A survey of fish and crayfish communities in Moälven River, Västernorrland County was carried out on behalf of Moälven FVO and Moälvsfisket. eDNA was analysed from 14 sites for fish and two sites for crayfish detections.
The eDNA multispecies analyses identified 21 unique fish species and one species complex. Twice as many fish species were found with eDNA compared to the electro- and net- fishing. River crayfish was recorded at one of the two investigated sites. Water chemistry, barriers and historical fish releases combined with eDNA at the sites, verify the presence of fish species with different tolerance to environmental disturbance, and showed the role of fish as environmental indicators. The results are used for knowledge-based decisions by the local municipality and county administrative board to restore the river in affected areas.