40 



the fish are lifted by means of a dip-net, and placed in 

 great spherical wicker store-pots till removal to the 

 preserving factory. 



This so-called fishing of the lagoon continues usually 

 during a period of three months. The amount of fish 

 collected each day in the various pounds varies with the 

 state of the weather. Large catches occur only on 

 moonless or overcast nights ; when storms from seaward, 

 especially the levante-sirocco blowing from E.S.E., 

 coincide with the occurrence of such black nights, the 

 quantity of fish that accumulates in the lavoriero is often 

 so exceedingly great that the inner pounds become 

 choked with a solid mass of struggling fish. Bonaveri* 

 records that after one such night (4th October 1697), 

 322,520 kilogrammes of fish were taken from the pounds, 

 as much as 64,504 kilos being yielded by one valle alone. 

 Ouantities so vast are inconvenient to handle, so when- 

 ever the workers find the fish accumulating too quickly 

 in the enclosures, they light bonfires at the sides of the 

 tressa and this has the effect of checking the migration 

 temporarily. 



The reason for the great rush of fish into the lavorieri 

 during a tempest is that when this is from the eastward 

 it raises the water unusually high in the tidal-canals and 

 thus induces an increased flow of water through the 

 palisade barriers into the lagoon — a call which the adult 

 eel and mullet hear and act upon immediately. Occasion- 

 ally at these times, the storm heaps up so great a 

 quantity of water in the canals, as to entail such pressure 

 upon the walls of the labyrinths as to compromise their 

 stability. To avoid this, although the proceeding tells 

 against the success of the day's fishing, it becomes 

 necessary to stop the flow of water through the palisades 

 into the lagoon by shutting certain sluice gates which 

 are provided for this purpose either in the covole or in 

 the sea-canals themselves. 



It is obvious that during the summer season when 

 the walls of the tresse are continuous, and also during the 

 fishing season when, although the tresse are open, the 

 terpiinal (inner) mouths of the sea-canals are completely 

 obstructed by the palisades of the labyrinths, special 

 means must be provided to permit the employes and 



* Storia della Citta di Comacchio, 1761. 



