Sari El Dine Ziad, Guinet Christophe, Picard Baptiste, Thyssen Melilotus, Duforêt-Gaurier Lucile, El Hourany Roy
Centre d'Etudes Biologiques de Chize, CEBC-CNRS UPR 1934, F 79360, Villiers en Bois, France.
Laboratoire d'Oceanologie et de Géosciences, Univ. Littoral Côte d'Opale, Univ. Lille, CNRS, IRD, UMR 8187, F 62930, Wimereux, France.
Commun Biol. 2025 Apr 16;8(1):620. doi: 10.1038/s42003-025-08049-0.
The intricate relationship between trophic levels in marine ecosystems remains largely unexplored, particularly in the Southern Ocean. To investigate the complex composition of water constituents, notably the phytoplankton community, we used machine learning techniques to classify six bio-optical classes from a comprehensive ocean-color data time-series. In situ data from the Southern Ocean further characterized these classes by predominant phytoplankton types. Bio-logging data from southern elephant seals revealed that 60% of prey-catch attempts were concentrated within the diatom-dominated class, despite its lower regional frequency. Seals exhibited enhanced foraging activity and prolonged residency periods, up to 42 consecutive days, in diatom-rich waters compared to 5-10 days in other classes. These findings suggest a preference among southern elephant seals for diatom-rich waters, indicating a selective foraging activity influenced by the phytoplankton community's structural composition rather than total biomass alone. This preference underscores the intricate interplay between marine top predators and ecosystem dynamics, hinting at mechanisms through which phytoplankton structure shapes seal activity.
海洋生态系统中营养级之间的复杂关系在很大程度上仍未得到探索，特别是在南大洋。为了研究水体成分的复杂组成，尤其是浮游植物群落，我们使用机器学习技术从一个全面的海洋颜色数据时间序列中对六个生物光学类别进行分类。南大洋的现场数据通过主要的浮游植物类型进一步表征了这些类别。来自南象海豹的生物记录数据显示，尽管硅藻主导的类别在该区域的出现频率较低，但60%的捕食尝试都集中在这一类别中。与其他类别中5 - 10天的停留时间相比，海豹在富含硅藻的水域表现出更强的觅食活动和更长的停留期，长达连续42天。这些发现表明南象海豹偏爱富含硅藻的水域，这表明其选择性觅食活动受浮游植物群落结构组成而非仅总生物量的影响。这种偏好强调了海洋顶级捕食者与生态系统动态之间的复杂相互作用，暗示了浮游植物结构影响海豹活动的机制。
