01-07-2025
South Australia's toxic algal bloom detected at West Lakes, Port River to be tested
The state government says preliminary samples show the toxic algal bloom that has been impacting parts of the South Australian coast has now been detected in West Lakes.
The toxic bloom has caused fish kills on the Fleurieu and Yorke peninsulas, Kangaroo Island and has recently also hit Adelaide's metropolitan beaches.
Dead fish and sea animals have been spotted on the shore from Sellicks Beach to North Haven, raising concerns for both local residents and authorities.
The Department for Environment and Water is now testing water from West Lakes and the Port River for the algae.
In a statement, the department said it had confirmed the presence of Karenia mikimotoi, the species of algae first detected on the Fleurieu Peninsula in March, in low levels in West Lakes.
The Port River is home to the Adelaide Dolphin Sanctuary, which is regularly monitored by the Environment Protection Authority (EPA).
The bloom has also been detected along the Spencer Gulf, Kangaroo Island, Troubridge Point on Yorke Peninsula, the Coorong's North Lagoon and along the coastline from Victor Harbor to Robe.
The department said it was also testing a dolphin carcass that was collected from Tennyson Beach on Monday.
It is also looking at a great white shark carcass from Port Broughton to determine if the bloom contributed to its death.
The bloom's impact has hit metropolitan Adelaide beaches, with locals capturing images of dead sharks and sea lions.
Scientists were hoping a drop in temperatures over winter would bring an end to the ecological disaster, which appeared after a range of environmental impacts hit the region, including water from the 2022/23 River Murray floods flowing into the Southern Ocean, followed by unseasonably cold and warm water.
But on Monday, Environment Minister Susan Close said she wanted to "prepare people" that the bloom was "not something that is likely to pass quickly" and "likely also to return at some point".
"We've seen the large mass of algae — the depth of some 20-metres and the size of Kangaroo Island — break up significantly," she said on Monday.
"But what's happened, is a lot of it has just been moved around into other parts of South Australian waters, including the metropolitan coast.
"This is of concern … because we're continuing to see marine life washing up dead on our coastline."
The government said the bloom was unlikely to dissipate quickly because an "ongoing marine heatwave" was continuing off SA's south coast.
Further complicating matters, Dr Close said, was that the species responsible for the bloom can drop to the seabed and survive if the conditions no longer suited it.
The department said the bloom occurred naturally and nothing could be done to dilute or dissipate it.
The bloom is considered non-toxic to humans, but can cause skin, eye and lung irritation.
