This is a video of a barbel in Germany.
Translated from Willem Kuijsten and Jan Kranenbarg in the Netherlands:
In the mid 20th century, water quality in the major Dutch rivers decreased badly. The nadir was in 1986, when during the Sandoz disaster twenty tons of very poisonous pesticides got into the Rhine water. As a consequence of pollution, the number of fish species in the Rhine decreased from 40 to 28. The barbel disappeared from the Dutch Rhine and its distributary branches as well. Ever since then, governments along the Rhine have taken water quality measures, and water quality has improved strongly. The number of fish species has increased again. Only the share of current loving fishes, like the barbel, lagged. However, this seems to be changing now! …
Fish in the Netherlands: here.