The Gulf of Finland (; ; ; ) is the easternmost arm of the Baltic Sea. It extends between Finland to the north and Estonia to the south, to Saint Petersburg—the second largest city of Russia—to the east, where the river Neva drains into it. Other major cities around the gulf include Helsinki and Tallinn. The eastern parts of the gulf belong to Russia, and some of Russia's most important oil harbors are located there, including Primorsk. As the seaway to Saint Petersburg, the gulf is of considerable strategic importance to Russia. Some of the environmental problems affecting the Baltic Sea are at their most pronounced in the shallow gulf. Proposals for an undersea Helsinki–Tallinn Tunnel through the gulf have been made.
Geography
The Gulf of Finland has an area of .Gulf of Finland Encyclopædia Britannica The length (from the Hanko Peninsula to Saint Petersburg) is and the width varies from near the entrance to on the meridian of Moshchny Island; in the Neva Bay, it decreases to . The gulf is relatively shallow, with the depth decreasing from the entrance to the gulf to the continent. The sharpest change occurs near Narva-Jõesuu, which is why this place is called the Narva wall. The average depth is with the maximum of . The depth of the Neva Bay is less than ; therefore, in March 2019, a channel was dug at the bottom for safe navigation. Because of the large influx of fresh water from rivers, especially from the Neva River (two-thirds of the total runoff), the gulf water has very low salinity – between 0.2 and 0.3 ‰ at the surface and 0.3–0.5 ‰ near the bottom. The average water temperature is close to in winter; in summer, it is at the surface and at the bottom. Parts of the gulf can freeze from late November to late April; the freezing starts in the east and gradually proceeds to the west. Complete freezing usually occurs by late January, and it may not occur in mild winters. Frequent strong western winds cause waves, surges of water and floods.Darinskii, A. V. Leningrad Oblast. Lenizdat, 1975
The northern coast of the gulf is high and winding, with abundant small bays and skerries, but only a few large bays (Vyborg) and peninsulas (Hanko and Porkkalanniemi). The coast is mostly sloping; there are abundant sandy dunes, with occasional pine trees. The southern shores are smooth and shallow, but along the entire coast runs a limestone escarpment, the Baltic Klint, with a height up to . In the east, the gulf ends with Neva Bay; in the west it merges with the Baltic Sea.
The gulf contains numerous banks, skerries and islands. The largest include Kotlin Island with the city of Kronstadt (population 42,800), Beryozovye Islands, Lisiy Island, Maly Vysotsky Island with the nearby city of Vysotsk (population 1706), Gogland (Suursaari), Moshtchny (Lavansaari), Bolshoy Tyuters (Tytärsaari), Sommers, Naissaar, Kimitoön, Kökar, Seskar (Seiskari), Pakri Islands and others.Atlas of the USSR. – M.: GUGK, 1984
Starting in 1700, Russia constructed nineteen artificial islands with fortresses in the gulf. They aimed to defend Russia from maritime attacks, especially in the context of the Great Northern War of 1700–1721. Such fortresses include Fort Alexander, Krasnaya Gorka, Ino, Totleben and .Gulf of Finland – Forts . Fingulf.ru. Retrieved on 2011-08-14.
The largest rivers flowing into the gulf are the Neva (from the east), the Narva (from the south), and the Kymi (from the north). Keila, Pirita, Jägala, Kunda, Luga, Sista and Kovashi flow into the gulf from the south. From the north flow the Sestra River, Porvoo, Vantaa and several other small rivers. The Saimaa Canal connects the gulf with the Saimaa lake.
Extent The International Hydrographic Organization defines the western limit of the Gulf of Finland as a line running from Spithami (59°13'N), in Estonia, through the Estonian island of Osmussaar from SE to NW and on to the SW extremity of Hanko Peninsula (22°54'E) in Finland.
Geological history
The modern depression can be traced to the incision of large rivers during the Cenozoic prior to the Quaternary glaciation. These rivers eroded the sedimentary strata above the Fennoscandian Shield. In particular the eroded material was made up of Ediacaran (Vendian) and Cambrian-aged claystone and sandstone. As erosion progressed, the rivers encountered harder layers of Ordovician-aged limestone, leading to the formation of the cliffs of Baltic Klint in northern Estonia and Ingria. Subsequently, the depression was somewhat reshaped by glacier activities. Its retreat formed the Littorina Sea, whose water level was some 7–9 metres higher than the present level of the Baltic Sea. Some 4,000 years ago the sea receded and shoals in the gulf have become its islands. Later uplifting of the Baltic Shield skewed the surface of the gulf; for this reason, its ancient northern shores are significantly higher than the southern ones.Saint Petersburg: Encyclopedia. – Moscow: Russian Political Encyclopedia. 2006
Flora and fauna
The climate in the area is humid continental climate, characterized by temperate to hot summers and cold, occasionally severe winters with regular precipitation. The vegetation is dominated by a mixture of coniferous and deciduous forests and treeless coastal meadows and cliffs. The major forest trees are pine, spruce, birch, willows, rowan, aspen, common and gray alder. In the far eastern part of the gulf vegetation of the marshy areas consists mainly of bulrush and reeds, as well as fully aquatic plants, such as white and yellow waterlilies and acute sedge. Aquatic plants in the shallow waters of the gulf include Ruppia and spiny naiad.Gulf of Finland – Nature . Fingulf.ru. Retrieved on 2011-08-14.
Fish species of the gulf include Atlantic salmon, viviparous eelpout, gobies, belica, loach, European chub, common minnow, silver bream, common dace, ruffe, Crucian carp, stickleback, European smelt, common rudd, brown trout, tench, pipefish, burbot, perch, gudgeon, lumpsucker, roach, lamprey, vendace, garfish, common whitefish, common bream, zander, orfe, northern pike, spined loach, sprat, Baltic herring, sabre carp, common bleak, European eel and Atlantic cod. Commercial fishing is carried out in spring and autumn. Grey seal and ringed seal are met in the gulf, but the latter is very rare.
History
Many ancient sites were discovered on the shores of the gulf dated to up to 9000 years old. Humans began to inhabit these places soon after the ice age glaciers retreated and the water level of the Littorina Sea lowered to reveal the land. Remains of about 11 Neolithic settlements were found since 1905 in the mouth of the river Sestra River (Leningrad Oblast). They contain arrow tips and scrapers made of quartz, numerous food utensils and traces of fire camps – all indicative of hunting rather than agricultural or animal husbandry activities.
The gulf coast was later populated by Finnic peoples. Estonians inhabited the region of the modern Estonia, Votes were living on the south of the gulf and Izhorians to the south of Neva River. Korela tribes settled to the west of Lake Ladoga. They were engaged in slash-and-burn agriculture, animal husbandry, hunting and fishing. From the 8th to the 13th century, the Gulf of Finland and Neva were parts of the waterway from Scandinavia to the Byzantine Empire.
From the 9th century, the eastern coast of the gulf was controlled by Veliky Novgorod and was called Vodskaya Pyatina. As a result of the 1219, crusade and the Battle of Lindanise, northern Estonia became part of Denmark (Danish Estonia). In the 13th century, the city of Reval (Tallinn) () was established on the site of modern Tallinn, capital of Estonia. As a result of the Estonian uprising in 1343, northern Estonia was taken over by the Teutonic Order and sold by Denmark in 1346. In 1559, during the Livonian War, the Bishop of Ösel-Wiek in Old Livonia sold his lands to King Frederick II of Denmark. The Danish king gave the territory to his younger brother Magnus who landed on Saaremaa with an army in 1560. The whole of Saaremaa became a Danish possession in 1573, and remained so until it was transferred to Sweden in 1645.Countries and Peoples: USSR. Baltic republics. Belarus. Ukraine. Moldova. – Moscow: Mysl, 1984.
In the 12th and 13th centuries, the Finnish tribes on the north of the gulf were conquered by the Swedes who then proceeded to the Slavs. The first encounter is attributed to 1142 when 60 Swedish ships attacked 3 Russian merchant vessels. After a Swedish attack in 1256, the Russian army of Alexander Nevsky crossed the frozen gulf and raided the Swedish territories in the modern Finland. In 1293, the Vyborg Castle and city of Vyborg was founded by the Swedish marshal Torkel Knutsson. The castle was fought over for decades between Sweden and the Novgorod Republic. By the Treaty of Nöteborg in 1323, Vyborg was finally recognized as a part of Sweden. It withstood a prolonged siege by Daniil Shchenya during the Russo-Swedish War of 1496–1499. The town's trade privileges were chartered by King Eric of Pomerania in 1403. Vyborg remained in Swedish hands until its capture by Peter the Great in the Great Northern War (1710).V. A. Ezhov Leningrad Oblast: a historical sketch, Lenizdat, 1986 (in Russian)
In 1323, the Treaty of Nöteborg set the border between Sweden and Russia along the river Sestra. In the 15th century, the Izhorian lands of the Novgorod Republic were attached to the Grand Duchy of Moscow. In 1550, Gustav I of Sweden founded a city on the site of modern Helsinki.A. F. Treshnikov Encyclopedic Dictionary of Geography: Geographical names – Moscow: Soviet Encyclopedia, 1983. As a result of the Russian defeat in the Ingrian War (1610–1617) and the Treaty of Stolbovo (1617) the lands on the Gulf of Finland and Neva River became part of the Swedish Ingria. Its capital Nyen was located in the delta of Neva River.
Russia reclaimed the eastern part of the gulf as a result of the victory in the Great Northern War (1700–1721). On 16 May 1703, Saint Petersburg was founded in the mouth of Neva River, not far from Nyen, and in 1712 it became the capital city of Russia. To protect the city from the Swedish fleet, the Kronshlot fortress was built on an artificial island near the Kotlin Island in May 1704. By 1705, five more such forts were built nearby composing the city Kronstadt. These fortifications, nicknamed by the contemporaries "the Russian Dardanelles", were designed to control the Gulf waterway.
In 1710, the cities of Peterhof and Oranienbaum were founded on the southern shore of the Gulf of Finland. On 27 July 1714, near the Hanko Peninsula, the Russian Navy won the Battle of Gangut – a decisive victory over the Imperial Swedish Navy.Great Russian Encyclopedia. "Russia". 2004 The Russo-Swedish war ended in 1721 by the Treaty of Nystad, by which Russia received all the lands along the Neva and the Gulf of Finland, as well as Estland, Swedish Livonia and western part of the Karelian Isthmus, including Vyborg. However, Finland was returned to Sweden.Lurie, F.M. Russian and world history in the tables: Synchronic table. – SPb.: Caravelle, 1995. The war resumed in (1788–1790), and the Battle of Hogland occurred on 6 July 1788 near the island Gogland. Both the battle and the war were relatively minor and indecisive, with the outcome of Russia retaining its territories.
The next Russo-Swedish war was fought in (1808–1809). It ended with the Treaty of Fredrikshamn giving the Russia rights on the territory of Finland and Åland. A newly established Grand Duchy of Finland in 1809 received broad autonomy from Russian Empire, and Western Karelia was returned to Finland.David Kirby (2006) A concise history of Finland. Cambridge University Press. On 6 December 1917, the Parliament of Finland promulgated the Finnish Declaration of Independence. Western Karelia was annexed by the Soviet Union after the Winter War.