Print PageThe impact of marine bacteria on the ecology, functioning, and ecosystem services of the world ocean is immense. Nonetheless, detailed knowledge of hotspots of diversity and the global drivers of bacterial biogeographic patterns have been difficult to quantify due to limited data regarding the ranges of bacterial taxa. To address this need, we compiled a global dataset of 16S rRNA sequences sampled from marine surface waters and identified bacterial genera present at each sampling location. We then combined this information with remote environmental data to predict the global ranges of all prevalent genera using species distribution models.
Results/Conclusions
Our spatially explicit range maps reveal significant variability in the niches of bacterial genera, and suggest three general spatial patterns. First, genus richness peaks at temperate latitudes, with relatively low richness in the tropics and polar latitudes, while diversity, as measured by the Simpson and Shannon indices, peaks in the polar latitudes. Second, both richness and diversity have local maxima in regions of high ocean mixing and in boundary currents. Last, marine bacteria follow Rapoport's Rule, with genera in the high latitudes having larger ranges than those in low latitudes. These findings provide the first global picture of marine bacterial ranges, and highlight several key differences between microbial and macrobial biogeography.
