Discover two new GEANS publications

21 January 2022 - Published by Nele Jacobs
GEANS scientists are still working on methodology and harmonization, but we are also applying our methods in several pilots and case studies. This is nicely illustrated by two recently published papers, one focusing on the effect of DNA and PCR replicates on diversity estimates helping to further harmonise DNA metabarcoding and one on the use of eDNA in biodiversity monitoring of boulder reefs.

 

The study by ILVO researcher Laure Van den Bulcke and co-authors aims to help harmonize DNA metabarcoding for monitoring of marine macrobenthos. It investigates the effect of DNA and PCR replicates on the detection of macrobenthos species in locations differing in diversity. The results show that 2 to 3 DNA replicates are needed to detect at least 80% of the species in locations with a high and medium diversity, while 3 to 4 replicates are needed in locations with low diversity. Larger body size or high abundance does not increase probability of detection among DNA replicates. Rare species, however, are less consistently detected across DNA replicates in high diversity compared to low diversity locations.

Read the full article in Metabarcoding & Metagenomics.

The second study in Danish marine waters investigates the use of eDNA metabarcoding for supplementing traditional diver-based monitoring of biodiversity of marine boulder reefs. Using eDNA, 400 species are detected, while diver-based observations identify 184. There is an overlap of 70 species (12%) and 81 genera (18%) between both methods. eDNA is better to identify infaunal species, whereas macroalgal species are dominating in diver-based observations. Nevertheless, both methods show very similar patterns. Additionally, the eDNA approach can identify significant differences in species composition between upstream, above-reef and downstream locations, suggesting that eDNA leaves a local footprint in benthic habitats. Aarhus University researcher Peter Staehr and co-workers show that eDNA sampling provides a substantial supplement to traditional diver-based monitoring and recommend to add the eDNA method to conventional monitoring programs in the future.

Read the full article in Frontiers in Marine Science.