When strong winds prevented filmmaker Jo Ruxton from sending a submarine to her chosen recording location off the coast of Marseille, she was naturally nervous.

The crew had just one chance to document evidence of the build-up of rubbish on the seabed for her award-winning film A Plastic Ocean, but were forced to divert miles from where divers had reported a growing dump.

She needn’t have worried. As the submersible reached a deep trench one mile from the surface, the team were confronted by a junk yard of human debris. Tyres, plastic water bottles, synthetic netting, unexploded bombs and even an old parachute emerged from the gloom.