Abstract：
While spatial distribution shifts have been documented in many marine fishes under global change, the responses of elasmobranchs have rarely been studied, which may have led to an underestimation of their potential additional threats. Given their irreplaceable role in ecosystems and their high extinction risk, we used a 24-year time series (1997-2020) of scientific bottom trawl surveys to examine the effects of climate change on the spatial distribution of nine elasmobranch species within Northeast Atlantic waters. Using a hierarchical modeling of species communities, belonging to the joint species distribution models, we found that suitable habitats for four species increased on average by a factor of 1.6 and, for six species, shifted north-eastwards and/or to deeper waters over the past two decades. By integrating species traits, we showed changes in habitat suitability led to changes in the elasmobranchs trait composition. Moreover, communities shifted to deeper waters and their mean trophic level decreased. We also note an increase in the mean community size at maturity concurrent with a decrease in fecundity. Because skates and sharks are functionally unique and dangerously vulnerable to both climate change and fishing, we advocate for urgent considerations of species traits in management measures. Their use would make it better to identify species whose loss could have irreversible impacts in face of the myriad of anthropogenic threats.
摘要：
虽然在全球变化下，许多海洋鱼类的空间分布变化已得到记录，弹枝的反应很少被研究，这可能导致低估了他们潜在的额外威胁。鉴于它们在生态系统中不可替代的作用和高灭绝风险，我们使用了24年的时间序列（1997-2020年）的科学底拖网调查来研究气候变化对东北大西洋水域内9种弹性分支物种空间分布的影响。使用物种群落的分层模型，属于联合物种分布模型，我们发现四个物种的合适栖息地平均增加了1.6倍，六个物种，在过去的二十年里，向北向东移动和/或向更深的水域移动。通过整合物种特征，我们显示栖息地适宜性的变化导致弹性枝性状组成的变化。此外，群落转移到更深的水域，其平均营养水平降低。我们还注意到成熟期的平均群落规模增加，同时繁殖力下降。因为滑冰鞋和鲨鱼在功能上是独特的，而且很容易受到气候变化和捕鱼的影响，我们主张在管理措施中紧急考虑物种特征。它们的使用将更好地识别物种，这些物种的损失可能会在面对无数的人为威胁时产生不可逆转的影响。
