The run-up to Christmas should be a time of brisk business and high spirits for the oyster farmers of France. In anticipation of the lavish plates that will be served up and savoured in dining rooms from Paris to Perpignan, demand is soaring and orders are flooding in.
But the mood among producers in the Bay of Arcachon is far from celebratory. They know that many of this year's delicacies will have been stolen from their harvesters - and they suspect that rogue members of the profession are the culprits.
Local police say about 15-16 tonnes of oysters have been stolen this year from under the noses of the farmers in the bassin - a threefold increase on last year.
The sharp increase in thefts, a familiar problem in the world's fourth-largest oyster producer, is blamed on the herpes-like virus that has blighted the shellfish for the past two years. The rarer the product, insiders say, the more tempting is its theft.
But what makes the trend particularly unpleasant for the farmers in the Bay of Arcachon, France's leading oyster-farming area on the southwestern Atlantic coast, is that they do not believe that outsiders are responsible for the rustling. Instead they point the finger at some of their colleagues.
"As there has been a high rate of mortality, the producers are lacking shells. And as businesses have been more than affected in recent years, some of them no longer hesitate to replenish their stocks by helping themselves to their neighbours'," said Olivier Laban, president of the Arcachon oyster farmers.
As a result, festive cheer is in short supply in the bay, a crucial location for France's €1 billion ($2.3 billion) per year industry. "It's a big disappointment and I'm almost ashamed to say it," Laban told La Depeche. "It's awful because it creates a kind of suspicion and a bad atmosphere among us. If it goes on, soon we'll be hiding our oyster sacks like you hide gold bars."
Vincent Eyquem, a farmer from the village of Gujan-Mestras who fell victim to the thieves in October, agreed. "Next year we're going to have to have a padlock on each sack," he said, explaining that two tonnes of oysters that he had packed and were ready for delivery "vanished" overnight. He estimates the loss at €8500 - a high price to pay in an industry already struggling to cope with the effects of the OsHV-1 virus, which is believed to have killed billions of young oysters in French waters since last year.
A spokesman for the Arcachon nautical police brigade, whose job it is to patrol the coastline and keep a watch out for unusual activity in the parcs, or farms, agreed that most of the time the thefts were carried out by professionals. "You can't be an amateur sailor. To steal oysters in those quantities you've got to have a proper boat," he said.
But he emphasised the difficulty in catching the culprits. "We know that they go out either well before low tide or well after low tide," he said.
"But it's very hard to know which boat, at which location, at which time."
To combat the rise in thefts, police have stepped up their presence at sea this season and have increased their helicopter surveillance of the area.
Laban and other farmers are pushing for more effective action to discourage the thieves, including harsher penalties for those caught.