Great white sharks avoid areas where they are captured, so this could be a way to deter them from hunting near swimmers.

They say it's a flight response. paul butcher In the New South Wales Department of Primary Industries, Australia. “It's the same with almost any animal, and it's the same with sharks.” The animals then “resume normal locomotor behavior as if nothing happened,” he says.

Butcher and his colleagues use smart (Real Time Shark Management Alerts) Drumlines: Baited hooks attached to buoys 500 meters off the coast in approximately 20 popular areas of New South Wales. Each of the 305 drumlines in total is equipped with a system to notify local response teams, which she aims to reach by boat within 30 minutes of a hooked shark feeding. Lines are set up fresh each morning and collected the same day, so they are never left overnight.

The team records the shark's size and health and tags it. Sharks considered to be more of a threat to swimmers, such as great whites, tiger sharks and bull sharks, are then moved 500 meters offshore and released. Other species, such as hammerhead sharks and gray nurse sharks, are released where they are captured.

Butcher and his colleagues monitored 36 great white sharks (carcharodon carcharius) had a satellite-linked radio-transmitting tag attached to its dorsal fin after being captured in five locations in 2016. During the first 3 days after release, all sharks moved away from the shoreline where they were captured and mostly stayed there. offshore.

“Ten days after release, sharks gradually moved closer to shore, but 77% of sharks remained more than 1.9 kilometers from shore, with an average of 5 kilometers from their tagged location,” the study said. they wrote in their paper.

Additionally, sharks are still being detected by tracking devices an average of nearly 600 days after release, indicating that the program is not increasing the risk of shark mortality.

Since 2015, more than 1,100 great white sharks, with an average length of about 7 feet, have been captured on SMART drumlines and more than 400 capture events have taken place, Butcher said.

The drumline is part of a larger effort in New South Wales to find non-lethal ways to keep great white, tiger and bull sharks away from people in the water. Drones are currently flying over up to 50 beaches to monitor for sharks and other potential threats during the school holidays, with the department using tagged sharks to detect when they pass nearby. It operates 37 listening station buoys. This information is transmitted to the public via: SharkSmart app.

This suite of tools could mean one day the controversial beach nets that captured 228 animals in New South Wales alone during the 2022/23 reporting period can be removed. Of these 228 animals, only 85 were released alive, and more than 200 were non-target species such as turtles, dolphins and seals.

david booth Researchers at the University of Technology Sydney say the findings are very good news. “And being able to see the captured and released animals again after so many years is very moving and certainly better than slaughtering them,” he says.