Conclusion
Robust data are necessary to assess and improve ecological status. Conventional methods are usually invasive or even destructive. To increase the use of novel non-invasive methods, validation is necessary. This study demonstrated that eDNA metabarcoding can provide valuable data for ecological interpretation. The synthesis of eDNA-based data with environmental data measured by mobile multiparameter devices has great potential to substitute conventional fish monitoring. Moreover, a combined analysis of both data types is suitable for addressing fundamental ecological questions. This research has contributed to a better understanding of eDNA dynamics and will motivate stakeholders for broader application. The application of eDNA metabarcoding for biomonitoring in heterogeneous ecosystems is a huge step forward to reach high quality data with a non-invasive method that is worthy of the 21st century.