Abstract

There has been debate in the literature over the use and success of spatial management zones (i.e. marine protected areas and time/area closures) as policy tools for commercially exploited sharks. The tiger shark (Galeocerdo cuvier) is a highly migratory predator found worldwide in warm temperate and tropical seas, which is caught in multiple US fisheries. We used a spatially explicit modelling approach to investigate the impact of varying spatial management options in the Western North Atlantic Ocean on tiger shark biomass, catch, and distribution, and impacts to other species in the ecosystem. Results suggest that under current management scenarios, tiger shark biomass will increase over time. Model outputs indicate that protecting additional habitats will have relatively minimal impacts on tiger shark biomass, as would increasing or decreasing protections in areas not highly suitable for tiger sharks. However, increasing spatial management protections in highly suitable habitats is predicted to have a positive effect on their biomass. Results also predict possible spill-over effects from current spatial protections. Our results provide insights for evaluating differing management strategies on tiger shark abundance patterns and suggest that management zones may be an effective conservation tool for highly migratory species if highly suitable habitat is protected.

中文翻译：

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评估美国大西洋水域虎鲨（Galeocerdo cuvier）保护的空间管理方案

摘要

关于将空间管理区（即海洋保护区和时间/区域封闭）作为商业开发鲨鱼的政策工具的使用和成功，文献中一直存在争论。虎鲨（Galeocerdo cuvier）是高度迁徙的捕食者，在全球温暖的温带和热带海域发现，被美国多家渔业捕捞。我们使用空间明确的建模方法来研究北大西洋西部不同空间管理方案对虎鲨生物量，捕获和分布的影响以及对生态系统中其他物种的影响。结果表明，在当前的管理方案下，虎鲨生物量将随着时间增加。模型输出表明，保护更多的栖息地对虎鲨生物量的影响相对较小，对不太适合虎鲨的地区增加或减少保护的情况也会如此。但是，预计在高度合适的栖息地中增加空间管理保护将对其生物量产生积极影响。结果还预测了当前空间保护可能产生的溢出效应。我们的结果为评估虎鲨丰度模式的不同管理策略提供了见识，并建议如果保护高度合适的栖息地，管理区可能是高度迁徙物种的有效保护工具。