Smukall Matthew J, Carlson John, Kessel Steven T, Guttridge Tristan L, Dhellemmes Félicie, Seitz Andrew C, Gruber Samuel
Bimini Biological Field Station Foundation, Bimini, The Bahamas.
University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fairbanks, Alaska, USA.
J Fish Biol. 2022 Jul;101(1):13-25. doi: 10.1111/jfb.15067. Epub 2022 May 24.
Abundances of large sharks are reported to have declined worldwide, and in response various levels of fisheries management and conservation efforts have been established. For example, marine-protected areas have been suggested as a means to protect large expanses of ocean from fishing and other industrial activities (e.g., habitat destruction), and in 2011 The Commonwealth of The Bahamas established The Bahamas Shark Sanctuary. Nonetheless, assessing the effectiveness of conservation efforts is challenging because consistent long-term data sets of shark abundances are often lacking, especially throughout the Caribbean and The Bahamas. In this study, the authors investigated the catch rates and demographics of tiger sharks Galeocerdo cuvier caught in a fishery-independent survey near Bimini, The Bahamas, from 1984 to 2019 to assess relative abundance trends following the banning of longline fishing in 1993 and the subsequent establishment of the shark sanctuary. To contextualize the relative abundance trends near Bimini, the authors compared this to the relative abundance of tiger sharks in a fishery-dependent survey from the Southeastern USA (SE USA), conducted from 1994 to 2019. The data of this study suggest that local abundance of tiger sharks has been stable near Bimini since the 1980s, including after the ban of longline fishing and the implementation of the shark sanctuary. In comparison, the abundance near the SE USA has slowly increased in the past decade, following potential declines in the decade preceding the USA Shark Management Plan. The results of this study provide some optimism that current conservation efforts in The Bahamas have been effective to maintain local tiger shark abundance within the protected area. In addition, current fisheries management in the SE USA is allowing this species to recover within those waters.
据报道，全球大型鲨鱼的数量已经下降，作为应对措施，已经建立了不同层面的渔业管理和保护措施。例如，海洋保护区被提议作为一种保护大片海洋免受捕捞和其他工业活动（如栖息地破坏）影响的手段，2011年巴哈马联邦建立了巴哈马鲨鱼保护区。然而，评估保护措施的有效性具有挑战性，因为通常缺乏关于鲨鱼数量的长期连贯数据集，尤其是在整个加勒比地区和巴哈马。在本研究中，作者调查了1984年至2019年在巴哈马比米尼附近一项与渔业无关的调查中捕获的居氏鼬鲨的捕获率和种群统计学特征，以评估1993年禁止延绳钓捕鱼以及随后建立鲨鱼保护区后相对丰度的趋势。为了将比米尼附近的相对丰度趋势置于背景中，作者将其与1994年至2019年在美国东南部（美国东南部）一项与渔业相关的调查中居氏鼬鲨的相对丰度进行了比较。本研究的数据表明，自20世纪80年代以来，比米尼附近居氏鼬鲨的当地丰度一直保持稳定，包括在禁止延绳钓捕鱼和实施鲨鱼保护区之后。相比之下，在美国鲨鱼管理计划之前的十年可能出现下降之后，美国东南部附近的丰度在过去十年中缓慢增加。本研究结果提供了一些乐观的依据，即巴哈马目前的保护措施有效地维持了保护区内当地居氏鼬鲨的数量。此外，美国东南部目前的渔业管理允许该物种在这些水域内恢复。
