Half a loaf is better left at home ... if you want to feed the swans

Mr Hitchcock said that more swans are gathering there than in previous years because more people are feeding them and the slipway is made even more slippery by the swans' mess left on it.

"We have counted more than 150 swans on the Arun at one time earlier this year, all the way up to Arundel, " he said. "They certainly come here in greater numbers these days.

"Although we've never had any reports of people being injured by them or anything like that, because people are feeding them on the slipway there's a lot of swan mess there, which can be a bit of a problem if you're getting a boat in or out.

"Many people come down especially to feed them and I would ask that if they do want to do that, then it's better if they feed them off the side of the walkway and not on the slipway."

Swans are among the heaviest birds in Britain. All swans that are unmarked, a practice that happens on the River Thames in London, belong to the Queen.

Klare Kennett, spokeswoman for the RSPCA, warned that although swans appear tame, they are still wild animals and people should be cautious of how and what they are going to feed them.

She said: "People do need to be careful around swans as they are big, strong animals and can break your arm with their wings.

"They're a wild bird at the end of the day and you need to be wary if you have small children who may run up to them or try to chase them.

"If people are going to feed swans then they should not feed them bread. Not only is bread of poor nutritional value and will discourage the swans from foraging for greenery, but it also pollutes the water. Instead, swans should be fed fresh beansprouts, cabbage, lettuce and even freshly- cut grass."