Not all electric shark deterrents are made equal: Effects of a commercial electric anklet deterrent on white shark behaviour

• DOI: 10.1371/journal.pone.0212851
• Publication Date: 2019-03-11T17:27:17Z
• Authors: Channing A. Egeberg; Ryan M. Kempster; Nathan S. Hart; Laura Ryan; Lucille Chapuis; Caroline C. Kerr; Carl Schmidt; Enrico Gennari; Kara E. Yopak; Shaun P. Collin
• Keywords: Carcharias; Biting

Personal shark deterrents offer the potential of a non-lethal solution to protect individuals from negative interactions with sharks, but claims effectiveness most are based on theory rather than robust testing devices themselves. Therefore, there is clear need for thorough commercially available provide public information their effectiveness. Using modified stereo-camera system, we quantified behavioural between Carcharodon carcharias (white sharks) and baited target in presence electric anklet deterrent, Electronic Shark Defense System (ESDS). The system enabled accurate assessment responses C. when approaching an ESDS. We found that ESDS had limited meaningful effect behaviour carcharias, no significant reduction proportion sharks interacting bait active device. At close proximity (< 15.5 cm), did show number biting bait, this was countered by increase other, less aggressive, interactions. discharged at frequency 7.8 Hz every 5.1 s 2.5 s, followed inactive interval 2.6 s. As result, many may have encountered device its state, resulting reduced response. Consequently, decreasing pulses improve overall device, would not effective deterrent range which primarily factor voltage gradient stimulus frequency. In conclusion, given very short unreliable effect, combined fact shark-bite incidents rare, it unlikely current significantly reduce risk interaction carcharias.