Ellie Harrison visits two very different rivers - the Tyne in Newcastle city centre and a chalk stream in rural Dorset - to find out how their wildlife is faring in this constantly changing habitat. She discovers an unusual arrival - a seabird nesting five miles from the sea on Tyne Bridge - and goes 'wild swimming' to recapture memories of her childhood.Gordon Buchanan finds out how we are giving river salmon a helping hand; Philippa Forrester goes in search of our most iconic and beautiful river bird, the kingfisher; and Miranda Krestovnikoff discovers how, at the 11th hour, we may be able to save the native white-clawed crayfish. Finally, Ellie goes in search of the elusive otter - will she see one?