The Fischermen's Union was founded in 1845 with the purpose of bringing together and organizing the Caorle's fischermen, taking care of union's interests and managing the marketing activity of products. This union has redressed the fischermen's bargaining powers and has stopped poaching, very widespread at the time. The Fischermen's Union has been emulated by many other associations both in Italy and in foreign countries. Untill 1929, the union owned about 1500 hectares of lagoon. The union's incomes were produced by the earnings of the cutting of the grass, by the tax that some fischermen of other towns had to pay to practice fishing inside Caorle's area and by a tax levied on local fischerment by the management of the Fischermen's Union at their own discretion.

The main expenses were the rent of the private, fishing areas, the salary of the secretary and the fee of the fischermen's doctor. Local fischermen were gathered into groups and each group had its own chief. He had to report every act contrary to the law, to the morality and to the union's regulations. Disciplinary measures were very strict.
On September fischermen could practise fishing separately from the union. Very interesting is the fishing trading.
It is based on a practise called "secret award ": fischermen, after having moored along the quay of the Porto del Varroggio, took their catch to the fish market. After a meticulous test and an igenic control, a trader bought the catch and resold it. The person, who whispered the highest price in trader's ear, would have buy it. This practise is the same as before and it confirmes the strong tie between the island and its traditions.