Microbial community structure at the air-sea interface in the North Sea: BASS1 sea-surface microlayer metagenome study

The BASS1 study characterizes microbial communities at the air–sea interface in the North Sea near Helgoland, Germany. On 21–22 September 2022, seawater was collected from the sea-surface microlayer (SML) and the underlying water (ULW, 1 m depth) using a remotely operated catamaran platform at four stations spanning 54.12–54.25° N, 7.67–7.96° E. To obtain operational fractions representing different ecological niches, water was sequentially filtered through 3.0 µm, 0.8 µm, and 0.2 µm membranes, defining large particle-associated (3.0 µm), small particle-associated (0.8 µm), and free-living (0.2 µm) size fractions in both layers. DNA was extracted and prepared for shotgun metagenomic sequencing (WGS) to compare taxonomic composition and functional potential between SML and ULW and across size fractions. This study will include raw sequence reads linked to sample records with comprehensive environmental metadata, and downstream submissions of metagenome-assembled genomes (MAGs) derived from these samples. Funding by the German Research Foundation (DFG) and the Austrian Science Fund (FWF) under grant number I 5942-N to Thomas Reinthaler.