Scientists have mapped the microbiome of the Great Barrier Reef, uncovering hundreds of thousands of previously unknown viral genomes and more than 500 bacterial species new to science.
Published in Nature, the study was led by researchers from the University of Queensland and the Australian Institute of Marine Science (AIMS). The team analysed DNA from seawater samples collected across 48 reefs to build the most comprehensive picture yet of the microbial communities that underpin reef ecosystems. Using advanced metagenomic approaches, researchers identified 808,585 viral genomes representing an estimated 362,802 distinct viruses, alongside 584 previously undescribed bacterial and archaeal species.
Microorganisms play fundamental roles in marine ecosystems, driving processes such as carbon cycling and supporting marine food webs. The newly mapped reef microbiome provides a valuable baseline for understanding what characterises a healthy reef ecosystem and how microbial communities respond to environmental pressures, including climate change, heat stress, coral bleaching and human impacts.
The researchers highlight that microbial communities can act as early indicators of ecosystem change, potentially revealing environmental disturbances before visible impacts occur. This work demonstrates the power of large-scale genomic resources to improve our understanding and monitoring of Australia’s unique ecosystems.
The study was supported by access to comprehensive microbial reference datasets developed through the Australian Microbiome Initiative. Led by Bioplatforms Australia, the initiative has created a publicly accessible database capturing microbial diversity across a broad range of Australian terrestrial and aquatic ecosystems. These resources help researchers characterise microbial communities, compare ecosystems and unlock new insights into Australia’s microbial biodiversity.
This article was adapted from reporting by Donna Lu in The Guardian, “Great Barrier Reef microbiome mapped as researchers discover 500 bacterial species previously unknown to science” (23 July 2026).