History of the North Sea great herring fishing industry resulting in Scotland becoming a European leader in that industry. During the First Schleswig War (1848–51), the Crimean War (1854–56) and the Second Schleswig War (1864), belligerents took steps to reduce or eliminate commerce in the North Sea by their enemies. In the first Schleswig War, Denmark was able to halt maritime commerce by Germany in the North Sea and in the second, imposed tolls on ships crossing through the Danish straits between the Baltic and North Seas. The Crimean War saw British and French expeditions sent into the Baltic to prevent Russian ships' egress into
Ports of the Baltic Sea Ports of the Baltic Sea There are over 200 ports in the Baltic Sea. When only those ports that handle a minimum of 50,000 tonnes of cargo annually, and where at least part of this cargo is international are taken into account, the number of ports reaches approximately 190. In 2008, the total amount of cargo handled in the Baltic Sea ports amounted to 822.4 million tonnes, which was 0.4 per cent less than in 2007. Primorsk, Saint Petersburg and Muuga were the biggest ports in the Baltic Sea in 2008. Together the three top ports handled over one fifth