Marine viral macro- and micro-diversity from pole to pole

Microbes drive most ecosystems and are modulated by viruses that impact their lifespan, gene flow and metabolic outputs. However, the influence of viral community diversity at the ecosystem level remains difficult to assess due to classification issues and few reference genomes. Here we establish a ~12-fold expanded global ocean virome dataset of 195,728 viral populations, now including the Arctic Ocean, and validate that these populations form discrete genotypic clusters. Meta-community analyses revealed just five ecological zones throughout the global ocean, and established local and global patterns and drivers in viral community diversity at levels of both macrodiversity (inter-population diversity) and microdiversity (intra-population genetic variation). These patterns sometimes, but not always, paralleled those from macro- organisms and revealed temperate and tropical surface waters and the Arctic as biodiversity hotspots and mechanistic hypotheses to explain them. With this further understanding of viral populations and ecology in the ocean, viruses can be more broadly included in ecosystem models.