Science. - Electric pulses to reduce bycatch of sharks

Madrid, 21 (Europe Press)

New research published in the journal Current Biology shows that the new device, called “SharkGuard,” is attached to longline fishing gear to scare away sharks and rays. In the study, conducted on French tuna fishing boats, lines equipped with this system reduced bycatch of blue sharks by 91% and rays by 71%.

Catch amounts from the target species, bluefin tuna, also appear to be declining, but more testing is needed to fully understand the effects of the device on the target species.

SharkGuard was developed by Fishtek Marine conservation engineers and tested by researchers at the University of Exeter, both in the UK.

Dr Phil Doherty, of the Center for Ecology and Conservation, Exeter Penrhyn, said: “Shark and rays are declining due to overfishing, especially oceanic species such as blue sharks and sea bass, which are commonly taken by longlines around the world.” Cornwall).

He continued, “There is an urgent need to reduce bycatch, which not only kills millions of sharks and rays each year, but also costs fishermen time and money.” And our study indicates that SharkGuard is remarkably effective at keeping blue sharks and sea bass off fishing hooks.

Commenting on the decline in bluefin tuna catches (42%), Dr. Doherty noted that the total number of catches in the trial period (on both lines with and without SharkGuard) was low, so further testing is necessary to fully explore the results.

“Following these exciting results, Fishtek Marine engineers are modifying ‘SharkGuard’ to be smaller and recharge itself after each crew,” said Doherty. The research will continue in Exeter, where we will test the effectiveness of SharkGuard at sea on a multitude of species and fisheries.”

Pete Kebbell, Co-Founder and Director of Fishtek Marine explains, “When using SharkGuard, sharks don’t take the bait or get caught, which gives us great hope. Against the backdrop of relentless stories of population declines occurring across all of our marine species It’s important to remember that there are people out there who are working hard to find solutions,” he adds.

He stresses that SharkGuard “is an example that, with the right support, it is possible to deploy the solution at a scale sufficient to reverse the current decline in global shark numbers.”

Powered by a small battery, SharkGuard targets the area around a shark’s nose and mouth, which is lined with electrical sensors called blisters of Lorenzini. These sensory organs are over-stimulated by the electric field generated by the SharkGuard, causing the sharks to turn away from the danger of baited hooks.

Professor Brendan Godley, who heads Exeter’s marine research group, said: “Working with partners such as Fishtek Marine allows us to combine Exeter’s marine research expertise with its fantastic engineering. A global game-changer for sustainable longline fishing.”