More than 20,000km of England’s rivers have been opened up to improve fish migration over the last 4 years the Environment Agency revealed on World Fish Migration May 21.
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This is the equivalent distance of London to Rio and back. Almost 200 obstructions have been overcome – this means fish passes installed or weirs removed. Migration is important because many species of fish need to migrate to reproduce, feed and complete their life cycles.
Weir removals and fish passes create "fish highways" making a faster, easier route from the sea right up to the upper reaches of rivers. This work benefits coarse fish that spend their entire lives in the river, as well as the species that migrate between the river and the sea, such as eel, salmon and sea trout.
Young eels make an incredible journey more than 5,000km across the Atlantic Ocean from the Sargasso Sea to rivers all over Europe – and adult fish make the return journey to spawn.
It’s not always possible to remove all weirs – for example, many are still being used and can’t be removed if buildings, walls or bridges could be damaged, where the risk of flooding would increase or if there is heritage interest. In these cases fish passes are the solution.
The Environment Agency has been working with partners on projects all over the country. One recent success of removing a barrier to migration is a new fish pass on the River Tyne.
Here the Tyne Rivers Trust worked with Northumberland County Council and the Environment Agency to build Hexham fish pass which opens up access to many kilometers of spawning and juvenile habitat.
In Yorkshire, the Environment Agency has worked with partners and made significant additions to Yorkshire’s "fish highways" – removing 2 weirs on the River Don in Sheffield and a weir on the River Aire in Leeds.
Both rivers are now returning to a natural series of shallow, fast sections separated by deeper pools – which provide a better habitat for the coarse fish, grayling and brown trout that live there and for the invertebrates that they feed on.
In Dorset it is now easier for salmon and sea trout to migrate up some of the county’s best-known rivers thanks to the efforts of a unique partnership that has been working to boost fish numbers by removing man-made obstacles such as hatches and weirs.
Improvements at 10 sites on the Rivers Frome, Piddle, Asker and Brit have made it possible for fish to swim upstream to spawning grounds for the first time in many years.
The World Fish Migration Day is a one day global-local event to create awareness on the importance of open rivers and migratory fish. More than 1,000 organizations around the globe are involved. ■