Grey seals bask in the morning sunshine near Ramsgate in Kent as the Zoological Society of London conducts its annual seal census to build a comprehensive picture of the population of adult seals and pups born during the breeding season in the Thames Estuary. /VCG Photo

Grey seals bask in the morning sunshine near Ramsgate in Kent as the Zoological Society of London conducts its annual seal census to build a comprehensive picture of the population of adult seals and pups born during the breeding season in the Thames Estuary. /VCG Photo

Grey seals bask in the morning sunshine near Ramsgate in Kent as the Zoological Society of London conducts its annual seal census to build a comprehensive picture of the population of adult seals and pups born during the breeding season in the Thames Estuary. /VCG Photo

A grey seal basks in the morning sunshine near Ramsgate in Kent as the Zoological Society of London conducts its annual seal census to build a comprehensive picture of the population of adult seals and pups born during the breeding season in the Thames Estuary. /VCG Photo

Grey seals bask in the morning sunshine near Ramsgate in Kent as the Zoological Society of London conducts its annual seal census to build a comprehensive picture of the population of adult seals and pups born during the breeding season in the Thames Estuary. /VCG Photo