An ecological disaster has been unfolding on Australia's coast

Australia Broadcast Center

23-05-2025

A mysterious, brown foam appeared on a beach an hour south of Adelaide. It was just the beginning of a toxic algal bloom that has now grown to thousands of square kilometres in size, killing precious sea life in its wake. Experts say it could be a sign of things to come.
Waitpinga Beach is popular with surfers and nature lovers. ( ABC News: Che Chorley )
The breathtaking coastline of Waitpinga Beach — known as "Waits" to locals — is famed for its strong swells and rugged hills.
Anthony Rowland first reported the situation to authorities in March. ( ABC News: Che Chorley )
But Waitpinga quite literally took Anthony Rowland's breath away, when he found himself in the middle of a toxic algal bloom not yet visible to the human eye.
Anthony Rowland says he has an "addiction" to the ocean. ( ABC News: Che Chorley )
In the early hours of Saturday, March 15, Mr Rowland went to Waits with some friends.
Shortly after arriving, he began to feel sick.
Anthony Rowland said he began to worry when he saw other people coughing after being near the sea. ( ABC News: Che Chorley )
"I did notice when I was walking down the steps that I felt like … maybe I've got a flu coming on," he recalled.
"You know, just your taste is a little bit off. But didn't think anything of it."
The water was glistening as usual, and as the sun rose more people arrived to catch a wave.
But it wasn't long before he and his friends started coughing, and when they returned to their cars, other beachgoers were experiencing the same symptoms.
Anthony Rowland said he felt as though authorities did not take his initial reports seriously. ( ABC News: Che Chorley )
"I started looking around, it was quite a busy car park and I noticed like these guys were coughing, they were coughing, everyone was coughing here and there, and I was like, 'alright, something's really not right here'…" he said.
Mr Rowland has become a keen citizen scientist, providing images and updates for the local community. ( ABC News: Che Chorley )
He took to social media to share his experience, and realised dozens of others, including those who hadn't been in the water, were also reporting coughs, sore throats and stinging eyes.
One surfer said his vision was impacted so badly it was like he was "looking through the end of two Coke bottles".
Mr Rowland reported the matter to authorities, but felt like no-one was taking him seriously.
The next day, a brown foam appeared at Waitpinga Beach, as well as a handful of dead leafy sea dragons.
A foam build up on Waitpinga Beach photographed on March 17, 2025. ( ABC News: Caroline Horn )
On Monday, Mr Rowland returned to the beach with ABC reporter Caroline Horn to find the foam "five times worse" as well as scores of dead sea creatures.
"Every lineal metre, there was at least five or six [dead] fish," he said.
By that afternoon, authorities closed both Waitpinga and Parsons beaches to investigate whether a "fish mortality event" had occurred and warned people not to swim.
Mr Rowland did not know it yet, but he and other beachgoers had come into contact with an algal bloom called Karenia mikimotoi , which can be lethal to sea life, and cause flu-like symptoms in humans.
Marine biologist and UTS researcher Shauna Murray said the bloom was a type of marine phytoplankton, which could not always be seen.
Karenia mikimotoi under the microscope. ( Supplied: Faith Coleman )
"So, they're not visible as cells to the naked eye, but you can see the colouring, so when they're extremely abundant you can see a sort of slight … water discolouration that is reddy, brown … but not always," she said.
"It depends on the density of the bloom at the time."
Ongoing marine heatwave to blame
Professor Murray said marine phytoplankton was a crucial part of the ecosystem, producing up to half the oxygen in the earth's atmosphere.
She said only a small percentage of the more than 100,000 different species of microalgae were toxic.
" Mikimotoi has probably had the most effects worldwide in terms of harmful algal impacts, especially on fisheries and aquaculture, but also just on the general marine environment of the Karenias ," she said.
UTS Professor Shauna Murray is one of only a handful of experts in Australia who research algal blooms. ( Supplied UTS: Toby Burrows )
On March 25, with the help of Professor Murray, authorities confirmed the algal bloom was Karenia mikimotoi .
The blame was placed on an "ongoing marine heatwave" which had seen water temperatures 2.5 degrees Celsius warmer than usual.
At the time, EPA principal marine scientist Sam Gaylard said weather conditions had been "just right" for a bloom, and the hope was for a "big cold front to come through" and disperse it.
The cold front never arrived.
Within weeks the bloom began to spread throughout the Fleurieu coastline and beyond, growing to more than 4,000 square kilometres in size, equal to about 72 Sydney Harbours.
This satellite map image, taken on May 11, shows in red where chlorophyll a, an indicator of bloom, is present.
Its impact leaving stark traces along the coast.
Satellite mapping taken on May 11 shows levels of chlorophyll - a in red. It is an indicator of where algal bloom is present. ( Supplied: oceancurrent.aodn.org.au/PIRSA )
Dead octopus washed up at Basham Beach on March 18, 2025. ( ABC News: Caroline Horn )
Dozens of dead octopuses and other marine life washed up at Encounter Bay and Basham Beach.
Dead pippis along the shoreline at Goolwa Beach. ( ABC News: Che Chorley )
Dead cuttlefish were found at Victor Harbor and dead pipis were strewn across Goolwa Beach.
The pristine waters of Kangaroo Island are a selling point for tourists and visitors alike. ( ABC News: Che Chorley )
The bloom spread to nearby Kangaroo Island, where residents reported dead skate and leather jackets. Divers in Edithburgh on the Yorke Peninsula reported mass deaths along the ocean floor.
A dead shark washed up on Henley Beach South on the morning of May 5, 2025. ( Supplied: Rebecca Morse )
The issue hit home for those living in metropolitan Adelaide, when a dead three-metre white shark appeared at Henley Beach.
As part of its investigation, the ABC visited multiple locations impacted by the outbreak.
The remnants of previous fish kills were still apparent, as were more recent deaths.
On Kangaroo Island, which reported its first fish kills in March, some beaches were so littered with dead sea life, the smell was overpowering.
'If we get the balance wrong ... all of it will fall over'
Many people living in or near impacted areas told the ABC they felt they had been left in the dark by authorities.
While state government bodies including SA Health, the Department of Primary Industries and Regions, South Australia (PIRSA) and the EPA have issued information on their websites and through the media, a lack of information in the days and weeks after the bloom prompted a movement of citizen scientists to collect their own samples and share their findings online.
Among them is Faith Coleman, an ecologist who started testing water samples from Waitpinga in the days after the initial algal bloom.
She has given weeks of her own time for free, but said being part of the citizen science cause was a "privilege".
Ecologist Faith Coleman has taken a keen interest in the algal bloom. ( ABC News: Che Chorley )
Faith Coleman is an ecologist. ( ABC News: Che Chorley )
"Human beings are part of our ecosystems, but if we get the balance wrong in the environment all of it will fall over ..." she said.
"And so, when there are community members who are distressed and we are seeing really clear signatures of climate change ... it's important that we get onto it very, very quickly."
She and others said a lack of readily-available information had led to misinformation being spread online, including the algal bloom being caused by the desalination plant or by Chinese warships.
But Environment Minister Susan Close said the state government had "provided clear, relevant and current health and other information via a range of mediums".
"This includes but is not limited to signage at affected beaches, regularly updated government websites, media releases, parliamentary statements and social media," Dr Close said.
She said the government had also provided detailed briefings to local councils, MPs and businesses and ministers and departmental experts had regularly made themselves available for interviews with both Australian and international news organisations.
Faith Coleman said she was "deeply concerned" that this wouldn't be the last toxic bloom in the region.
"The magnitude of these blooms is changing around the world, not just this species but all hazardous species, and we are seeing in some areas ... [blooms] are now happening along the entire Californian coastline or throughout the [Gulf] of Mexico," she said.
A dead fish on Waitpinga Beach photographed on March 17, 2025. ( ABC News: Caroline Horn )
This picture of a globe fish on the beach at Waitpinga, south of Victor Harbor has been uploaded to iNaturalists and will form part of the data set used by scientists when studying the impact of the algal bloom. ( ABC South East SA: Caroline Horn )
Dead fish can be found strewn along the coastline of the peninsula and Kangaroo Island. ( ABC News: Che Chorley )
A dead shark on the shoreline at Kangaroo Island. ( ABC News: Che Chorley )
On Kangaroo Island, Kathryn Lewis is one of dozens documenting fish kills on local beaches, and uploading them on citizen science platform iNaturalist.
"It's a very sad experience," she said.
"I've never seen anything like it … but you want to do something about it and the best thing to do is to support scientists in their research and find solutions."
Kathryn Lewis lives on Kangaroo Island and has been monitoring the impact of the bloom. ( ABC News: Che Chorley )
The fish kills have been a hot topic on the island since the beginning of the algal bloom outbreak. ( ABC News: Che Chorley )
Kathryn Lewis has been walking the beaches of Kangaroo Island, monitoring the deaths of sea creatures. ( ABC News: Che Chorley )
Dead sea life can be seen along South Australia's coast, including this eagle ray. ( ABC News: Che Chorley )
As the citizen science movement continues, state government experts say they are monitoring the bloom closely.
The South Australian Research and Development Institute (SARDI), which is the research arm of PIRSA, is conducting water testing, autopsies on dead sea life and forecasting where the bloom could go next.
SARDI oceanographer Mark Doubell said satellite imagery showed visible signs of chlorophyll a, an indicator of a bloom's presence, as early as March 10.
South Australian Research and Development Institute (SARDI) Research Scientist Mark Doubell.
He said a range of environmental impacts had occurred before the bloom, including water from the 2022/23 River Murray floods flowing into the Southern Ocean, followed by unseasonably cold and warm water.
"Globally, there's an increase in the intensity and frequency of harmful algal blooms around the world over the last 20 years and we've often thought down on the southern end of Australia we're immune, maybe a little bit more immune or protected from those impacts but definitely we're seeing large shifts, climatic driven shifts in our environmental conditions," he said.
He said all that could be done now was to wait for "Mother Nature" to disperse the bloom as the weather cooled.
'This could be the beginning of the end'
While the impact on marine life is being studied, other impacts are being felt.
Kangaroo Island tour operator Andrew Neighbour stopped his dolphin swimming tours early due to the "manky" state of the water.
Andrew Neighbour, who runs a dolphin tour company, stopped his season early due the bloom outbreak. ( ABC News: Che Chorley )
Andrew Neighbour said the water was not nice for visitors to swim in. ( ABC News: Che Chorley )
In Goolwa, Kuti Co, a First Nations business, has been monitoring the situation closely after thousands of dead pipis, or kuti, washed ashore last month.
Kuti Co manager and Ngarrindjeri elder Derek Walker said he was thankful its harvest zone had not been impacted by the bloom, but said he was feeling the cultural impact of the marine deaths.
"[Kuti has] been a protein source sustaining us for millennia and its, culturally, was part of our cultural economy as far as Ngarrindjeri are concerned," he said.
"It's very important from our cultural heritage, certainly important from a native title perspective but really important around continuing our practice that goes back through the ages.
Ngarrindjeri elder and managing director of Kuti Co, Derek Walker. ( ABC News: Che Chorley )
Derek Walker said the impact on the environment had been hard to see from both a business and cultural perspective.
"It's been a worry ... there are some things you have to deal with in a business sense but from a cultural, ecological perspective it is concerning for us Ngarrindjeri too as well because it's not just the kuti or pipis it's affecting ... other fish species, but it's also affecting humans.
"We were noting that people, their eyes were stinging when they were on the beach, and even away from the beach.
"It brings a whole heap of emotion and thoughts around this because ecologically the decline ... in probably the last 30 years has been greater than any other time in history, so that always concerns us."
Anthony said it felt as though the ocean was trying to send a warning. ( ABC News: Che Chorley )
For Anthony Rowland, his dedication to the cause has been unwavering.
He joked his obsession and daily social media updates had likely lost him some friends.
But it's all for a good cause.
Anthony Rowland says more needs to be done to monitor coastlines. ( ABC News: Che Chorley )
"The ocean's my life ... since a young age," he said.
"My mum passed away when I was young and I think as a part of my coping with that from the age of eight onwards I was just addicted to the beach."
He believed the bloom was among the first glimpses of the impact of climate change.
Anthony says he is worried about the continued impact on local ecosystems. ( ABC News: Che Chorley )
"This is potentially the start of the decay of the oceans, which is going to be the start of the decay of mankind..." he said.
"We still don't know the severity of it in our area.
Dead stringrays have washed up on the coastline of Kangaroo Island. ( ABC News: Che Chorley )
"There has to be a way of letting the world realise this could be the beginning of the end.
"It's just giving us warning signs."
Credits
Reporting: Leah MacLennan
Words and digital production: Jessica Haynes
Photography and videography: Che Chorley
Editing: Sara Garcia
Additional reporting: Jessica Haynes and Caroline Horn
Additional photos: Caroline Horn, Toby Burrows, Rebecca Morse and IMOS OceanCurrent