We investigated two salt pans or playas located in the Namib Desert (Hosabes and Eisfeld). Playas found in this desert are moist, salt-covered, sediment-filled depressions which form in drainage channels whose surface and groundwater flow is obstructed by linear bedrock outcrops. This creates a saline to hypersaline environment, in which the temperature can easily rise to 50°C, harboring potential unique viral communities.

The use of a combination of multiple displacement amplification of metaviromic DNA and deep sequencing provided us with comprehensive sequence data on both ssDNA and dsDNA viral community structures. Read and contig annotations through online pipelines showed that the salt pans were comprised largely of unknown viral communities. By read mapping and network analysis, we were able to assign a large portion of the unknown reads to a diverse group of ssDNA viruses. Upon further investigation of a subset of these ssDNA viruses, we found that contigs belonging to the family Microviridae, and more specifically the subfamily Gokushovirinae, were common in both environmental datasets. Analysis of haloarchaeal virus contigs revealed the presence of three contigs distantly related with His1, indicating a possible new lineage of salterproviruses in the Hosabes playa. Based on viral richness and read mapping analyses, the salt pan metaviromes were novel and most closely related to each other while showing a low degree of overlap with other environmental viromes.