The Guardian reports it has been a highway, a sewer and was declared biologically dead in the 1950s but the River Thames is now a nursery for 138 baby seals, according to the first comprehensive count of pups.

Scientists from ZSL analysed photographs taken from a specially-chartered light aircraft to identify and count harbour seal pups, which rest on sandbanks and creeks around the Thames estuary, downstream from London, during the summer, shortly after they are born.