The dark world of eel poaching was exposed in France when two fishermen went on trial accused of selling tens of thousands of euros worth of the delicacy known as white gold.

Franck Marques, 34, and his brother, Thierry, 32, were charged with catching more than 300kg (660lb) of young eels in a case that has highlighted the growing threat to an already endangered species.

The trial came amid evidence that dozens of poachers have decimated the European eel population to supply restaurants in France and breeders in Japan, where the fish is also highly prized. The black market price for a kilo of elvers is €500 (£360) and twice as much in Japan, the court in Bordeaux was told.

Gastronomes in southwestern France call the tiny transparent elvers l'or blanc (white gold) because they are considered to be one of the finest local dishes when fried with garlic, red peppers and olive oil. Each weighs only 0.2g.

They rarely feature on the official menu because restaurateurs do not want to attract attention and awkward questions. But l'or blanc is usually available for regulars who are in the know, especially in January, when it is in season.

François Ruffié, a lawyer for the French Federation of Fishery Protection Officers, said, however, that elver numbers were falling. “White gold is disappearing partly because the waters are polluted and partly because of poaching.” He told the hearing this week that the Marques brothers had been caught poaching regularly but never paid their fines “because they have organised their bankruptcy”. Marianne Doménach, the state prosecutor, called for Franck Marques to be given an 18-month suspended prison sentence and his brother six months. She said that they should also be ordered to do community service.

The court was told that they had supplied 313kg of elvers over a ten-year period to an intermediary identified only as Popaul, who sold the ingredients to local chefs or Japanese middlemen.

The Marques brothers noted all their deals in a book, giving gendarmes the evidence that they needed for a prosecution.

Detectives believe that the brothers — who are also suspected of a black-market trade in secondhand cars — made about €10,000 a year from their poaching activities.

They admitted poaching but called for a lenient sentence because they said that they used a small net. Judgment was suspended until January.

With scientists saying the European eel population has fallen by up to 75 per cent over the past 20 years, gendarmes have begun a crackdown during the winter fishing season. Teams have been scouring the Gironde and Loire estuaries, where elvers are to be found, sometimes accompanied by helicopters with searchlights at night.

But a gendarmerie spokesman said: “There are up to 200 poachers working in gangs and most are well organised with spotters to say when we are coming.”

About 200 fishermen have licences enabling them to fish for elvers legally in France.

SERVES TWO

Ingredients

400g elvers
100g garlic
25g crushed Espelette pepper
Olive oil, salt, pepper
Parsley to taste

Method

Fry the garlic and Espelette pepper in very hot olive oil, add the elvers, cook for two minutes, add salt and pepper and serve with parsley

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