The aim of this project is to compile a reference database of Nordic Seas DNA metabarcodes and to better understand the eDNA taphonomy related to the transfer of plankton DNA to the sediments.
Recent development of DNA metabarcoding led to spectacular accumulation of metabarcoding data, especially for microbial and meiofaunal biomes. However, despite rapidly increasing number of DNA metabarcodes, their taxonomic assignment is still very limited. The large proportion of metabarcodes remains unassigned even at higher taxonomic level, impeding their ecological interpretation and sometimes making it difficult to distinguish between planktonic and benthic taxa. To overcome this issue, we propose to establish a reference database of barcodes obtained from morphospecies known to be present in the Nordic Seas and metabarcodes obtained in this and other eDNA studies from the same area. We will target selected taxonomic groups that are of particular interest to this study, e.g. foraminifera, diatoms, and copepods. Moreover, we will assign metabarcodes to plankton and benthic community, based on their occurrence and relative frequency in water column and sediment DNA datasets. We expect that this will help to better understand the taphonomic processes involved in a transfer of DNA from water column to the sediment, and to determine whether all planktonic taxa are equally recorded in sedimentary DNA.