Latest news with #algalbloom
Yahoo
10 hours ago
- Science
- Yahoo
Research team develops game-changing device to fight dangerous toxins in water supply: 'Demonstrated exceptional robustness'
Scientists have developed an affordable, real-time algal bloom monitoring system, as relayed by Its optical sensors achieve high accuracy, outperforming complex AI models. The device could revolutionize how we protect our water quality and aquatic ecosystems. Harmful algal blooms, or HABs, are a serious environmental issue. Rapid growth of algae can produce toxins dangerous to humans and animals. They can contaminate drinking water and deplete the oxygen in water. Water without oxygen is known as a "dead zone," which kills fish and other aquatic life. Traditional detection of HABs is expensive and not suitable for continual, on-the-ground monitoring. Satellite imaging or drone remote sensing, for example, makes it difficult to get early warnings and quick responses. The Korea Institute of Civil Engineering and Building Technology tackled this challenge. A research team led by Dr. Jai-Yeop Lee created a compact, sensor-based probe. The device integrates readily available ambient light and sunlight sensors into a microcontroller. It analyzes lux (brightness), ultraviolet, infrared, and visible light. These readings help categorize water surface conditions as "algae," "sunny," "shade," or "aqua." Lee and his team produced a system with an impressive 100% prediction accuracy. This is possible due to an enhanced Support Vector Machine classifier with a sequential logic-based algorithm. The system surpassed standard AI models like Random Forest and Gradient Boosting. Intelligent design like this is effective for real-world deployment in low-power, field-based systems. The device can also quantify Chlorophyll-a concentrations, a key indicator of algal blooms. The promising monitoring system is a means to protect reliable, clean water. Low-cost, real-time detection alerts authorities to potential HABs much earlier. Issuing public health warnings and treating affected bodies of water can be done more efficiently. How often do you worry about the quality of your drinking water? Never Sometimes Often Always Click your choice to see results and speak your mind. Preventing the spread of algal blooms is the device's main purpose. It reduces exposure to toxins, safeguards potable water, and preserves aquatic ecosystems. As a result, the system protects public health and supports fishing and recreation. "The logic-based framework demonstrated exceptional robustness and interpretability, especially for real-time deployment in embedded systems," said Dr. Lee. Making this technology accessible empowers communities to better manage their water resources. Improved detection marks a significant step forward in affordable water quality monitoring. Simple, responsive algal bloom detection — without the need for expensive hardware or extensive data — will keep our waters safe and our environment healthy. Join our free newsletter for good news and useful tips, and don't miss this cool list of easy ways to help yourself while helping the planet.
The Guardian
6 days ago
- 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.'
Irish Times
10-06-2025
- Science
- Irish Times
Dead elephants and feral sea lions: how poisonous algal blooms harm the planet
Before the elephants collapsed, they walked in aimless circles. Some fell head first, dying where they stood moments earlier; their carcasses scattered near watering holes across the Okavango delta in Botswana. The unexplained deaths in May 2020 alarmed conservationists. By July at least 350 elephants had died and nobody knew why. 'The animals all had their tusks, so poaching was unlikely. A lot of them had obviously died relatively suddenly: they had dropped on to their sternums, which was indicating a sudden loss of muscle function or neural capacity,' says Niall McCann, director of the conservation group National Park Rescue. Nearly five years later, in November 2024, scientists finally published a paper indicating what they believe to be the reason behind the deaths: toxic water caused by an algal bloom. READ MORE A sudden shift between dry and wet conditions in 2019 and 2020 created perfect conditions for cyanobacteria that release toxins lethal to the elephants, although the researchers could not make definitive conclusions as samples were not taken quickly enough in 2020 due to the pandemic. 'Blooms' are a rapid increase in the amount of algae, often occurring in shallow, slow-moving warm water. They can transform a sea, lake or river into a mass of green, yellow, brown or even red, sometimes for several weeks. Not all blooms are harmful – many sustain important fisheries. But sometimes algae forms such a thick layer that it blocks out sunlight in critical habitats; others can release harmful toxins. When the algae die, they rapidly deplete oxygen in water – often creating 'dead zones' where few fish can survive. As the Earth warms, harmful algal blooms are on the rise – even creeping into polar waters. They are driven by a mixture of pollution from agriculture, runoff from human waste and, increasingly, global heating – sometimes with dramatic consequences for wildlife and humans. As they spread, they are changing the colour of the world's lakes, rivers and oceans. [ UN Ocean Conference 3: will it lead to protecting the high seas from all extraction, forever? Opens in new window ] Nearly two-thirds of all lakes have changed colour in the past 40 years, a recent study shows. A third are blue – but as temperatures warm, they are likely to turn a murky green or brown, other research has found. The planet's oceans are turning green as they warm, a result of absorbing more than 90 per cent of excess heat from global warming. At sea, the size and frequency of blooms in coastal areas has risen by 13.2 per cent and 59.2 per cent respectively in 2003-2020, a 2024 study revealed. In freshwater systems blooms became 44 per cent more frequent globally in the 2010s, according to a 2022 global assessment of 248,000 lakes. The rise was largely driven by places in Asia and Africa that remain reliant on agricultural fertiliser. While progress has been made in North America, Europe and Oceania to stabilise blooms, the climate crisis has driven their resurgence in some freshwater systems. The fertilisers that people use to grow plants – including reactive nitrogen and phosphates – also supercharge algal growth. As they are washed off fields and pour into water bodies around the world, they significantly alter how ecosystems function. 'Humans are today loading more reactive nitrogen into the biosphere than the natural cycle [is],' said Johan Rockström, director of the Potsdam Institute for Climate Impact Research. He was co-author of a 2023 assessment that found that humanity had now gone far beyond the planet's natural limits for nitrogen and phosphorus. [ Commitment to climate action hard to find in Government Opens in new window ] 'We need to reduce the supply of reactive human nitrogen by over 75 per cent. It's a dramatic change and there's a lot of scientific debate about this,' he says. 'Most agricultural scientists say that it is not possible because we cannot feed humanity. We have a contradiction here: is our first objective to keep the planet's freshwater systems, coastal zones, ecosystems and climate stable – or is it to feed humanity?' Others warn that it is not a simple choice between food and the environment. In northern Norway repeated algal blooms have wiped out millions of farmed salmon and cod in recent years. A single bloom killed more than seven million salmon in 2019. This year another has wiped out up to a million more fish. As has just happened in South Australia, where it spanned 8,800 sq km, scores of fish and dead sea life wash up on beaches once a huge algal bloom spreads. Deepwater sharks, crabs, lobsters and prawns are among those found dead as a result of the toxic blanket created by Karenia mikimotoi algae, with the ocean 2.5 degrees hotter than usual for the season. In March a teenager was attacked by a 'feral' sea lion off the coast of southern California, where there has been an increase in aggressive behaviour from the animals linked to a large algal bloom, which can poison and induce seizures in the mammals due to the domoic acid neurotoxin it produces. While there are signs that the bloom is waning, it was the fourth consecutive year that California had experienced a significant outbreak. However, not everything dies in a dead zone. Once the putrid expanse of algae has dispersed and those that can swim away have left, aquatic species better adapted to low levels of oxygen, or hypoxia, move in. This has led to a boom in jellyfish numbers in many parts of the world. Denise Breitburg, of the Smithsonian Environmental Research Center, has studied Chesapeake Bay, the largest estuary in the US to experience algal blooms, for decades, says: 'The jellyfish we have here are way more tolerant of low oxygen in the water than species they would be competing with for food. They become more efficient predators and can utilise habitat that fin fish are excluded from.' As the world heats, the disruptions that algal blooms cause to ecosystems will be hard to stop, experts warn. Prof Donald Boesch, who helped first identify the dead zone in the Gulf of Mexico, which last year reached 17,000 sq km, the 12th largest in 38 years of records, says the process will get worse if the world does not prevent rising temperatures. 'As the liquid heats up, its ability to dissolve gases is reduced, so it holds less oxygen. Warmer surface waters can increase the stratification of layers in the ocean. It means that the warmer waters at the surface are less dense than the bottom waters, so they don't get mixed up. 'It's going to get worse,' says Boesch.
The Guardian
10-06-2025
- Science
- The Guardian
Dead elephants and feral sea lions: how poisonous algal blooms harm the planet
Before the elephants collapsed, they walked in aimless circles. Some fell head first, dying where they stood moments earlier; their carcasses scattered near watering holes across the Okavango delta. The unexplained deaths in May 2020 alarmed conservationists. By July, at least 350 elephants had died and nobody knew why. 'The animals all had their tusks, so poaching was unlikely. A lot of them had obviously died relatively suddenly: they had dropped on to their sternums, which was indicating a sudden loss of muscle function or neural capacity,' says Niall McCann, director of the conservation group National Park Rescue. Nearly five years later, in November 2024, scientists finally published a paper indicating what they believe to be the reason behind the deaths: toxic water caused by an algal bloom. A sudden shift between dry and wet conditions in 2019 and 2020 created perfect conditions for cyanobacteria that release toxins lethal to the elephants, although the researchers could not make definitive conclusions as samples were not taken quickly enough in 2020 due to the pandemic. 'Blooms' are a rapid increase in the amount of algae, often occurring in shallow, slow-moving warm water. They can transform a sea, lake or river into a mass of green, yellow, brown or even red, sometimes for several weeks. Not all blooms are harmful – many sustain important fisheries. But sometimes algae forms such a thick layer that it blocks out sunlight in critical habitats; others can release harmful toxins. When the algae die, they rapidly deplete oxygen in water – often creating 'dead zones' where few fish can survive. As the Earth warms, harmful algal blooms are on the rise – even creeping into polar waters. They are driven by a mixture of pollution from agriculture, runoff from human waste and, increasingly, global heating – sometimes with dramatic consequences for wildlife and humans. As they spread, they are changing the colour of the world's lakes, rivers and oceans. Nearly two-thirds of all lakes have changed colour in the past 40 years, according to a recent study. A third are blue – but as temperatures warm, they are likely to turn a murky green or brown, other research has found. The planet's oceans are turning green as they warm, a result of absorbing more than 90% of excess heat from global warming. At sea, the size and frequency of blooms in coastal areas has risen by 13.2% and 59.2% respectively between 2003 and 2020, according to a 2024 study. In freshwater systems, blooms became 44% more frequent globally in the 2010s, according to a 2022 global assessment of 248,000 lakes. The rise was largely driven by places in Asia and Africa that remain reliant on agricultural fertiliser. While progress has been made in North America, Europe and Oceania to stabilise blooms, the climate crisis has driven their resurgence in some freshwater systems. The fertilisers that people use to grow plants – including reactive nitrogen and phosphates – also supercharge algal growth. As they are washed off fields and pour into water bodies around the world, they significantly alter how ecosystems function. 'Humans are today loading more reactive nitrogen into the biosphere than the natural cycle [is],' said Johan Rockström, director of the Potsdam Institute for Climate Impact Research. He was co-author of a 2023 assessment that found that humanity had now gone far beyond the planet's natural limits for nitrogen and phosphorus. 'We need to reduce the supply of reactive human nitrogen by over 75%. It's a dramatic change and there's a lot of scientific debate about this,' he says. 'Most agricultural scientists say that it is not possible because we cannot feed humanity. We have a contradiction here: is our first objective to keep the planet's freshwater systems, coastal zones, ecosystems and climate stable – or is it to feed humanity?' Others warn that it is not a simple choice between food and the environment. In northern Norway, repeated algal blooms have wiped out millions of farmed salmon and cod in recent years. A single bloom killed more than seven million salmon in 2019. This year, another has wiped out up to a million more fish. As has just happened in South Australia, where it spanned 8,800 sq km (3,400 sq miles), scores of fish and dead sea life wash up on beaches once a huge algal bloom spreads. Deep-water sharks, crabs, lobsters and prawns are among those found dead as a result of the toxic blanket created by Karenia mikimotoi algae, with the ocean 2.5C (4.5F) hotter than usual for the season. In March, a teenager was attacked by a 'feral' sea lion off the coast of southern California, where there has been an increase in aggressive behaviour from the animals linked to a large algal bloom, which can poison and induce seizures in the mammals due to the domoic acid neurotoxin it produces. While there are signs that the bloom is waning, it was the fourth consecutive year that California had experienced a significant outbreak. However, not everything dies in a dead zone. Once the putrid expanse of algae has dispersed and those that can swim away have left, aquatic species better adapted to low levels of oxygen, or hypoxia, move in. This has led to a boom in jellyfish numbers in many parts of the world. Denise Breitburg, of the Smithsonian Environmental Research Center, has studied Chesapeake Bay, the largest estuary in the US to experience algal blooms, for decades, says: 'The jellyfish we have here are way more tolerant of low oxygen in the water than species they would be competing with for food. They become more efficient predators and can utilise habitat that fin fish are excluded from.' As the world heats, the disruptions that algal blooms cause to ecosystems will be hard to stop, experts warn. Prof Donald Boesch, who helped first identify the dead zone in the Gulf of Mexico, which last year reached 17,000 sq km, the 12th largest in 38 years of records, says the process will get worse if the world does not prevent rising temperatures. 'As the liquid heats up, its ability to dissolve gases is reduced, so it holds less oxygen. Warmer surface waters can increase the stratification of layers in the ocean. It means that the warmer waters at the surface are less dense than the bottom waters, so they don't get mixed up. 'It's going to get worse,' says Boesch. Find more age of extinction coverage here, and follow the biodiversity reporters Phoebe Weston and Patrick Greenfield in the Guardian app for more nature coverage
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."
