Latest news with #JulieCoetzee
Yahoo
16-04-2025
- Science
- Yahoo
Government unleashes tiny insects to combat full-blown public crisis: 'The solution is laws addressing this source'
The South African government has a new weapon in its fight against invasive water plants: a tiny aquatic weevil from Florida, Devdiscourse reported. The salvinia weevil is named for its favorite food. It eats massive quantities of common salvinia, a plant that is creeping across South Africa. This water weed is an invasive species — a species that has traveled beyond its native environment to a new location where it is multiplying at a destructive pace. Left alone, it will take over, crowding out and killing off a wide range of other species and destroying the natural balance that has existed in that area for millennia. In the case of salvinia, it was first sighted at Hartbeespoort Dam in 2011. Since then, it has spread as far as the Limpopo River, to the edge of Botswana. It clogs the water, interfering with the livelihoods of everyone who relies on the river as well as the diversity of water plants and the quality of the water. The weevils are expected to multiply just as fast to address the problem. Crucially, they only eat salvinia. "This biological control programme will be closely monitored to assess the weevil's progress and effectiveness in reducing common salvinia. Importantly, these weevils exclusively target the salvinia minima plant and do not pose risks to other aquatic vegetation, crops, or ornamental plants," said professor Julie Coetzee, deputy director of the Rhodes University Centre for Biological Control and principal scientist at the National Research Foundation's South African Institute for Aquatic Biodiversity, per Devdiscourse. Water and Sanitation Deputy Minister Sello Seitlholo emphasized that a major cause of salvinia's spread, and one that must be addressed, is the excess nutrients in incorrectly processed wastewater. "What is also important is for us to have serious discussions with municipalities in the upper catchment areas. The inadequate treatment of wastewater leads to high nutrient levels in the water, which in turn fuels the spread of invasive aquatic plants, degrading the ecosystem, affecting recreational activities, and hampering the local economy," Seitlholo said, per Devdiscourse. The solution is a law to address this source of pollution — which will lead to cleaner, healthier water for all. Should we be actively working to kill invasive species? Absolutely It depends on the species I don't know No — leave nature alone Click your choice to see results and speak your mind. 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.
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. ___
