The Institute of Hydrobiology and Aquatic Ecosystem Management, Department of Water, Atmosphere and Environment of the University of Natural Resources and Applied Life Sciences, Vienna investigates the fishecological developement of the new fishway and the new situation at the mouth of the Ybbs. The monitoring includes three topics:

  • Investigation of functionality of the fishway

  • Fishecological situation before and after the river restoration work at the mouth of the Ybbs

  • Migrationstudy by Telemetry (= investigation of fishmigration by radio transmitters)

Fishecological investigations of the Austrian Danube show a spectrum of  72 fish species. Out of these 57 are autochtoneous, 15 species non native. It is possible that all 72 species can occour during the monitoring investigations. 

Short Info of Monitoring confluence Zone of River Ybbs

The new mouth of the Ybbs shows good habitat conditions for fish species, especially for juvenile fish. Today the fishecologists find 20 fish species (before the restoration work 13 species). A special benefit is proved for rheophilic species like Nase (Chondrostoma nasus) an Barbel (Barbus barbus).
The confluence zone is habitat for 8 FFH- Annex II species:

Huchen (Hucho hucho), Schrätzer (Gymnocephalus schraetzer), Streber (Zingel streber), Zingel (Zingel zingel) und Strömer (Leuciscus souffia agassizi), Schied (Aspius aspius), Frauennerfling (Rutilus pigus virgo) und Koppe (Cottus gobio).

Detailed Info in German Language >

Short Info of Monitoring fishway at the Melk Power Plant on the Danube

From the beginning of the investigations in march 2007 till today 40 fish species migrated into the new construction. Fish of all lengths and year classes are present. In the fish spectrum there are  6 FFH- Annex II species:
Schrätzer (Gymnocephalus schraetzer), Zingel (Zingel zingel), Schied (Aspius aspius), Frauennerfling (Rutilus pigus virgo) Weißflossengründling (Gobio albipinnatus) und Koppe (Cottus gobio)

In the first year the focus of the investigations layed on fish traps. The traps were situated inside the migration facility about 200m from the upper and the lower end. From March till July 2007 3.529 fish out of 39 fish species were trapped and again released. At the 18th of Juli  2007 electro- fishing shows thousands of fish at the upper and lower end of the migration facility.

In 2008 some problems with the trapping occurs because of defects in electric equippement and huge drift of algae. Because of this situation the team layed the focus on electro fishing. A new run of electro- fishing took place at the 2nd of Juli 2008  in 4 stretches of the migration facility after removing of the fish traps one month ago. The fish density reached 268 fish/100 m in mean. Adult individuals of Chondrostoma nasus and Barbus barbus were in the migration facility. Calculating the catch up to 2 Kilometers length of the migration facility shows that there must be a fish stock of some thousand individuals which migrate into the construction within only one month.

The team is now working on a design for the monitoring of the year 2009.

Detailed Info in German Language >