Women in Diving: Dr Sara Andreotti White Shark Researcher

Dr Sara Andreotti is a Marine Biologist and diver based in Stellenbosch in the Western Cape province of South Africa. Her research work on the White Shark population along the South African Coast is recognised worldwide. 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.

"My name is Dr Sara Andreotti. I am a marine biologist and commercial diver, studying great white sharks around the coast of South Africa. I am based at the University of Stellenbosch in the Western Cape.

I started diving at the age of 17 and initially qualified as a CMAS diver in Italy. According to my parents I was always going towards the sea. Since I was able to walk, I would head towards the sea. Taking my first breath underwater with a regulator and experiencing this amazing, alive and different world, was mind blowing. Thus, I pursued a career as a marine biologist, mainly because of my love of diving and the ocean.

I 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 my study. This also made it possible to determine if there is one population of shark or several smaller groups around the South African coastline. During my studies we were also able to determine how many White Sharks were left around our coastline. I build 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 also became clear that we needed to do more to protect this population and to find a way to monitor them constantly. One of the big issues when monitoring the population was to keep track of individual sharks. Identifying individual animals and preventing double counting had to be avoided. To do this we developed a software program Called IdentiFin. In IdentiFin we created algorithm that can scan through a database of images, and enabled us to quickly identify or match new images of sharks with the existing image database. Sorting through hundreds of images to ID a single shark became easier with the software, matching images of dorsal fins in a matter of minutes. We were finally able to keep track of the population and understand if it was growing or declining over time.

About Great white Sharks

Since publishing our estimated count of the White Shark population along the South African coastline, not much more have been done since, to ensure their protection. 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. In False Bay we have not seen a great white for more than a year and this is causing a domino effect on the entire ecosystem. It not only has effect on the local diving companies and fisheries, but also on the balance of the ocean as a whole.
Also, the genetic diversity of the group is very poor and we don’t know if it is at all possible to get other White Shark, from other areas to replenish the population here. We have to do everything in our power to protect the white shark population in South Africa waters, their environment and their food resources. We have to do far better than we have been up until now.

Protecting sharks and humans

Beside the photographic and genetic work I am directly involved in another project called the SharkSafe Barrier ^TM, for which I had to become a certified commercial diver.  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 bio-mimicry the visual effect of a thick Kelp forest.  The 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 we hope we can, in time, replace all shark nets and drumline with this eco-friendly, shark specific alternative. This will keep both sharks and beachgoers safe.

Besides myself, The SharkSafe Barrier^TM  was developed by additional three inventors: Michael Rutzen, Dr. Craig O’Connell and Conrad Matthee from the University of Stellenbosch  and on-going input from coastal engineer Laurie Barwell, INNOVUS team, Labscheme Allchem team, additional contracted commercial divers and the financial and in-kind sponsorship from a number of likely minded organisation. So, when we go out to do this work on the barriers it is not only myself that I have to think about. When we dive at these sites, I need DAN cover to know we are going to be safe in case of any accident, while we are out there working underwater.

To connect with Dr Andreotti and the Shark Safe Barrier team or to donate to their cause visit the website www.sharksafesolution.com or find them on Facebook at www.facebook.com/Sharksafebarrier