Sub‐mesoscale fronts—with scales from 1 to 50 km are ubiquitous in satellite images of the world oceans. They are known to generate strong vertical velocities with significant impacts on biogeochemical fluxes and pelagic ecosystems. Here, we use a unique data set, combining high‐resolution behavioral and physical measurements, to determine the effects of sub‐mesoscale structures on the foraging behavior of 12 instrumented female southern elephant seals. These marine mammals make long voyages (several months over more than 2000 km), diving and feeding continuously in the Antarctic Circumpolar Current. Our results show that elephant seals change their foraging behavior when crossing sub‐mesoscale fronts: They forage more and at shallower depths inside sub‐mesoscale fronts compared to nonfrontal areas, and they also reduce their horizontal velocity likely to concentrate on their vertical diving activity. The results highlight the importance of sub‐mesoscale fronts in enhancing prey accessibility for upper trophic levels, and suggest that trophic interactions are stimulated in these structures.

中文翻译：

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亚中尺度的锋面改变了象海豹的觅食行为

在世界海洋的卫星图像中，普遍存在亚中尺度的前沿，其尺度从1到50 km。众所周知，它们产生强大的垂直速度，对生物地球化学通量和中上层生态系统产生重大影响。在这里，我们使用一个独特的数据集，结合了高分辨率的行为和物理测量，以确定亚中尺度结构对12具工具南部象海豹的觅食行为的影响。这些海洋哺乳动物进行长途航行（超过2000公里的几个月），在南极绕极洋流中不断潜水和觅食。我们的结果表明，海象越过亚中尺度的锋面时会改变它们的觅食行为：与非额叶区域相比，它们在亚中尺度的锋面内觅食更多且深度更浅，并且还会降低其水平速度，而这些速度可能会集中于垂直潜水活动。结果突出了亚中尺度战线在增强高层营养层的猎物可及性方面的重要性，并表明在这些结构中营养相互作用被激发。