Fall of the Republic of Venice with Napoleon. On 10 June, the heir to the Duchy of Parma, Louis of Bourbon, and two days later, Napoleon invaded the Romagna, which belonged to the Papal States; on 23 June the Pope had to accept the French occupation of the northern Legations, allowing the French to occupy the port city of Ancona on the Adriatic Sea. The appearance of French warships in the Adriatic led Venice to renew the ancient decree that prohibited the entry of foreign fleets in the Venetian Lagoon, and informed Paris of that. Flotillas and fortifications were established along the lagoon's shores with the
Gulf of Bothnia a number of rivers from both sides; consequently, a salinity gradient exists from north to south. In the south the water is the normal brackish water of the Baltic Sea, but in the north, in the Bothnian Bay, the salinity is so low, from 0.4% near Kvarken to 0.2% in the northernmost part, that many freshwater fish such as the pike, whitefish and perch thrive in it. Being nearly fresh, the gulf is frozen over five months every year. The icing of the Baltic Sea begins and ends in the northern Gulf of Bothnia. Traffic restrictions for icebreaker assistance are