Revolutionizing how we assess the development of electrical shark deterrents

The detrimental decline of sharks, and the significant role of incidental commercial fishing by- catch and lethal shark attack mitigation strategies such as culls and baited drumlines is well documented. A potential solution is electronic deterrents, devices which emit strong electrical pulses designed to overstimulate the shark’s electrosensory organs and thereby trigger a retreat response. It has been demonstrated that such technology is capable of deployment on long-lines, along coastlines, or personally worn by water users such as surfers, thereby preventing interactions between sharks and fishing equipment/humans. Unfortunately, widespread uptake is yet to occur, owing to significant reliability concerns, such as a very small deterrent threshold distance (~1.5m) and significant variability in effectiveness across species. A prime reason for these concerns, and why they are yet to be understood, is because all studies up to date have entirely relied on trial-and-error testing with free-swimming sharks in the wild. Though valuable, such trials fail to capture mechanisms by which strong electrical pulses will impact shark behaviour and physiology. They are also difficult to achieve, owing to high costs, limited access to enough sharks under suitable environmental conditions for consistent trials, and the production of inconsistent results due to interference from various other factors. Our research proposes a targeted approach, focusing on precisely mapping the interaction between electrical pulse characteristics and the neurophysiological properties of the shark electroreceptors and body.