Very very occasionally, swimming or surfing humans get bitten by a shark, sometimes leading to severe injuries. One way to mitigate the impacts of a bite is to wear a wetsuit made out of protective material, and now, Flinders University scientists have investigated the effectiveness of a new kind of lightweight protective material. How? By dangling it in front of hungry white sharks, of course.
The researchers note in PLOS ONE that blood loss is the leading cause of death from shark encounters, so finding ways to minimize wounds is key.
“Despite previous shark-proof suits being bulky and cumbersome, new technological advances in fabric has allowed the development of lightweight alternatives that can be incorporated onto traditional wetsuits,” write the researchers. “The ability for these fabrics to withstand shark bites has not been scientifically tested.” That is, until now.
The team investigated two newly developed fabrics called SharkStop and ActionTX, which are made from ultra-high molecular weight polyethylene fiber incorporated onto neoprene, and determined how they fared against bog-standard neoprene materials. Neoprene is a very resistant synthetic polymer.
The researchers tested the materials in the lab, assessing how well they survived punctures and lacerations, before putting them to the test out in the open ocean. They created a gelatine mixture that mimicked the consistency of human flesh and used a special foam to mimic human bone and covered them with the materials. In the lab, SharkStop and Action TX were more resistant to simulated bites than standard neoprene, experiencing smaller and shallower puncture marks and lacerations than other materials. Meanwhile, a greater force was required to puncture them in the first place.
Then, the team headed to the Neptune Islands Group Marine Park in South Africa to see how the materials coped when bitten by actual sharks. They placed sensors inside foam blocks, which allowed bite force to be measured. The white sharks (Carcharodon carcharias) were encouraged to bite the foam with little morsels of tuna attached to it. To test out the neoprene materials, the researchers wrapped them around foam-covered wooden boards to assess how easily they were torn or punctured.
Overall, the shark-proof materials required greater bite force to be damaged and gained smaller puncture marks and lacerations than the less protective materials, suggesting that SharkStop and ActionTX could prove useful tools in minimizing bleeding caused by shark bites.
While promising, the researchers note that more research is needed to determine how well the materials reduce physical damage to flesh substitutes – finding volunteers willing to be bitten for science might prove somewhat challenging.
“While we incorporated flesh mimics (e.g. foam and gelatine), the damages to these and the correlation between those and human injuries is unclear,” they write.
They also note that the materials might not be as lightweight and flexible as traditional wetsuit materials, which could impede the swimming or surfing abilities of the wearer. Nevertheless, the materials could prove hugely beneficial by reducing the severity of shark-related injuries in those unlucky enough to sustain them.
Don’t forget you’re more likely to die taking a selfie than from an encounter with a shark. Or be killed by a popping champagne cork. Or an ant. Meanwhile, we kill an estimated 100 million sharks every single year.