Wildlife Australia Magazine Spring 2025 Volume 62 Number 3 Edição anterior

FIRST WORD

How to handle SA’s deadly marine algal bloom

THE SOUTH AUSTRALIAN foreshore—about 500km of it—as fallen foul of a toxic and deadly algal bloom brought on by one of the many marine waters heatwaves circulating around Australia.

The Great Barrier Reef has again been impacted by widespread coral bleaching. Coral bleaching on the Western Australian reefs—ranging from Pilbara to Ningaloo—may be worse in its long-term impact, according to scientific observers.

But the algal bloom foreshore ‘invasion’ of SA is of a severity and scale that puts it on a new level of impact. People can see the devastating effects for themselves at their local beaches and favourite fishing spots.

More than 450 marine species have been washed up on SA coastlines, with over 14,000 observations recorded by citizen scientists. Underwater there are vast seascapes of dead and dying sea creatures.

The Biodiversity Council has succinctly described the event as, “man-made, inevitable, and likely to recur regularly without major action”.

The council’s expert group said the impacts would be far-reaching, and the bloom itself is just one consequence of the marine heatwaves ringing the country.

The Biodiversity Council said, “This event was foreseeable and even predicted … It is a human-mediated disaster—enabled by an extended marine heatwave, likely fed by a large pulse of nutrient-rich floodwater and coastal upwelling, and exacerbated by widespread loss of marine ecosystems that once provided natural water filtering and resilience against natural as well as human threats.”

The algal bloom is already being described by the Biodiversity Council as the marine equivalent of the Black Summer Bushfires, from which $200 million was allocated to wildlife recovery action. Does the algal bloom require similar support?

Read about plans to mitigate such an algal bloom happening again in this edition.