The Predicted Impact of Climate Change on Toxic Algal (Cyanobacterial) Blooms and Toxin Production in Queensland

Research on proposed global climate change in Australia has highlighted changes that will influence both the human and natural environments. To date, however, no estimates of the effects of climate change on public health aspects of toxic freshwater algae have been performed. The aim of this article is to review and discuss the proposed outcomes of climate change and how they might affect cyanobacterial (blue-green algal) proliferation and toxin production in Queensland. Factors such as increased temperatures, the trend towards more El-Nino like conditions, and increased intensity of the heaviest rainfall events have been interpreted in terms of effects on cyanobacteria in water reservoirs. This information has then been evaluated in terms of potential public health effects. It is predicted that changes in climatic factors might enhance the levels of cyanobacteria, extend their season, and cause a change in distribution to favour the more tropical species, Cylindrospermopsis raciborskii on a state and nation-wide basis. Public health implications exist both for drinking water containing cyanotoxins and recreational exposure to cyanobacteria in water reservoirs. The toxins produced by the cyanobacteria considered in this study are hepatotoxins and neurotoxins and in some cases these might be present at levels that are well in excess of proposed guideline values.