Latest news with #Salviniaminima
The South African
01-07-2025
- General
- The South African
Action taken against invasive hyacinth at Vaalkop Dam
Deputy Minister of Water and Sanitation, Sello Seitlholo, has committed to take decisive and sustained action to address the growing infestation of invasive alien vegetation at Vaalkop Dam in Rustenburg in the North West province. During a two-day oversight working visit from 27 to 28 June 2025, Seitlholo announced the establishment of a multi-stakeholder working group and committed to personally overseeing the complete removal of the infestation from the dam. 'I am taking personal responsibility to ensure that the infestation at Vaalkop Dam is eradicated,' Seitlholo said. The infestation, primarily caused by water hyacinth and Salvinia minima, has severely impacted the operations of the Vaalkop Water Treatment Works, posing serious threat to water abstraction, treatment capacity, and regional water supply. The Deputy Minister attributed the explosion of invasive weeds to a combination of factors, including heavy rainfall, which carried high concentrations of nutrients from upstream sources into the dam. These include discharges from wastewater treatment plants, agricultural runoff, urban drainage, and pollution from informal settlements and mining activities. 'Nutrients from bottom sediment recirculation have also added to the dam's ecological load. The combination of historically low water levels, the presence of invasive seeds, and nutrient flooding created ideal conditions for the aggressive spread of the aquatic weeds. The Deputy Minister also announced his intention to formally propose that water pollution be declared a national crisis, warning that South Africa can no longer afford to treat pollution as a localised or isolated problem. 'We cannot allow pollution and negligence to cripple our water systems any further. I will also be proposing that water pollution be declared a national crisis. It is time we recognise that this threat affects the health, economy, and future of our nation,' Seitlholo said. Declaring a national crisis, he said, is necessary to unlock the urgency, coordination, and resources required to protect South Africa's already stressed water systems. The Deputy Minister also issued a stern warning to municipalities that fail to meet their wastewater management responsibilities. 'Let me be very clear, municipalities that continue to pollute our rivers and dams with untreated waste are directly contributing to the destruction of our water resources. This negligence will not be tolerated,' Seitlholo warned. He announced that the department will intensify compliance monitoring, and where wrongdoing is found, 'there will be serious consequences.' The Deputy Minister's planned working group will bring together representatives from the Department of Water and Sanitation, Magalies Water, affected municipalities, environmental scientists, and other critical partners. 'The group will assess the scale of the infestation, recommend both immediate and long-term interventions, and oversee the implementation of recovery plans for the dam and surrounding systems,' Seitlholo said. He emphasised that this initiative is part of a broader departmental effort to strengthening environmental enforcement, restoring infrastructure resilience, and addressing the growing national threat posed by pollution and invasive species. Since assuming office nearly a year ago, Seitlholo has led numerous oversight inspections across the country, confronting issues of water pollution and infrastructure failure head-on. He has consistently called for accountability and improved service delivery. The Deputy Minister is expected to soon announce a set of coordinated and strategic national interventions to tackle the pollution of South Africa's water sources and restore the health of critical water ecosystems. Let us know by leaving a comment below, or send a WhatsApp to 060 011 021 1 Subscribe to The South African website's newsletters and follow us on WhatsApp, Facebook, X and Bluesky for the latest news.
Washington Post
31-03-2025
- Science
- Washington Post
Scientists hope hungry weevils from Louisiana can tackle South Africa's invasive water plants
HARTBEESPOORT, South Africa — Dozens of tiny black weevils cling onto a fern plant as it is tossed onto a leafy green mat coating the surface of South Africa's Crocodile River. Those weevils aren't tossed into the river by accident: scientists hope that the insects and their larvae will munch their way through the green mat, which is made up of an unwanted, invasive South American aquatic plant called Salvinia minima. The plant is steadily taking over freshwater bodies in the northern region of South Africa, suffocating aquatic life, including on the Crocodile River and the Hartbeespoort Dam it flows into. The weevils, which have been used effectively elsewhere in the world to fight water weeds, are now leading South Africa's charge against the life-sucking plants threatening ecosystems in at least three northern provinces and creeping into neighboring countries. After the weevils helped control the spread of salvinia in parts of the United States, scientists from both countries worked together on a project to gather a starter population in South Africa. The 1-millimeter-long (0.03 inches) insects were brought over 8,700 miles from Louisiana. Rearing stations are being set up near several dams to grow the weevil population. Once released at an infested site, the beetles make themselves at home on the salvinia, the only thing they eat, without damaging the local ecosystem, scientists say. 'They lay eggs on this plant, feed on this plant and die on this plant. If this plant dies, they will die as well,' said professor Julie Coetzee, the principal scientist at the South African Institute for Aquatic Biodiversity. 'They damage certain tissues, those tissues become waterlogged and then those plants sink to the bottom.' Hartbeespoort Dam north of Johannesburg, the location for the pilot project, is an important source of irrigation for nearby farms and a popular recreation site. 'When we bought the property there was this beautiful little floating plant on the dam and I thought well that's quite nice,' said 53-year-old resident and business operator Max Moller. 'Little did I realize this little floating fern was an absolute menace.' Moller, the owner of Mogi's hiking trail, said the salvinia have clogged up and damaged boat engines and also hurt fishing communities over the nine years that he has lived in the area. South Africa's already vulnerable freshwater systems face a significant threat from salvinia, scientists say. The plants have had two major growth spurts in 2021 and 2022, surviving on the high nitrate contents in the water. The plant initially surfaced more than a decade ago at the dam, which has also long been battling with a water hyacinth invasion, another problematic species. 'If you pull the hyacinth away, this plant is lurking,' said Coetzee. The invasive plants block out the sunlight, which means no oxygen in the water, she said. 'If there is no oxygen, there's no fish, there's no crab, there's no insects and so you completely destroy or alter the aquatic ecosystem,' she said. Salvinia has a rapid growth rate and its spread has been most notable across Gauteng province, where South Africa's biggest city of Johannesburg and its capital, Pretoria, are located. The plant is compounding existing water supply problems by depleting the oxygen and sapping the supply in a country that's already struggling with increasing demand and deteriorating water infrastructure. While releasing the weevils will help combat salvinia, experts warn that there could be unintended side-effects. Anthony Turton, a water expert and researcher at South Africa's University of the Free State, cautioned that their introduction could turn rivers and dams into more suitable homes for bacteria and dangerous organisms. That includes poisonous blue-green algae, known as cyanobacteria, which flourish in nutrient-rich, contaminated waterways and already affect almost 60% of the nation's dams. 'With more light and less competition for nutrients, those cyanobacteria will go into a condition known as a bloom,' he said. 'This is exponential population growth that radically populates the entire water column.' Turnton said simultaneous action to repair damaged sewage systems and limit agriculture fertilizer runoff are essential for a lasting solution. 'Unless there are efforts to reduce the inflow of nutrients from sewage flows, then we are only creating space for cyanobacteria to grow without competition from floating weeds,' he said. The weevils aren't the first insects to be introduced to curb an invasive threat in South Africa. The country brought in a bug in the 1930s to control the spread of a hardy cactus native to Mexico that was hurting ecosystems. That project was viewed as a success. The speedy growth of the salvinia has put pressure on the government to act, particularly as researchers warn that neighboring countries also now face an invasion. Coetzee said that salvinia was popping up on the confluence of the Crocodile and Limpopo rivers in the far north of South Africa. 'That now poses a huge threat to our neighbors because this plant has been transported by our rivers onto our borders,' she said. 'It is likely to go all the way along the Limpopo, along Botswana and Zimbabwe's borders and into Mozambique.' 'We really have a responsibility to control this plant,' she added. ___ AP Africa news:
Yahoo
30-03-2025
- Science
- Yahoo
Scientists hope hungry weevils from Louisiana can tackle South Africa's invasive water plants
HARTBEESPOORT, South Africa (AP) — Dozens of tiny black weevils cling onto a fern plant as it is tossed onto a leafy green mat coating the surface of South Africa's Crocodile River. Those weevils aren't tossed into the river by accident: scientists hope that the insects and their larvae will munch their way through the green mat, which is made up of an unwanted, invasive South American aquatic plant called Salvinia minima. The plant is steadily taking over freshwater bodies in the northern region of South Africa, suffocating aquatic life, including on the Crocodile River and the Hartbeespoort Dam it flows into. The weevils, which have been used effectively elsewhere in the world to fight water weeds, are now leading South Africa's charge against the life-sucking plants threatening ecosystems in at least three northern provinces and creeping into neighboring countries. After the weevils helped control the spread of salvinia in parts of the United States, scientists from both countries worked together on a project to gather a starter population in South Africa. The 1-millimeter-long (0.03 inches) insects were brought over 8,700 miles from Louisiana. Rearing stations are being set up near several dams to grow the weevil population. Once released at an infested site, the beetles make themselves at home on the salvinia, the only thing they eat, without damaging the local ecosystem, scientists say. 'They lay eggs on this plant, feed on this plant and die on this plant. If this plant dies, they will die as well,' said professor Julie Coetzee, the principal scientist at the South African Institute for Aquatic Biodiversity. 'They damage certain tissues, those tissues become waterlogged and then those plants sink to the bottom.' A floating menace Hartbeespoort Dam north of Johannesburg, the location for the pilot project, is an important source of irrigation for nearby farms and a popular recreation site. 'When we bought the property there was this beautiful little floating plant on the dam and I thought well that's quite nice,' said 53-year-old resident and business operator Max Moller. 'Little did I realize this little floating fern was an absolute menace.' Moller, the owner of Mogi's hiking trail, said the salvinia have clogged up and damaged boat engines and also hurt fishing communities over the nine years that he has lived in the area. South Africa's already vulnerable freshwater systems face a significant threat from salvinia, scientists say. The plants have had two major growth spurts in 2021 and 2022, surviving on the high nitrate contents in the water. The plant initially surfaced more than a decade ago at the dam, which has also long been battling with a water hyacinth invasion, another problematic species. 'If you pull the hyacinth away, this plant is lurking,' said Coetzee. The invasive plants block out the sunlight, which means no oxygen in the water, she said. "If there is no oxygen, there's no fish, there's no crab, there's no insects and so you completely destroy or alter the aquatic ecosystem,' she said. Salvinia has a rapid growth rate and its spread has been most notable across Gauteng province, where South Africa's biggest city of Johannesburg and its capital, Pretoria, are located. The plant is compounding existing water supply problems by depleting the oxygen and sapping the supply in a country that's already struggling with increasing demand and deteriorating water infrastructure. Concerns over the weevils' impact While releasing the weevils will help combat salvinia, experts warn that there could be unintended side-effects. Anthony Turton, a water expert and researcher at South Africa's University of the Free State, cautioned that their introduction could turn rivers and dams into more suitable homes for bacteria and dangerous organisms. That includes poisonous blue-green algae, known as cyanobacteria, which flourish in nutrient-rich, contaminated waterways and already affect almost 60% of the nation's dams. 'With more light and less competition for nutrients, those cyanobacteria will go into a condition known as a bloom,' he said. 'This is exponential population growth that radically populates the entire water column.' Turnton said simultaneous action to repair damaged sewage systems and limit agriculture fertilizer runoff are essential for a lasting solution. 'Unless there are efforts to reduce the inflow of nutrients from sewage flows, then we are only creating space for cyanobacteria to grow without competition from floating weeds,' he said. Threat of spreading to other countries The weevils aren't the first insects to be introduced to curb an invasive threat in South Africa. The country brought in a bug in the 1930s to control the spread of a hardy cactus native to Mexico that was hurting ecosystems. That project was viewed as a success. The speedy growth of the salvinia has put pressure on the government to act, particularly as researchers warn that neighboring countries also now face an invasion. Coetzee said that salvinia was popping up on the confluence of the Crocodile and Limpopo rivers in the far north of South Africa. 'That now poses a huge threat to our neighbors because this plant has been transported by our rivers onto our borders,' she said. 'It is likely to go all the way along the Limpopo, along Botswana and Zimbabwe's borders and into Mozambique.' 'We really have a responsibility to control this plant," she added. ___ AP Africa news:
Associated Press
30-03-2025
- Science
- Associated Press
Scientists hope hungry weevils from Louisiana can tackle South Africa's invasive water plants
HARTBEESPOORT, South Africa (AP) — Dozens of tiny black weevils cling onto a fern plant as it is tossed onto a leafy green mat coating the surface of South Africa's Crocodile River. Those weevils aren't tossed into the river by accident: scientists hope that the insects and their larvae will munch their way through the green mat, which is made up of an unwanted, invasive South American aquatic plant called Salvinia minima. The plant is steadily taking over freshwater bodies in the northern region of South Africa, suffocating aquatic life, including on the Crocodile River and the Hartbeespoort Dam it flows into. The weevils, which have been used effectively elsewhere in the world to fight water weeds, are now leading South Africa's charge against the life-sucking plants threatening ecosystems in at least three northern provinces and creeping into neighboring countries. After the weevils helped control the spread of salvinia in parts of the United States, scientists from both countries worked together on a project to gather a starter population in South Africa. The 1-millimeter-long (0.03 inches) insects were brought over 8,700 miles from Louisiana. Rearing stations are being set up near several dams to grow the weevil population. Once released at an infested site, the beetles make themselves at home on the salvinia, the only thing they eat, without damaging the local ecosystem, scientists say. 'They lay eggs on this plant, feed on this plant and die on this plant. If this plant dies, they will die as well,' said professor Julie Coetzee, the principal scientist at the South African Institute for Aquatic Biodiversity. 'They damage certain tissues, those tissues become waterlogged and then those plants sink to the bottom.' A floating menace Hartbeespoort Dam north of Johannesburg, the location for the pilot project, is an important source of irrigation for nearby farms and a popular recreation site. 'When we bought the property there was this beautiful little floating plant on the dam and I thought well that's quite nice,' said 53-year-old resident and business operator Max Moller. 'Little did I realize this little floating fern was an absolute menace.' Moller, the owner of Mogi's hiking trail, said the salvinia have clogged up and damaged boat engines and also hurt fishing communities over the nine years that he has lived in the area. South Africa's already vulnerable freshwater systems face a significant threat from salvinia, scientists say. The plants have had two major growth spurts in 2021 and 2022, surviving on the high nitrate contents in the water. The plant initially surfaced more than a decade ago at the dam, which has also long been battling with a water hyacinth invasion, another problematic species. 'If you pull the hyacinth away, this plant is lurking,' said Coetzee. The invasive plants block out the sunlight, which means no oxygen in the water, she said. 'If there is no oxygen, there's no fish, there's no crab, there's no insects and so you completely destroy or alter the aquatic ecosystem,' she said. Salvinia has a rapid growth rate and its spread has been most notable across Gauteng province, where South Africa's biggest city of Johannesburg and its capital, Pretoria, are located. The plant is compounding existing water supply problems by depleting the oxygen and sapping the supply in a country that's already struggling with increasing demand and deteriorating water infrastructure. Concerns over the weevils' impact While releasing the weevils will help combat salvinia, experts warn that there could be unintended side-effects. Anthony Turton, a water expert and researcher at South Africa's University of the Free State, cautioned that their introduction could turn rivers and dams into more suitable homes for bacteria and dangerous organisms. That includes poisonous blue-green algae, known as cyanobacteria, which flourish in nutrient-rich, contaminated waterways and already affect almost 60% of the nation's dams. 'With more light and less competition for nutrients, those cyanobacteria will go into a condition known as a bloom,' he said. 'This is exponential population growth that radically populates the entire water column.' Turnton said simultaneous action to repair damaged sewage systems and limit agriculture fertilizer runoff are essential for a lasting solution. 'Unless there are efforts to reduce the inflow of nutrients from sewage flows, then we are only creating space for cyanobacteria to grow without competition from floating weeds,' he said. Threat of spreading to other countries The weevils aren't the first insects to be introduced to curb an invasive threat in South Africa. The country brought in a bug in the 1930s to control the spread of a hardy cactus native to Mexico that was hurting ecosystems. That project was viewed as a success. The speedy growth of the salvinia has put pressure on the government to act, particularly as researchers warn that neighboring countries also now face an invasion. Coetzee said that salvinia was popping up on the confluence of the Crocodile and Limpopo rivers in the far north of South Africa. 'That now poses a huge threat to our neighbors because this plant has been transported by our rivers onto our borders,' she said. 'It is likely to go all the way along the Limpopo, along Botswana and Zimbabwe's borders and into Mozambique.' 'We really have a responsibility to control this plant,' she added. ___
