Shark Smart Drum Lines More Effective Than Nets So Far

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New figures from the Department of Primary Industries (DPI) show the smart drum lines deployed off the New South Wales north coast are more efficient than shark nets when it comes to catching target species.

Twenty-five smart drum lines have been used between Lennox Head and Evans Head since December 2016.

A smart drum line is based on the traditional drum line design, but includes technology that can alert rangers to the capture of marine life and they can then attend the device if sea conditions permit and allows the animals to be tagged and released.

Fourteen great whites, two tiger sharks and two grey nurses have been hooked in that time in smart drum lines.

DPI scientist Paul Butcher said all were successfully released.

“And we do know once the animals are tagged, they’re often 20 to 40 kilometres away the next day,” he said.
The drum lines are part of a $16-million shark management strategy announced in the wake of an unprecedented spate of attacks in the region over 2015-16.

Halfway Point in Six-Month Trial

A six-month trial of various risk-mitigation strategies also involves shark nets, aerial surveillance and acoustic buoys.

At the halfway point in the trial, 22 sharks have been trapped by the nets, with 19 dying before they could be released.

Of those caught, five would be considered dangerous to humans (two great whites, two tiger sharks and one bull shark).

The most common species snared is the great hammerhead (17).

Other non-target species caught in the nets include a bottlenose dolphin, nine turtles and 109 rays.

Greens Call for Nets to be Scrapped

NSW Greens Marine and Fisheries spokesman, Justin Field, said the meshing trial should be scrapped immediately.

“We’ve had a look at the three months of data, and I think what we’re seeing is target species are not being caught and the nets are not being checked as often as they’re required to be,” he said.

“I’m actually calling for the nets to come out now.

“End the trial and let’s go and look at non-lethal management options.”
Too early to judge success

But Dr Butcher said it was too early to make a call about which strategies were the most effective.

“As we’ve seen with the drum lines, the catch has changed between December, January and February and it could change again in the next couple of months,” he said.

“Until we finish that six-month trial, and then we can compare wholly the results from the smart drum lines and the nets, then it’s too early to say anything on what’s a success and what’s not.”

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