ABSTRACT. In 1969, the Vistula River was dammed in Włocławek 266 km from the river mouth. This drastically reduced populations of migratory fishes in the river system. The poorly functioning fishway in the dam was modified into a vertical slot pass at the end of 2014. Fish passage through the new fishway was monitored with a Riverwatcher VAKI automatic fish counter. It recorded 3882 fish migrating upstream in 2015, mainly in May-June and October-November. Anadromous fishes dominated: sea trout and vimba both passed through it in numbers of approximately 1500 individuals. There were also catfish and bream in numbers above 200, as well as some barbel, asp, carp, salmon, and ide.
Keywords: fish migration, fishway, fish counter, Vistula river
Przyjęto po recenzji 8.08.2016 r.