Floodwater, Heatwave Fueled SA's Catastrophic Algal Bloom Crisis, Report Finds

South Australia's devastating algal bloom crisis, which began in March 2025, has been attributed to a confluence of environmental factors, according to a long-awaited report from the SA government. The report, released after more than 18 months of uncertainty, identifies floodwater, a coastal upwelling, and a marine heatwave as the primary contributors to the marine event, emphasizing that there was no single trigger.

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We know from the beginning they [SA government] were too slow to act and asleep at the wheel.

The preliminary investigation by the South Australian Research and Development Institute (SARDI) was followed by an independent peer-review process. However, the report's release has been met with criticism. Greens senator Sarah Hanson-Young slammed the state government for its perceived lack of transparency and slow response, stating they were "asleep at the wheel" from the beginning and had tried to "downplay the impact."

Primary Industries Minister Clare Scriven defended the delay, explaining the report needed to undergo necessary processes, including peer review by independent experts from Tasmania and the United States. Conversely, ecologist Faith Coleman, who resigned from advisory committees earlier this year, argued that the peer-review process was unnecessary and took too long, suggesting the report should have been released much sooner. Despite these criticisms, Coleman welcomed the transparency and stated the findings would be useful going forward.

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It needed to go to the Algal Bloom Taskforce, and be analysed by my office and the taskforce.

The report details how the bloom intensified during an unprecedented marine heatwave. While the government highlights the findings as a step toward understanding the crisis, some, like Coleman, are calling for the release of more data to further inform future actions and prevent similar ecological disasters.

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It shouldn't have needed to gone off and spend all the time from April to now being peer-reviewed, that is a lot of months.