18S rRNA V9 metabarcoding of freshwater biodiversity
The aim of this study was to investigate species diversity including protists up to larger invertebrates organized in size classes (nano-, micro, meio- and macrofauna) from a long-term ecological research site (LTER-D REES) at the Lower Rhine in North Rhine-Westphalia including two riprap river Rhine sections, two oxbows as well as two gravel-pit lakes in the floodplain. The aim of the LTER-D project REES is to investigate the eco-evolutionary dynamics along a trophic cascade integrating species representatives from protists up to fish with regards to abundance as well as genomic evolution. Within this study the initial biodiversity of the targeted REES habitats was assessed from protists up to larger invertebrates (excluding fish) not only to obtain the status quo of the water bodies with regards on biodiversity, but also to create a biodiversity inventory to choose representative species along a trophic cascade for the long-term study. Diversity was assessed through morphotype richness and metabarcoding, as well as accounting for sediment composition. Furthermore, this study gave insight into how much time, expertise and what kind of mismatch we would observe by targeting biodiversity from a morphological and molecular perspective when people of different expertise and career level are contributing to the assessment.