The effects of ocean climate change on environmental niches of pelagic sharks

作为气候变化的主要后果，海洋生物的分布和丰度的变化正在全球范围内发生。海鱼也不例外，记录了不同分类群的显著变化[1]。然而，通过比较，人们对海洋变暖对海洋中上层鲨鱼生态位的影响知之甚少。例如，在北大西洋，目前还没有关于远洋鲨鱼可能如何应对未来海洋环境变化的预测。此外，对许多中上层鲨鱼物种的过度捕捞已经发生，公海渔业每年捕获数千万条鲨鱼，记录的许多物种的捕获率大幅下降。因此，迫切需要了解海洋气候变化如何改变分布和丰度中心，这可能与渔业相互作用，进一步影响未来人口的可持续性[3]。该项目的目的是利用一个独特的数据库，记录2 000条卫星追踪的中上层鲨鱼(23种)的活动情况，并提取每个地点的3-D环境变量，以确定目前的分布和环境生态位。这些关系将被用来模拟全球鲨鱼的空间密度和生态位，并通过应用全球地球系统模型的输出，探索鲨鱼的分布在下个世纪可能会发生什么变化。

Shifts in the distributions and abundance of marine organisms are occurring globally as a major consequence of climate change. Marine fish are no exception, with significant changes documented across taxa [1]. However, the effects of ocean warming on the niches of oceanic pelagic sharks are poorly understood by comparison [2]. For example, in the North Atlantic Ocean, there are currently no predictions available about how pelagic sharks may respond to future ocean environmental change. Additionally, overfishing of many pelagic shark species is already occurring with tens of millions of individuals caught each year by high-seas fisheries with significant reductions in catch rates documented for many species. Thus, there is an urgent need to understand how ocean climate changes may alter distributions and centres of abundance, which may interact with fisheries to further impact future sustainability of populations [3]. The aim of this project is to use a unique database of the movements of 2,000 satellite-tracked pelagic sharks (23 species) with 3-D environmental variables extracted per location, to determine present day distributions and environmental niches. These relationships will be used to model global spatial densities and niches of sharks, and by applying outputs from global Earth System models, will explore how shark distributions may change over the next century.