Researchers map the Great Barrier Reef’s microbiome by analyzing DNA taken from seawater across multiple reef locations. According to reporting, scientists collect samples from 48 reefs and use DNA sequencing to characterize microbial communities associated with the reef ecosystem. The studies identify a large number of viral sequences and estimate the diversity of viruses present, with one account citing 808,585 viral genomes and an estimate of 362,802 different viruses. Alongside viruses, the research documents substantial bacterial diversity, including more than 500 bacterial species previously unknown to science. The mapping builds on earlier work that helped establish microbiome research as a way to understand how complex microbial communities affect health and environments. In this case, the results provide a detailed baseline description of the reef’s microbial life, which can support future studies on reef ecology, ecosystem change, and how microbial communities respond to environmental pressures. The reporting also emphasizes that the work substantially expands what is known about the genetic diversity of microorganisms in a major marine habitat.