Seamounts are typical deep-sea geomorphological structures and are widely recognized as biodiversity hotspots. Yet, comprehensive assessments of their biodiversity and influence factor remain limited. Here, we conducted a depth-stratified environmental DNA (eDNA) survey on samples from four water layers across five stations in the Beipo Seamount of the South China Sea (SCS). Using multiple eDNA metabarcoding targeting bacteria, algae, protozoa and metazoans, we investigated community structure, connectivity, and co-occurrence networks within the seamount ecosystem. The results revealed strong vertical stratification in community structure across all taxa, driven primarily by depth-related environmental gradients. Adjacent layers exhibited partial vertical connectivity, likely facilitated by seamount-induced vertical mixing. In contrast, horizontal connectivity below the seamount summit was significantly lower than that above, suggesting that the seamount may act as a barrier to deep-sea biological exchange. Co-occurrence networks displayed depth-specific structural complexity and stability, with algal-dominated surface networks, bacterial-dominated deep networks, and increasing robustness alongside decreasing vulnerability with depth. These findings reveal depth-dependent biodiversity patterns and interaction dynamics in seamount communities, providing new insights for the ecological assessment and conservation of deep-sea ecosystems. • eDNA metabarcoding revealed vertical biodiversity patterns of multiple taxa in the Beipo Seamount. • Seamount mixing enhanced adjacent-layer connectivity but weakened horizontal connectivity in deep waters. • Community stability increased with depth, and vulnerability decreased along the depth gradient.
Yang et al. (Tue,) studied this question.