Hugh Bonneville is the latest celebrity to pose semi-naked with a sea creature to highlight the global threats to ocean life.

The Downton Abbey and W1A actor was photographed with a Norway Red Fish for Fishlove — a campaign that highlights issues such as illegal fishing, over-fishing and pollution, and urges consumers to buy only sustainably caught fresh and tinned fish.

Actresses Dame Judi Dench, Julie Christie, Zoë Wanamaker and Fiona Shaw all posed for similar shots for the new Fishlove collection, by British photographer John Swannell, ahead of World Oceans Day on June 8. Previous supporters of the cause include Helena Bonham Carter and Gillian Anderson.

Bonneville, 51, said: “I’d never done a photo shoot with a fish before. It was a surreal experience. Especially when he whispered in my ear, ‘I know a man’s gotta eat but please — fish fairly.’ Fair point from a fine fish. Fish fairly.”

Dame Judi said: “I chose a lobster because I have a passion for them… it is not every day you get to cuddle a lobster.”

Fishlove was launched in 2009 by actress Greta Scacchi and Nicholas Röhl, the co-owner of Brighton restaurant MOSHIMO.

Mr Röhl said of Bonneville: “He was fantastic. I originally wanted to get him to pose with an eel — but I didn’t think it wise to get the Earl of Grantham covered in eel gunk.”