Around two thirds of fibres produced globally are synthetic material - many used in our clothing. It's emerged that plastic microfibres are being shed when we wear and wash these items - which ironically include fleeces and kit worn by 'outdoorsy types' like Tom Heap. With microplastics in the marine environment now high on the agenda, Tom hears how these tiny invisible strands can be a major contributor to the scale of plastics in the oceans. They also pollute land and freshwater and are being consumed by creatures in our rivers as well as the seas.

Tom takes his 'blue fleece of doom' to the experts - Professor Richard Thompson has been leading research on marine plastics for many years. He and Imogen Napper at the University of Plymouth have offered to wash his fleece to show how much it's shedding, where the fibres go and to discuss how much of a threat they might be to animals and humans.

Is Tom to purge the plastics and pursue a life of naturism...or natural fibres only?

Sophie Mather from Biov8tion hopes not. She says plastics have 'many beautiful benefits' and it's just a case of developing 'good' synthetic yarns. After being frustrated by the pace of microfibre research she crowdfunded to commission research form the University of Leeds to assess which factors affect breakage. Her years in textile innovation for some of the world's largest brands makes her believe fabrics can be designed to shed less and she is sharing the research with industry. Can she help save the synthetics and the fish?

Presented by Tom Heap