title: 18S rRNA amplicon from middle of sediment core
design: Daily, a sediment core was collected from each beach and divided into surface, middle and bottom layers. 100 mL of water was filtered through a 0.22 um filter. The filter was flash frozen in liquid nitrogen and stored at -80C. The DNA was extracted using a modified CTAB method and the V4-5 region of the 16S rRNA gene and the V4 region of the 18S rRNA gene were amplified with fusion primers. For sediment samples, 0.5 g were extracted with a Qiagen Power Soil DNA extraction kit and the same PCR amplifications were completed. Cleaned products were pooled and sequenced using 300 bp paired-end methods on an Illumina MiSeq.