A £12m Environment Agency project to make the Trent more fish friendly has been opened in Colwick Country Park, opening up the river and its tributaries to migratory fish including salmon, trout and eels, and making more habitat accessible for fish.
It’s been two years in the making, and Steve Lawrie, Area Environment Manager at the Environment Agency said: “The fish pass provides a significant step in restoring the River Trent catchment to its former glory for salmon and other coarse and migratory fish. It also includes an eel pass to help support the critically endangered European eel.
“We also have a public viewing platform above the water, with highly visual interpretation boards. They inform and advise visitors about the local wildlife in and around the river, including the fish that are expected to use the pass.”
The Colwick fish pass is 200 metres long, 6 metres deep and 6.5 metres wide, and means fish can navigate past the Environment Agency-owned Holme Sluices built in the 1950s as part of a large-scale flood defence scheme helping to protect Nottingham from flooding.
The pass is divided into 20 ascending chambers into which water flows through narrow slots. Fish of all species can swim upstream to lay their eggs in the gravel riverbeds of the Trent tributaries such as the River Dove and the River Derwent. They will be able to pass through these slots and rest in the chamber above before continuing.
The direct environmental benefits of the fish pass will be £18.6m. This includes 60 kilometres of river improvement from poor to good status for fish, as well as 60 kilometres of new spawning habitat immediately upstream of the barrier. It will also aid interconnectivity with numerous other fish passage schemes previously constructed upstream by the Environment Agency.
The decline of migratory fish in the Trent catchment dates back to the Industrial Revolution, when large weirs were built to open up the river for trade. While some fish were able to overcome these barriers not all of them could.
