En-route metabarcoding study of ballast water - comparative study of ballast water assessment using molecular apporaches (eDNA/eRNA metabarcoding and ATP tests). Metabarcoding study of ballast water onboard RV "Polarstern" - first day DNA samples, 3 fractions

"The samples were collected from the sounding pipe on the aft ballast tank of the RV “Polarstern”, filled with North Sea coastal water on 12 Nov 2016. Every second day (starting on 13 Nov), three replicates of BW, 100 L each, were sequentially filtered through 50 µm, 10 µm and 2.7 µm membranes (corresponding to the BWMC Regulation D-2 requirements). For each fraction, one half of membrane was analysed on-board using an adenosine triphosphate (ATP) testing kit for BW (AquaTools). Half of the filtered samples were preserved in RNA buffer for further metabarcoding analysis (DNA/RNA). The study is aimed to compare potential methods for BW compliance assessment (ATP quantification tests, visual analysis, flow-cytometry and molecular techniques); to evaluate consistency, sensitivity and accuracy of reporting signals from viable ballast water biota along a cross-latitudinal journey (Northern to Southern Hemisphere). Here, we provide data from the first sampling day, 3 sampled fractions, DNA only."