New report reveals what triggered South Australia's worst algal bloom crisis

After more than 18 months of questions and concern, the South Australian government has released a long-awaited report about the state's worst algal bloom crisis ever. The report looked into what caused a massive growth of harmful algae in the ocean off South Australia's coast. Scientists found that three major things worked together to create the crisis — not just one single trigger.

The report was put together by the South Australian Research and Development Institute, also known as SARDI. Researchers found that floodwater, a coastal upwelling, and a marine heatwave all helped create the right conditions for the algae to grow. A coastal upwelling is when cold water from deep in the ocean rises up to the surface, bringing extra nutrients with it.

One important type of algae involved was called Karenia, a tiny sea organism that can be harmful to marine life. The report said that during the heatwave, the ocean water became very calm and still, with little wind mixing. These calm, warm conditions allowed the algae to spread quickly and grow out of control.

Scientists also said the bloom did not appear out of nowhere. Data going back many decades showed that the ocean had been building up toward these conditions over a long period of time. Professor Mike Steer, the executive director of SARDI, said understanding these long-term patterns is key to being ready in the future.

The report had been finished back in May, but it was only released to the public recently. This delay upset some people, including Greens Senator Sarah Hanson-Young. She said the South Australian government was 'too slow to act and asleep at the wheel' from the very beginning.

When asked about the delay, Primary Industries Minister Clare Scriven said the report needed to go through a careful review process first. She said it was checked by independent scientists from Tasmania and the United States. She said that process takes time to do properly.

However, ecologist Faith Coleman disagreed with the Minister's explanation. She had quit two government advisory groups earlier in the year and said the review should not have taken so long. Still, she said it was good that the report was finally made public.

Dr. Coleman also asked the government to share more data with the public. She said the report only focused on Karenia and did not look at other harmful algae species in the water. She also wants officials to rethink how much blame they placed on the Murray River, saying it could affect how Australia manages one of its most important waterways.

Professor Steer admitted that there are still gaps in what scientists know about the bloom. He said that answering one question in science often leads to ten more new questions. But he said the report gives researchers a strong starting point to keep studying the problem.

Going forward, scientists plan to study the chemicals produced by harmful algae and how blooms affect fishing and marine ecosystems. Professor Steer said the crisis and this report will help set an example for how to handle similar events in the future. 'Our focus now is on improving our science and understanding it so we're better prepared in the future,' he said.