food web, are of growing concern for Australia. These harmful algae pose a threat to ecosystem and human health, as well as constraining the progress of aquaculture, one of the fastest growing food sectors in the world. With better monitoring, advanced analytical skills and an increase in microalgal expertise, many phycotoxins have been identified in Australian coastal waters in recent years. The most concerning of these toxins are ciguatoxin, paralytic shellfish toxins, okadaic acid and domoic acid, with palytoxin and karlotoxin increasing in significance. The potential for tetrodotoxin, maitotoxin and palytoxin to contaminate seafood is also of concern, warranting future investigation. The largest and most significant toxic bloom in Tasmania in 2012 resulted in an estimated total economic loss of ~AUD$23M, indicating that there is an imperative to improve toxin and organism detection methods, clarify the toxin profiles of species of phytoplankton and carry out both intra- and inter-species toxicity comparisons. Future work also includes the application of rapid, real-time molecular assays for the detection of harmful species and toxin genes. This information, in conjunction with a better understanding of the life histories and ecology of harmful bloom species, may lead to more appropriate management of environmental, health and economic resources.