This year, South Australia experienced a devastating bloom of the toxic algae Karenia mikimotoi, killing marine life in Gulf St Vincent and parts of the Spencer Gulf. Professor Perran Cook explains that while algae are essential to marine food webs, harmful blooms occur when growth outpaces natural controls, often triggered by warm, still waters and excess nutrients. In this case, unusually high ocean temperatures, calm seas, and lingering nutrients from past floods and upwelling likely contributed. Karenia mikimotoi is particularly dangerous because it can both photosynthesise and feed on organic matter, including decaying fish it kills, creating a destructive feedback loop. Climate change is expected to increase the frequency and severity of such blooms by warming waters, altering weather patterns, and increasing nutrient runoff, making both climate mitigation and better nutrient management crucial.

Read the full Biodiversity Council article here: https://biodiversitycouncil.org.au/news/the-drivers-of-algal-blooms-in-australia