Fishfaunistical monitoring of the Hungarian part of the River Drava (1999-2004)

Abstract

Fishfaunistical monitoring in the Hungarian part of the river Drava between 1999 and 2004 wa carried out. A small-capacity, pulsating direct current electric fishing machine with rechargeable battery was used for the surveys. During the monitoring altogether 22.649 fish specimen were caught and identified, representing 44 species. Beyond the monitoring sites, fishfaunistical data were collected in other types of habitats, in side arms, the main channel and backwater arms as well. In addition, our own data was complemented with verified data supported by evidence species or picture documentation regarding the occurrence of species, and also with catching data from the fishery database, so the presence of altogether 57 species has been confirmed. Out of the 57 species of verified occurrence, 23 species have nature conservation status. 5 of these protected species have highest level protection status (Eudontomyzon mariae, Hucho hucho, Umbra krameri, Zingel zingel, Zingel stréber). Out of the identified species 22 species are listed in the Annexes of the Habitat Directive. Based on the number of species found, the absolute (TA: 114) and relative natural value (TR: 2.036) of the fish fauna was defined. The recent fauna list of the river has been compiled using literature and own data; based on this, the occasional or regular occurrence of altogether 63 species is presumable in the river Drava. Compared to previously published species list, 8 new species could be identified in the Hungarian segment of the Drava, namely: Eudontomyzon mariae, Alburnoides bipunctatus, Gobio uranoscopus, Gobio kessleri, Sabanejewia bulgarica, Barbatula barbatula, Umbra krameri, Neogobius fluviatilis.