CANCELLED - Environmental DNA analysis is unsuitable for biodiversity exploration at the species level – A case study from Aotearoa / New Zealand

Background/Question/Methods

: Effective management of biodiversity requires regular surveillance of multiple species. Analysis of environmental DNA by metabarcoding (eDNA) holds promise to achieve this relatively easily. However, taxonomic inquiries into eDNA data need suitable molecular reference data, which are often lacking, particularly at the specie level. We evaluate the impact of this data void in a case study of fish diversity in the remote fiords of New Zealand. We compared eDNA-derived species identifications against Baited Remote Underwater Video (BRUV) data collected at the same time and locations as the eDNA data. Furthermore, we cross referenced both eDNA and BRUV data against species lists for the same region obtained from literature surveys and the Ocean Biodiversity Information System (OBIS).

Results/Conclusions

: Concordance of taxonomies between the data sources dissolved with lowering taxonomic levels, most decisively so for eDNA data. BRUV agreed with local biodiversity information much better and fared better in detecting regional biodiversity dissimilarities. We show that that eDNA metabarcoding is unsuitable for species-level biodiversity exploration, but is well suited as a surveillance tool for a readily known community, when locally generated reference data is available.