People taking to the waters off the coast of Sheppey can expect to see more seals after a rise in their population locally.

Numbers in the Greater Thames Estuary have grown from 685 to 938 since last year, according to the Zoological Society of London.

The survey was carried out by conservationists and volunteers who took to the skies, boarded boats and walked across marshland to cover more than 1,500 sq miles between Deal and Felixstowe in Suffolk.

The area is home to harbour and grey seals and, despite their close proximity to the capital, they are some of the least understood populations in the UK.

ZSL conservationist Joanna Barker said: “With harbour seal numbers remaining stable and grey seal numbers more than doubling since last year, the result of this year’s survey is a good indicator of the health of the Greater Thames Estuary.”

The boom may be down to the animals travelling down from Norfolk, Suffolk and the Wash to feed or rest.

Islanders can help make the most of an annual moult – where harbour seals shuffle on to sandbanks to shed their coat and grow a new layer of fur for winter – by adding their sightings to its marine mammal map at zsl.org/inthethames