If we remove plastic from the sea, what are we going to do with it?

New solutions needed for difficult to recycle materials, because the problem will be with us for centuries, writes Ian Lambert

Beachcombing has long been a part of life for island communities. On the southwestern edge of Scarp, a small, treeless island off the coast of Harris in the Outer Hebrides, the Mol Mòr (“big beach”) was where locals went to collect driftwood for repairing buildings and making furniture and coffins.today there is still much driftwood – but as much, or more, plastic.

Scarp was abandoned in 1972 andthe island is now used only in summer by owners of a small number of holiday homes. But across Harris and the Hebrides, people continue to make practical and decorative use of beachcombed plastic items.

Many homes will have a few buoys and trawler floats hanging on fences and gateposts. Black plastic PVC pipe, in plentiful supply from fish farms wrecked by storms, is often used for footpath drainage or filled with concrete and used as fence posts. Larger pipe can be split lengthways to make feeder troughs for the famously hardy Highland cattle.

Rope and netting are used as windbreaks or to prevent ground erosion. Many islanders use fish boxes – large plastic crates washed ashore – for storage. There is a small craft industry that repurposes found objects as tourist souvenirs, turning plastic tat into anything from bird feeders to buttons.

But this beachcombing, recycling and re-use of larger plastic items does not even scratch the surface of the problem. The smaller fragments of plastic that are harder to collect are more likely to enter the food chain, or be drawn back into the sea.

Storms cutting away at riverbanks often reveal an alarming plastic geology, with layers of fragments in the soil several feet below the

surface. Reports indicating the scale of plastic pollution in the world’s oceans have become widespread in the past ten years, with the final episode of the BBC’S Blue Planet II in 2017 with David Attenborough marking a high-water point of recognition of the problem. Estimates of the amount of plastic entering the oceans each year range from 8 million tonnes to 12m tonnes, although there is no way of accurately measuring this.

It is not a new problem – one of the islanders who has spent 35 years holidaying on Scarp said that the variety of objects found on Mol Mòr had diminished since New York stopped dumping rubbish at sea in 1994. But a reduction in diversity has been more than matched by an increase in quantity: the BBC Radio 4 programme Costing the Earth reported in 2010 that plastic litter on beaches has doubled since 1994.

Growing awareness of ocean plastic has prompted local efforts to keep beaches clean. But the amount of discards collected poses the question of what to do with it. Ocean plastic photo-degenerates with long exposure to sunlight, sometimes making it difficult to identify, and difficult to recycle as it is contaminated with salt and often with sea life growing on its surface.

Some recycling methods can be successful only with a maximum ratio of 10 per cent ocean plastic to 90 per cent plastic from domestic sources.

Local groups sometimes work together to collect large amounts plastic from the beaches, but for local authorities the challenge is how to deal with a problematic material that is hard or impossible to recycle. The alternative is landfill with an £80 per tonne fee.

Lecturer and jewellery-maker Kathy Vones and I examined the