The relative abundances of taxa in selected subnetworks were used to estimate carbon export and to identify key lineages associated with the process. a, The selected eukaryotic subnetwork (n = 49, see Supplementary Table 2) can predict carbon export with high accuracy (PLS regression, LOOCV, R² = 0.69, see Extended Data Fig. 2g). Lineages with the highest VIP score (dot size is proportional to the VIP score in the scatter plot) in the PLS are depicted as red dots corresponding to three Rhizaria (Collodaria, Collozoum inerme and Sticholonche sp.), one copepod (Oithona sp.), one siphonophore (Lilyopsis), three Dinophyceae and one ciliate (Spirotontonia turbinata). b, The selected prokaryotic subnetwork (n = 109, see Supplementary Table 3) can predict carbon export with good accuracy (PLS regression, LOOCV, R² = 0.60, see Extended Data Fig. 2h). c, The selected viral population subnetwork (n = 277, see Supplementary Table 4) can predict carbon export with high accuracy (PLS regression, LOOCV, R² = 0.89, see Extended Data Fig. 2i). Two viral populations with a high VIP score (red dots) are predicted as Synechococcus phages (see Supplementary Table 4).