The Scotia Sea is a productive pelagic ecosystem in the Southern Ocean, which is rapidly changing as a consequence of global warming. Species range shifts are particularly evident, as sub-Antarctic species expand their range from North to South, potentially rearranging the structure of this ecosystem. Thus, studies are needed to determine the current extent of variation in food web structure between these two biogeographic regions of the Scotia Sea and to investigate whether the observed patterns are consistent among depth zones. We compiled a database of 10,888 feeding interactions among 228 pelagic taxa, underpinned by surveys and dietary studies conducted in the Scotia Sea. Network analysis indicated that the Northern Scotia Sea (NSS), relative to the Southern Scotia Sea (SSS), is more complex: with higher species richness (more nodes) and trophic interactions (more links) is more connected overall (greater connectance and linkage density). Moreover, the NSS is characterised by more groups of strongly interacting organisms (greater node clustering) than the SSS, suggesting a higher trophic specialisation of Antarctic compared to sub-Antarctic species. Depth also played a key role in structuring these networks, with higher mean trophic position and more dietary generalism in the mesopelagic and bathypelagic zones relative to the epipelagic zones. This suggests that direct access to primary producers is a key factor influencing the trophic structure of these communities. Our results suggest that under current levels of warming the SSS ecosystem will likely become more connected and less modular, resembling the current structure of the NSS.

斯科舍海是南大洋中一个多产的远洋生态系统，由于全球变暖，该生态系统正在迅速变化。物种范围的变化特别明显，因为亚南极物种的范围从北到南扩大，可能会重新安排这个生态系统的结构。因此，需要研究来确定斯科舍海这两个生物地理区域之间食物网结构的当前变化程度，并调查观察到的模式在深度区域之间是否一致。我们编制了一个数据库，其中包含 228 个远洋分类群之间的 10,888 次进食相互作用，以在斯科舍海进行的调查和饮食研究为基础。网络分析表明，北斯科舍海 (NSS) 相对于南斯科舍海 (SSS) 更为复杂：具有更高的物种丰富度（更多节点）和营养相互作用（更多链接），整体上的联系更加紧密（更大的联系和联系密度）。此外，NSS 的特征是比 SSS 有更多的强相互作用生物群（更大的节点集群），这表明与亚南极物种相比，南极的营养专业化程度更高。深度在构建这些网络方面也发挥了关键作用，相对于远洋区，中层和深海区具有更高的平均营养位置和更多的饮食普遍性。这表明直接接触初级生产者是影响这些群落营养结构的关键因素。我们的研究结果表明，在目前的变暖水平下，SSS 生态系统可能会变得更加联系，模块化程度更低，类似于 NSS 的当前结构。