Acknowledgements

This work was carried out in the framework of the Fourth Joint Danube Survey (JDS4) and was led and funded by the International Commission for the Protection of the Danube River (I.C.P.D. R) and in collaboration with the EU COST Action DNAqua-Net (CA15219) and the INTEREG MEASURES programme (DTP2-038-2.3). Additional funding was provided by the Austrian Federal Ministry of Agriculture, Regions and Tourism (BMLRT) and the ÖK-IAD (Österreichisches Komitee der Internationalen Arbeitsgemeinschaft Donauforschung). This publication is also part of the bilateral Austrian-Hungarian Joint Research Project RIMECO “Functioning of vertebrate metacommunities in dynamic riverine landscapes: an innovative approach using eDNA metabarcoding” supported by the Austrian Science Fund (FWF) (I 5006) and the ANN-OTKA (141884) grant. We thank SPYGEN staff for their help in eDNA analysis in the laboratory.