Young salmon have been found in a river in South Yorkshire for the first time for more than 150 years after engineering work to restore a polluted river system, the Environment Agency says.
The juvenile 14cm (5.5 inch) salmon found during routine checks in the River Dearne is the first evidence of the fish spawning in the waterway, a tributary of the River Don, since the mid 19th century.
Salmon populations in the river were hit by industrialisation of the region, with weirs built to power industry or provide deep water for boats acting as barriers to the fish reaching their spawning grounds, and they were all but gone by the mid 19th century.
But in the last year a fish pass was completed at Sprotbrough Weir, opening up 55km (34 miles) of the River Don, almost half the length of the river to salmon and other fish.
The pass reconnects the rivers Don and Dearne back to the Humber Estuary and is part of a plan to create “fish highways”, providing passage for fish between the sea and upper reaches of rivers, the Environment Agency said.
Jerome Masters, Environment Agency fisheries technical officer, said: “Our rivers are the healthiest for more than 20 years and otters, salmon and other wildlife are returning for the first time since the industrial revolution.
“But there is still more to be done. The construction of the fish pass at Sprotbrough Weir is a significant step in getting salmon back to rivers across South Yorkshire.
“The River Don already supports a healthy population of coarse fish, and adult salmon have been caught in the river in the recent past, but the discovery of this juvenile salmon in the River Dearne is hugely exciting.”
He said the size of the fish indicates it was born in early 2014, which means its parents probably used the fish pass on the weir shortly after it opened.
The construction of the fish pass saw the Environment Agency (EA) working closely with the Canal & River Trust, Don Gorge Community Group, a local landowner and Doncaster Council. It was funded by the EA, with support from LaFarge Quarries.