For eDNA extraction and subsequent analysis sediments have to be sampled and preserved in the correct way to avoid cross contamination with fish or sediment residues from other hauls. To guarantee traceability of samples a correct labelling and documentation of sediment sampling is needed. Using a van Veen grab sampler, which is a clamshell bucket made of stainless steel, sediment samples are taken from the sea bottom. After the gear is back on board again subsamples in duplicates are taken out, labelled and preserved in ethanol.
Blancke et al. (Tue,) studied this question.