Effectiveness of bite-resistant materials to reduce injuries from white shark (Carcharodon carcharias) and tiger shark (Galeocerdo cuvier) bites

Context Shark bites on humans are rare but can have substantial consequences for local coastal communities and businesses, often prompting pressure to implement effective mitigation measures. Wetsuits that incorporate bite-resistant materials have emerged as a new mitigation strategy that aims to reduce fatalities from shark bites, by reducing the severity of injuries inflicted from bites (e.g. lacerations, punctures, tissue and blood loss). Chainmail protective suits were developed in the 1970s, but lack the flexibility required for most aquatic activities (e.g. surfing, diving). More recently, lightweight puncture-resistant materials (e.g. Kevlar, ultra-high molecular weight polyethylene) have been incorporated into wetsuits, providing more flexibility for the user compared to chainmail suits, while reducing abrasions and cuts. However, despite the availability of bite-resistant wetsuits for commercial and public purchase, their ability to reduce injuries from large, predatory sharks (i.e. white shark, Carcharodon carcharias, and tiger shark, Galeocerdo cuvier) is unknown. Aims We tested the efficacy of four bite-resistant wetsuit materials (Aqua Armour, Shark Stop, ActionTX-S and Brewster material) to reduce damage incurred from white and tiger shark bites. Methods The ability to reduce injuries from shark bites was quantified by comparing the proportion of the bitten surface area across four damage categories of increasing severity (i.e. C1, superficial; C2, slight; C3, substantial; or C4, critical) between a control material (3-mm-thick neoprene) and the four bite-resistant materials. Key results All bite-resistant materials reduced the proportional area of bites in substantial and critical damage categories, the categories associated with haemorrhaging and major vascular injury. However, there were limited to no differences in substantial and critical damage categories across the bite-resistant materials. Shark length also influenced the proportion of damage from tiger shark bites, but not from white shark bites. Conclusions Although internal and crushing injuries might still occur, bite-resistant materials offer an improved level of protection that can reduce severe wounds and blood loss, and should be considered as part of the toolbox and measures available to reduce shark-bite risk and resulting injuries. Implications These findings will allow for informed decisions to be made about the use of bite-resistant wetsuit materials for ocean users.