The SharkSafe Barrier, an eco-friendly alternative to the traditional shark-control programmes, have withstood two years of testing in Réunion's bay of St Paul. This is part of ongoing efforts by the island's shark security centre Centre Sécurité Requin (CSR) to find a workable and eco-friendly solution to the island's shark crisis.
The SharkSafe BarrierTM technology, originally developed in South Africa, bio-mimicks a thick forest of kelp. Combined with shark-repellent magnets to further deter sharks, the technology has been undergoing rigorous testing in South Africa and The Bahamas since 2012, with the results of these tests published in various peer reviewed scientific journals.
A test barrier of 200 pipes was constructed in February 2019 to form a 10m x 10m square in order to replicate, in La Réunion waters, previously published experiments. The aim was to test the efficacy of the SharkSafe BarrierTM to exclude local bull sharks from a food source.
According to Centre Sécurité Requin (CSR) Director of Operations Michael Hoarau, the barrier's efficiency to exclude bull and tiger sharks species in this instance could not be established, as the underwater cameras and the sonar did not record any bull and tiger sharks approaching the barrier during the tests. However, the developers are encouraged by the fact that the structure, which consists of vertical pipes anchored to the sea bottom, survived two seasons' winter swell, with minimum maintenance.
“This means that the maintenance of this technology during the last two years was three times cheaper than it would have been to deploy shark exclusion nets," explain Dr Sara Andreotti, COO of SharkSafe Barrier Pty.
Ongoing research and product development
In parallel with the St Paul experiment, differently designed units were tested in Etang-Salé, to form part of an ongoing research and development effort in the high energy zone (perpendicular to the shoreline). This research aimed to adapt the current design to enable more versatile installations across the globe. The designs were installed at different water depths and across different substrates, testing cost-effective options to provide robust solutions. The Etang-Salé experiment was sponsored entirely by the SharkSafe Barrier Pty start-up, and was conducted between January 2019 and June 2020. Three rounds of increasingly expensive and robust designs have been installed during the trials, but none proved robust enough for the Etang-Salé conditions.
The costs associated with the experimentation in Etang Salé prompted the decision to suspend the research and development efforts in Réunion, and to continue the product development tests in South Africa. The different designs tests are being continued in Glencairn in South Africa and these are showing promising results.
Global solution to replace current shark-control programs
According to Dr Sara Andreotti, one of the co-inventors of the SharkSafe BarrierTM technology, there is an urgent need to find an alternative to traditional shark-control programs worldwide: “The SharkSafe Barrier is currently the only available eco-friendly and shark-specific technology to reduce shark-human conflict."
“In the case of Réunion, for example, a non-invasive shark barrier will have a positive impact on the local ecology by protecting top-predators and their key role in the marine ecosystem. It will also positively impact on the local economy, by protecting beach-goers and thereby promote potential tourism revenue. Lastly, it can help the community to better cope with the historical trauma associated with a number of shark accidents since 2011.
“Irresponsible and unsustainable fishery practices are still undoubtedly the biggest global threat to sharks. The socio economic and ecological impact of a solution such as the SharkSafe BarrierTM, is a step in the right direction. For Blue Economy inspired countries such as France, it could prove key to ensuring long term and peaceful coexistence between humans and sharks, while promoting ocean sustainability and coastal eco-tourism," she concludes.
For the editors
- Developed in South Africa the SharkSafe BarrierTM is the only eco-friendly shark management method in the world combining biomimicry and magnetism to reduce shark-human conflict, by keeping sharks and surfers physically separated from each other. Distributed by SharkSafe Barrier Pty Ltd, a start-up spin-off company of Stellenbosch University, the SharkSafe BarrierTM is designed to be a visual shark-deterrent by mimicking a thick forest of kelp composing of vertical recycled plastic pipes, coupled to a strong magnetic field, also tested and proven to affect the swimming behaviour of large sharks.
- Réunion's Centre Sécurité Requin (CSR) and SharkSafe Barrier Pty Ltd respectively contributed 66% and 34% towards the construction and installation of the test barrier at St Paul. The pipes were constructed in South Africa, and shipped to Réunion at the end of 2018. The construction of 40 meters of barrier at St Paul took nine days, and was performed in collaboration with local subcontractors TSMOI, as well as a crane boat and four divers.
- To collect data on the bull sharks' behaviour the CSR operators deployed underwater cameras and sonar, with a canister of fish positioned in the middle of the exclusion square. This activity was performed sixty three times over the two year period. Unfortunately, no bull and tiger sharks were recorded during the data collection, despite adjacent acoustic tags indicating the sporadic presence of bull sharks in the bay. This resulted in the experiment being inconclusive.
- The CSR's research permit conditions require that the installation in St Paul must now be removed from the bay.
- The SharkSafe BarrierTM was also labelled as a Solar Impulse Efficient Solution in 2020, completed the Oceanhub Africa business accelerator program, was the recipient of the prestigious NSTF-Lewis Foundation Green Economy Award at the National Science and Technology Forum and was one of the finalists in the Smart-Eco-responsible Tourism category of the France Tech4Island Award. More recently the company was recognised by the World Economic Forum's digital platform UpLink as one of its top ocean innovators.
Dr Sara Andreotti
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