Algal bloom turns coast into a 'marine graveyard'
The microalgae, karenia mikimotoi, was identified off South Australia's Fleurieu Peninsula in March.
The bloom grew to an unprecedented scale, close to the size of Kangaroo Island, at more than 4400 sq km, and as deep as 25m.
It's now breaking up and has spread into most of Gulf St Vincent, including along Adelaide's beaches and south into the Coorong wetlands.
There have been hundreds of reports of marine deaths, ranging from sharks and penguins to popular fishing species such as flathead, squid, crabs, and rock lobsters.
Greens senator Sarah Hanson-Young said the bloom was a horrific and heartbreaking "environmental catastrophe".
"When parliament resumes in two weeks time in Canberra, I will be moving for a federal parliamentary inquiry," she told reporters on Friday.
"We need proper investigation and proper federal support."
Beaches have become "graveyards" for marine species, and the fishing and tourism industries have been significantly impacted, she said.
Ms Hanson-Young claimed the federal government ignored warnings about the algae before it took hold.
"It is very concerning that the country's leading marine scientists have been ignored and dismissed," she said.
Experts believe there are three potential plausible contributing factors causing the bloom, the SA government said.
One is a marine heatwave that started in September 2024, with sea temperatures about 2.5°C warmer than usual, combined with calm conditions, light winds and small swells.
Another is the 2022-23 River Murray flood washing extra nutrients into the sea and an unprecedented cold-water upwelling in summer 2023-24 that brought nutrient-rich water to the surface.
SA Environment Minister Susan Close said the bloom had lasted longer than experts thought it would.
"Now that it's here, it's going to be hard to get rid of," she said.
"It's easy to feel helpless, because the bloom itself is something that we can't stop."
The SA government met with impacted commercial fishers, tourism operators and local councils about support packages.
"It's been very, very distressing for people, and it's affected people's livelihoods," Ms Close said.
The state government is also starting work on a recovery plan.
This could include creating artificial reefs to help build up marine life, restocking fish into the ocean and increasing the number of marine sanctuary zones along the coast.
"Although we're looking forward to the end of this experience, we cannot assume it's the last time we've had it," Ms Close said.
Karenia mikimotoi is in SA's waterways and waiting to come back to life when conditions are right, she said.
"This is what climate change means."
OzFish previously said more than 200 species of fish, sharks and other marine creatures had been killed by the algae bloom.
This includes rarely encountered deepwater sharks and leafy sea dragons, and recreational fishing species like flathead, squid, crabs, and rock lobsters.
Karenia mikimotoi is toxic to fish and invertebrates but does not cause long-term harmful effects in humans.
But, exposure to discoloured or foamy water can cause short-term skin or eye irritation and respiratory symptoms, including coughing or shortness of breath.
The last large event of this type of algae recorded in SA was at Coffin Bay in 2014.
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CNN
26-07-2025
- CNN
Toxic algae are turning South Australia's coral reefs into underwater graveyards – and there's no end in sight
OceaniaFacebookTweetLink Follow What struck Scott Bennett most were the razor clams. The long saltwater clams, resembling old-fashioned razors, normally burrow into sand to avoid predators. But when Bennett, an ecologist, visited South Australia's Great Southern Reef last month, he saw thousands of them rotting on the sea floor. '100% of them were dead and wasting away on the bottom,' Bennett told CNN. Since March, a harmful algal bloom, fueled by a marine heat wave, has been choking South Australia's coastline, turning once-colorful ecosystems filled with thriving marine life into underwater graveyards. The bloom has killed about 15,000 animals from over 450 species, according to observations on the citizen science site iNaturalist. They include longfinned worm eels, surf crabs, warty prowfish, leafy seadragons, hairy mussels and common bottlenose dolphins. The algae have poisoned more than 4,500 square kilometers (1,737 square miles) of the state's waters – an area larger than Rhode Island – littering beaches with carcasses and ravaging an area known for its diversity. It's 'one of the worst marine disasters in living memory,' according to a report by the Biodiversity Council, an independent expert group founded by 11 Australian universities. The toxic algal bloom has devastated South Australia's fishing industry and repelled beachgoers, serving as a stark warning of what happens when climate change goes unchecked. Once a bloom begins, there is no way of stopping it. 'This shouldn't be treated as an isolated event,' Bennett said. 'This is symptomatic of climate driven impacts that we're seeing across Australia due to climate change.' It all started back in March, when dozens of surfers at beaches outside Gulf St Vincent, about an hour south of state capital Adelaide, reported experiencing a sore throat, dry cough and blurred vision after emerging from the sea. Shortly after, a mysterious yellow foam appeared in the surf. Then, dead marine animals started washing up. Scientists at the University of Technology Sydney soon confirmed the culprit: a buildup of a tiny planktonic algae called Karenia mikimotoi. And it was spreading. In early May, the government of Kangaroo Island, a popular eco-tourism destination, said the algal bloom had reached its coastline. A storm at the end of May pushed the algae down the coast into the Coorong lagoon. By July, it had reached the beaches of Adelaide. Diverse algae are essential to healthy marine ecosystems, converting carbon dioxide into oxygen and benefiting organisms all the way up the food chain, from sea sponges and crabs to whales. But too much of one specific type of algae can be toxic, causing a harmful algal bloom, also sometimes known as a red tide. While Karenia mikimotoi does not cause long-term harm to humans, it can damage the gills of fish and shellfish, preventing them from breathing. Algal blooms can also cause discoloration in the water and block sunlight from coming in, harming ecosystems. The Great Southern Reef is a haven for 'really unique' biodiversity, said Bennett, a researcher at the University of Tasmania, who coined the name for the interconnected reef system which spans Australia's south coast. About 70% of the species that live there are endemic to the area, he said, meaning they are found nowhere else in the world. 'For these species, once they're gone, they're gone.' Nathan Eatts hasn't caught a single squid since April. On a good day, Eatts could catch 100 in the waters where he's fished commercially for 15 years off South Australia's Fleurieu Peninsula. Since the harmful algal bloom began, his business, Cape Calamari, has gone 'pretty much down to zero,' Eatts said. While more mobile fish can move to cleaner waters during an algal bloom, invertebrates like shellfish and sea stars, and other species associated with the reef, are suffocated by toxic algae. 'We don't know whether they've all died, or they're just seeking refuge in deeper water, waiting for it all to clear,' he said. Many fishers have lost their livelihoods overnight, with about a third of the state waters completely devoid of fish, according to Pat Tripodi, the executive officer of the Marine Fishers Association, which represents the interests of most commercial fishing license holders in the state. 'Wherever the algal bloom hits, there is zero life,' Tripodi said. 'It's a really high emotional and mental strain on these individuals, because many of them don't know how or if they will ever recover from it.' Beyond the fishers themselves, the bloom is having a knock-on effect on the state's seafood industry, which is valued at almost 480 million Australian dollars ($315 million). Seafood processors, transport companies, grocers and restaurants are all feeling the pain, Tripodi said. Eatts comes from a long line of fishers, and they've never seen anything like this. The last time a harmful agal bloom swept South Australia was in 2014, but it was much more localized. Toxic algal blooms are naturally occurring and are common around the world, including in the US. But climate change is making them more frequent and more severe. The foundation for the South Australian bloom was laid back in 2022, experts believe, when catastrophic flooding swept the Murray, Australia's longest river, washing extra nutrients into the Southern Ocean. The next summer, currents brought nutrient-rich water to the surface in a process called cold water upwelling. Then, a marine heatwave in September 2024 caused ocean temperatures to be about 2.5 degrees Celsius warmer than usual. That, combined with calm water conditions and light wind created conditions for the algae to grow and spread. There is no way for humans to stop a harmful algal bloom – its trajectory largely depends on natural factors like wind and weather patterns. Peter Malinauskas, South Australia's premier, told public broadcaster the ABC on Tuesday that the crisis is a 'natural disaster, but it's different to ones that we're familiar with in Australia.' 'With a bushfire, you can put the fire out. If there's a flood, you can do the modeling to have a sense of where the water is going to go, whereas this is so entirely unprecedented. We don't really know how it's going to play out over coming weeks and months ahead.' This week, Prime Minister Anthony Albanese's government announced a support package of 14 million Australian dollars ($9.2 million), which has been matched by the state, to help with the cleanup and economic fallout from the ecological crisis. But Canberra stopped short of calling it a natural disaster, a declaration which would have unlocked additional funding. As extreme heat events become more common around the world, Bennett said the government needs to do more to prevent and protect against future algal blooms – first and foremost by cutting carbon emissions. Marine ecosystems can be 'resilient,' Bennett said. But he added that Australia must protect habitats, such as kelp forests, seagrass meadows, and oyster reefs, which absorb excess nutrients and keep the oceans healthy. Eatts, the calamari fisher, said it 'hits home hard' to see South Australia's natural beauty spoiled by this crisis. The other day, he saw a dead dolphin on his local beach. 'You take it for granted where you live and what you see on a daily basis,' he said. 'But it takes one event of nature like this to come through, and it breaks your heart watching it unfold.'
Yahoo
24-07-2025
- Yahoo
500km Australian toxic crisis triggers release of seven-point plan: 'Nowhere is safe'
As the worst Australian algal bloom in recorded history continues to kill almost everything in its path across 500km of coastline, the nation's top experts have released a seven-point plan to deal with the problem. With extreme events like this expected to occur not just in South Australia but around the country as climate change worsens, the Biodiversity Council – an independent expert group founded by 11 universities – has created a plan to protect tourism and fishing jobs as well as the environment. One of the plan's authors, Dr Scott Bennet, from the University of Tasmania Institute of Marine and Antarctic Studies, warned that 'sadly, nowhere is safe' from marine heatwaves. 'We don't see this as an isolated event. This is symptomatic of broader climate change and marine heatwave impacts that are happening around the country,' he told Yahoo News. 'Until this event, South Australia had been relatively immune, and it was an area of least concern. All the ingredients are in these other places for similar events to happen, and they have happened on the east and west coasts, just at a smaller scale.' What is the seven-point plan? The seven-point plan is contained within a new report, Key actions needed to respond to South Australia's catastrophic toxic algal bloom, and the recommendations are: 1. Investigate and fast-track emergency interventions for species at high risk of extinction or major population declines. 2. Immediately invest a minimum of $10 million to start research to understand the impact of this bloom and inform plans for what to do when the next bloom hits. 3. Accelerate Australia's decarbonisation efforts and become a global leader in climate action. 4. Reduce nutrient and dissolved carbon pollution. 5. Restore and protect marine ecosystems. 6. Establish a long-term monitoring program for the Great Southern Reef 7. Establish mechanisms to plan for and respond to catastrophic natural disasters Key sign algal bloom is now fuelling itself The scale of the karenia mikimotoi algal bloom is associated with events linked to climate change. The first was the flooding of the Murray River, which resulted in nutrient-rich water entering the Southern Ocean in 2022/2023. The second was a cold upswelling that drew this runoff to the surface. And the third was a marine heatwave that began in September, 2024. It was in March, 2025 that dying fish began to be documented, and a group of beachgoers reported feeling sick. Since then, more than 14,000 observations of dead marine species have been recorded, and 450 species have been impacted. Some, like the giant cuttlefish and leafy seadragon, have restricted ranges, and their long-term future is in doubt. 'We did initial surveys at a couple of sites that were known as good "leafy" sites, but we didn't see any,' Bennett said. 'They're only found in southern Australia, so if we lose these local populations, that's most of the species' distribution. And once they're gone, they're gone, we can't bring them back.' The problem is greatest when you look under the surface of the ocean, as report author and Biodiversity Council member Professor Gretta Pecl explained. 'Looking at the footage under the water, it's absolute devastation. What's turning up on beaches in South Australia is only the tip of the iceberg. There are dead bodies lying everywhere, decaying,' she said. Bennett added that because everything across the ecosystem has been impacted, there's nothing to feed on the bodies of dead organisms. 'There's an idea now that the bloom is fueling itself… the dead stuff is just decomposing, and all those nutrients are then recycling back into the system,' he said. It had been hoped the problem would dissipate over winter as the air temperature cooled, but this has not occurred. Now the winter solstice has passed, and the weather is warming again. Calls for Albanese Government to declare a disaster While the Albanese Government has committed $14 million to help South Australia respond to the problem, Environment Minister Murray Watt has said he's not able to officially declare the situation a Natural Disaster. The Malinauskas state government has connected the bloom to climate change and voiced concerns the problem will occur again. It is understood to have spoken to the Commonwealth about updating the 2018 Disaster Recovery Funding Arrangements, so future blooms can be declared Natural Disasters like floods or bushfires, streamlining the process for securing federal funding. Greens senator Sarah Hanson-Young has called for the Albanese Government to declare the situation a 'national disaster', referencing the National Emergency Declaration laws that were introduced in 2020. This was activated once before in 2022, when flooding along Australia's east coast killed 26 people and displaced thousands. It would need to be declared by the Governor General at the request of the Prime Minister, and it would open up significant emergency management resources to tackle the problem. Yahoo has asked Minister Watt's office if he has broached this idea with Albanese, but it has yet to respond. In a statement, a Commonwealth government spokesperson said the response was the 'primary responsibility' of the South Australian government, but it would support its efforts. 'The health and resilience of Australia's ocean is a high priority for the Albanese Government. We are deeply concerned by the widespread marine species mortalities caused by this extreme event,' it said. Marine heatwave bigger than South Australia Pecl, who is also a professor at the University of Tasmania, said she believes the response from government should match the scale of the impact and the risk. 'For example, when we had the massive Black Summer bushfires, there was $2 billion in the national bushfire recovery fund, including a $200 million response for wildlife,' she said. The marine heatwave isn't just isolated to South Australia, the problem has been detected all around Australia's coastline, killing up to 80 per cent of corals in one surveyed region in Western Australia, and bleaching reefs on the east coast at the same time. 'Scientists have been banging on about this for 30 years now, so it's not a surprise to us. These patterns are entirely consistent with what we thought would happen. They are a very strong indication of exactly the magnitude of the challenges we'll face in the future,' Pecl said. Addressing whether Australia is doing enough to slow climate change, her response was blunt. 'I can conclusively say that whatever we're doing is not enough,' she said. Love Australia's weird and wonderful environment? 🐊🦘😳 Get our new newsletter showcasing the week's best stories.
Bloomberg
21-07-2025
- Bloomberg
Australia's Growing Algal Crisis in South Devastates Marine Life
Australia's government has unveiled an assistance package of at least A$14 million ($9.1 million) to help tackle a growing algal bloom crisis off the southern coast that's killing marine life and damaging regional fisheries. Environment Minister Murray Watt announced the funding package in the southern city of Adelaide on Monday after inspecting the damage. He described the unfolding natural disaster as 'a very serious event.'
