Eleven swans from the Garricks's Ait area of the Thames have died from lead shot poisoning in the seven weeks since the start of the coarse angling season.
This is believed to be one of the worst death tolls since the Second World War, although anglers are banned from using lead to weight lines.
The organization Swan Lifeline yesterday took a further three poisoned swans from the area, making a total of 50 which have been lifted from the Thames between Abingdon in Oxfordshire and Hampton, west London.
Of these, 39 have come from the 500-yard stretch close to Garrick's Ait, near Hampton Court Palace, west London, where the Queen owns about two-thirds of the swans. Last night, two more seemed certain to die.
Affected swans usually have up to seven pieces of shot inside them, but up to 50 pieces have been found in some of those taken in the past few days. Most of the affected swans are aged between 12 months and three years. But some three-week-old cygnets, after being x-rayed, have been found with nothing in their gizzards but lead shot.
Mr Roy Headley, of Swan Lifeline, said: "Lead shot has been banned from the Thames but anglers continue using it. I'm sure many fishermen are reasonable but these people must be very callous."
Mr Tim Heron, the chairman, said: "This is the worst example this century of lead poisoning."
Yesterday, the Thames Water Authority was dredging a one-foot swathe along the Surrey bank, hoping to pick up wasted shot, hooks and line. It was being replaced with tons of gravel, which swans use to help digest water weeds.
Usually, the gravel passes through the swan's gizzard, but the lead becomes caught and a slow grinding reduces it until the lead passes into the blood stream, affecting the kidneys and heart.
The injured swans are being taken to the Swan Lifeline sanctuary near Egham, Surrey. The Worshipful Company of Vintners, which owns swams together with the Worshipful Company of Dyers, has given รบ500 for the swans' treatment.
So far, three have been returned to the Thames at Windsor. Mrs Dorothy Beeson, who helps run the sanctuary, said treatment consists largely of anti-lead drugs, antibiotics, anabolic steroids and a multi-vitamin feed.
