OzFish launches bid to track Fleuriea Peninsula marine death reports amid toxic algae outbreak

A volunteer fishing group tracking grim reports along SA’s algae-hit coastline are pinpointing which creatures and areas appear to be suffering the worst.

A volunteer organisation has taken the lead in tracking more than 1500 reports of dead sea life, devastated by a “toxic blanket” in SA waters.

This new initiative comes as fresh fears have emerged for how a toxic algae bloom in the Fleurieu Peninsula could impact migrating whales and bring more sharks to shore.

More than 200 marine species have been recorded as dead due to a toxic algae bloom in South Australia. Picture: Supplied

More than 200 marine species have been recorded as dead due to a toxic algae bloom in South Australia. Picture: Supplied

Not-for-profit organisation OzFish has started a formal journal and monitoring project to map and identify the deaths of marine species around the state because of the algae bloom.

As of May 10, there had been 1632 observations reported since February, identifying 218 different species killed – the majority of reports in the Fleurieu Peninsula, and around Kangaroo Island.

Most of the dead animals are “sea floor species”, including crabs, pufferfish, and sharks living near the floor or reefs OzFish SA project manager Brad Martin said.

More than 200 marine species have been recorded as dead due to a toxic algae bloom in South Australia. Picture: Supplied

OzFish SA project manager Brad Martin is concerned about the ongoing marine deaths across the state. Picture: OzFish

“Many of the impacted creatures reside on reefs or hide in sand, and unfortunately, the sheer size of the algae bloom means that they can’t escape it,” he said.

Mr Martin said it would “take years for populations to recover” from the algae bloom.

“It acts like a toxic blanket that suffocates marine life,” he said.

“It can suffocate fish from their gills, cause haemorrhaging by attacking their red blood cells, and act as a neurotoxin and attack the fish’s nervous system and brain, causing unusual behaviour.

“This is why some fish and sharks are acting so strangely, and why many of the dead have a red tinge – it is like a horror movie for fish.”

OzFish encouraged anyone that spots dead sea life to photograph it make a report in the SA Marine Mortality events 2025 journal on iNaturalist.

Originally published as OzFish launches bid to track Fleuriea Peninsula marine death reports amid toxic algae outbreak