Discussion
Our study demonstrates that eDNA metabarcoding is a useful tool for the
assessment of fish diversity in spatially heterogeneous temperate water
bodies. This novel molecular approach can be used to provide baseline
data for reliable and sustainable longāterm monitoring of these systems.
The studied reservoirs exemplify heterogeneous water bodies with
pronounced environmental gradients affecting spatial distribution of
organisms that is not easy to capture with conventional monitoring
methods. In this study, weather conditions during sample collection were
typical for temperate regions, with a hot dry summer followed by cold
wet autumn. The morphology of the studied reservoirs is similar, but
their trophic status and hydrodynamics are different. However, despite
such complex background variation, similar ecological relationships
between biological and environmental factors were detected in different
water bodies. Our results can therefore be used as an example of the
applications for other heterogeneous systems.