The environmental DNA method (eDNA) is used for single-species identification and community analysis when doing a biodiversity assessment.
The monitoring of rare and threatened species in freshwater and marine ecosystems can sometimes be a challenge when using the conventional monitoring method. By taking water samples in a water body, we are able to identify the presence of a species by extracting its eDNA. Faeces, eggs, saliva, urine and epidermal cells are believed to be the predominant sources of environmental DNA.
In the case of RECONECT, AMPHI monitored in Aarhus (demonstrator B) the presence/absence of the protected species Great Crested Newt and the species quantification in already implemented NBS. This is done by comparing two methods, eDNA water sampling method and traditional monitoring. The species is an indicator of good habitat quality.
eDNA sampling consists of taking water samples in the most strategic places of the pond, namely where the species is most likely to occur.
The traditional monitoring consists of catching with a net around the pond and do counting of individuals. This method was combined with the German counting method, by using traps. These traps are emptied every day during 3 days.
The purpose of comparing these two methods is to assess i) whether the species is detected with both methods or not, ii) whether eDNA species quantification is as reliable as the traditional method for estimating the population size of a species in a pond.
eDNA is being tested in Lystrup for the Great Crested Newt. The monitoring was performed in 2020 by comparing two methods, the traditional monitoring with dipnet and nets, together with the eDNA monitoring. Amphi are not only comparing whether the species is detected as present/absent in the ponds, but also whether they can quantify the population size in each site.