River Welland swans covered in oil after drums dumped
More than 20 swans have been covered in oil after a number of drums were dumped in a river.
Lincolnshire Wildlife Trust said about 7km (4.3 miles) of the River Welland had been polluted, with at least 22 swans contaminated with oil.
If left untreated, the swans and other wildlife could swallow the oil and die, the trust said.
The stretch of affected river runs between Peakirk in Cambridgeshire and Crowland.
David Vandome, manager at the Deeping Lakes nature reserve, said: "It appears that five drums of oil were dumped in the river at Peakirk and some of the drums and oil have come downstream close to the reserve."
Efforts were continuing to treat the birds after a failed attempt to "round them up" on Tuesday, he added.
Mr Vandome said at least 22 swans had "been oiled", as well as some ducks and their offspring, and it was vital the affected birds were treated before they tried to clean themselves.
"They will prune off the oil and then swallow it and die," he said.
The Environment Agency said it was assisting the RSPCA in rescuing and caring for a number of swans and other birds which have been affected.
It has also set up a boom at Crowland to collect the oil. The drums have been taken away for analysis.
The RSPCA said it had caught three swans which were now being transferred to the East Winch wildlife centre for treatment.
"Many of the birds are still able to fly but we will continue to rescue as many of those contaminated over the coming days as possible," a spokesperson said.