Abstract Oceanic sharks are vulnerable to overexploitation due to their life-history strategies, and efforts to protect them in the wild have been stalled by transjurisdictional conflicts of interest. The pelagic thresher shark (Alopias pelagicus) is one such species that visits a seamount in the Philippines where its dependable presence has catalysed a burgeoning dive tourism industry and the designation of a conservation area. Nothing is known of the range and turnover of this population, but the regularity with which these sharks interact with cleaner wrasse on the seamount provides important stability for regional businesses that lack empirical knowledge of their vulnerability. We fitted 14 pelagic thresher sharks with acoustic tags and monitored their fine scale movements for 66 days (June to mid-August 2014). Individuals were present at the seamount for 32% of their days at liberty, and 42% of the tagged sharks were still being detected there at the end of the study. Thresher sharks showed preferences for visiting specific locations on the seamount where they interact with cleaner fish, and estimates of their fidelity to these sites provided scalars for visual census. Pelagic thresher sharks moved away from the seamount after early morning visits to cleaning stations using swim speeds of 3.79 km h−1 (±SD 1.43). These movements demonstrated that they have access to the jurisdictional waters of five provincial territories when dispersing from and returning to the seamount on a diurnal basis. While the seamount offers cleaner-associated services and refuge provision for pelagic thresher sharks, their scale of movement leaves them vulnerable to fisheries that operate in the region. Natural history observations provide context and reveal bias for their application in the management and conservation of this rare and vulnerable shark species.

中文翻译：

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风险和复原力：鲨鱼跨辖区移动以使用保护区的风险很高

摘要 大洋鲨因其生活史策略而容易受到过度捕捞，而在野外保护它们的努力因跨辖区的利益冲突而停滞不前。远洋长尾鲨（Alopias pelagicus）就是这样一种物种，它们会造访菲律宾的海山，其可靠的存在促进了新兴的潜水旅游业和保护区的指定。对该种群的范围和周转率一无所知，但这些鲨鱼与海山上的清洁濑鱼互动的规律性为缺乏对其脆弱性的经验知识的区域企业提供了重要的稳定性。我们为 14 条远洋长尾鲨安装了声学标签，并监测了 66 天（2014 年 6 月至 8 月中旬）的精细鳞片运动。个体有 32% 的时间在海山自由活动，在研究结束时仍有 42% 的标记鲨鱼在那里被发现。长尾鲨表现出偏好访问海山上与清洁鱼互动的特定地点，并且估计它们对这些地点的忠诚度为视觉普查提供了标量。在清晨访问清洁站后，远洋长尾鲨以 3.79 km h-1 (±SD 1.43) 的游泳速度离开海山。这些运动表明，他们在白天从海山散开和返回海山时，可以进入五个省辖区的管辖水域。虽然海山为远洋长尾鲨提供清洁相关的服务和避难所，它们的移动规模使它们容易受到在该地区经营的渔业的影响。自然历史观察为它们在管理和保护这种稀有和脆弱的鲨鱼物种中的应用提供了背景并揭示了偏见。