Conference Proceedings - IAD

39th IAD Conference, August 2012, Szentendre, Hungary
Russian sturgeons migrated up to the Bavarian Danube. It is also said to be rare
by Fitzinger & Heckel (1839), but this might be the same situation as described
with the ship sturgeon. A catch near Schärding (Brod 1980) shows the presence
of this species in the Inn and it probably also occurred in the Salzach upstream
to Tittmonig. In the March it is stated upstream to Hodonin (Weeger 1884). For
other tributaries the same situation as for the ship sturgeon can be assumed.
Some authors suspect the species in the Mura along the Austrian - Slovenian
border (Zauner et al. 2000).
There are no reports of stellate sturgeons in Austrian waters, only two
statements from the 19 th century saying that it very seldom entered the Austrian
Danube (Fitzinger & Heckel 1839) and that it rarely occurred in the Isar in
Bavaria (Siebold 1863). It probably was more abundant in earlier times and used
similar habitat and stretches as the other species. In the Ural River the
spawning migration of the stellate sturgeon is considerably shorter than of
Russian and beluga sturgeon (Lagutov & Lagutov 2008), which might be similar
in the Danube, being an indication that the species might have been less
frequent than others.
The beluga sturgeon occurred throughout the Austrian Danube and Inn. In the
Salzach it migrated at least up to Tittmonig (Hochleithner 2004). Again this
species was stated as rare in Austrian waters in the 19 th century (Fitzinger &
Heckel 1839). In this case the same authors state it was abundant in former
times, which directly indicates overfishing in earlier centuries. For the March
catches are stated as far upstream as Hodonin (Weeger 1884). For the other
rivers the situation might be the same as with the Russian and ship sturgeon.
Stocking
Stocking is and was conducted in various Austrian rivers, especially in the
Danube and the Drava. Most stocked fish are sterlets and there were also some
stocking actions with extinct species like Russian sturgeon. Problematic is the
high number of illegally stocked or escaped alien sturgeon specimens. In the
Drava a high number of sterlets was stocked between 1982 and 1995 in various
impoundments (Honsig - Erlenburg & Friedl 1999). In the Danube stocking
efforts with sterlets concentrated near Vienna and in the Donau - Auen National
Park area from 1994 to 2010.
Recent catch
In total 220 specimens from Austrian rivers could be included in the database. It
can be estimated however that the real number is two to four times higher.
Around 90 reported catches are sterlets, half of them from the Danube and the
other half from the Drava. Over 100 fish could not be identified due to lack of
pictures or usable morphological information. Most likely most of these fish are
sterlets and Siberian sturgeon. 12 Siberian sturgeons could be reported. In river
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