Bourassine and his crew had set out with three other fishing boats from Zuwara on the western Libyan coast. After passing a migrant boat in distress the fishermen radioed authorities for help. Two days later, realizing that the boat was still adrift, Bourassine took action, according to AFP.

Fishermen from Zarzis, a town in southeastern Tunisia, have saved the lives of hundreds of migrants in recent years, but the numbers have increased even further since the decline in humanitarian and European naval patrols along the stretch of water between Libya and Italy.

"The area where we fish is a crossing point" between Zuwara and the Italian island of Lampedusa, explained fisherman Badreddine Mecherek. "First we warn the authorities, but in the end we end up saving them ourselves," he told AFP. "Now most often we are the first to arrive... if we aren't there, the migrants die."

The Italian government has taken an increasingly hard line on irregular migrants, including banning boats from docking at its ports, while the European Union earlier this year suspended its anti-piracy mission "Operation Sophia" in the Mediterranean. The Tunisian navy has limited resources and only rescues boats inside the country's territorial waters.

According to AFP, Tunisian authorities have also refused to allow 75 migrants, saved in international waters by a Tunisian-Egyptian tug boat, to disembark. The agency says it contacted Tunisian authorities several times but they made no comment.

'Sent by God'

On May 10, just a day before Bourassine was involved in the rescue of 69 migrants, the crew of another Tunisian fishing trawler managed to save16 people whose boat had sunk eight hours earlier. Around sixty others drowned before the fishermen arrived.

The migrants had set out in a large boat from Zuwara in Libya, before transferring to a smaller inflatable, which sank within ten minutes. The trawler came across the inflatable boat several hours later.

One of the survivors, Ahmed Sijur, said the fishing boat's appearance was like that of "an angel.” “I was losing hope myself, but God sent us the fishermen to save us," the 30-year-old from Bangladesh told AFP.

Tunisian Red Crescent official Mongi Slim says the fishermen have almost become "the police of the sea." Mecherek says he will not stop rescuing stranded migrants. "Local fishermen will never let people die at sea," he says.

However, Mecherek says there are too many corpses. “We want to catch fish, not people."

Fishermen under strain

The large number of migrants needing to be rescued is putting the fishing crews under growing strain. Fishermen who come across migrants on their second day out at sea are at least able to have done a day's work, Mecherek explains, "but if we find them on the first night, we have to go back.”

"I have 20 seamen on board asking, 'Who will feed our families?'," he said.

Because of pressure to catch their quota during a short annual season, some of the large tuna boats out of Zarzis call the coast guard instead of stopping to help, according to AFP. "We report the migrants, but we can't bring them back to shore... We only have a few weeks to fish," one crew member said.

Tougher laws against civil society groups or individuals becoming involved in rescuing migrants have further increased the risks to the fishermen, especially when they find migrants adrift closer to Italy.

Last year, when Bourassine and his crew tugged a boat that was adrift without a motor towards the Italian island of Lampedusa,  they were arrested and spent four weeks in custody in Sicily for helping the migrants.

The fishermen said they had initially tried to persuade the 14 migrants on board the boat to return to Tunisia before towing them towards Italy so that the Italian coastguard could find them. They were cleared of the charges in September.