A NEW method of sonar shark detection is being trialled by a Byron Bay team in a bid to provide a safe and discrete warning system for beachgoers.

The project is being run by Australian inventor Ric Richardson, Lara Alberd and researcher Kirra Pendergast.

Ms Pendergast, who has a background in technology project management, said testing had begun this week using passive sonar devices to detect creatures larger than 2.5m near Julian Rocks.

She said the passive sonar devices they were testing were "listening" devices that wouldn't interfere with marine creature like dolphins and whales, as oppose to "active" sonar devices which emit a ping.

Ms Pendergast said the testing phase would look at how different ocean animals and elements, such as crashing waves, show up on sonar.

The final product would be a sonar device that sits on the ocean floor and can detect sharks over 2.5m long, before sending an alarm to notify beachgoers the creature is 100m away.

Mr Richardson said he first started talking about the project with Byron Mayor Simon Richardson after he lost his neighbour to a shark attack in the shallows of Clarke's Beach in front of the Beach Café.

He likened Byron Bay's marine park sanctuary to Africa's Serengeti.

"The beaut thing about wildlife parks is that you can see the lions and leopards at a distance before they get close," he wrote on his website.

"And this is the problem with sharks. They are beautiful, powerful animals, but when they sneak up on you there is not much you can do.

"Having quadracopters following lion prides around the countryside may be safe but it is just a painful exercise and expensive.

"Nets are even worse. What use is a wildlife sanctuary where the fences can't tell the difference between dangerous animals and everything else.

"At this time we are about 60% sure of a solution. There are some really promising candidate technologies and we are testing them and researching them at the moment.

"Things are looking promising."

Mayor Richardson said he was impressed by the idea of using sonar for early warning systems.

"To me the good thing about it is it takes us beyond that fight or flight instinctual response," he said.

"Obviously we want people to feel safe in the water."