Swans, goslings and 12 Canada Geese were rescued after a diesel spillage along a stretch of canal in Manchester city centre.Firefighters and the RSPCA were involved in the operation at three locations on the Bridgewater Canal.Officers from the charity were first called on Wednesday, when the geese were recovered.But they were forced to return today to rescue swans and goslings covered in diesel.The RSPCA said it acted after reports of diesel in the waterway which had covered the birds.Animal welfare officer Steve Wickham and collection officer Lauren Bradshaw raised the alarm after reports from concerned members of the public.