Khaleedah al-Hokmani glides barefoot through the murky waters, holding a rusty iron spear. She walks in silence – until her spear plunges into the water. There’s a sound like a deflating balloon. Seconds later, a silver cuttlefish emerges, sputtering black ink on her clothes.

She rips the cuttlefish into pieces. This one is female and has eggs, she says, as she scoops them out and swallows them whole. A blue ink sack dangles between her fingers and she holds it up to her mouth and sucks it dry. Smiling, she flashes black teeth.

“This is how we stay strong,” she says.

Such are the ways of the roughly 400 Bedouin fisherwomen in central Oman who practise a lifestyle inherited from their mothers: fishing for invertebrates. The trade is so ingrained in Oman that fisherwomen exclusively run the freshwater snail fishery, known locally as rahas. With spears, they hunt cuttlefish, rays and octopus, and scour shorelines for oysters and clams to sell in local markets.

But the increasing commercialisation of Oman’s industrial fisheries – which are male-dominated – is pushing the women’s trade into decline.

Most of the fisherwomen live and work in Mahout, a remote coastal town of 17,000 Bedouin families and migrant salt-factory workers, and neighbouring Masirah Island, both in Al Wusta, the most productive fishing region in Oman.

But although – or perhaps because – the country is more than 95% reliant on small-scale fishers, it is heavily investing in larger commercial and offshore fisheries projects, including a 24m Omani riyal (£52m) seafood canning plant in Al Wusta, set to open in 2024, and the purchase of three large pelagic freezer trawlers.

Meanwhile, 70km away in Masirah Island, a village is being built to attract fishermen to the island. Announced last year, the site aims to house residential units, an ice factory and maintenance workshops for fishing boats.

While the expansion is set to provide opportunities for local fishermen and foreign workers, Oman’s fisherwomen are entirely overlooked in the projects being built right next to them, says Farha al-Kindi, founder of Sea Delights seafood company, who works with the fisherwomen to sell their products.

“They are completely isolated,” says Kindi. “There are many opportunities for these fisherwomen to participate in the industry. But still in Oman, we are not able to involve them.”

The work is becoming increasingly insecure, agrees Hokmani, who at 14 was taught rahas and spearfishing by her mother, and married a year later. She is now divorced and supports eight children. She spends her mornings as a bus driver – but the rest of her income comes from fishing.

Hokmani and her spearfishing friends introduce themselves playfully as “the bad gang”. To fish, they drive 50km from their homes to the fishing grounds, where they unload their equipment: iron spears, plastic fuel canisters with ropes to drag their catch along the water – and plenty of homemade cake and tea.