Mary River cod turns the tables on one of its biggest threats by eating them
A critically-endangered fish could be turning the tables on one of its biggest threats by eating them.
In the Mary River, stretching 291 kilometres from the Sunshine Coast to the Great Sandy Strait, the invasive pest species tilapia have been an ongoing problem.
They compete for food and habitat, as well as eating the eggs and juveniles of the river's endangered species such as the "bum-breathing" Mary River turtle, Australian lungfish, the white-throated snapping turtle, and the Mary River cod.
During a routine survey last month by Burnett Mary Regional Group (BMRG) conservationists tilapia remains were found in the mouths of two Mary River cod.
Its chief executive Tom Espinoza said they were not surprised by the finding, even documenting a cod eating a tilapia, but were excited to finally have evidence of the predation.
"There was always the hope and suspicion that they [cod] were eating everything," Mr Espinoza said.
"One of the cod that had the tilapia in its mouth would have been about 80cm long, and the tilapia was close to 40cm long, so they can eat a fish almost half their size — which is great.
"It's provided a lot of hope for people that are invested in healthy cod populations across the board."
While the Mary River cod is considered an apex predator in the river system, it now occurs in less than 30 per cent of their former known range.
Griffith University's Professor Mark Kennard, who works with the National Environmental Science Program, said the cod would eat a lot of different types of large animals.
"We've collected cod that have regurgitated possums and lizards so they are a large, top-level predator in freshwater systems," Professor Kennard said.
He said researchers believed tilapia would be a food source for the cod.
"But there hasn't been much documented evidence of our large-body native species actually eating non-native fish like tilapia," Professor Kennard said.
Environmental groups, researchers and traditional owners have been co-ordinating conservation efforts along the Mary River for decades.
Professor Kennard said tilapia had increased in abundance in the Mary River, especially since the last big flood in 2022.
Tilapia are so successful as an invasive fish that eradication is not considered possible with the species found in 26 of Queensland's 67 catchments.
"Part of the solution is things like enhancing benefits for native species," Professor Kennard said.
Professor Kennard was part of an extensive mapping of the unique river system, which runs south to north.
It has led to innovative conservation ideas such as cod logs and tilapia fertiliser.
"There's still a lot of work to do. The threatened species have not come back as much as we would like," he said.
"They're still rare and restricted in certain parts of the catchment despite 30 years of on-ground work doing restocking of fish, that kind of thing.
"So I think we do need to be making a concerted effort now and in the coming years."
Mr Espinoza said the finding would "increase our resolve" to put in place short and long-term solutions for managing invasive species in the delicate system.
"Hopefully in 10, 15, 20 years' time we've got a population of large cod that can do the rest of the job themselves," he said.
"It's a real natural, sustainable solution."
Hashtags
Try Our AI Features
Explore what Daily8 AI can do for you:
Comments
No comments yet...
Related Articles
Daily Telegraph
20 hours ago
- Daily Telegraph
TGA approves Mounjaro as first medicine registered to treat obstructive sleep apnoea in adults with obesity
Don't miss out on the headlines from Lifestyle. Followed categories will be added to My News. A new drug is expected to be approved by Australia's Therapeutic Goods Association (TGA) as the first ever prescribed medicinal treatment for Obstructive Sleep Apnoea (OSA). The medicine, called Mounjaro (tirzepatide) is designed specifically to treat adults with OSA - a disease which affects around 780,000 Australians. The drug is designed specifically to help treat people who are diagnosed with OSA as a result of obesity given the strong link that exists between both conditions. Andrew Beveridge with the machine that helps him breath at night during sleep. Picture: Tricia Watkinson Respiratory and sleep specialist Professor Brendon Yee said the drug was a 'treatment option' for patients with moderate-to-severe OSA. 'You wouldn't use this medication in sleep apnoea patients who are not obese - which is maybe about 20% of patients,' Professor Yee said. 'There isn't one kind of treatment for the disease…it's important to assess patients based on what the best treatment is for them. Sometimes it may be a combination of things, for instance a combination of weight loss plus a trial of CPAP (continuous positive airway pressure) machines,' he said. 'Mounjaro is private script only, it's TGA approved. It's based on a sleep study and patients have to have obesity… it has the advantage that people can lose weight… but you have to sustain that weight loss.' Damon Sedgwick works in IT and loves performing in amateur theatre - something he found himself doing less and less after he was diagnosed with OSA. 'My partner noticed I was snoring in bed and I would stop breathing at times. I went and had a sleep study and was diagnosed with OSA,' Mr Wedgwick said. 'I tried to use a CPAP…I was using it and I did have a lot of success, but I was still overweight and I still had a dependence on the machine. It was a bit of a burden,' he said. Mounjaro fat-loss drug. Picture: Supplied 'A professor put me in touch with the Woolcock Institute…they said there's a new drug they're trialling and I said yes… the outcome of that after I finished was that I lost about 50 kilos.' Mr Sedgwick said he was able to reclaim the parts of his life which had been put on hold. 'It made a massive difference to my life. I don't snore at night anymore. I used to wake up 60 times on any given night, and now I barely do it once. It's good to be able to move - even walking to the shops is easy now,' he said. 'It's not a miracle shot. It's not a magic bullet, you have to work hard. I still have to watch what I eat and drink, I still have to exercise. It can't be used in isolation, you have to put the hard yards in.' Do you have a story for The Daily Telegraph? Message 0481 056 618 or email tips@
ABC News
21 hours ago
- ABC News
Brain Rot: Is there any proof your phone is destroying your attention span?
Everyone seems to have a hunch that their phone is destroying their attention span, but is there any science to back it up? In episode one of Brain Rot, we're doing our best to focus on the topic of attention for a full 25 minutes — and find out what's actually happening in your brain every time your phone buzzes or dings. Is brain rot a real thing? Or just another moral panic? And how do you know when your own screen use has gone too far? Brain Rot is a new five part series from the ABC's Science Friction about how tech is changing our brains, hosted by Ange Lavoipierre. Guests: Anna Seirian CEO, Internet People Dr Mark Williams Professor, Macquarie University; Cognitive neuroscientist Michoel Moshel Clinical Neuropsychologist Registrar; Phd Candidate, Macquarie University Professor Marion Thain Professor of Culture and Technology, University of Edinburgh; Director, Edinburgh Futures Institute Credits: Presenter: Ange Lavoipierre Presenter: Ange Lavoipierre Producer: Fiona Pepper Producer: Fiona Pepper Senior Producer: James Bullen Senior Producer: James Bullen Sound Engineer: Brendan O'Neill This story was made on the lands of the Gadigal and Menang Noongar peoples. More information: Neuropsychological Deficits in Disordered Screen Use Behaviours: A Systematic Review and Meta‑Analysis - Neuropsychology Review, 2024. Do we have your attention? How people focus and live in the modern information environment - King's College London, 2022. Internet addiction-induced brain structure and function alterations: a systematic review and meta-analysis of voxel-based morphometry and resting-state functional connectivity studies - Brain Imaging and Behavior, 2023.
ABC News
21 hours ago
- ABC News
Sydney's sulphur-crested cockatoos spotted using drinking fountains
First they opened bins, now crackles of Sydney's sulphur-crested cockatoos (Cacatua galerita) have been recorded by scientists waiting their turn to use drinking fountains. The birds, which roost around the Western Sydney Parklands, have figured out how to operate twist-handled bubblers, according to a new study. The behaviour was observed in a group of up to 200 birds, scientists report in The Royal Society Biology Letters. Study co-author Lucy Aplin, a behavioural and cognitive ecologist from the Australian National University, said it took coordinated actions for the birds to access water from the spring-loaded fountains. "It's just one of your bog-standard old-fashioned drinking fountains that you find all across sports fields in Australia," she said. "They [cockatoos] hold on to the stem and they twist with their foot but then they have to lean their weight while they twist as well. Dr Aplin said the whole process looked a "bit funny". "It's a bit of an awkward body position they have to hold, but it's pretty impressive," she said. Sulphur-crested cockatoos are well-known for their urban antics causing havoc on bin night in more than 60 suburbs in Sydney's south. But the population in Western Sydney is a different mob. After the study's lead author, the Max Planck Institute of Animal Behavior's Barbara Klump, saw the drinking behaviour first-hand, she set up a study to track the behaviour of cockatoos around a well-used drinking fountain. First the researchers identified 24 individual birds by painting them with dots, then they used wildlife cameras to monitor attempts to use the bubblers by these and other birds in the local area. Over 44 days, the cameras recorded 525 attempts and collectively the birds were successful 41 per cent of the time they tried to drink, with the marked birds being slightly more successful. Dr Aplin said about 70 per cent of the local birds, which roosted close by, were using the drinking fountain. "They use them as a preferred place to drink no matter whether it's hot or if there's other water sources available," she said. All ages and sexes participated too, unlike with the bin opening behaviour, which is mostly done by males. "Something about the bin opening requires strength, and that's why it's male biased," Dr Aplin said. "[Drinking from bubblers is] a very complex behaviour that requires lots of different fine scale motor actions, but not brute force." Cockatoos are able to work out something tricky like turning a handle because they have brains that are relatively large for their bodies. Their forebrain, which deals with advanced cognitive abilities like tool use, is packed full of neurons like chimpanzees, which also excel at complex problems. Alex Taylor, who studies biological intelligence at the the Autonomous University of Barcelona, said it was clearly tricky to get a tap to work when you had the body of a bird. "Which explains why birds are only successful 50 per cent of the time when trying to use the tap," Dr Taylor, who was not involved with the research, said. "Still this is a pretty good success rate on a hot day when you are thirsty." Dr Taylor said the study begged the question of why only a single species was exploiting human water taps and not others. The exact reason the cockatoos use the bubbler instead of other water sources like a lake or creek is not understood. But there are several hypotheses that researchers want to test. "One possibility is the water just tastes better," Dr Aplin said. That's a theory Irene Pepperberg, an animal behaviourist from Boston University who was not involved in the study, also thought was possible. "The resource is unlimited, so it is probably worth it to keep trying until they figure out the successful behaviour and, if they fail, they seem to have other water sources. "The birds do seem to learn about the source from one another; whether they learn the specific technique from each other is a bit less clear." Another idea is the birds like how the bubblers sit about 1 metre off the ground. Alice Auersperg, a cognitive biologist from the University of Veterinary Medicine who was not part of the study, said this was because drinking from a ground source was risky and left them exposed to predators. But she said another reason they might use the bubblers was because the birds liked to undertake an activity even if there was no food reward. Dr Pepperberg said she recently did a study with umbrella cockatoos where 40 per cent of the time they chose to shell nuts rather than eat ones that were already shelled. The team behind the new bubbler research hopes to drill down into the reasons behind the behaviour as well as other cockatoo innovations in future studies. Dr Aplin said she had received other reports of cockatoos using bubblers with levers and unzipping bags to access lunch boxes. She encouraged people who saw these kinds of behaviour to report it through the Big City Birds App. Gisela Kaplan, an emeritus professor of animal behaviour from the University of New England, said several bird species seemed to exploit taps in the outback in different ways to cockatoos. "The moment [the taps] are used, the birds now fly in and take the drops that fall down and then, once the person has left, also lick out the last drops that are in the tap," Professor Kaplan, who was not involved with the study, said. She said she had witnessed a great bowerbird in Larrimah, Northern Territory, work with its beak at a tap nozzle attachment until water drops were generated. Dr Aplin said ultimately there was an important message behind all these observed behaviours beyond just funny anecdotes. "Urban animals that are adaptable and have expressed behavioural flexibility and have large brains are going to try and use the habitats that we provide them with," she said. "So if we want to increase biodiversity in cities, we need to think about increasing the sort of habitat requirements for species that might not be so adaptable." On the other hand, Dr Aplin added, we could also use urban design to manage those species that are more adaptable.
