Death in Venice as gangs clash in clam warfare

Details have been slow to emerge: witnesses were in short supply. What is clear is that, as the men hurled threats and abuse at each other, the presidents of their respective co-operatives, Acquaviva and Imperiale, squared up on the bridge. One, maybe more, knives were drawn - and then it was all over, with Claudio Carisi, 41, on the ground, mortally wounded, and Derri Perini, 50, his presumed killer, thrown bodily (by one account) into the canal. He was later fished out and arrested.

The Italian for clams is vongole, and spaghetti alle vongole is one of Italy's simplest and most popular dishes; made with garlic, chilli, coriander leaves and olive oil as well as clams, it is as common in Venice as anywhere else in Italy. But visitors to Venice in mid-August would have realised that something strange was afoot when dozens of clam-fishers' boats blocked the Grand Canal for three days of demonstrations. They were protesting against the belated arrival of a tough environmental regime, intended to prevent what is left of the bottom of the Venice lagoon from being lacerated by the clam-fishers' rakes.

Clams are newcomers in the lagoon. They were introduced in 1983 to address a dramatic shortage of fish caused by industrial pollution. Tapes philippinarum, known locally as "caparozzolo", adapted well to its new surroundings and Venice became the first producer of this variety of clam in Europe, hauling up some 40,000 tons a year. More and more fishermen abandoned their traditional activities to go after the clams, attracted by earnings of up to €500 (£340) per day. Clams could be fished all year round. All that was required was a small boat and an illegal tool called a dump rake for scouring the lagoon floor.

The inevitable followed: the fishermen got greedy, the lagoon bottom began to suffer acute erosion, its biodiversity went into decline. Clam-fishing was banned at Porto Marghera, site of the lagoon's oil refinery, because the clams that grow there are poisonous because of the high levels of pollution - but they also grow appetisingly large, so they find a ready market, and many fishermen defied the police to harvest them. Two years ago, the province of Venezia finally called a halt to the whole filthy affair. It banned the mechanical rake fishing that was causing such damage to the lagoon and decreed that only clam-farming and harvesting by hand rake was to be allowed.

The 1,500 Venetian clam fishermen have seen their earnings tumble as a result. They are organised in 105 co-operatives, each co-op belonging to one of three associations. Each of the associations has its political affiliation, with the biggest adhering to Left Democrats, the former Communist Party, and the others divided between Berlusconi's Forza Italia and the centre-left Margherita party.

The competition between the three associations for permits to seed the new clam farms in the lagoon which are intended to bring about a revival of the clam population has been intense. Around 150 fishermen have been arrested for fishing in prohibited waters since the clampdown, and last month five tax police and one fishermen were injured after a high-speed chase through the lagoon.

The killing of Claudio Carisi, one of the 150 men who had previously been arrested, has further poisoned a situation that was already grim.