A tiger shark hooked, tagged and released off Sydney's Tamarama Beach yesterday morning has reignited debate about SMART drumlines.
The devices are heralded as a non-lethal method of shark control because a GPS communications unit sends an alert once an animal has been hooked.
From there, boats go out and the animal is tagged and released.
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Drone Shark App founder Jason Iggleden captured yesterday's capture from the air and called into question how this plays out in practice.
A tiger shark is seen tied at the back of a boat for "at least 45 minutes" after being pulled to the surface.
Iggleden said it appeared "quite motionless" as it was finally released.
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"I've spotted my first tiger shark here in Sydney but this is not how I wanted to see it," Iggleden said, adding that after the shark was tagged it wasn't released for 20 minutes.
"To be honest, I'm not really sure if the shark was still alive once released as it was quite motionless as it sank below the surface."
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NSW'S Department of Primary Industries (DPI) confirmed a 2.45-metre shark was caught off the popular swimming spot yesterday and was released alive.
"The SMART drumline was activated at 10.24am and the contractors' boat arrived at 10.45am," a spokesperson said.
"The shark was tagged and released in good health at 11.23am."
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When asked whether it's standard practice to leave a shark for 20 minutes after it's tagged, DPI didn't answer.
But in a statement issued online, the NSW Shark Smart program said, "the contractor operated in accordance with all DPI protocols and the contractual requirement to respond to alerts within 30 minutes".
Marine ecologist at Flinders University Charlie Huveneers told 9news.com.au he's captured and released sharks under similar conditions.
"Depending on conditions, taking accurate measurements, sampling, and tagging can take 15-20 minutes," he said.
"Tiger sharks are also quite robust with high post-release survival and they do not need to be energetically swimming upon release for them to still be alive.
"We have successfully caught, sampled, and tagged more than 80 tiger sharks using similar protocols to NSW DPI and have not had any mortality."
Debate over SMART drumlines rages online
While the shark was alive when released, some of Iggleden's followers expressed shock at the footage, with one writing, "40 minutes? Seems like a long time to put a tag in… what were they doing the whole time?"
Another said: "Sad. Drum lines need to go."
Others questioned what alternative measures might look like.
"Might have survived if the the boat was in motion while it was tied up like that," one wrote.
Another added: "It's a tiger shark for goodness sake and it was tagged and released and you're still complaining?"
Tiger sharks are one of three species of "target" sharks listed by the DPI.
The other two species include great white sharks and bull sharks.
DPI said 15 SMART drumlines are "installed daily between Bondi and Little Bay" in Sydney.
This is in addition to 15 SMART drumlines between Greenhills and Oak Park in Sutherland LGA, and 30 across the Northern Beaches – covering Manly to Palm Beach.
It comes following the fatal attack of dive instructor Simon Nellist off Little Bay in February.
The attack by a great white at least three metres in length was Sydney's first shark fatality in nearly 60 years.
The great white responsible was never captured but in the week following the attack two tiger sharks were captured and released via SMART drumlines off the eastern suburbs.