Over 50,000 slippery customers have been welcomed to the Dearne under a plan to boost nature under water at a nature reserve.
An avalanche of eels was released in to the River Dearne at Wombwell’s RSPB Old Moor site, to boost dwindling fish numbers.
Industrial pollution saw eel presence in the river dip by 95 per cent and they became an endangered species.
But the river has been cleaned up and The Don Rivers’ Trust received £92,000 from DEFRA to support the eel re-introductions.
The trust teamed up with the RSPB to identify suitable watery homes for eels, and the Dearne washlands of Old Moor, Bolton Ings and Edderthorpe Flash was found to be ideal.
A number of eel-passes were installed to allow the creatures to make their way up river and past the weirs to breed.