The project VIRTIDE addresses important research questions regarding a) the temporal-spatial dynamics of viral-bacterial assemblages and viral function as reservoir for antibiotic resistance genes in visible marine surface films (“slicks”) and b) the nature, abundance, and sources of atmospheric phages and their potential for infecting sea surface microbiota after deposition with rainwater. This will be achieved by combining state-of-the-art techniques including metagenomics, virus-host infection histories inferred from CRISPR systems, flow cytometry and cultivation. By filling these knowledge gaps, the project will make an important contribution to understand the ecology of viruses in understudied aquatic ecosystems. Unravelling the viral role in dispersal processes will unfold societal value by making steps towards reducing greenhouse gas emissions and promoting human health. Project duration: 2024-2028