Lake Ladoga Stolbovo, the northern and western coast was ceded by Russia to Sweden. In 1721, after the Great Northern War, it was restitution to Russia by the Treaty of Nystad. Later, in 1812–1940 the lake was shared between Finland and Russia. According to the conditions of the 1920 Tartu Peace Treaty militarization of the lake was severely restricted. However, both Soviet Russia and Finland had flotillas in Ladoga (see also Finnish Ladoga Naval Detachment). After the Winter War (1939–40) according to the Moscow Peace Treaty, Ladoga, previously shared with Finland, became an internal basin of the Soviet Union. During the Continuation
Lake Ladoga After the war, between 1945–1954, the total annual catch increased and reached a maximum of 4,900 tonnes. However, unbalanced fishery led to the drastic decrease of catch in 1955–1963, sometimes to 1,600 tonnes per year. Trawling has been forbidden in Lake Ladoga since 1956 and some other restrictions were imposed. The situation gradually recovered, and in 1971–1990 the catch ranged between 4,900 and 6,900 tonnes per year, about the same level as the total catch in 1938. Fish farms and recreational fishing are developing. It has its own endemic ringed seal subspecies known as the Ladoga seal. Since the beginning