title: DWTP-7-PF
design: Filter material (15 mL each) was collected from the top of each filter using a 1% hypochlorite-wiped stainless steel grab sampler. Filter material was immediately placed into cryotubes, then immersed in liquid nitrogen, and stored at -80 ¡C for further analysis. Extraction of DNA from 0.5 g of sand material from each sample was carried out using the MP FastDNA Spin Kit. DNA was amplified using 16S rRNA total bacteria primers 341F 805R. Library preparation and Illumina MiSeq sequencing was carried out by DMAC (DTU Multi-Assay Core Facility, Kgs Lyngby, DK).