Danube Fish Monitoring Reveals Healthy, Diverse Populations and Rare Species

Researchers from the HUN-REN Institute of Aquatic Ecology, in collaboration with the Danube–Drava National Park Directorate and the HUN-REN Veterinary Medical Research Institute, conducted expeditions at six Hungarian sites from Győr to Mohács, sampling both shoreline and deep-channel habitats.

A total of 34 fish species were identified — 21 in deep waters and 33 in nearshore zones. The most frequent species included the protected pale-spotted stickleback, non-native round gobies, and sand smelts.
Encouragingly, researchers rediscovered new specimens of the rare stickleback species once thought extinct, as well as sturgeon, spined loach, and young asp and barbel, indicating a strong breeding season.

Fish samples were also tested for fin rot, a common indicator of fish health, with only one positive case among 27 samples, confirming that Danube fish populations are overall healthy.

IDR (comment):
“These findings confirm the ecological resilience of the Danube’s aquatic ecosystem.
The rediscovery of rare species demonstrates the effectiveness of ongoing habitat protection and water quality programs.
This monitoring directly supports the EU Water Framework Directive and SDG 14 — ‘Life Below Water’.”