Environmental DNA & biodiversity

In addition to the changes in microbial activity that could derive from the cyclic temperature variations induced by the operation of the energy storage facility, potential changes in the fauna should not be excluded. This is directly linked to the optimal temperature range at which certain groups of organisms grow and reproduce. Changes in temperature around 20℃ to 40℃, which can be expected from the full use of the facility, could affect dramatically not only the microbial community composition, but also the composition of other type of organisms populating the aquifer, with potential implications for the aquifer’s biodiversity.

To analyze these potential changes, traces and remains of the groundwater fauna are sampled periodically through filtration of the groundwater pumped out from different depths at all three observation boreholes. These environmental DNA (eDNA) samples are then used to establish the groundwater fauna present in the project area, comparable to forensic methods based on traces left by the organisms such as excretions or body material. Using an eDNA metabarcoding approach, we are able to identify the presence of different species and small animals, such as groundwater amphipods. The results of these periodic analyses will shed light, firstly, on the existing changes in the groundwater fauna over the aquifer’s depth, and secondly, on the effects of the cyclic temperature variation on its composition.