Piotr Dębowski, Jarosław Gancarczyk
ABSTRACT. The Kamienna Hydropower Station on the Drawa River, located 32 km from its mouth, is the first barrage upstream from the sea. This obstacle prevents the further migration of anadromous fishes in this river system despite the fish pass that was installed when the dam was constructed a hundred years ago. The aim of the present study was to determine the effectiveness of the fish pass. Two methods were applied: occasional catches made at the fish pass excluding those from upstream waters (1997-1998); a Riverwatcher (VAKI Aquaculture Systems Ltd.) automatic fish counter that operated between September 2008 and June 2010. There was no significant fish migration through the pass, and only individuals of different species were noted at higher frequencies in late spring. Most of fish were small, and the few large fish noted migrating in fall were identified as sea trout. Substantial differentiation in the ichthyofauna upstream and downstream from the dam suggests that exchange between these two areas is impossible. The results of this study confirm the inefficacy of the fish pass.
Keywords: dam, fish migration, fish pass, fish counter
Przyjęto po recenzji 01.07.2013 r.