title: RioDoce18ST
design: Prior to DNA extraction, we elutriated the sediment samples using 45 m sieves. After elutriation, DNA was extracted from the sediment samples separately using the PowerSoil DNA Isolation kit (Qiagen) following the manufacturers instructions. The V9 hypervariable region of the 18S SSU rRNA gene was amplified using primers Euk_1391 forward (GTACACACCGCCCGTC).