River lampreys back in river after century

This 18 April 2016 video from Ireland says about itself:

First River Lamprey Lampetra fluviatilis spawning activity we observed in 2016: Castleconnell, Lower River Shannon. Also note that there is a Brook Lamprey L. planeri getting involved! Unfortunately, water quality problems also apparent in these photos. River Lampreys are listed under Annex II and V of the Habitats Directive. The Lower River Shannon is designated as a SAC for the three Irish lamprey species.

Translated from Waterschap Rijn en IJssel in Gelderland province in the Netherlands, 12 March 2020:

The start of the migration and spawning season for fish is a good time to see how many and which fish use the fish passage at Doesburg. The first results are promising: many roaches, ides and even river lampreys are using the passage through swimming from the IJssel to the Oude IJssel. River lampreys have not been seen in the Oude IJssel for 100 years.

The fish passage was taken into use last September and connects the Oude IJssel to the Gelderse IJssel. Due to the great height differences of these rivers, up to five meters, the fish passage in Doesburg is one of the largest and most innovative in the Netherlands.