A vertical microbiome investigation from coastal to open ocean.

The coastal-to-open ocean vertical microbiome was investigated using water samples from the Santos Basin, Southwest Atlantic Ocean. Using a spatial and vertical metagenomics approach, we assessed the diversity and distribution of pelagic microbes, identified major bacterial and archaeal taxa, and inferred their ecosystem functions. A total of 67 water samples were collected during the SANAGU 2019 expedition, corresponding to 28 different sampling stations distributed across the Santos Basin. Six discrete sampling depths (1M, deep chlorophyll maximum layer [DCM], 250, 900, and 2300M) were chosen within the water masses (TW - Tropical Water, CW - Coastal Water, SACW - South Atlantic Central Water, AIW - Antarctic Intermediate Water, and CSW - Circumpolar Superior Water) at each oceanographic station.