Recent Trends in Marine Phycotoxins from Australian Coastal Waters

Abstract

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.

A Review on the Biodiversity and Biogeography of Toxigenic Benthic Marine Dinoflagellates of the Coasts of Latin America

“…Palytoxins (PLTXs) are complex polyhydroxylated polyketides with both lipophilic and hydrophilic moieties ( Figure 5; Ramos and Vasconcelos, 2010); PLTX is considered to be among the most potent non-proteinaceous toxins, second only to MTX with respect to intraperitoneal toxicity in mice. Recently, members of the genus Ostreopsis have been found to produce PLTX, and almost 20 analogs are known to date (Ajani et al, 2017). Four structural sub-groups of these toxins have been defined: palytoxins, ostreocins, ovatoxins and mascarenotoxins (Tubaro et al, 2012), but toxigenicity of most individual analogs remains undetermined.…”

Amnesic Shellfish Poisoning (ASP) and Paralytic Shellfish Poisoning (PSP) in Nigerian Coast, Gulf of Guinea

“…Amnesic shellfish poisoning is symptomatic of a pathological loss of short-term memory, dizziness, loss of balance, headache, disorientation, nausea, and vomiting (Lucas et al, 2005) while sensational vibration of the perioral area, respiratory distress, frequent and excessive bowel movements, nausea, slow and continued increase in grave paralysis, spiky responsiveness of the fingertips, headache, dizziness, fever, ataxia, protem blindness and eventual death via respiratory paralysis are signs of PSP (Van Dolah, 2000;Kadiri, 2011;Trainer and Hardy, 2015;Ajani et al, 2017). Domoic acid which is responsible for ASP, is classified as tricarboxylic amino acid on the basis of chemical structure, while saxitoxin which causes PSP, is a purine-derived heterocyclic guanidine compound Zaccaroni and Scaravelli (2008).…”

“…They are both hydrophilic neurotoxic compounds affecting the exchange of information between the brain and the tendons (Arapov, 2013). Some effects of these toxins range from loss of short term memory to gastrointestinal disorders, diarrhea, vomiting, headache, abdominal cramps, loss of balance, nausea, dizziness, incomprehension and paralysis (Lucas et al, 2005;Ajani et al, 2017).…”

“…In the in-land and coastal Nigerian waters, just like other coastal areas in the world, variation in climate, pollution and eutrophication resulting from environmental changes can cause an upsurge in toxin amounts by indirect initiation of massive bloom of algae Ajani et al (2017), though Trainer and Hardy (2015) opined that they can also occur in pristine areas with little or no influence of nutrients input from anthropogenic activities. Shellfish transplantation and transportation of ballast water at the seaports can facilitate the in-flow of harmful/toxic, exotic species in and out of a country (Hallegraeff, 1998;Zhang and Dickman, 1999).…”

The Genus Alexandrium (Dinophyceae, Dinophyta) in Brazilian Coastal Waters

“…It has also been suggested that the higher number of blooms reported nowadays is a direct result of increased monitoring activities and the implementation of more sensitive tools to detect and prevent the negative effects of HABs worldwide, particularly in aquaculture areas (Anderson, 2007;Anderson et al, 2015). Both toxic and non-toxic blooms of Alexandrium species have been reported from distinct geographic regions, e.g., Japan (Kodama, 2010), Mediterranean Sea (Karydis and Kitsiou, 2012), China (Lu et al, 2014), Argentina Sea (Fabro et al, 2017), Australia (Ajani et al, 2017), and the Bering Sea (Natsuike et al, 2017).…”