“Every year it gets worse,” complains Lima fisherman Ricardo Ayaucan as he rushes to haul the driftnet aboard his small boat floating in the Pacific swell before sea lions devour his meager catch .

Like his father and grandfather, fishing is the only profession Mr. Ayaucan, 46, has ever known. “But my son will do something else,” he says as seagulls and pelicans bombard the shoal. “There is no future in this. At this rate, the fish will soon be gone.

Mr. Ayaucan’s experience is mirrored by fishermen along Peru’s 1,500-mile coastline. A recent study found that Peruvian fishermen had to spend more and more time getting smaller and smaller catches. He reported that many were now earning only half the Peruvian minimum wage, currently 930 soles (£190) a month.

Worse still, this month the Spanish oil company Repsol managed to dump 11,000 barrels of crude from its Lima refinery. So far, the slick has wiped out wildlife along 100 miles of coastline.

The situation is urgent, warns Evelyn Luna-Victoria, head of the oceans program at the Peru branch of the World Wide Fund for Nature, who says Chinese fishing has seen a “significant” increase in recent times.

“If we continue like this, we will deplete stocks, thousands of fishermen will find themselves unemployed and Peruvian exports will lose competitiveness because consumers demand sustainability,” Luna-Victoria adds.