During the past three decades, capture fisheries production has increased from 69m to 93m tonnes, while aquaculture fish production has skyrocketed from 5m to 63m tonnes, the World Bank reports (pdf). With one tonne of fish fillets generally resulting in 40kgs of discarded skin (pdf), that’s thousands of tonnes of fish skin that could be put to productive use.

And much of it already is. Fish leftovers are often ground up and turned into fish meal for animals. But there are more glamorous uses for this byproduct than an ingredient in fish meal paste. With their layered patterns, fish skins possess an elegant quality, and they’re flexible too. Increasingly, they are finding a new life as leather.

“The method of making leather from fish skin has existed for a long time and has been used mostly by poor people,” notes Laura Storm, executive director of the Danish sustainability think tank Sustainia. “Atlantic Leather (the Icelandic fish-leather company) started making fish leather 20 years ago. But now interest is really growing. Fish leather is an old technique being resurrected as a modern solution.” Today Atlantic Leather supplies famous brands including Prada, Dior, Nike, Ferragamo and Puma.

A host of small designer companies specialise in fish leather, seeing it as a high-profile niche market. “I had started designing silk necklaces and wanted to move on to leather,” recalls Hanna Altmann, a Swedish designer. “Fish leather is incredibly soft, and you can get it in many small pieces and range of colours.” Because most fish are smaller than, say, a calf, fish skins are ideally suited to smaller items of clothing.

While Nike and other brands combine small pieces of fish leather with regular leather, other makers opt to combine several fish skins to make larger pieces. “Fish leather is about the same price as regular leather, but it has the advantage that you can buy smaller quantities instead of having to buy a whole calf,” reports Altmann.

Malou Koldenhof, co-owner of the Wales-based firm The Fish Leather Company, adds: “I’ve noticed that more and more people are becoming interested in fish leather, and we’re seeing an increase in sales and inquiries, but at the same time there are still many people who don’t know about it. A lot of art and fashion students have shown interest in the material, so perhaps the next generation will use it more.”

Indeed, given the availability of fish skins as a byproduct of the fishing industry, using them as leather presents a good solution. Cows and calves are eaten as well of course, but demand for leather is rising much faster than the supply, resulting in dramatic price rises. If the trend continues, only wealthy consumers will be able to afford leather shoes and leather bags, while others have to make do with synthetic materials, or fish leather.

For now however, salmon shoes and bags remain relatively pricey, as do the more common fish leather iPhone and iPad covers, wallets and belts. “There’s definitely a market for high-end fish leather products and it makes more financial sense to use fish skins in high-margin items like handbags than as fish meal,” says Dr Cecile Brugere, a research associate at the Stockholm Environment Institute, specialising in aquaculture. “But with most fish skins already being used for fish meal, fish leather doesn’t solve a big waste problem.”

The sustainability win, then, is that if fish leather is widely adopted, it could relieve demand for cow leather and help reduce CO2 emissions from the notoriously gassy animals. “Fish leather could also help create jobs in existing processing locations, for example around Lake Victoria,” says Brugere. To this end, Kenya’s Industrial Research and Development Institute is working with the Danish development agency Danida on a project to turn the country’s sizeable fish skin waste into leather.

The few tanneries that specialise in fish leather won’t reveal how they make it, but the general process involves soaking the skins in a special mix of chemicals for some 30 days to remove the fish’s smells and oils. (Atlantic Leather even makes a machine-washable salmon leather version.) If soaked for too long, the skin falls apart. In this process, argues Brugere, lies the challenge: “We have to consider the environmental cost of the tanning process, the tanning might be too energy consuming to make fish leather a large-scale solution. Plus the fact that fish leather will compete with fish meal for the skins.”

Perhaps the most prominent consumer challenge facing fish leather – concerns about the smell – seems to be fading away as it becomes better-known. “When I show my necklaces, the first thing that happens is that people walk up and smell them,” reports Altmann. “But once they’re familiar with the material, I only get positive reactions.”