![]()
The built barrages enhanced the water level compensating the effect
of former river basin acquittance but on the other hand these
barrages embarrassed the free movement of water animals along the
river.
Test fishing performed in November 2007 and research work in fish
biology squarely proved successful functioning of fish-ladders.
Fish faunistics were newly checked in springtime 2008 by experts of
Hungarian Danube Research Station of the Hungarian Scientific
Academy. According to the results the new ecological corridor is
used by several fish species. It’s a great pleasure to see
the spawning common nase (Chondrostoma nasus) - formerly
representing the rich fish stock of the river - in the revitalised
oxbow of Ipolytölgyes.
„On the whole, the diverse composition of fish species
showed 15 species in the lower stretch of the tributary. (…)
Not only migrating but local resident exemplars were also found,
indicating that fish species composition noticeably strongly
depends on water flow circumstances. In the low stream stretch,
this year offspring of pike (Esox lucius) were found, showing the
bowl of this species here.” …
The finished fish-ladders and revitalised oxbows mean remarkable
touristical sights, assisting in population retention of the area,
creating some new workplaces too. Fish-ladders and revitalised
oxbows are to be find on the web-sites of the surrounding villages
and a new campsite is also planned at the oxbow of
Ipolytölgyes.
After having finished the fish-ladders, further challenges are
waiting us, ecological study-pathways are planned to make complete
the new works. Beside their regional effect, these fish-steps give
solutions for mostly local problems. Long term complex acquittance
of the whole Ipoly valley needs a row of interventions on the whole
catchment area according to principles drafted
earlier.