The efficiency of the fish ladder of Szentgotthárd has been proven
In order to mitigate the negative effects of transverse structures, dams, and power stations on watercourses, fish ladders were developed in many places. In most cases, these will bypass the dam and provide the wildlife with long-term interoperability under appropriate flow conditions. Their primary function is to allow fish to migrate between their foraging and breeding sites. Although several variations of the fish ladders have been built in the Rába catchment area, we have still no clear evidence that they really serve their desired function.
For this reason, we examine and compare three different fish ladders with different designs, two of them at Rába, in Szentgotthárd and Ikervár, and one at Pinka in Felsőcsatár. The ladder of Szentgotthárd is completely artificial, it is partly artificial in the Felsőcsatár, while it is quiet natural in Ikervár. In our research, fish are provided with a microchip and then released downstream of the ladder. We try to detect fish passing through over the dam with a receiver antenna upstream of the ladder.
So far we have achieved results at the fish ladder of Szentgotthárd, where we equipped nearly 200 fish with microchips. Out of these, 15 individuals were detected upstream. According to our results, 8 barbel, 6 chubs and 1 roach surely surged up the fish ladder.
Investigations were also started at the other two fish ladders and we will report on their results later.