Risks of Microplastics Shaping Viral Communities and Functions in Real Marine Environments

Microplastic (MP) pollution has become a global issue, especially in the oceans. However, the extent of changes in the ecological states of viruses that coexist with MPs and their subsequent influence on the biogeochemical cycle remain unclear. We found that the subtropical Atlantic has emerged as a viral diversity hotspot, while the hotspots of increasing viral diversity are concentrated in the South China and Eastern Archipelagic Seas, with 87.57% of the area showing increasing trends. Ignoring the effects of MPs would result in more than 15% underestimation of viral diversity in the Mediterranean region and temperate zone of the Indian Ocean, which is notably higher than the global overall underestimation of 2.4% for viral diversity. Beyond a critical MP threshold (1 × 10⁴ items·km^-2, accounting for 55.26% of marine zones during 2025), a distinct positive association with marine viral diversity was observed, especially in low-diversity regions. In regions with higher MP concentrations, viral community networks exhibited higher connectivity and lower modularity, coinciding with a stronger presence of lytic bacteriophages for lysogenization. MPs emerge as significant environmental indicators linked to marine viral ecological niches and host-virus interactions. This work addresses the non-negligible role of MPs in shaping marine ecosystems by viruses.