Figure 2.

Latitudinal Patterns of Marine Plankton Diversity

(A) LDGs at the sea surface for all MPGs (STAR Methods).

(B) Morphological diversity as analyzed from more than 77,000 organisms collected with the bongo net (imaging | 300 μm). Morphological measurements were normalized and subjected to a t-distributed stochastic neighbor embedding (t-SNE) ordination analysis using all samples (STAR Methods). In the central 2D t-SNE ordination, each dot corresponds to an organism and its color to its taxonomic assignation (>100 taxa). For ease of interpretation, the points corresponding to a subset of abundant groups are displayed separately. The three t-SNE ordinations displayed on the right show dots from three stations distantly located and from different latitudes, as shown in the map. Six images are also presented as examples of the underlying data (STAR Methods); 1-mm scale bars are shown below each picture.

(C and D) Patterns of the whole plankton community using different sampling protocols at (C) the sea surface (16S/18S/FC/LM) or a larger integrative depth of 500 m (imaging) and (D) in mesopelagic (average depth, 540 m) or bathypelagic layers (BAT; average depth, 4000 m, Malaspina expedition). In all cases, solid lines correspond to GAM smooth trends and gray ribbons to the 95% confidence intervals of the Shannon latitudinal trend predicted by the GAMs (see also Figures S4 and S7 for individual curves and explained deviance). These trends are drawn for illustrative purposes and were not used in downstream analyses. 16S and 18S refer to the different rRNA subunit genes used as marker genes for metagenomics and metabarcoding, respectively. Imaging refers to the identification method for large eukaryotes captured with nets. FC refers to flow cytometry for the picoplankton and LM to the light microscopy-based survey of microphytoplankton (STAR Methods). Numbers refer to the filter mesh size.