PIT-Tag/marked fish

The Institute of Hydrobiology and Water Management at the University of Natural Resources and Applied Life Sciences Vienna is conducting fish ecological studies in the Danube and relevant tributaries in the section between Altenwörth and the area of the Danube Floodplain National Park as part of the project “Christian Doppler Laboratory on the Dynamics of Meta-ecosystems in Regulated Riverine Landscapes“.

As part of the research, fish are tagged with a “Passive-Integrated-Transponder-Tag” (PIT-tag for short). These are small “chips” that were specially developed for use on wild animals (comparable to the “chipping” of pets). They do not have their own battery and are therefore environmentally safe to use. The tags have a length of 12 or 23 mm (depending on the size of the fish) and are injected into the muscle flesh below the dorsal fin. In principle, all fish species are tagged, but primarily adult individuals of large species (nase, barbel, aitel, nerfling, female nerfling, pikeperch, sooty nase, archery, pike, etc.).

The marking of fish serves to generate valuable information on the migration behaviour of fish in the Danube. The aim is to contribute to the development of targeted and effective measures that will improve the Danube ecosystem and ultimately lead to the sustainable and effective protection of fish populations.

The markings of the fish are always made below the dorsal fin. Bream and carp, however, are marked between the pelvic fins.