This study is a research and management project on dragonflies and autochthonous and invasive crayfish, which assesses the potential of DNA barcoding methods for detection of these species in waterbodies of the rural areas of Vienna. The focus is on the detection of crustacean and dragonfly species using eDNA barcoding (environmental DNA). This method has been developed to detect species by their DNA traces in water bodies.

The already established DNA barcoding methods for dragonflies (eDNA; DNA barcoding of exuviae) will be refined for application-oriented use in order to test their applicability for ecological assessments and the monitoring of FFH species. The collected data will be used for evaluating the ecological status of the investigated waterbodies.

In the project part that concerns the crayfish, eDNA barcoding will be established for the detection of native and invasive crayfish species. Invasive crayfish species are (potential) carriers of the crayfish plague (Aphanomyces astaci) and pose a threat to autochthonous species due to their increasing dispersal. This study will create the basis to evaluate the method for the detection of crayfish in comparison to traditional sampling methods.

The investigation of streams with syntopic occurrence of crayfish and the FFH dragonfly species Cordulegaster heros (Balkan Goldenring) will allow to analyse the influence of crayfish on Cordulegaster heros populations.

Hence, the project will provide important information on the ecological status of Vienna’s waterbodies and help to evaluate classical field methods in comparison to eDNA barcoding. The results of the study will also form the basis for further management measures.