On a beach in Costa Rica, as fishermen land the day's catch, two women are hard at work on a slimy sea bass skin, rubbing, scraping, washing and tanning the hide to turn it into leather. Two years ago, both Mauren Castro, 41, and Marta Sosa, 70, were stay-at-home mums dependent on their fishermen husbands to provide for their families of four and six, respectively. Today, they are part of the all-female Piel Marina (Marine Skin) cooperative, which turns fish skins that used to be discarded at sea into sustainable fashion.

For generations, fishing was the economic mainstay in Costa De Pajaros, a village situated about 62 miles (100 kilometers) west of the capital San Jose. But fishermen say that regulations aimed at making stocks more sustainable, which this year included a complete ban on fishing between May and July, have made it harder to live off the sea. Enter the NGO MarViva, which helped train 15 women to establish themselves as seafront tanners two years ago.

The women were skeptical at first about the sartorial possibilities of fish skins. "We said 'how can a skin, which is something that gets smelly, which is waste, be the raw material for women to be able to get ahead'"? Castro, 41, said. But over time they honed their trade and are helping supplementing their families' meagre incomes.

Read more: 'Billions of birds killed': Stella McCartney calls for fashion world to change Facebook and Instagram Wearing blue rubber gloves and white T-shirts bearing the words Piel M.