A paper co-authored by researchers from IMBE, MIO and OSU Pythéas has just been published in Molecular Ecology Resources, following on from the Seamobb project. This study is the result of a fruitful collaboration, which brought together expertise ranging from from diving and sampling to genetics and bioinformatics, via the marine taxonomy and community ecology.
In this study, Anne Chenuil and his colleagues are investigating the use of environmental DNA to improve the monitoring of marine biodiversity. They combine an analysis using DNA metabarcoding with photographic observations carried out on artificial reef monitoring structures, the ARMS (Autonomous Reef Monitoring Structures).
The study focuses on 10 sites in the north-western Mediterranean. The researchers first optimised the experimental protocols, in particular DNA extraction and the choice of polymerase, and then used a bioinformatics analysis method to minimise false positives and ensure the traceability of the results.
Particular attention was paid to the very structure of the ARMS. Rather than grouping together the organisms present on all the faces, the researchers analysed the different faces of the structures separately, in order to better take into account the microhabitats that they offer.
Metabarcoding has thus detected a species richness of approximately 15 times greater compared with that revealed by photographic surveys at the site level. However, the two methods provide complementary information: DNA analysis allows for the detection of greater taxonomic diversity, whilst photography provides information, in particular, on the major groups of organisms and their area coverage.
Above all, the results show that It is essential to preserve the spatial structure of the ARMS to fully exploit the potential of metabarcoding. The authors therefore propose grouping the 17 faces of each structure into five structural categories, a more operational approach to developing a reproducible, large-scale monitoring system for marine biodiversity.
Read more at Molecular Ecology Resources : Distinguishing Faces in ARMS Metabarcoding Improves Marine Biodiversity Monitoring: A Comparison Across Protocols, Experimental Designs and Photographic Surveys
