fisheat

Emilia Romagna goro: clam fisheries in the lagoon, farming the sea

5.5% of the national fishing fleet
9,7% Dredges
44,0% Demersal trawl
4,8% Long lines
61,7% Small scale fisheries
2,5% Purse seine

Schermata 2015-09-16 alle 21.52.00

The sea inlet called “Sacca”

The delta is a fascinating place, unique in Italy, where water and land merge together, where the marks on the houses bear witness to the eternal struggle between man and the sea. Here fishing has always been an essential activity, central to the daily life of those living in this borderline town.

The town of Goro was established during the eighteenth century on a strip of land along the right bank of the Po river: a tiny plot of land that gradually grew bigger thanks to the slow and meticulous work of those living there who, metre by metre, stole land from the marshes. In the 1600s the Venetians had already diverted the course of the Po river towards the south-east, known as the Porto Viro division, thus changing the appearance of the Ferrara delta near Goro, exacerbating the phenomenon of coastal expansion caused by deposits from the river. Nowadays, although we consider the battle against natural swamp formation to be over due to a complex drainage system designed in the 1960’s, the imposing silhouettes of hydraulic locks dot the landscape as far as the eye can see.

Fisheries

Initially fisheries activities were carried out in the valleys, in the Goro and Scardovari sea inlets and various mouths of the Po river. In the 19th century fishing became increasingly important and in the 20th century even more so, developing into the town’s main activity and transforming this maritime district into one of the most important in the northern Adriatic Sea. Today fishing is the primary activity in the local economy, employing about 65% of the population. Of the hundreds of fishing vessels that bring the port to life, about half are engaged in mollusc farming: both mussel breeding in the Sacca lagoon (recognised in 1981 as a wetland of international importance by the Ramsar Convention) and offshore, as well as clam breeding with designated areas in which to plant and fatten smooth clams.

The Goro maritime district is one of the most important productive areas in Europe where fish farming is concerned, in particular for the breeding of bivalve molluscs and for clam farming.

The Goro clam

In the early 1970s all the fishing cooperatives were officially merged into the “Consorzio Pescatori di Goro”, and this marked the beginning of exploitation of a bed of native clams. In 1985 the Co.Pe.Go. decided to plant an experimental bed of Manila clams, an exotic species originally from the Indo-pacific region but which proved to adapt very well to the Sacca inlet area. The town therefore became Europe’s biggest producer and exporter of this mollusc.

There are currently 1300 fish farmers in the Goro maritime district, the molluscs are taken to enclosures for examination, depuration and packaging. The cooperatives guarantee product traceability and are certified according to ISO 9001 and 14000 standards.

Scientific support for the development of shellfish farming has always been provided by the Department of Biology of the University of Ferrara, where numerous research programmes have been conducted on the Manila clam and on the best culture systems for this species. At the moment the long and difficult process is underway to obtain EU recognition of Protected Geographical Indication (PGI) status.

The Manila clam Tapes philippinarum is a non-native species of Indo-Pacific origin. Currently the species is used in aquaculture virtually worldwide. In Italy this species was deliberately introduced for the first time in 1983 in the Venice lagoon. Superficially T. philippinarum can be confused by the inexpert observer with the congeneric Tapes decussatus. The most obvious feature that distinguishes the two species is the position of the siphons, in T. decussatus they are clearly separate from the base, while in T. philippinarum they are joined almost to the rim.

Manila clams were first introduced to the Sacca area of Goro in 1984 and they found favourable environmental conditions for reproduction, growth, and therefore for farming. Natural dispersal has meant that the Manila clam has established itself in all the areas of the north Adriatic where there are favourable conditions. Clam resources are exploited through culture based fisheries, not simple capture fisheries.

Clam culture activities have seen unparalleled development and today the local economy is based almost entirely on the exploitation of this resource. Farming is carried out by fisheries associations, usually fishers’ cooperatives, which request specific, delineated areas. In these areas, commonly called concessions, all the stages of farming are carried out, in short these are: cleaning of the seabed, sowing the clams, moving the product (if necessary), harvest.

Most of these concessions are within the Sacca inlet, only a small number are on the outside of the sandy bank. The most important element in this culture system is the seed, often abundantly available in the areas defined as “nurseries”. Here the conditions are such that there is a high level of natural recruitment. By their nature, nursery areas are not normally granted as concessions, as they should be available for everyone to use, they are also subjected to a thorough census as well as mapping so as to quantify their potential and distribution.

The productive potential of the Sacca area is not uniform in its distribution because clam farming depends on various factors, first of all the movement of the water, the texture of the sediment, salinity, oxygen content and depth. There is therefore a continuum of situations, caused by the overlap of these parameters with the chemical-physical parameters, which create environments that more or less favorable to the T. philippinarum breeding and, consequently, establish the productive potential of each area.

It should be noted that lagoon environments, such as the Goro inlet, are constantly changing and as a result the various areas also change quickly, with visible transformations even in the space of a year, which therefore also varies productive potential for clams.