Darwin teams milk cane toad toxin for trap bait to protect native wildlife
Milky liquid squeezed from the glands of cane toads could be key to controlling the invasive pests in Australia.
BiodiversityWatch coordinator Graeme Sawyer is working with fellow Top End toad busters to trap tadpoles and adult toads, minimising populations to take the pressure off iconic native species.
Mr Sawyer says one of the "really big problems in the Northern Territory since toads arrived" is that potentially billions of the invasive pests compete with other wildlife to access the exact same food sources.
But by using the amphibian's own toxic milk to attract them into funnel-shaped tadpole traps, the success of cane toad breeding is restricted.
"If you get rid of the toads, it leaves the food supply for a whole range of native animals," Mr Sawyer says.
Milking the amphibian's parotoid gland extracts cane toad toxin, which is then placed inside the underwater traps.
A gentle squeeze to the gland is all it takes to secrete the liquid, in a process that resembles pimple popping.
With further planning and a strategic approach, Mr Sawyer says the traps "could probably wipe those tadpoles out of these waterways completely".
The strategy is safe for natives too, since only cane toads and some feral fish associate the smell with food.
Unlaid eggs carried by female cane toads are laced with the toxin too, so they also work "very well" in traps.
Mr Sawyer has been collaborating with the City of Darwin to remove 900 cane toads from East Point and another 900 from Jingili Water Gardens this year alone.
The council's environment and climate change coordinator Emma Smith says his "wealth of knowledge" has been vital.
In return, Mr Sawyer says he has been impressed by the council's efforts, but believes more action could spread the success even further.
He points to a trial of traps at the Marrara Golf Course which successfully eliminated "every single tadpole in a couple of days" from the facility's ponds two years ago.
"One of the traps took out 16,000 tadpoles in one night," he says.
"But to do it on a broader scale is something that needs some serious attention.
Ms Smith says cane toad busts first started in Darwin's inner-north "biodiversity asset" of East Point, and this year expanded into the Jingili Water Gardens, which he called "cane toad heaven".
He says the shallow fresh water attracts breeding toads, which is a hazard for other species living there.
The yellow-spotted monitor can mistake juvenile cane toads for food, which can kill the threatened lizards when the toads are ingested.
Ms Smith says the monitor — along with the iconic blue-tongue and frilled-neck lizards — "used to be everywhere" in Darwin, but local reptile populations had "declined dramatically since cane toads arrived".
However, toad busting efforts seem to be working, with the number being collected also starting to trend downwards.
Mr Sawyer is encouraging the public to get involved, describing the trapping strategy as "deadset easy".
Teams in Queensland have developed traps with artificial bait tablets, which can be purchased "if you're not up to milking cane toads yourself".
And if you find eggs in a pond, they can also be used in the traps.
"You make a box, or you can buy a commercial one, put that in the water body and drop these baits in," Mr Sawyer says.
"Every other day you come along and tip all the tadpoles into a net, then euthanise them."
Freezing cane toads is the most humane way to do it, but tadpoles will die without water — so leaving them to dry on the ground also works.
Ms Smith advises putting adult toads in the fridge for 12 hours first, then the freezer for 12 hours, and says the dead toads can be buried or disposed of via compost bins.
She says she'd like to see more community education around cane toads, because the public "could really help" if they understand how to spot and kill the pests, pointing to a February bust where 322 were caught in a matter of hours.
Mr Sawyer says it's important for NT residents to do their bit.
"Anything you can do to keep toad numbers as low as possible is helping the other native wildlife."
To keep toads out of pools and ponds, Mr Sawyer recommends constructing a small barrier with a smooth material — not a fine mesh like chicken wire.
Native tree frogs have padded toes, so they can scale windows with ease, but cane toads don't have the same pads so can only climb surfaces that have texture to grip onto.
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
ABC News
38 minutes ago
- ABC News
Blue-green algae concerns prompt push for demolition of Mannus Lake Dam
Over a decade, Leigh McColl and his family would walk down to a nearby creek to cool off in the warmer months. The family swims ended in 2017 after testing of the water showed it contained blue-green algae, a bacteria that causes blooms in bodies of warm and still water. "Charlotte, my middle daughter, got extremely sick … we used to swim in [Mannus Creek] every night," Mr McColl said. Charlotte's symptoms included fatigue, respiratory infections, "ice-pick" pain, joint pain and severe brain fog. Mannus Creek runs through Mr McColl's property, south of Mannus Lake Dam at Tooma, in the New South Wales Riverina. The farmer said he had not been able to use the creek water for agriculture due to the algae blooms. "I've got business implications … we are in the second year of drought and we've got water that we can't use," Mr McColl said. The dam in the NSW Snowy Mountains was built in the early 1980s by a local man for private fishing use. It became property of the Snowy Valleys Council following the man's death and remains under council operation. Mr McColl is part of a group of landholders calling for the dam to be destroyed and turned into a wetland. A report to the council estimates the demolition cost would be $13 million. Simon Mitrovic, professor of freshwater ecology at the University of Technology Sydney, said blue-green algae was becoming more prevalent across Australia, with summer the most common season for blooms. "The surface of the water gets hotter than the bottom of the water, and those two layers actually separate," Dr Mitrovic said. Mr McColl's mother-in-law, Yola Cox, moved to Tooma in 1977 and lived on a property surrounded by Mannus Creek. "It was the most beautiful crystal-clear water and had every fish variety, and every platypus and every frog," she said. "Since then, a lot has changed. "We used to use it as drinking water. All my children grew up on the Mannus Creek water, and so did all of my animals." The federal government's Water Quality Australia website states that exposure to blue-green algae can cause damage to the nervous system and liver, as well as irritation to the skin and eyes. Mannus Lake Dam is no longer a source of drinking water, but Dr Mitrovic said the algae was "also a potential risk for people using water recreationally" and some animals. Dr Mitrovic was contracted by the Snowy Valleys Council in 2018 to conduct a study into the dam's blue-green algae. He recommended a mixer be placed in the dam in 2019 to help circulate the water, however, a follow-up report in 2022 found the effectiveness was minimal. Dr Mitrovic said his team had to wait until "a low inflow period" to test the efficacy of the mixer. "At that time, it did coincide with more algae blooms," he said. His most recent report, which indicated it would cost up to $13 million to deconstruct the dam, was discussed by the council last month. Councillors voted to further investigate the feasibility of a wetland. The Downstream Users Group advocates for demolishing the dam, which was under green alert last month for blue-green algae at low water densities. The algae blooms have been present at Mannus Lake Dam for about seven years. Spokesperson John Williams, who is Ms Cox's partner, said turning the dam into a wetland would "soak up" the algae. "The flow will be running the whole time," he said. "There will still be swimming, fishing, everything will be here, and it would be a lot better area." Fellow Tooma resident and Downstream Users Group member Roger Paton said it had been a long campaign calling for the destruction of the dam. "Whatever we send downstream goes to South Australia, so pretty much everyone will feel the consequences of it." Mr McColl believes his daughter's illness was the result of exposure to the blue-green algae. The family received inconclusive results after several medical appointments. After exhausting all options, they contacted a naturopath in Western Australia in 2024, who found Charlotte had Chronic Inflammatory Response Syndrome (CIRS). CIRS is a multi-symptom illness caused by inhaling biotoxins, which include mould and blue-green algae. The disease is not formally recognised in Australia, however, its biomarkers are the subject of a Macquarie University study in relation to mould and dampness.
ABC News
an hour ago
- ABC News
Death of Symerien Brooking at Perth Children's Hospital sparks calls for coronial inquest
The parents of a 10-year-old girl who died in WA's main paediatric hospital last August say their desperate pleas for a brain scan were ignored until it was too late — and they want a coronial inquest. WARNING: This story contains the name and image of an Indigenous person who has died. Symerien Brooking was taken to Perth Children's Hospital (PCH) via ambulance when her mother, Sharyn Morris, found her unresponsive on the dining room floor. The young girl was unable to stop vomiting and once in hospital, had multiple seizures, one of which lasted for 45 minutes. Symerien — who was born with an extremely rare and complex congenital disease and who lived with numerous medical conditions — was under the care of a neurologist at PCH and had presented twice that year with seizure activity. Ms Morris and her partner Aaron Bransby say they repeatedly asked for a CT scan of Symerien's brain, but one wasn't done until seven hours after she arrived. The scan found significant bleeding, and surgery was done to insert drains to remove the fluid, but it didn't work. Ms Morris and Mr Bransby had to make the decision to take their daughter off life support. "We both had a lot of people around us, obviously friends and family supporting us," Mr Bransby said. "But it doesn't take the pain away from losing someone that you never think you're going to lose." Symmie — as she was known — died in the hospital almost 48 hours after she had arrived. The loss is almost too much to bear for Ms Morris who was herself a grandmother when she took on caring for 10-day-old Symmie in 2014. "It has changed my life forever," she said, tears streaming down her face. "My life will never be the same. Never. "I will never hear her say, 'I love you Mummy' again. "I will never get to hold her and feel her love ever again because they wouldn't listen." The ABC first told the story of Symmie's remarkable life and Ms Morris' relentless pursuit for her daughter's survival in 2019. When Symmie was born, doctors gave her little more than a year to live. But the girl with the "cheeky smile and infectious laugh" didn't abide by anyone else's rules, she made her own. And with the ongoing love, support and advocacy of Ms Morris, and later Mr Bransby, Symmie defied almost every expectation her medical condition dictated. She wasn't expected to walk. She did. She wasn't expected to talk. She did. "She was excelling, she was growing, she was developing — not just in her body but developing in her mind," Ms Morris said. "Her brain turned into a little sponge, and she just wanted to know so much … she knew the solar system, she knew it inside and out, she could line all the planets up." Ms Morris said Symmie's prognosis had never been more positive and her overall care plan had gone from being one focused on providing quality of life to including quantity. One of Symmie's doctors had even told her he expected her daughter would outlive her, she said. "I felt my role in the last 12 months of Symmie's life was to teach her to be as independent as possible," Ms Morris said. "I was teaching her to be strong enough to survive in this world without me, not me without her." According to the coroner, Symmie died from complications of a brain bleed, its cause still not clear to Ms Morris and Mr Bransby. It's why they want a coronial inquest. A hospital investigation into Symmie's death found the care she received was appropriate and her death was non-preventable, with her medical history highlighted as a factor. Ms Morris and Mr Bransby don't agree. Ms Morris said she was told the scan wasn't done because of concerns about radiation exposure, so she asked for her daughter's neurologist at the hospital to be contacted. But this was was not done, she said. "I yelled and I screamed, and I begged but I was not heard," Ms Morris said. "No one listened to us." Their anguish aligns with that of other parents whose children have died in WA hospitals, including that of Aishwarya Aswath in 2021 at PCH, and Sandipan Dhar who died in March last year at Joondalup Health Campus. Ms Morris wants systemic and cultural change so more weight is given to the voices of patients, parents and caregivers — and so Symmie's death was not in vain. "She was here for a reason," Ms Morris said. "She touched so many people's lives, and she taught so many people so much about life. "She's an unforgettable person." The ABC sent a list of detailed questions about Symmie's death and the investigation to the Department of Health and the Child and Adolescent Health Service, which oversees PCH, but did not receive a response. Health Minister Meredith Hammat attended Symmie's funeral as the family's local member and said she would continue to support Ms Morris to get answers. But she stopped short of supporting her calls for an inquest. "Symmie was an incredible little girl and loved by many people in our community," Ms Hammat said. "Sharyn is a strong woman and a fearless advocate, and I'm sorry for her loss. "I won't discuss the details of our meetings, but it is my firm view that parents and guardians should be listened to. They know their child best."
ABC News
an hour ago
- ABC News
GrainCorp class action alleges noise, odour pollution by Numurkah's main employer
A resident of Numurkah in northern Victoria has launched a class action against manufacturing giant GrainCorp Oilseeds over allegations of noise and odour from the town's factory, which he claims has affected his health and cost him his job. Kevin Carling Green, 63, has been in a four-year fight with Numurkah's major employer, which processes canola oil in the middle of the town. Mr Green's lawyer Dominica Tannock alleged her client and his family could not sleep, had broken out in skin rashes, and their property had been devalued because of factory emissions. "The defendant, GrainCorp Oilseeds, owes a general environmental duty under the EPA Act to Mr Green and [class action] group members … to minimise the risk of harm to their health and to the environment from pollution," Ms Tannock said. Mr Green and his family have lived in their home, 100 metres from the factory, for 27 years. What started as a civil matter between Mr Green and the company has now turned into a class action encompassing other residents within 1 kilometre of the factory who also allege they have been negatively impacted. Ms Tannock said just three people opted out. The matter is set to be heard in the Supreme Court later this year. Documents filed to the court allege that noise and odour from the factory were "intrusive" to neighbouring properties. It is alleged that rumbles, beeping, hissing steam, and trucks entering and exiting the factory are "especially noticeable during early mornings, evenings and nights", affecting residents' sleep. An evidence document claims that in March 2018, Mr Green experienced concentration lapses in his work as a heavy machinery operator with a local employer not connected to GrainCorp. The documents said Mr Green told his doctor he was experiencing day-time fatigue and that "he believed this was due to the noise and odour from the GrainCorp factory, which was waking him up." It is alleged that Mr Green's doctor declared him incapable of normal employment duties for around four weeks between April and May 2018, and he was later dismissed from his job because of his condition. Ms Tannock said the alleged noise and odour pollution was the result of an increase in the factory's production between 2015 and 2016. Ms Tannock alleged the unpleasant "grainy, chemical" odour wakes the family up, and affects their sleep and their amenity. It is also alleged that Mr Green's daughter breaks out in rashes, and others in the area say their eyes get itchy. Ms Tannock said Mr Green had tried to resolve the issue through Environment Protection Authority Victoria (EPA) and the local Moira Shire Council with little success. "The EPA, we would say, has sat on its hands and done very little," she said. "I have written extensively, before the litigation, to the EPA and [was] essentially stonewalled by the EPA." The ABC contacted the Moira Shire Council and the EPA, and both said they would not comment as the matter was before the courts. In a statement, a GrainCorp spokesperson said the company was "vigorously defending the proceedings". "As the matter is before the court, we will not be making further comment at this time." The class action will go to trial in October unless it is settled beforehand.
