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ABC News
a day ago
- Climate
- ABC News
What is happening with SA's algal bloom and why should the rest of Australia care?
South Australia is dealing with an "unprecedented" environmental disaster, which has spread throughout the coastline, killing thousands of sea creatures and taking a toll on businesses, tourism and the mental health of those who live and work near the sea. Authorities and scientists say climate change has been a key driver in the algal bloom and warn the bloom is unlikely to go away anytime soon. Here's what we know so far. What causes algal blooms? UTS marine biologist Shauna Murray told the ABC earlier this year that marine phytoplankton were generally a good thing for the environment, creating up to a half of the world's oxygen. But a small percentage of the more than 100,000 different species of microalgae are harmful or toxic. What is the algal bloom in South Australia? The harmful algal bloom dominating South Australia's coastline is Karenia mikimotoi . In low numbers, the microscopic algae cannot be seen by the naked eye. Here's what it looks like under a microscope: The samples that showed karenia mikimotoi to be present in the Coorong were collected by Glen and Tracy Hill. ( 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," UTS researcher Shauna Murray told the ABC earlier this year. And from the coastline, it can wash up a brown-coloured foam, which looks like this: The algae produced large amounts of foam again at Knights Beach at Port Elliot over Easter. ( ABC South East SA: Caroline Horn ) How did the bloom begin? SA Environment Minister Susan Close said the outbreak followed three key events. In 2022/23 the state experienced flooding along the River Murray, which saw run-off enter the Southern Ocean. Here's an image of the run off from above: After that, in 2023/24 a cold upswelling brought nutrient rich water to the surface. And in September 2024, a marine heatwave began, which saw temperatures 2.5 degrees Celsius above normal levels. On March 15, surfers and beachgoers reported illnesses after visiting Waitpinga Beach on the Fleurieu Peninsula. By March 16, a brown foam and dead sea life was found on the beach, marking the beginning of a months-long crisis along SA's coastlines. Dr Close said all of those events could be attributed to climate change. What does the algal bloom do to humans? Health authorities say contact with Karenia mikimotoi can cause flu-like symptoms, including skin rashes and respiratory symptoms, but no long-term health impacts. For surfer Anthony Rowland, who first felt the impact of the bloom at Waitpinga Beach, it started as a tickle in his throat and then progressed to a cough. Anthony Rowland said he felt as though authorities did not take his initial reports seriously. ( ABC News: Che Chorley ) He reported other surfers in the area having blurred vision, wheezing and sore throats. How do you treat algal bloom sickness symptoms? SA Health's advice is to stay out of waters where the bloom appears to be present, but if you do come into contact with it to leave the area and wash yourself. "If symptoms are more severe or do not resolve, seek medical advice from a GP and call 000 if it is a medical emergency," SA Health states on its website. How does it kill fish? Professor Murray said the algae affects fish gills and skin. " Karenia mikimotoi doesn't actually produce a toxin but it does produce what's called reactive oxygen species so this can damage the gills of fish and it can affect skin cells," she said. "What this damaging the gills of the fish means is marine animals basically drown if their gills become too damaged." A globe fish on the beach at Waitpinga, south of Victor Harbor, after the initial outbreak in March. ( ABC South East SA: Caroline Horn ) Other dead sea mammals have been found dead along the coast, including dolphins and sea lions. The official advice is that Karenia mikimotoi isn't toxic to mammals. The government said it was not uncommon for marine mammal carcasses to wash ashore after winter storms. SA authorities are performing autopsies to determine the cause. Where is the algal bloom at the moment? As of July 18, authorities say the bloom is present in the Gulf Saint Vincent, which covers many of Adelaide's metropolitan beaches, as well as areas in the Fleurieu Peninsula and the Spencer Gulf. This satellite image shows levels of chlorophyll a in red, which is an indicator of the bloom's presence: A July 16, 2025, sea surface map of chlorophyll-a levels on the South Australian coast, which can indicate algae concentrations. ( Department of Primary Industries and Regions SA ) On Wednesday, a dead sea turtle found at Glenelg was among the latest casualties. What kills an algal bloom? According to the latest science, nothing can be done to dilute or dissipate the bloom. When it first appeared, scientists predicted a cold winter front would help dissipate it. But the ongoing marine heatwave and drought conditions meant rain did not arrive until winter, and the storm fronts have done little to hamper the bloom so far. A birdseye view of the algal bloom in waters off the Fleurieu Peninsula. ( ABC News: Che Chorley ) There have been some glimmers of hope though. Estuarine ecologist Faith Coleman detected Noctiluca scintillans — the algae which causes "sea sparkle". "What they do is they go round, they eat other bacteria and algae, and in this case it looks like they're probably eating Karenia mikimotoi ," Ms Coleman said. Is it safe to eat fish? Fishing businesses and scientists have told the ABC catches are down 50 per cent in some parts of the state, but for those still fishing, business is also being impacted by the news of the bloom. SA Environment Minister Susan Close said she would be looking at further measures to remind consumers that fish for sale was still safe to eat. "SA Health advises that fish caught live are safe to eat," PIRSA's website states. "However, SA Health does not recommend people eat fish or cockles found dead because of likely spoilage and decomposition." South Australian Fisherman Co-Operative Limited manager Ian Mitchell told the ABC earlier this week he had "fishermen in tears on the phone", but the mood was better following the announcement of state and federal funding. This week, the federal government announced $14 million in funding to help South Australia deal with the algal bloom outbreak, but stopped short of declaring it a national disaster. On Tuesday, the SA government said it would match federal funding, with the resources to go to helping impacted industries, further research and monitoring and holding public community information forums. "The feeling was a lot better today than the last three months. There was a fair bit of fish considering the weather was pretty poor, and prices were up a little bit so it seems like the public is listening to, you know, it is safe to eat," Mr Mitchell said. What has the impact been and what's next? The bloom has killed thousands of sea creatures, decimated local sea habitats and has spread at an unprecedented level. It has had a huge impact on commercial fishing, tourism and other businesses who operate in or near the sea. The fish kills have been a hot topic on the island since the beginning of the algal bloom outbreak. ( ABC News: Che Chorley ) The toll on those who work in the space has also been significant. So what's next? Flinders University Associate Professor of Natural Sciences (Oceanography) Jochen Kaempf has developed a computer model to predict where the algae will spread next. While awaiting peer review, the model predicts the bloom will ease over winter, but worsen next summer. "There is nothing you can actually do to prevent it. The only thing you can do is you can hope that there is enough of the zooplankton, which are swimming, small marine plankton that actually eat, take up enough of the algae so that it can't re-evolve in the next summer when the water gets warmer again," Professor Kaempf said. "The only thing that can actually only clear it up is if it's consumed, if it's eaten by other marine organisms of the food chain."
ABC News
16-07-2025
- Climate
- ABC News
Algal bloom leaves Coorong facing 'ecological collapse', advocates warn
The internationally significant Coorong wetlands are at risk of becoming a "wasteland" due to the toxic algal bloom that is ravaging South Australia's coastal ecosystems, according to advocates who say the area is now at a "threshold" moment. The shallow saline lagoon, which stretches roughly 130 kilometres along the state's south-east coast, has been dealing with a multitude of environmental pressures since the 1970s, with conservationists fearing this year's bloom will be "the straw that's broken the camel's back". The state government is also "deeply concerned" about the Coorong's future, with Acting Premier Susan Close warning that the area has been "on the brink for a very long time". But she cautioned that the extent to which the Karenia mikimotoi bloom will cause a permanent change to the Coorong's ecology is "not yet certain". The toxic algae — which has been ravaging SA's marine life since March and disrupting fishing, aquaculture and tourism businesses — is believed to have entered the Coorong's North Lagoon at the end of May via the mouth of the River Murray. It has since killed thousands of the Coorong's polychaete worms, crabs and fish. "We're looking at an ecological collapse," said Dr Jonathan Sobels, chair of the Coorong Environmental Trust (CET). "The likelihood of anybody being able to get a livelihood out of the Coorong as a fisherman is compromised. "There's a significant threat to livelihoods and to the food chains that support a wide variety of plants, fish, microbes, little crustaceans, shellfish — the whole lot." The Coorong, which formed the backdrop of Colin Thiele's classic Australian book Storm Boy, is also known as a breeding site for pelicans and migratory birds. According to the Environment Department, the region supports 11 threatened species, six threatened migratory waterbird species and two threatened ecological communities. There are now fears about what those migratory birds will eat given the widespread fish kills. Commercial fisherman Garry Hera-Singh, who first started fishing in the Coorong in 1974, said he has seen smaller fish, crabs and marine worms "washing in by the acres". "To me, the alarm bells are going off," he said. Mr Hera-Singh, a third-generation fisher, said he has already advised his son, also a fisher, to "seriously … consider changing course and changing occupations if this bloom re-occurs". The Coorong is listed as a wetland of international importance under the 1971 Ramsar Convention, an international treaty aimed at halting the loss of wetlands. Dr Sobels, the CET chair, said the bloom's degradation could put the Coorong's Ramsar listing "in jeopardy". "I wouldn't want to be the government that was known to be responsible for the loss of the significant international wetland," he said. The federal government is responsible for nominating and conserving Australia's Ramsar-listed wetlands. The Coorong was added to the list in 1985 — one of six Ramsar sites in SA and among more than 60 across Australia. The ABC contacted Environment Minister Murray Watt for comment. The Coorong is divided into a North and South Lagoon, with the latter suffering considerable environmental degradation since the 1980s. This has been partly attributed to poor water management between the Murray Darling Basin states as well as the Millennium Drought, which saw River Murray flows drop to record lows over the 2000s. Dr Sobels said the South Lagoon is "essentially a bacterial soup" and the North Lagoon is "now moving in the same direction" because of the bloom. "So, the crisis is that the Coorong might end up being much more of a wasteland than it currently is," he said. Estuarine ecologist Faith Coleman said Karenia's entry into the North Lagoon has caused "extensive deaths" in the "one truly healthy area of the Coorong that was remaining". "It [the bloom] has been the straw that's broken the camel's back," she said. "We previously had 20 to 30 per cent of the Coorong that was healthy, and that is the area that the Karenia bloom has hit. "I believe that this Karenia bloom is the threshold that the South Lagoon went through in … the late '70s, where it went from that beauty to a septic pit." The CET has put forward a four-point plan to address the issues in the Coorong, describing it as a "last-ditch attempt" to fix the issues in the North and South lagoons. The plan includes keeping the salinity of the South Lagoon within a narrow range, maximising flows into the South Lagoon, operating water efficiently and using burnt lime to boost water health. Ms Coleman, a founding member of the CET, said successive governments have failed to address the Coorong's decline despite millions in research funding. Acting Premier and Environment Minister Susan Close said Ms Coleman presented the four-point plan to her "a couple of weeks ago". "We're looking really favourably on all of the points that she's making," Dr Close said on Tuesday. "We're working through the detail of how they can be enacted." The acting premier said the state government was doing weekly algal testing in the Coorong. She said the bloom was "yet another attack" on the Coorong, arguing the area has copped "a hell of a hammering over the last few decades because of the way that the Murray-Darling Basin has been treated by other states". "Being able to flush the Coorong with freshwater at a time that helps the environment makes all the difference, and not having that has been a big problem." The acting premier said while the government was "deeply concerned" about the Coorong, there were still "things that can be done". She said the state government has investigated adding a clay that can deal with Karenia mikimotoi but was advised by scientists that it's "likely to cause more harm than good". "We're looking at ways in which we can manage water in order to push the Coorong's salinity out of the comfort zone for Karenia mikimotoi," she said. "But again, we don't want to flush too much because then the Karenia mikimotoi makes its way to the South Lagoon. "The fact that we are still working through this does not mean that we are not paying very careful attention and getting all of the best scientific expertise on the case."
The Guardian
06-07-2025
- Climate
- The Guardian
South Australia ‘helpless' in face of deadly marine algal bloom spreading to Adelaide beaches
South Australia's toxic algal bloom has arrived on Adelaide's beaches, deepening public concern about the unfolding catastrophe, which has affected the state's coastline since March. Until recently, city beaches had escaped the worst of the deadly bloom of Karenia mikimotoi algae, which had devastated marine life from the Fleurieu peninsula, to Kangaroo Island, the Yorke peninsula and the Ramsar-listed Coorong, amid warmer than normal sea temperatures. But in the wake of a major storm on 24 June, masses of dead rays, fish and rare and unusual marine life began washing up from north of Grange jetty to south of Christies beach surf club. 'Until that time, it hadn't hit metro Adelaide,' said marine biologist Dr Michael Bossley. 'Suddenly, the people of Adelaide and the government and just about everybody are doubling down on their concern.' This week, South Australia's environment minister Dr Susan Close said the state was 'helpless in the force of nature'. She said the bloom was unlikely to disappear any time soon, and could return in future. 'The algal bloom is a dynamic situation. Its movement depends on weather and water conditions, and [that] makes the effect on people and wildlife unpredictable.' The state government had hoped that storms and cooler water temperatures would help break up the bloom. So far that hasn't happened; instead storms have helped the algae spread to new waterways. Testing by the state government confirmed the algae's presence in West Lakes, a lake-side suburb in Adelaide's west, with further testing being done at 14 sites, including the Port River, home to the Adelaide Dolphin Sanctuary. A persistent marine heatwave affects the waters off South Australia, kicked off with sea surface temperatures reaching 2.5C above average. A mysterious sea foam appears at beaches on the Fleurieu Peninsula, with reports of more than 100 surfers becoming ill, and deaths of leafy sea dragons, fish and octopi. Marine biologists from the University of Technology Sydney find high numbers of a tiny harmful algal species called Karenia mikimotoi in water samples collected from affected beaches. Prof Shauna Murray – who identified the algae under the microscope and by analysing its DNA – says while still not well understood, K mikimotoi is thought to produce a reactive oxygen that caused gill cell damage in fish – which means they can not breathe. By this point, more than 200 marine species have been killed by the bloom, which stretches along more than 150 kilometres worth of coastline. A powerful storm and high tides washes the algae into the Coorong, staining the water like strong tea before turning it into a slurry. Water testing confirms the presence of the algae in the Coorong. Abnormally high tides, strong winds and large waves lashes the South Australian coastline, with multiple reports of fish deaths along the Adelaide metropolitan coastline reported in the aftermath. Testing confirms the toxic algae had entered West Lakes. While the algae has been detected at the inlet, it had not yet been detected at three other testing sites. Since the start of the bloom in March, about 8,000 dead marine animals have been recorded as part of the SA Marine Mortalities project, affecting 390 different species. Sign up to get climate and environment editor Adam Morton's Clear Air column as a free newsletter Fishing conservation charity OzFish has been part of that statewide citizen science effort. 'We know that sponge gardens and shellfish beds – mussels, native oysters, razor fish – a lot of those areas are now considered graveyards, because they've been completely wiped out by the bloom,' OzFish South Australian project manager Brad Martin said. Sign up to Breaking News Australia Get the most important news as it breaks after newsletter promotion 'The concern at the moment is whether [the algae] is going to enter urban estuaries and waterways,' he said. 'The Onkaparinga, West Lakes and the Port River are all areas of concern; they're popular recreational fishing sites, with access to the ocean.' The fish were being 'poisoned, they're being choked to death, and they need to bounce back as quickly as possible,' said Asher Dezsery, executive officer for RecFish SA, the peak body for fishers and tackle shops. That not only affected catches – some fisheries, like Goolwa pipis, had experienced mortality rates of 37% – but had flow-on effects for tourism and businesses. Many tackle stores were on the brink of shutting down, he said. On Friday, the state government met commercial fishers, tourism operators and local councils as it prepared a recovery plan for when the bloom eventually recedes. While sea surface temperatures in shallow waters have been falling, marine heatwave conditions – with water temperatures 1 to 2C above average – have persisted in deeper continental shelf waters around Kangaroo Island and southern Yorke peninsula. Marine heatwaves, which had triggered the bloom, were happening around Australia and all around the world, Bossley said. 'It's climate change happening.'
The Guardian
14-06-2025
- Climate
- The Guardian
Deadly algal bloom in South Australia's Coorong an environmental ‘eye opener', ecologist says
When South Australia's algal bloom arrived in the Coorong, it stained the water like strong tea before turning it into a slurry of dead worms. Many had hoped the storm in late May would break up the bloom of Karenia mikimotoi algae, which has killed more than 200 different marine species. Instead, high tides swept the algae into the Coorong, an internationally significant Ramsar wetland at the mouth of the Murray River. Once there, the algae began 'reproducing madly' in the nutrient rich waters of the North Lagoon, according to estuarine ecologist Faith Coleman. Among the dead were mostly benthic species – estuarine snails, shore crabs, baby flounder and 'a thick stew of dead polychaete worms' – a crucial food source for shorebirds and fish. Levels had declined from their peak but the smell of rotting fish remained, along with algal spores buried in the sediment. 'As soon as it warms up again, the likelihood is [the algal bloom will] be back,' Coleman said. The marine heatwave, a contributing factor to the bloom, persisted off the coast of SA, according to an 11 June update, which showed increases in chlorophyll – an indicator of algae concentrations – along the Coorong coast and western Gulf Saint Vincent. Fourth generation fisherman Gary Hera-Singh was one of the first to notice the lagoon's colour turn a 'dark, orangey-brown'. 'We had a big storm event, a lot of seawater got pushed around, and this algal bloom found its way into the Coorong and has just created havoc since,' he said, and there were still 'massive patches – 100 acres at a time' where the bloom was flourishing. Hera-Singh has witnessed the health of the Coorong decline in his lifetime, but said in 41 years of fishing the impact of the algal bloom was the worst event he had seen. The Coorong, a 120km narrow band of water separated by sand dunes from the Southern Ocean, together with lakes Alexandrina and Albert, is considered a wetland of international significance, providing critical habitat for fish, water birds and many threatened species. The North Lagoon – the area affected – is an important nursery for fish such as mulloway and bream. Sign up for Guardian Australia's breaking news email Prof Peter Gell, an expert in Ramsar listed wetlands, said the wetlands had degraded over a long period of time, with barrages (structures that control water flow) added in the 1950s, higher nutrient loads and extended periods of reduced flow from the Murray. Algal blooms were symptoms of broader changes, he said. 'Because of this we're seeing – both offshore and within the Coorong – substantial changes in the food web.' As a wetland of international significance, the Australian government was obliged to report environmental changes to the Coorong under the Ramsar convention, Gell said, a process that usually triggered restoration efforts. Federal and state governments were liaising about the situation, including any long-term impacts likely to affect the ecological character of the Coorong, a federal environment department spokesperson said. 'We understand that, given the dynamics of the North Lagoon, it is difficult to dissipate the bloom and it might remain for some time.' Fresh water may help the situation, Coleman said, given the algae thrived at salinity levels of 18-37 grams per litre. Restoration efforts would help build the resilience of the Coorong and marine areas, she said. The system was already under pressure, said Dr Nick Whiterod, an ecologist and science program manager at the Coorong Lower Lakes Murray Mouth Research Centre. But the recent drought and unusual algal blooms had been 'eye openers' to many people, he said. Last year, a tropical species of blue-green algal bloomed in Lake Alexandrina for the first time, and had persisted, Whiterod said. Now that karenia mikimotoi had got into the Coorong, there was concern it too would bloom again. The Coorong was vulnerable to the impacts of climate change, like sea level rise and reduced river flows, he said. 'Ocean temperatures are heating up. It's creating conditions that are conducive to algal blooms all around the world,' he said. 'Our ecosystems are really stressed, we are getting to a period of time where some may not have the capacity to recover.'
ABC News
03-06-2025
- Business
- ABC News
Marine algal bloom spreads to SA's Coorong as fishers find dead creatures in North Lagoon
Algae from a bloom that has killed marine life throughout South Australian seas over the past few months has been detected in the fragile saline environment of the Coorong. The Karenia mikimotoi-dominated algae mix is believed to have entered the North Lagoon via the mouth of the River Murray during last week's stormy weather and high tides. It has killed thousands of polychaete worms, as well as crabs and small fish, with fishers concerned for the environment and commercial fishery that depends on its health. The Coorong is a Ramsar-listed wetland known for its global importance as a breeding site for pelicans and migratory birds. Estuarine ecologist Faith Coleman, who has spent much of the past few months helping coastal communities understand the algal bloom, said she was "devastated" when she realised the algae was in her beloved Coorong. The sample Ms Coleman examined was brought to her by commercial fishers Tracy and Glen Hill. While fishing in the southernmost part of the North Lagoon late last week, Mr Hill noticed the water had a strange reddish-pink colour, and in places was full of dead or dying creatures. "There were huge numbers of polychaete worms, all different sizes, types," Mr Hill said. While Mr Hill was familiar with fish kill events happening in the more saline South Lagoon after stormy weather, he thought of the North Lagoon as a "refuge zone". "I spent a fair bit of time crying over what I was seeing." Fellow commercial fisher Gary Hera-Singh also noticed the change in the water. "It's not a bloom I've ever seen before … it gives off this very pungent odour," Mr Hera-Singh said. Mr Hera-Singh described the water as "nearly black" on the side of the lagoon next to the dunes that separate it from the ocean. Like Mr Hill, Mr Hera-Singh was shaken by the sheer number of dead worms. He believed the full extent of the aquatic deaths would not be known until more material at the bottom of the lagoon washed ashore on windy days. He said other fishers had told him the bloom now extended as far north as Long Point and was affecting around half of the North Lagoon. He said commercial catches in the affected areas were "non-existent", and he had grave concerns for the future of the fishery and thousands of birds that lived in or visited the Coorong. Ms Coleman said the algae was already showing signs it could become established in the lagoon environment. While samples of the algae collected from the sea were shown to be reproducing via cell division, she said the algae in the Coorong was reacting in a different way. "In the Coorong, there is so much food, and the salinity is so good, that we're seeing sexual reproduction occur," Ms Coleman said. Ms Coleman said that reproduction often led to more persistent blooms, and where the algae had penetrated lagoon areas overseas, blooms had even become annual events. Mr Hera-Singh said much more extensive research was needed. "This bloom has come in with a massive thump," he said. "I'm still waiting to collect enough evidence to say whether we've got a future [as fishers] or not. The South Australian Primary Industries and Regions Department (PIRSA) said it was investigating reports of a bony bream fish kill in the Woods Well Bay area and a polychaete fish kill at the Long Point area of the Coorong. "Samples [including water samples] have been collected for both locations with results still pending," a spokesperson said. "PIRSA would like to remind the public of the advice from SA Health for people to avoid collecting or eating any fish or marine organism found washed up and either dying or dead."
