Shark-Human Conflict

Dr Sara Andreotti | Interviewed by Nicolene Olckers

Over the last decade, shark-related accidents involving swimmers and surfers became widespread, receiving extensive media and movie attention. With the steady increase in human recreational use of beaches at the beginning of the twentieth century, the general public became more exposed to interactions with sharks, sometimes with fatal results.

Australia started implementing a policy of "the more sharks we kill, the fewer shark-human encounters we are going to have" in 1937. South Africa followed suit in 1950, and Reunion Island in 2014. The newest to pursue this line of thinking is New Caledonia which implemented similar policies in 2020.
 
It is difficult to believe that in our time, when we pay more attention to sustainability and nature conservation, we still have countries that are killing marine life for fear of negative encounters with sharks.

The current culling methods need a physical separation between beachgoers and sharks. Shark-culling policies are carried out by fishing the local bull sharks and tiger sharks or by deploying shark nets and drumlines. Drumlines consist of heavily baited hooks deployed to fish, primarily sharks. In New South Wales, Australia, 65% of shark bites occur at netted beaches. Shark nets also resulted in the large-scale, unjustified killing of other marine animals, such as whales, turtles and dolphins.

WHAT IS THE SHARKSAFE BARRIER?

The SharkSafe Barrier is a novel and eco-friendly approach to the shark-human conflict. It aims to prevent the trauma associated with shark accidents by keeping sharks and people separate from each other.
 
It is the first eco-friendly and shark-specific technology to reduce shark-human conflict. It was developed from the sharks' point of view. Produced and distributed by SharkSafe Barrier Pty Ltd, a start-up company of Stellenbosch University in South Africa. The SharkSafe™ is designed to be a visual shark-deterrent by mimicking a thick kelp forest. It comprises vertical recycled plastic pipes coupled with a strong magnetic field. It was tested and proven to affect the swimming behaviour of large sharks.

Adding strong barium-ferrite magnets inside the outer row of tubes, it mimics the stalks of a dense kelp forest. The vertical buoyant plastic pipes are anchored to the sea floor. This design was scientifically tested from 2012 to 2016 and proven to prevent motivated sharks from entering a specific area, even when baited.
 
This barrier provides a separation between humans and sharks, and there is no indiscriminate killing of marine life. It is superior to exclusion nets (small-mesh nets, deployed daily in good weather around swimmers only) since SharkSafe Barrier is shark specific; it works 24/7 and can withstand harsh sea conditions, culminating in low maintenance cost. Its design also provides passage to boats, oceanic debris and other animals not deterred by magnetism.

Thanks to various sponsors, such as Shark Project, White Shark Diving Company, Dive Team, Just Africa Scuba, the Technology Innovation Agency, Stellenbosch University Faculty of Science and Itatile, The SharkSafe Barrier™ has been undergoing rigorous testing.

Test and trial installations were conducted with 63 white sharks in South Africa and 48 bull sharks in The Bahamas from 2012 to 2016. The results of these tests were published in various peer-reviewed scientific journals. To convince the sharks to cross the barrier, we deployed baits (fish buckets) inside the exclusion area. In all instances where the barrier was built correctly, we never had a shark crossing it.

THE BARRIER AT REUNION ISLAND

A test barrier of 200 pipes was constructed in February 2019 to form a 10 meters x 10 meters square to replicate previously published experiments. The aim was to test the efficacy of the barrier in collaboration with the local Shark Security Centre to exclude local bull sharks from a food source. These 200 pipes were deployed at sea for over two years and required minimal maintenance. They also created a fantastic artificial reef, showing that even hard corals could grow on the structure.

This study was designed to exclude bull sharks from a baited area to support its full-scale implementation. Unfortunately, no bull sharks approached the experimental site. Reunion's Shark Security Centre plans to replicate the experiment in New Caledonia, where more bull sharks were recently sighted.

CURRENT WORK & TESTING

The SharkSafe Barrier™ team is working to adapt the current design to enable more versatile installations across the globe. Installation is tested at different water depths and across other sea substrates.

The anchorage system could be tested when the southeast storms hit the bay. One such test site is at Mackrel Beach (next to Glencairn, South Africa), where we installed a cluster of pipes in the shallow area and a few 6 meters deep water. This site was selected to try out the latest design for deep sand anchorage. The pipes were installed in November 2021 and required minimal maintenance. The condition and location provided a great testing ground to try out different options to secure our anchor grid and ultimately select the most cost-efficient and robust option. (DISCLOSURE: the installation in Mackrel Beach does not form an enclosed to keep sharks out – we are just testing the design with a few pipes).

OTHER WORK IS NEEDED & THE PLETTENBERG BAY INCIDENTS

We are proud to announce that our team welcomed two new sea-loving investors and directors, bringing additional strength, knowledge and skills to our team. We are always busy expanding our network. The World Economic Forum, the Solar Impulse Foundation and the National Science and Technology Forum have endorsed us.

Despite ongoing international work, we are focusing our attention closer to home, to Plettenberg Bay, following this year's shark accidents. The Bitou council approved a SharkSafe Barrier installation in August this year. We are now assisting the local community in raising the needed funds to produce and install the barrier.
 
"We sincerely hope that our technology will assist them to peacefully coexist with the white sharks using the area in the long term. When shark attacks happen, it is a tragedy on many fronts. We were pleasantly surprised with our interactions with the local community of Plettenberg Bay and the Bitou Council. They showed genuine love for their marine environment and are looking for an eco-friendly solution that won't damage the local fauna," said Sarah.
Should you wish to get involved and assist with the work in Plettenberg Bay, please keep an eye on their website and social media pages to connect and support their efforts to make beaches safer.

TO CONCLUDE
 
Bycatch, shark finning, overfishing of their food resources, climate change and pollution are among the biggest threats to shark populations worldwide. Shark-culling policies are a constant source of shark mortality. We can eliminate these destructive habits by changing our ways. "We hope that our work on the SharkSafe Barrier™ will soon relegate shark nets from the history books, promote peaceful coexistence with sharks and prevent fear-based conservation policies, said  Dr Sarah Andreotti.

Website & Social Media Links
Website: www.sharksafesolution.com
Facebook: @Sharksafebarrier
LinkedIn: @sharksafe-barrier-rf
Instagram: @sharksafebarrier
Twitter: @SharksafeB