Ramondenc Simon, Eveillard Damien, Metfies Katja, Iversen Morten H, Nöthig Eva-Maria, Piepenburg Dieter, Hasemann Christiane, Soltwedel Thomas
Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany.
MARUM, Center for Marine Environmental Sciences, University of Bremen, Bremen, Germany.
Nat Commun. 2025 Jan 20;16(1):840. doi: 10.1038/s41467-024-55221-x.
Settling aggregates transport organic matter from the ocean surface to the deep sea and seafloor. Though plankton communities impact carbon export, how specific organisms and their interactions affect export efficiency is unknown. Looking at 15 years of eDNA sequences (18S-V4) from settling and sedimented organic matter in the Fram Strait, here we observe that most phylogenetic groups were transferred from pelagic to benthic ecosystems. Chaetoceros socialis, sea-ice diatoms, Radiolaria, and Chaetognatha are critical components of vertical carbon flux to 200 m depth. In contrast, the diatom C. socialis alone is essential for the amount of organic carbon reaching the seafloor. Spatiotemporal changes in community composition show decreasing diatom abundance during warm anomalies, which would reduce the efficiency of a diatom-driven biological carbon pump. Interestingly, several parasites are also tightly associated with carbon flux and show a strong vertical connectivity, suggesting a potential role in sedimentation processes involving their hosts, especially through interactions with resting spores, which could have implications for pelagic-benthic coupling and overall ecosystem functioning.
沉降聚集体将有机物从海洋表层输送到深海和海底。虽然浮游生物群落会影响碳输出，但具体的生物及其相互作用如何影响输出效率尚不清楚。通过研究弗拉姆海峡沉降和沉积有机物中15年的环境DNA序列（18S-V4），我们发现大多数系统发育类群从浮游生态系统转移到了底栖生态系统。群居角毛藻、海冰硅藻、放射虫和毛颚动物是垂直碳通量至200米深度的关键组成部分。相比之下，仅群居角毛藻对于到达海底的有机碳量至关重要。群落组成的时空变化表明，在暖异常期间硅藻丰度下降，这将降低硅藻驱动的生物碳泵的效率。有趣的是，几种寄生虫也与碳通量紧密相关，并表现出很强的垂直连通性，这表明它们在涉及宿主的沉降过程中可能发挥作用，特别是通过与休眠孢子的相互作用，这可能对浮游-底栖耦合和整体生态系统功能产生影响。
