The fish pass, which has been installed at Hellesdon Mill in Norwich, will help all fish species migrate upstream of the mill.
Manufactured structures like mills, weirs and sluices can prevent fish from moving freely around the river so if it is not possible to remove an obstruction, a fish pass is a favourable option.
Jez Wood, a fisheries specialist at the Environment Agency in East Anglia, said:
The Environment Agency owns sluices at Hellesdon Mill which needed upgrading for health and safety.
We always look for opportunities to make environmental benefits as part of any on-site work and therefore investigated the opportunity to tackle the largest environmental issue at the site: fish passage.
The fish pass means all fish species, including sea trout and the critically endangered eel, are now able to travel upstream, which is great for the river and for the fish population.
The European eel is a critically endangered species. There are many reasons for this but there is evidence to show that barriers preventing migration has an impact on the species.
Numbers have fallen 95% over the last 30 years but by adding fish passes the Environment Agency helps this protected species to continue its fascinating life cycle.
