Lake Onega or Onego is located in the northwestern
part of Russia. The lake is the second largest in Europe after
Lake Ladoga. It is located on the territory of three regions of Russia:
the Republic of Karelia, the Vologda and Leningrad regions.
Lake Onega stretches from the north-west to the south-east, the
length is about 290 km, the maximum width is 82 km. The
surface area is 9.7 thousand km2. The greatest depth in the northern
part of the lake reaches 127 meters. The average depth in the
central part is 50-60 meters, closer to the south, the depth
decreases to 20-30 meters. The lake is a source of pure fresh water,
in the middle of the lake water can be safely consumed without any
preparation.
About 50 non-navigable rivers flow into Lake
Onega, only one river flows out - the Svir River. In addition to the
shipping Svir, which flows out of the lake in the south-western part
of the lake near the village of Voznesenie, the lake communicates
with the White Sea through the White Sea-Baltic Canal, exit in the
northern part of the village Povenets. There is also a shipping link
with the Volga through the Volga-Baltic Canal, which goes to Onego
in the south, 15 kilometers north of Vytegra.
In the early Russian written monuments, the lake is
referred to as Onego. The exact origin of its name is unknown; possibly
of ancient, Dauphine origin.
There are several versions of the
origin of the name:
Academician A. M. Sjogren produces the name
of the lake from Fin. ääni "sound, voice", the Vepsian name for the lake
(Änine - from än' "voice" and the diminutive suffix -ine) literally
means "voice"; hence the “sounding (“noisy”) lake”;
A. L. Pogodin
believes that the toponym comes from the Sami words agne "sand" + jegge
"low-lying plain";
professor and doctor of philological sciences I.
I. Mullonen believes that the name of the lake could come from the
Saami. äne and the Baltic-Finnish änine / äniz, which means "big,
significant."
Contrary to popular belief, the name of the lake has
nothing to do with the name of the Onega River, which flows into the
White Sea.
History
of study
In 1874-1894, a hydrographic expedition operated - “Separate
survey of Lake Onega”, organized by the Maritime Ministry of the Russian
Empire with the aim of conducting a topographic survey of the coastal
strip, measuring depths, studying bottom sediments, currents, thermal
and level regimes of Lake Onega. As a result of the research, a general
map of the lake was drawn up, "Guidelines for swimming in Lake Onega".
Navigation charts were first published in 1906. In the future,
navigation charts were repeatedly refined and reprinted.
The basin of Lake Onega of glacial-tectonic origin. In the Paleozoic (300-400 million years ago), the entire territory of the modern basin of Lake Onega was covered by a shelf sea in the vicinity of the ancient Baltic continent, which was also located in equatorial latitudes. Sedimentary deposits of that time - sandstones, sands, clays, limestones - cover with a thick layer (over 200 m) a crystalline basement consisting of granites, gneisses and diabases. The modern relief was formed as a result of the activity of the ice sheet (the last, Valdai glaciation, ended about 12 thousand years ago). After the retreat of the glacier, the Littorina Sea was formed, the level of which was 7–9 m higher than the present level of the Baltic Sea.
The surface area of Lake
Onega is 9720 km2 (without islands), the maximum length is 248 km, the
maximum width is 83 km (from Petrozavodsk to the mouth of the Vodla
River). The northern shores are rocky, strongly indented, the southern
ones are mostly low, undivided. In the northern part of the lake,
numerous bays deeply protrude into the mainland and there is the
Zaonezhie peninsula, the largest on the lake. To the south of the
peninsula is the largest island on the lake - Bolshoi Klimetsky. To the
west of the island is the deepest (up to 100 m or more) part of the lake
- Bolshoye Onego Bay with Kondopoga Bay (with depths up to 78 m),
Ilem-Gorskaya (42 m), Lizhemskaya (82 m) and Unitskaya (44 m) . In the
northeastern part of the lake, a large bay stretches northward, the
northern part of which is called the Povenets Bay, the middle part is
the Zaonezhsky Bay, and the southern part is the Maloe Onego Bay with
depths of 40-50 m. Deep sections here alternate with shoals and groups
of islands, which divide the bay into several parts. There are many
stones along the shores of the lake.
The main part of the lake -
Central Onego - has an area of 5685 km², including the Petrozavodsk
and Svir bays.
The average depth of the lake is 31 m, the maximum
depth in the deepest northern part of the lake reaches 127 m. The
average depth in the central part is 50–60 m, closer to the south the
bottom rises to 20–30 m. bottom depressions. In the northern part of the
lake there are many troughs, alternating with high bottom rises, forming
banks, on which industrial trawlers often fish. Much of the bottom is
covered with silt. Typical forms are luds (shallow stony shoals), selgas
(deep-water elevations of the bottom with stony and sandy soils, in the
southern part of the lake), underwater ridges and ridges, as well as
depressions and pits. Such a relief creates favorable conditions for the
life of fish.
The regime of Lake Onega is characterized by a
spring rise in water, which lasts 1.5-2 months, with annual fluctuations
in the water level up to 0.9-1 m. The flow from the lake is regulated by
the Verkhne-Svirskaya hydroelectric power station. Rivers bring up to
74% of the incoming part of the water balance (15.6 km³ per year), 25%
falls on precipitation. 84% of the expenditure part of the water balance
falls on the runoff from the lake along the Svir River (an average of
17.6 km³ per year), 16% - on evaporation from the water surface. The
highest water levels of the lake are in June-August, the lowest - in
March and April. There are frequent unrest, the height of storm waves
reaches 3.5 m. The lake freezes in the central part in mid-January, in
the coastal part and in the bays - in late November - December. At the
end of April, the mouths of the tributaries are opened, the open part of
the lake - in May. The water in the open deep parts of the lake is
transparent, with visibility up to 7-8 m. In the bays - a little less,
up to one meter or less. The water is fresh, with a mineralization of 10
mg/l.
The basin area of Lake Onega is 53,100
km².
More than 1000 streams flow into the lake, of which 52 are
rivers with a length of more than 10 km and 8 - more than 100 km. The
largest of them are Vodla and Suna. Also, the lake is filled with its
waters by Korovya, Gimrek, Rybrek, Sheltozerka, Yani, Shoksha,
Petruchey, Merozlov, Vantik, Bolshaya Uya, Uyka, Derevyanka, Orzega,
Neluxa, Stone stream, Lososinka, Neglinka, Padas, Nyuchkina, Anga,
Syalnaga, Chapa , Chebinka, Vikshrechka, Listiga, Unitsa, Small Pigma,
Matkozero, Vozhmarikha, Pizhey, Lelrechka, Sudma, Tambitsa, Kaley,
Tsarevka, Makushikha, Vichka, Lumbushka, Pindushka, White Sea-Baltic
Canal, Northern Izhmuksa, Southern Izhmuksa, Arzhema, Vozritsa ,
Neleksa, Shoivana, Nemina, Lukdozhma, Kodach, Pyalma, Pudozh, Tuba,
Yalganda, Oravruchey, Chazhva, Somba, Andoma, Vytegra, Megra,
Pertruchey, Oshta, Puinzha, Black and others.
In the Svir Bay of
the southern part of the lake, there is the source of the only river
Svir flowing out of the lake, on which the Verkhne-Svirskaya
hydroelectric power station was built in 1953.
The White
Sea-Baltic Canal connects the lake with the White Sea, and through the
Volga-Baltic Waterway - with the Volga, the Caspian and Black Seas. With
the creation of the Verkhne-Svirsky reservoir in 1951-1953, the lake
became a reservoir (area - 9720 km²).
The total number of islands
in Lake Onega reaches 1650, and their area is 250 km² (according to
other sources, 224 km²). The most famous of the Onega Islands is the
island of Kizhi, on which the museum-reserve of the same name with
wooden churches of the 18th century is located: Spaso-Preobrazhensky and
Pokrovsky. The largest island is Bolshoy Klimetsky (147 km²). There are
several settlements on it, there is a school. Other islands: Bolshoy
Lelikovsky, Suysari, South Deer Island.
The low shores of Lake Onega are swamped and flooded when the water
level rises. On the shores of the lake and on its islands, in reed and
reed thickets, ducks, geese and swans nest. The coastal area is covered
with dense taiga forests in a virgin state.
There are cases of
observation of seals on Lake Onega.
Lake Onega is distinguished
by a significant variety of fish and aquatic invertebrates, including a
significant number of relics of the Ice Age. In the lake there are
sterlet, lake salmon, lake trout, brook trout, ludnaya char, pit char,
vendace, vendace-kilets, whitefish, grayling, smelt, pike, roach, dace,
silver bream, bream, sabrefish, golden carp, char, loach , catfish, eel,
pike perch, perch, ruff, Onega slingshot, sculpin, burbot, river and
stream lamprey. In total, 47 species and varieties of fish belonging to
13 families and 34 species are found in Lake Onega.
Ecological
state
In the second half of the 20th century, the impact on the
ecosystem of Lake Onega increased intensively, especially in terms of
pollution. The greatest pressure is experienced by the northwestern and
northern parts of the lake, where the Petrozavodsk, Kondopoga and
Medvezhyegorsk industrial hubs are located. 80% of the population and
more than 90% of the industrial potential of the basin are concentrated
here. The accounted pollution from three industrial hubs is about 190
million m³ of sewage and drainage water and 150 thousand tons of
emissions into the atmosphere per year. The volume of technogenic
effluents in the Onega Lake basin is about 315 million m³ per year, of
which 46% is industrial and economic, 25% is storm water and 16% is
drainage and reclamation water. The intake of biogenic elements into the
lake is: phosphorus - 810 tons, total nitrogen - 17 thousand tons per
year, and 280 tons of phosphorus and 11.8 thousand tons of nitrogen are
taken out of the lake with the waters of the Svir River, that is, 68% of
phosphorus and 31% are accumulated in the lake. % nitrogen. The fleet
and motor boats (about 8000 units) with exhaust gases, discharge from
cooling systems, leaks pollute the aquatic environment mainly with oil
products (about 830 tons per navigation), phenols (0.5 tons), lead (0.1
tons), sulfur oxides , nitrogen and carbon.
From the beginning of
the 1990s to the end of the 2010s, due to the warming of the climate of
Karelia, more and more organic (humic) substances were carried into the
lake and such parameters as water color, suspended matter content (from
1.6 to 3 mg/l), iron (from 0.12 to 0.42 mg/l), phosphorus (from 12 to 22
µg/l) and carbon dioxide (from 1.2 to 3.0 mg/l). At the same time, the
acidity of the water and the oxygen content fell (respectively, from
7.22 to 7.12 and from 101 to 92% saturation). A sharp increase in the
concentration of iron in the upper layer of silt caused a decrease in
the number of macrozoobenthos by 6-7 times. In addition, from 2007 to
2016, more than 80 thousand tons of pollutants were discharged into the
lake basin from point sources, more than half of the emissions occur in
Petrozavodsk and Kondopoga. However, the water of the lake is of high
quality and belongs to class 2 (“slightly polluted”) or 3 “a”
(“polluted”). Of the 28 pollutants found in water, only 6 were of
strictly anthropogenic origin.
A 2018 study showed that the
overall species composition and seasonal dynamics of zooplankton in
Petrozavodsk Bay has remained unchanged since the 1960s.
The cities of Petrozavodsk, Kondopoga, Medvezhyegorsk, and the
urban-type settlement of Povenets are located on the shores of Lake
Onega. The lake is navigable, it is part of the waterway, which is part
of the Volga-Baltic waterway and the White Sea-Baltic Canal, connecting
the basins of the Baltic, Caspian and northern seas. Through the system
of canals and rivers, cargoes from Petrozavodsk can be sent to any
countries of the coastal sea zone: from Germany to Iran. Along the
southern shore of the lake from the Svir River to the Vytegra River, the
Onega Shipping Canal was dug.
On the shores of Lake Onega there
are 2 ports (Petrozavodsk port and the port of Medvezhyegorsk), 5
marinas (Kondopoga, Povenets, Shala, Vytegra, Voznesenye) and several
stopping points.
There is no regular passenger service on the
lake, but regularly, several times a day, during navigation along the
routes Petrozavodsk - Kizhi and Petrozavodsk - Velikaya Guba, tourist
ships and "meteors" go. In addition, passenger ships operate on the
route Petrozavodsk - Shala[.
In the waters of Lake Onega, since
1972, the largest Russian sailing regatta, the Onega Sailing Regatta,
has been held annually at the end of July - the open championship of
Russia in sailing among cruising yachts.
Fishing is developed in
the lake. The following 17 species are of the most important commercial
importance: vendace, smelt, whitefish, burbot, pike perch, roach, ruff,
perch, bream, pike, salmon and char; the smaller ones are ide, grayling,
dace, bleak and crucian carp.
Cities
The city of Petrozavodsk is the capital of the Republic of
Karelia, the largest city on the shores of Lake Onega. Founded in 1703
by Peter I. There are a large number of architectural monuments on the
territory of Petrozavodsk. The most famous of them are: the
architectural ensemble of the Round Square of the end of the 18th
century, the building of the former provincial male gymnasium of 1790,
the architectural ensemble of Karl Marx Avenue of the 1950-1960s, the
embankment of Lake Onega with a large number of sculptures - gifts from
sister cities and others.
Kondopoga has been known since 1495.
The main attraction of the city was the Assumption Church, a monument of
wooden architecture. The church was erected in 1774. Its height was 42
meters, which made it one of the tallest wooden churches in the Russian
North. In August 2018, the church was destroyed by fire. The city has
two carillons of 23 and 18 bells, the Ice Palace and the Palace of Arts
with an organ hall.
Medvezhyegorsk was founded in 1916. Since
1931 - the capital of the construction of the White Sea-Baltic Canal. 15
km from Medvezhyegorsk is Sandarmokh - the place of mass executions of
the NKVD and the burial places of prisoners who worked on the canal.
Kizhi Island
The main attraction of the lake is the Kizhi Island
with the eponymous State Historical, Architectural and Ethnographic
Museum-Reserve. On its territory there are 89 monuments of wooden
architecture of the XV-XX centuries. The center of the island is the
architectural ensemble of the Kizhi Pogost of the 18th century,
consisting of the twenty-two-domed summer church of the Transfiguration
of the Lord, the nine-domed winter church of the Intercession of the
Virgin and the hipped bell tower. In 1990, the Kizhi Pogost was included
in the UNESCO World Heritage List.
Onega petroglyphs
Onega
petroglyphs are located on the eastern coast of Lake Onega. They date
back to the 4th-2nd millennium BC. Petroglyphs are scattered in
scattered groups on the rocks of capes Besov Nos, Kladovets, Gazhiy,
Peri Nos and on Gury Island. In general, the Onega petroglyphs cover a
section of the lake shore 20.5 km long and include approximately 1200
figures and signs.
In July 2021, the petroglyphs of Lake Onega
(along with the petroglyphs of the White Sea) were included in the list
of UNESCO cultural heritage sites.