A SENIOR vet fears swans are being deliberately poisoned with lead in a North-East park.

Gillian Maxwell, practice principal at Cestria Veterinary Centre, says the sudden spate of deaths on the River Wear at Chester-le-Street is the worst she has seen in her 17-year career – and fears that all 100 swans on the river could be wiped out by the summer if the current death rate continues.

She said: “We’re reluctantly coming to the conclusion that this might be a deliberate poisoning with lead powder.”

Since January, 23 swans have died on the stretch of river which runs through Riverside Park.

Post-mortem examinations carried out on 19 of the birds revealed extremely high levels of lead in the stomach and gizzard.

The recent deaths are the latest in a rising trend of swan deaths in the County Durham area, with 36 apparently healthy swans dying in the past year.

Ms Maxwell said: “We had six dead swans brought in last weekend, and three more on Monday. There are only about 100 swans on the river – by summer there will be no more left if this continues.”

Local experts have ruled out the initial suspicion that the poisoning was caused by swans eating the lead weights sometimes used by the anglers who frequent the river, as pellets were not found in the bodies of any of the dead swans.

While it is possible there may have been a change in the river’s natural lead deposits, leading to swans ingesting lead from the riverbed, Ms Maxwell believes that the possibility the deaths were caused deliberately should not be overlooked.

“When it comes to a possible contamination in the water, you can usually see the lead during the post-mortem,” she said. “These swans didn’t have any visible lead inside them, and there isn’t any indication of an industrial spill.”

The Environment Agency is investigating the incident.

A spokesman said: “We will be examining the quality of the water taken from our routine sampling points along the river, and have also taken samples of river sediments which we will be checking to determine if there is anything in the water which could have contributed to the death of these birds.”