Calls are growing for immediate federal support and intervention in SA's algae crisis, as fishing and tourism industries struggle with the impact of a months-long bloom with no end in sight.
The naturally occurring algal bloom has killed tens of thousands of marine animals of almost 400 species and caused widespread disruption to commercial fisheries and aquaculture since being identified off the Fleurieu Peninsula in March.
SA senator Sarah Hanson-Young said the algal bloom was a national disaster requiring a national response, calling on Prime Minister Anthony Albanese "to come to Adelaide to stand on the beaches with me and to take some action".
"People are seeing dead fish and marine life washed up on our metro and country beaches every day, people are reporting their dogs are getting sick after walking along the beach," the Greens senator said on Wednesday.
Australian Climate and Biodiversity Foundation chair Ken Henry said the massive destruction of marine life was "not an early warning, that's a late warning".
"It's well past time that we and others in the world dealt properly with threats of climate change and the warming of the oceans, which ... lies at the heart of the catastrophe that's occurring (in SA)," Dr Henry told the National Press Club in Canberra on Wednesday.
On Tuesday, SA Environment Minister Susan Close said the bloom was a natural disaster but it did not fit the criteria of the National Natural Disaster Arrangements.
The state government was working with the federal government on ways to tackle it, she said.
A fisheries patrol vessel began underwater observations in the Gulf of St Vincent on Wednesday to understand the effect of the bloom on the ecosystem.
Opposition primary industries spokeswoman Nicola Centofanti said she was shocked the government waited almost four months to start monitoring the impact on marine life.
The algal bloom has spread along the SA coastline to the upper Spencer Gulf, the north coast of Kangaroo Island, the Fleurieu Peninsula, the Coorong and Adelaide's Port River.
Toxins linked to the bloom have been found in oysters and mussels at Port Lincoln, and harvesting at local farms has been halted for at least four weeks.
Senator Hanson-Young hosted a community forum in Adelaide on Tuesday attended by hundreds of people, and will call for a parliamentary inquiry into the algal bloom when federal parliament returns next week.
