I’ll be honest, I’m a bit of a ninny when it comes to sharks. Not all sharks mind you. Just as long as they aren’t bigger than me. Okay fine, just as long as they aren’t bigger than a Labrador. That’s not to say I don’t appreciate their pivotal role in maintaining to health and biodiversity of our magical underwater world though. So when we saw the installation of the Shark Safe barriers along Glencairn Beach from the safety of the Glencairn Hotel balcony, I was intrigued.
Dr Sara Andreotti is a Marine Biologist and commercial diver based in Stellenbosch. Her research work on the White Shark population along the South African Coast is recognised worldwide and she is also one of the co-inventors of the SharkSafe Barrier. With the development of this shark-specific and eco-friendly barrier, they aim to protect and minimise the shark to human interaction on South African beaches and also avoid killing the already declining white shark population.
She started diving at the age of 17 and initially qualified as a CMAS diver in Italy. And she pursued a career as a marine biologist, mainly because of her love of diving and the ocean.
She decided to move to South Africa to study the Great White Shark in association with the University of Stellenbosch, to work on a PHD in white shark conservation. The study on the White Shark population dynamics and genetics formed the basis of the study. Dr Andreotti built up a database of the individual animals using both genetics and positive photographic identification of the dorsal fin of the shark, to confirm positive identification of each individuals. The combination of these studies confirmed an estimated number of a single population of white shark around the SA coastline of between 300-500 animals, with very poor genetic diversity.
It became clear that more needed to be done to protect this population and to find a way to monitor them constantly.
What makes these animals so important, is that they are at the top of the food chain and unfortunately now, 5 years down the line, we have stopped seeing the sharks in the area that was once known as the white Shark Capital of the world.
One of the reasons for the decline and disappearance of white shark in South Africa have been the active killing of shark through the use of shark nets and drumlines. Since 1937 in Australia and 1950 in South Africa, the shark nets and drumlines has been used to limit the shark- human interaction, by killing as many sharks as possible, to reduce the population of shark, and minimise the chances of shark-human encounters. That is where the SharkSafe Barrier TM works differently.
The barrier mimics the visual effect of a thick Kelp forest and kelp forests are recognised by large shark as a natural barrier. The barrier consisting of long flexible tubes containing magnets. The tubes mimic this natural underwater thick kelp forests and the magnets form a constant magnetic field. These magnetic fields overwhelm one of the shark senses called the Ampullae of Lorenzini. The combination of these deterrents, the magnetic field from the magnets and the simulated Kelp forest, have proved extremely effective to keep sharks away from baits in all the tests conducted, so hopefully we can, in time, replace all shark nets and drumline with this eco-friendly, shark specific alternative.