The sight of plastic pollution in the world's oceans has become familiar, with 8 million tonnes ending up there every year.
But now the ocean is fighting back, with the help of a start-up that turns lobster shells into a plastic alternative.
Lobster shells are high in a bio-polymer called chitin (pronounced kai-tin), which can be developed into a biodegradable and recyclable material that could offer a solution to the scourge of single-use plastic.
London-based start-up the Shellworks is developing a method to transform chitin from the shells – usually destined for the rubbish tip – into a novel bioplastic. Co-founder Insiya Jafferjee said: "We started with lobster shells because it has the highest content of chitin, it makes up about 30 to 40 per cent of the shell. It's an untapped waste stream."
The shells are pulverised in a blender before being broken down further in various solutions to extract the chitin.
Jafferjee's fellow founder Amir Afshar explained: "We take lobster shells, we crush them up and then we use an acid and alkali solution to strip away mineral and protein layers to get to the chitin nano-fibres.
"We can then add that chitosan powder to household vinegar and that gives us a bioplastics solution. And then we use that solution with our custom-made machines to form three dimensional things."
The Shellworks is now testing chitin-based recipes for products traditionally made from single-use plastic, including the pervasive plastic shopping bag.
"We're trying to understand whether the material can withstand the pressures needed to become a viable alternative," said Afshar, adding that the bioplastic has other useful properties too.
"It's antifungal and antibacterial which means that it would be really interesting for storing foods and at the end of life it's actually a non-polluting fertiliser," he said.
According to Jafferjee, there are enough waste shells to make a serious dent in the UK's plastic use. One London lobster chain with nine restaurants, she said, produces 375 tonnes of waste shells a year: "Chitin content-wise, that's 125,000kg. And from that every year we could make about 7.5 million plastic bags.
"We've been speaking to different chains in London and getting the shells from them because it's quite an easy collection point. They actually have to separate their shellfish waste from their food waste. So it's already separated and we can kind of just collect it and use it for our experiments."
Globally, some 500 billion disposable plastic bags are used every year, according to the United Nations.