(ANSA) - The native Italian clam appears to be heading towards extinction and is being replaced on plates of linguini by a homegrown version of its exotic Philippine cousin.
The Philippine clam was introduced to Italy over 20 years ago in an experiment carried out by the National Research Council (CNR) and has now developed into a major economic resource for Italy.
In fact, Italy has become Europe's leading producer of Philippine clams and has now even begun to export the tasty bivalve molluscs.
The CNR originally tried to develop mass farming of the native clams, Tapes decussatus, but the difficulties encountered in getting them to reproduce under controlled conditions convinced researchers to try the Tapes Philippinarum.
Visually there is little difference between the two, but once in the water the Italian clam opens to show two distinct mouth tubes while those of the Philippine clam are attached for two-thirds of their length.
The Philippine clam has the advantage of having a longer reproductive period, four months instead of the two for native clams, its females produce more eggs and the clams reach commercial size in less time, two years as opposed to three.
It also proved to have a greater tolerance to disease and pollution.
The first experiment in farming Philippine clams took place in 1983 in the waters of the Venice Lagoon near Chioggia and was so successful that many private clam farms opened beds with the CNR's scientific support.
These farms were first opened in the upper Adriatic but quickly spread down the Italian east coast to Puglia. The Philippine clams are now even being raised as far as Sardinia. The clam also spread away from controlled farms and adapted easily to Mediterranean waters to thrive to the extent that fishermen were soon able to gather them freely off Italy's coasts and islands.
According to the CNR, the spread of the Philippine clam has not been at the expense of its Italian cousin because it only occupies available areas. The greatest risk to native clams, CNR explained, is
from a proliferating algae which has made it increasingly difficult for the small and delicate indigenous clams to survive.
The Philippine clam, on the other hand, has better resistance against the Caulepra taxifolia algae, dubbed the "killer" for its thirst for oxygen. The cultivation of the Philippine clam, however, has
had a downside as well and experts have warned that the extensive use of outlawed harvesting methods is devastating the ecology of the Venice Lagoon.
According to Patrizia Torricelli, professor of ecology at the University of Venice, even if these illegal clam harvesting methods were suspended today it would take at least six years to restore the environmental balance in the lagoon.
The industrial cultivation of Philippine clams, she explained, has radically changed traditional clam fishing in the upper Adriatic and as many as 800 trawlers are currently using the unauthorized marine turbo-vacuum cleaners and other illegal systems which damage the seabed by raking it.
Torricelli, an expert on the Venice Lagoon and author of the book Behavioral Ecology of Fishes, said she was convinced that "if local authorities took into consideration progress made by the scientific community they could adopt a series of initiatives which could maximize productivity while guaranteeing the integrity of the environment."
However, she admitted, "quick profit today is the only thing that matters without taking into consideration that soon the Lagoon will be unable to produce anything."
