Depth profiles of heterotrophic prokaryotic abundance (A), <i>Prochlorococcus</i> abundance (B) <i>Synechococcus</i> abundance (C) and picoeukaryotes abundance (D) in the whole water column (0–3000 m) of the 22 vertical-sampling stations, respectively.

<p>The solid line is the average value, while the error bars represent 95% confidential intervals. The water depths of samples were considered as 2500 m when the bottom depths were between 2500 and 2700 m and as 3000 m when the depths were between 2900 and 3150 m.