State Government considers more shark attack mitigation measures after Stella Berry’s tragic Swan River death

The State Government is being urged to consider expanding tagging programs to include bull sharks after 16-year-old Stella Berry was killed while swimming in the Swan River at the weekend. It’s believed the teen was mauled by a bull shark after spotting a pod of dolphins and jumping into the water from a jet ski about 2.5km from the mouth of the river near the Fremantle traffic bridge on Saturday afternoon. Bull sharks are known for their ability to swim far upriver, being able to live in both fresh and salt water. “It’s just a very, very sad and tragic event, and totally unexpected and shocking for the young woman involved and her family,” Premier Mark McGowan said on Monday. “These things are difficult to predict and difficult to avoid. No one is at fault. “We’ll get a report from the Fisheries Department into the whole issue. “If there’s anything that can be improved, we will look at any such measures, but it’s just a terrible tragedy.” His comments came after Fisheries Minister Don Punch said on Sunday that his department would immediately investigate what new mitigation measures could be adopted to make river swimming safer. He ruled out drum lines but said shark barriers could be considered. Fremantle mayor Hannah Fitzhardinge told radio on Monday nets were a tricky proposition for the part of the river where the attack occurred. The City of Melville is looking into possibly installing a barrier at Bicton Baths jetty — not far from Blackwall Reach where Cameron Wrathall survived being mauled by a bull shark while swimming in January 2021. Mayor George Gear said nets were not being considered due to entanglement risks. The barriers being investigated were made of recyclable materials and flexible enough to allow small marine life to pass through but rigid enough to prevent bigger aquatic animals from entering, he said, adding repellent technology was also being considered. Subject to approvals by several State Government departments, community feedback and council approval, it could be in place by next summer, Mr Gear said. Liberal leader Libby Mettam declined to engage in debate over whether the McGowan Government had failed to act in the wake of Mr Wrathall’s near-fatal attack, saying she would support any “science and evidence-based approach” to prevent shark attacks in the Swan River. “First and foremost, my heart goes out to the Berry family and everybody, the whole community, who have been rocked by this tragedy,” Ms Mettam said. “Quite clearly we do need to look at how we can better provide safety for the Swan River and other areas when it comes to shark mitigation. “We do need to look at expanding the tagging program to include bull sharks . . . netting has been raised as well.” Griffith University marine ecologist Johan Gustafson advocates tagging and monitoring bull sharks, saying it had been done on the east coast and given valuable insight into the species. A Department of Primary Industries and Regional Development spokeswoman said the focus remained on great white sharks, which presented the greatest risk in southern waters. But the DPIRD was looking into ways that key information gaps on bull sharks, including the Swan-Canning estuarine system, might be addressed. “A more comprehensive understanding of shark behaviour in the Swan, including determining what shark species are present in the lower reaches of the river, is critical to informing what, if any, mitigation measures might prove effective,” the spokeswoman said. “The DPIRD is continuing to monitor the situation and warnings will be issued via the SharkSmart website and app if there is new information.” Dr Gustafson warned that bull sharks came close to river mouth areas when ready to pup around November and December, moving into brackish waters to prevent their young being preyed upon by other sharks. They could also be attracted to river areas by other marine life such as dolphins feeding on fish. “If you’ve got a fish feeding frenzy . . . you’re going to have sharks in the area, same as what it is in the coastal waters,” Dr Gustafson told radio. “If you spook them . . . if the water is very dirty, they can’t see you, so the probability for an accidental interaction can actually increase.” Macquarie University honorary professor of marine ecology Rob Harcourt said river mouths were not a good place to swim as fish often concentrated there, so were a focus for predators. “The strong currents and tidal exchanges also increase risk,” he told The West Australian. Professor Harcourt said drones were a major shark attack mitigation tool on the east coast, with clean ocean water providing good visibility, but they were less effective in murky, opaque Australian rivers, especially with traffic stirring up silt.