In the 1970’s, industrial pollution took a big chunk out of the fishing and aquaculture economy of the Venetian lagoon, throwing fishermen and fish farmers into crisis. In response, in 1983, the Italian National Research Council experimentally introduced a variety of Philippine clam into the lagoon, near Chioggia. Mission: find a clam that both reproduced like rabbits and was able to tolerate the chemical poisons dripping into the veins of the lagoon from places like Porto Marghera.
It worked – not just in Venice, as it turns out, but in virtually all of Italy. Today, says Italian news agency ANSA, the “Manila clam” has all but pushed the native Italian clam into permanent retirement. There was an unexpected bonus, too. Unlike its Italian cugino, the Manila is resistant to a nasty strain of oxygen-hogging, clam-choking algae -- C. taxifolia -- that was accidentally introduced into the Mediterranean in the 1980’s, and has spread to become a major menace to this day. (There was an entire episode of PBS’ Nova dedicated to C. taxifolia: follow this link.)
In Venice, the Manila clam been particularly successful. According to a fascinating paper by Alberto Longo, of the University of Venice :
more and more fishermen have left traditional fishing activities in order to harvest the [Manila clam], which also guarantees high incomes (it has been estimated that a clam fisherman earns about €500 a day). These clams are not particularly influenced by seasons and can therefore be fished all year long. The capital required to set about clam fishing is also very low; only a small two-three person boat and a dump rake (called “rusca”) are necessary for the harvest. All these elements have fostered clam fishing, which has … become very popular among the young.
Of course, there’s a rub. All that bivalve booty has brought out pirates. All kinds of illegal harvesting methods are being used, and it is sucking the precious sediment out of the lagoon, severely damaging its health. Especially harmful is the use of marine turbo-vacuum cleaners to hoover the mud.
I remember how a friend once warned me to securely chain my outboard to my boat when I docked it, because he had heard that a group of fisherman from Chioggia often snuck into the canals of Giudecca at night to steal motors for use in churning up the clam beds. This may have been paranoia, but the local newspapers are rife with stories of the arrests of illegal clammers. As recently as last September 16th, the Gazzettino reported that 9 fisherman (including a 72-year-old) from Burano were popped for using high-powered outboards to stir up over a ton of clams.
According to Patrizia Torricelli, professor of ecology at the University of Venice, even if these abuses stopped cold today, it would still take 6 years to restore the lagoon to health.
But I wouldn’t count on that happening too soon. The lure of the Philippino gold is too strong.
I’m trying to get an interview with Patrizia, so stay tuned on this story.
The Manila Clam (Tapes Philippinarum)