Abstract:
The frequency of unprovoked shark bites is increasing worldwide, leading to a growing pressure for mitigation measures to reduce shark-bite risk while maintaining conservation objectives. Personal shark deterrents are a promising and non-lethal strategy that can protect ocean users, but few have been independently and scientifically tested. In Australia, bull (Carcharhinus leucas), tiger (Galeocerdo cuvier), and white sharks (Carcharodon carcharias) are responsible for the highest number of bites and fatalities. We tested the effects of two electric deterrents (Ocean Guardian\'s Freedom+ Surf and Freedom7) on the behaviour of these three species. The surf product reduced the probability of bites by 54% across all three species. The diving product had a similar effect on tiger shark bites (69% reduction) but did not reduce the frequency of bites from white sharks (1% increase), likely because the electrodes were placed further away from the bait. Electric deterrents also increased the time for bites to occur, and frequency of reactions and passes for all species tested. Our findings reveal that both Freedom+ Surf and Freedom7 electric deterrents affect shark behaviour and can reduce shark-bite risk for water users, but neither product eliminated the risk of shark bites entirely. The increasing number of studies showing the ability of personal electric deterrents to reduce shark-bite risk highlights personal protection as an effective and important part of the toolbox of shark-bite mitigation measures.
摘要:
世界范围内无缘无故的鲨鱼咬伤的频率正在增加,导致缓解措施的压力越来越大,以减少鲨鱼咬伤的风险,同时保持保护目标。个人鲨鱼威慑是一种有前途的非致命策略,可以保护海洋使用者,但是很少有人经过独立和科学的测试。在澳大利亚,公牛(Carcharhinusleucas),老虎(Galeocerdocuvier),和白鲨(Carcharodoncarcharias)造成的叮咬和死亡人数最高。我们测试了两种电子威慑物(海洋卫士的自由冲浪和自由7)对这三个物种行为的影响。冲浪产品将所有三个物种的咬伤概率降低了54%。潜水产品对虎鲨咬伤有类似的效果(减少69%),但并未减少白鲨咬伤的频率(增加1%),可能是因为电极放置在远离诱饵的地方。电子威慑也增加了叮咬发生的时间,以及所有测试物种的反应和通过频率。我们的研究结果表明,Freedom+Surf和Freedom7电子威慑都会影响鲨鱼的行为,并可以降低水使用者被鲨鱼咬伤的风险。但这两种产品都没有完全消除鲨鱼咬伤的风险。越来越多的研究表明个人电子威慑人员能够减少鲨鱼咬伤的风险,这突出表明个人防护是鲨鱼咬伤缓解措施工具箱中有效和重要的一部分。