University of Exeter researchers and conservation engineers at Fishtek Marine developed the ‘SharkGuard’ device, which attaches to longline fishing rigs to scare off sharks and rays.

It tested the device on French boats fishing for tuna and saw reductions in so-called bycatch (i.e. accidental catching) of blue sharks by 91 per cent and stingrays by 71 per cent.

Powered by a small battery, the device works by targeting the area around a shark’s nose and mouth, which is packed with electrical sensors, called the ampullae of Lorenzini.

These sensory organs get overstimulated by the electric field generated by the line’s pulse device, which makes the sharks swim away from the danger of the baited fishing hooks.

Image credit: Fishtek Marine

Catch of the target species, bluefin tuna, also appeared...