Assessing environmental drivers of toxin-producing cyanobacteria and phytoplankton in Antarctic and sub-Antarctic waters

Abstract The interaction between climate change and anthropogenic activities in Antarctica is facilitating the invasion of temperate microorganisms into its aquatic ecosystems, including toxic species that could impact these ecosystems. This review aims to identify the toxic cyanobacteria and microalgae species detected thus far in sub-Antarctic and Antarctic waters and to explore long-term trends in key environmental parameters—such as temperature, salinity, chlorophyll-a concentrations, and dust deposition—in the areas where these species have been found. To date, five marine species ( Pseudo-nitzschia sp., Pseudo-nitzschia subcurvata , Alexandrium tamarense , Karenia papilionacea and Dinophysis spp.) and nine freshwater species ( Nostoc sp., Phormidium spp., Planktothrix sp., Anabaena sp., Anagnostidinema pseudacutissimum , Oscillatoria sp., Microcoleus autumnalis , Phormidesmis priestleyi , and Wilmottia murrayi ) have been identified as producing toxins and/or having the genes to potentially produce them. It is hypothesized that the environmental changes stemming from climate change and the increasing human presence in Antarctica will create conditions conducive to new invasions of toxic phytoplankton and cyanobacteria species, potentially resulting in harmful blooms with unpredictable consequences for Antarctic biota.