Blue crab puts the balance of the Sacca di Goro at risk
Alarm in the Ferrara area: clam production endangered
15, Jun 2023
Among the effects of ongoing climate change is that of the proliferation of the blue crab, which, however, threatens the entire balance of the Sacca di Goro, the area dedicated to clams in the Ferrara area. Helping to undermine the delicate environmental balance of the Sacca for the past few years is the fearsome blue crab (Gallinectus sapidus), an allochthonous fish species. After gradually engulfing other species, it is now endangering clam production as well.
This is no small problem, since spaghetti allo scoglio and other pasta dishes with sauces made with the flesh of the blue crab are popular and in demand in restaurants, but the out-of-control proliferation of this crustacean that arrived, a decade or so ago from the tropics, raises serious concerns for the future of the Gorese economy, which is primarily governed by the shellfish sector. «The blue crabs are destroying everything» is the outburst of Fausto Gianella, president of the La Vela cooperative reported by La Nuova Ferrara. «They also eat the clams and if we go on like this we risk losing all production, because it will be increasingly difficult to farm veracious. In one day I caught a quintal of blue crabs» he continued, «That's a lot: if you consider that a female produces two thousand three times a year, it's easy to understand the size of the problem».
The Sacca di Goro lacks natural predators: this is why blue crabs are multiplying unchecked, so much so that after feeding so far on shrimp, schille and even eels, they are starting to target clams. The only "competitor" currently present is the sea turtle, but for Gianella it is necessary to introduce incentives, to allow fishermen to catch more and more blue crabs, so as to counter the current invasion «as happened in 1970 with the invasion of bluefish. I have already detailed the problem to Congressman Mauro Malaguti in his capacity as a member of the Agriculture Committee. Proposals are being finalized to move forward, to curb the uncontrolled expansion of blue crab. We will make, in the short term an interregional meeting with colleagues from the Sacca di Scardovari, who are experiencing the same problem. I have also involved Senator Alberto Balboni, who has been working to get blue crabs to become a fish species of commercial interest, and finally, now there is this opportunity».
As an expert connoisseur of the Sacca, in his capacity as biologist and fisherman, Diego Viviani, former mayor of Goro, also spoke. "True clams were not the food the blue crabs originally targeted «he explains, "but they are becoming so now, because their other sources of sustenance are beginning to run out. They have come from the Atlantic Ocean and tropical seas. They are targeting the tiny ones, up to over 1 centimeter, and they are succeeding because they have greater strength than the native crabs, which instead prey on clams of a few millimeters».
«The problem is not easy to solve — adds the former first citizen — because as a biologist I can say that when an allochthonous species, arrived from outside, preys on a new environment it either disappears immediately or expands wildly until, in turn, it is preyed upon. Currently, only catches are made to sell blue crabs and not to limit the species». Viviani also considers the introduction of containment measures to be essential as a strategic action, since the capture of blue crabs for sale is selective. On the market, last year, the price ranged from 4 to 6 euros per kilo (for medium-sized specimens) reaching 12 euros for large blue crabs: this year, the larger specimens left and the medium-small ones remained, on the sales counters, sold at lower prices due to the exponential increase in product. The cost further decreases by a third if the crabs for sale are already dead.