Diversity and Ecological Potentials of Marine Viruses Inhabiting Continental Shelf Seas.

Viruses are critical components of all marine ecosystems. However, the role of viruses in continental shelf seas, which are usually areas of intense economic development, remain poorly characterized. Here, 62 seawater viromes from the eastern continental shelf seas of China (ECSSC), collected between 2017 and 2022, are systematically analyzed. A total of 310,628 viral operational taxonomic units (vOTUs) are identified, providing the most comprehensive overview of DNA viral communities in the ECSSC. Among them, 136,652 (42.3%) vOTUs could be classified into 89 families, dominated by Kyanoviridae, Autographiviridae and Zobellviridae. Only 31,994 (10.3%) of the vOTUs have predicted putative hosts, of which 91.4% are associated with specific hosts, including 31 bacterial and 10 archaeal phyla. The uniqueness and novelty of viruses from the ECSSC are identified and found to be much greater than those from GOV 2.0 and other environmental viromes. Viral communities undergo significant seasonal changes in different seasons and regions of the ECSSC. Here, 20,146 auxiliary metabolic genes are identified, of which carbohydrate, sulfur, and photosynthetic pathways are significantly enriched in the ECSSC compared to other marine ecosystems. This study establishes a foundational baseline for seawater viruses in the ECSSC, highlighting viral diversity and its potential impact on the biogeochemistry of continental shelf sea ecosystems.