In Antico Borgo Marinaro, an elegant restaurant in Mazara del Vallo, on the west coast of Sicily, a dish of uncooked red prawns with melon, chili pepper and pomegranate costs €12. Fishermen fear these same red prawns could cost them their lives.

Since the mid-90s when Libya began protecting its fishing waters from foreign vessels with the use of force, a little-known conflict has been rumbling in the 180 miles of sea that separates Libya from Italy, which are also the fishing grounds for one of the world’s most prized crustaceans.

The most recent red prawn incident took place on 6 September, when a Sicilian fishing boat was attacked with machine gun fire from a Libyan coastguard vessel. Two months earlier, another boat fishing for red prawns was detained by authorities in Tripoli and released only after the Italian authorities intervened.

Domenico “Mimmo” Asaro has fished the troubled waters of the Mediterranean for 40 years and was one of the first to come under attack. On 22 March 1996 his boat was flanked by a Libyan coastguard vessel just under 50 miles off the port of Misrata. Before he realised what was happening, a bullet grazed him and blood was streaming down the back of his neck. He ordered his crew to take shelter out of sight as machine gun fire rippled across the bridge, piercing it like paper.

Facebook Twitter Pinterest Captain Mimmo Asaro on a fishing boat at the port of Mazara del Vallo. In 1996 his boat was machine-gunned by Libyans. He was arrested and detained for six months accused of fishing for red prawns in Libyan waters. Photograph: Alessio Mamo/Guardian

Asaro and his crew were brought in by the coastguard and jailed in Misrata for six months. When Asaro was released from prison, he was unrecognisable, having lost 22kg (48lb) in detention. “But the real shot to my heart,” he says, “was having to tell my father that I had lost the fishing boat that had been his and my grandfather’s. You see, not only our economy is being destroyed. The red prawn war is erasing our history.”

The fishing grounds for the red prawn stretch south and west of Sicily towards north Africa. For the Libyans, fishing by foreign vessels is perceived as a territorial invasion as well as an exploitation, if not a theft, of their natural resources.

According to data from Sicily’s Distretto della Pesca, a cooperative that unites stakeholders in the fishing industry, in the last 25 years more than 50 boats have been seized, two confiscated, about 30 fishermen detained and dozens of people injured.

It is not lost on the fisherman that since Rome and Tripoli signed an agreement in 2017, with EU backing, to curb migrant flows across the same stretch of water, Italy has been helping to train and equip the Libyan coastguard.

The majority of the Italian fishermen live in Mazara del Vallo, home to the country’s largest fishing fleet.

Facebook Twitter Pinterest Chef Bartolomeo Marmoreo, 48, in the kitchen of his restaurant Antico Borgo Marinaro, in the seaport of Mazara del Vallo. Photograph: Alessio Mamo/Guardian

Sicilian red prawns are no ordinary prawn but one of the most sought-after crustaceans in restaurants across Europe and a symbol of southern Italian culinary excellence.

“It lives in muddy expanses between 400 and 700 metres under water and in specific areas of the Mediterranean,” explains Bartolomeo Marmoreo, a chef at Antico Borgo.

“The extreme depth of its habitat enriches the prawn with mineral salts, giving it a unique flavour, slightly sweet and smoked. This is why the red prawn, at its best when eaten raw, is one of the most prized food items in Mediterranean cooking and why it is exported the world over.”

Facebook Twitter Pinterest A one kilo case of red prawns frozen is sold for €50 to €70. Photograph: Alessio Mamo/Guardian

Every day at the port of Mazara, Spanish, French and British suppliers queue up in front of the warehouses where top-quality red prawns are stocked and packaged in 1kg trays, which fishmongers sell for €50 to €70.

But things have changed since the red prawn war heated up. “At the end of the 90s there were over 350 fishing vessels in Mazara,” says Tommaso Macaddino, 49, the regional secretary of the labour union UILA Pesca. “Today there are fewer than 70. Few fishermen are willing to risk their lives for the red prawn.”

Seizures of fishing boats became more frequent in 2005, when Muammar Gaddafi unilaterally decided to extend Libya’s territorial waters from 12 miles offshore to 74. “That’s when the real problems started,” says Francesco Mezzapelle, 45, a journalist and sociologist in Mazara and author of a book on the red prawn war. “It was a clear violation of international law. Such a unilateral extension can be good for countries on the ocean but not in the Mediterranean, where dozens of countries coexist around the same sea.”

Facebook Twitter Pinterest The fishmarket of Mazara del Vallo with red prawns on sale. Photograph: Alessio Mamo/Guardian

According to Distretto della Pesca, the red prawn war has cost the Italian fishing industry nearly €50m over the last 25 years, and Mazara del Vallo has lost more than 4,000 jobs just in the last 10. Seizures are often carried out by the Libyans with the sole aim of receiving up to €50,000 from Rome for the release of each vessel.

The economic crisis has driven Italian fishermen to forge ties with the eastern Libyan warlord Khalifa Haftar, who is in open conflict with the UN-recognised government in Tripoli. Last September Federpesca, an organisation that brings together several fishing companies, announced a deal with Haftar’s Libyan National Army that aimed to protect them against the intimidations of Tripoli. The agreement was abandoned a few days after protests from the leader of Libya’s UN-recognised government, Fayez al-Sarraj.

It has contributed to growing anti-EU sentiments among fishermen, with Rome and Brussels seen as “traitors” over the Libya deal, which Italy has announced it intends to renew. Last April Asaro ran unsuccessfully in local elections for Matteo Salvini’s far-right League, which is known for its anti-EU rhetoric.

Trawling for the red prawn with 1km-long nets, fishermen remain at sea for up to 30 days. To stay that long at sea, the boats need at least 40 tonnes of diesel fuel, which can cost as much as €40,000. “It’s a lot of money that can go up in smoke if the Libyans decide to impound your boat,” says Asaro.