LAKE ONEGO

A view on the lakeshore Photo: M. I. Fedorov  
 

A. LOCATION

• Karelian ASSR, Leningrad and Vologda regions of RSFSR, Russia.*
• 60:55-62:55N, 34:14-36:30E; 35 m above sea level.

* Place names are not updated.

 

B. DESCRIPTION

Lake Onego is the second largest lake in Europe next to Lake Ladoga. The lake basin is situated on two contrasting parts of the earth crust with different geological histories, Baltic shield and Russian plate. The boundary runs approximately along the line connecting the mouths of the Vodla River and the Shuja River. To the north of the boundary, the shoreline is extremely jagged, and the greater part of islands and numerous fjord-type bays are found. The northern basin is surrounded by hills and cliffs consisting of crystalline rocks. There, land relief forms are oriented from northwest to southeast, following the direction of ice flow during glacial periods. Deep hollows (90- 100 m deep) are interspersed with ridges only 1-2 m below the water surface. The southern basin is relatively shallow with a mean depth of 30 m and more or less flat bottom. Shorelines are less jagged, and are frequently covered by marsh.
Tectonic processes in the pre-glacial period, combined with glacial erosion and transport, formed the specific hydrographical network. The history of Lake Onego experienced several glacial periods, when its flora and fauna were exterminated. The last glaciation ended 11,000-12,000 years ago. The lakeshore became inhabited some 9,000 years ago. Some 800 rock drawings or so-called petrogliffs, which were made from the end of the third to the beginning of the second millennium B. C., are invaluable heritage in the history human culture. On the lake shore, there are also a number of wood architectures of 17-18th centuries including world-famous Kizhi-ensemble.
Lake Onego is now the source of freshwater of high quality (total mineral concentration 34-36 mg l-1). It also forms part of the major waterborne transport system in the USSR, and serves as a reservoir for hydroelectric power generation and an important fishing ground.

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C. PHYSICAL DIMENSIONS (Q)

 

Surface area [km2]	9,890
Volume [km3]	280
Maximum depth [m]	120
Mean depth [m]	30
Water level	Regulated
Normal range of annual water level fluctuation [m]	0.5
Residence time [yr]	12
Catchment area [km2]	51,540

 

 

D. PHYSIOGRAPHIC FEATURES

D1 GEOGRAPHICAL (Q)

• Sketch map: Fig. EUR-36-01.
• Names of main islands

Klimenetskiy (148 km2), Lelikovskiy (21 km2) and Suisari (19.3 km2).
• Number of outflowing rivers and channels (name): 1 (Svir R.).

D2 CLIMATIC

• Climatic data, 1870-1950

 

Mean temp. [deg C]*1
Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.
-9.8	-10.1	-6.1	1.3	1.3	19.0	16.3	14.3	9.4	3.4	-2.1	-6.6	2.5
Precipitation [mm]*2
35	29	29	34	42	50	65	69	66	62	43	43	567
*1 Petrozavodsk. *2 Shvets P.D.

 

• Number of hours of bright sunshine (Petrozavodsk): 1,719 hr yr-1.
• Solar radiation: 4.21 MJ m-2 day-1.

Fig. EUR-36-01
Sketch map of the lake (Q).

 

• Water temperature [deg C]

 

1972-1984
Depth [m]	Jan-Feb-Mar-Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
0.5	Ice cover	2.7	8.9	15.2	12.5	11.5	7.2	3.5	0.8

 

• Freezing period (Tichomirov, 1948-1967): 18 January-18 May.
• Mixing type: Dimictic.
• Notes on water mixing and thermocline formation

Thermal bar disappears at the end of June. Hydrological summer is 65-70 days. Maximum heating in August. Epilimnion about 20-30 m deep. Temperature in metalimnion is around 10deg C, hypolimnion 4-5deg C. Autumn thermal bar is observed in November.

Fig. EUR-36-02
Seasonal change of water temperature, 1956-1988 (Q).

 

E. LAKE WATER QUALITY (Q)

E1 TRANSPARENCY [m]

 

Lake centre, 1989
Depth [m]	Jan-Feb-Mar-Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
	Ice cover	3.5	3.7	3.5	3.5	3.5	3.5	3.5	3.7

 

E2 pH

 

Lake centre, 1989
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
S*1	-	-	-	-	7.4	7.4	7.8	7.7	7.5	7.5	-	-
5.0	-	-	-	-	7.4	7.4	7.8	7.8	7.6	7.5	-	-
10.0	-	-	-	-	7.4	7.4	7.7	7.6	7.5	7.5	-	-
20.0	-	-	-	-	7.4	7.4	7.4	7.4	7.4	7.4	-	-
40.0	-	-	-	-	7.4	7.4	7.4	7.4	7.4	7.4	-	-
80.0	-	-	-	-	7.4	7.4	7.4	7.4	7.4	7.4	-	-
B*2	-	-	-	-	7.4	7.4	7.4	7.4	7.3	7.3	-	-
*1 Surface. *2 Bottom.

 

E3 SS [mg l-1]

1966-1987: 0.2.

E4 DO [mg l-1]

 

Lake centre, 1989
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
S*1	-	-	-	-	13.1	13.1	10.8	9.4	10.5	-	-	-
5.0	-	-	-	-	13.1	13.2	10.5	9.3	10.4	-	-	-
10.0	-	-	-	-	13.0	13.0	10.7	9.2	10.3	-	-	-
20.0	-	-	-	-	13.2	12.5	11.8	9.2	11.0	-	-	-
40.0	-	-	-	-	13.2	12.8	12.2	12.5	11.4	-	-	-
80.0	-	-	-	-	13.1	13.1	12.0	12.6	11.6	-	-	-
B*2	-	-	-	-	13.2	12.9	12.0	12.8	12.0	-	-	-
*1 Surface. *2 Bottom.

 

E5 COD [mg l-1] 1970-1988

• Determined by KMnO4 method: 7.1.
• Determined by K2Cr2O7 method: 14.7.

E6 CHLOROPHYLL CONCENTRATION [micro g l-1]

 

Lake centre, 1989
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
S*	-	-	-	-	0.8	1.4	5.8	5.2	-	-	-	-
5.0	-	-	-	-	-	1.2	3.8	4.5	-	-	-	-
10.0	-	-	-	-	-	1.0	3.2	2.6	-	-	-	-
* Surface.

 

E7 NITROGEN CONCENTRATION

• Total-N [mg l-1]

 

Lake centre, 1989
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
S*1	-	-	-	-	0.45	0.60	0.85	0.49	0.45	-	-	-
5.0	-	-	-	-	0.41	0.62	0.66	0.51	0.58	-	-	-
10.0	-	-	-	-	0.45	0.60	0.50	0.49	0.54	-	-	-
20.0	-	-	-	-	0.44	0.70	0.50	0.49	0.65	-	-	-
40.0	-	-	-	-	0.48	0.76	0.50	0.56	0.68	-	-	-
80.0	-	-	-	-	0.36	0.80	0.70	0.51	0.65	-	-	-
B*2	-	-	-	-	0.31	0.64	0.50	0.51	0.60	-	-	-
*1 Surface. *2 Bottom.

 

E8 PHOSPHORUS CONCENTRATION

• Total-P [micro g l-1]

 

Lake centre, 1989
Depth [m]	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
S*1	-	-	-	-	8	6	7	10	7	-	-	-
5.0	-	-	-	-	9	7	7	10	6	-	-	-
10.0	-	-	-	-	9	7	7	7	5	-	-	-
20.0	-	-	-	-	10	7	6	5	6	-	-	-
40.0	-	-	-	-	5	6	8	6	6	-	-	-
80.0	-	-	-	-	5	6	8	6	6	-	-	-
B*2	-	-	-	-	14	11	9	8	6	-	-	-
*1 Surface. *2 Bottom.

 

 

F. BIOLOGICAL FEATURES (Q)

F1 FLORA

• Emerged macrophytes

Phragmites australis, Scirpus lacustris, Equisetum fluviatile.
• Floating macrophytes: Nuphar lutea, Polygonum amphibium.
• Submerged macrophytes

Potamogeton perfoliatus, P. luceus, P. praelongus, Batrachium eradicatum, B. gilibertii.
• Phytoplankton

Spring: Melosira islandica subsp. helvetica, M. italica, M. distans var. alpigena, Asterionella formosa, Tabellaria fenestrata. Summer: Dinobryon divergens, D. bavaricum, Coelosphaerium kuettzingianum, Oscillatoria tenuis, Sphaerocystis schroeteri.

F2 FAUNA

• Zooplankton

Spring: Strombidium viride, Lembadion lucens, Limnocalanus macrurus, Cyclops abissorum, Eudiaptomus gracilis, Kellicottia longispina. Summer: Vorticella anabaena, Tintinnopsis cratera, Limnocalanus macrurus, Cyclops abissorum, Diaptomus gracilis, Mesocyclops oithonoids, Daphnia cristata, Bosmina obtusirostris, Kellicottia longispina, Asplanchna priodonta.
• Benthos

Pontoporeia affinis, Pallasea quadrispinosa, Lampodrilus isoporus, Stylodrilus heringianus, Spirosperma ferax, Procladius sp., Trissocladius parataricus, Protanypus sp., Prodiamesa bathyla, Neopisidium conventus.
• Fish

Coregonus albula, C. lavaretus, Osmerus eperlanus, Lucioperca lucioperca.
• Supplementary notes on the biota

There are noteworthy relict species such as Pontoporeia affinis, Pallasea quadrispinosa, Mysis oculata var. relicta, Gammarocanthus lacustris and Lampodrilus isoporus.

F3 PRIMARY PRODUCTION RATE [mg C m-2 day-1]

 

Lake centre, 1989
Gross production
Jan	Feb	Mar	Apr	May	jun	Jul	Aug	Sep	Oct	Nov	Dec	Ann.
-	-	-	-	-	17.6	40.3	52.8	79.9	-	-	-	7.6

 

F4 BIOMASS

• Macrophytes [g m-2]

 

1989
Phragmites	220
Scirpus	187
Equisetum fluviatile	100
Potamogeton natans	142
P. perfoliatus	32
Polygonum amphibium	77

 

• Phytoplankton [g (fresh wt.) m-2]

 

1989
Regions	Jun	Jul	Aug	Sep
Bolshoje Onego Gulf	34.7	12.5	5.7	4.7
Petrozavodsk Bay	42.0	4.0	12.0	4.5
Kondopoga Bay	114.8	8.9	4.3	22.3

 

• Bacterioplankton [g (fresh wt.) m-2]

 

1989
Regions	Jun	Jul	Aug	Sep
Bolshoje Onego Gulf	65.8	61.2	60.2	106.7
Petrozavodsk Bay	28.2	29.5	33.1	52.8
Kondopoga Bay	61.5	91.4	52.1	119.4

 

• Protozoa [g (fresh wt.) m-2]

 

1989
Regions of the lake	Jun	Jul	Aug	SeP	Oct
Bolshoje Onego Gulf	0.2	1.0	0.7	2.9	2.9
Petrozavodsk Bay	0.4	4.7	1.1	0.2	2.7
Kondopoga Bay	1.4	3.1	0.2	0.5	1.4

 

• Zooplankton [g (fresh wt.) m-2]

 

1989
Regions of the lake	Jun	Jul	Aug	Sep	Oct
Bolshoje Onego Gulf	3.2	6.5	12.2	5.6	4.0
Petrozavodsk Bay	4.2	5.9	8.3	6.0	1.6
Kondopoga Bay	5.2	13.0	19.3	5.5	6.2

 

F5 FISHERY PRODUCTS

• Annual fish catch [metric tons]

1990: 2,100.

 

G. SOCIO-ECONOMIC CONDITIONS (Q)

G1 LAND USE IN THE CATCHMENT AREA

 

1988
	Area [km2]*	[%]
- Natural landscape
Woody vegetation	36,800	71.6
Herbaceous vegetation	400	0.8
Swamp	9,800	19.1
Others	3,700	7.2
- Agricultural land
Crop field	300	0.6
Pasture land	200	0.4
- Residential area	200	0.4
- Total	51,400	100.0
* Approximate.

 

• Types of important forest: Spruce, pine, birch, aspen.
• Main kinds of crops: Potato, cabbage, carrot, perennial, herbs.
• Levels of fertilizer application on crop fields: Moderate.
• Trends of change in land use in recent years

Expansion of agricultural lands; reduction of forest felling.

G2 INDUSTRIES IN THE CATCHMENT AREA AND THE LAKE

 

1989
	Gross product during the year [US $]	No. of engaged persons	No. of establishments
- Primary industry	-	8,982	1,371
Crop production	13,632	-	-
Animal husbandry	61,792	-	-
- Secondary and Tertiary industry
Timber and wood-working	132,236	21,915	2,698
Cellulose and paper	127,418	5,281	713
Building materials	67,607	9,054	1,382
Machine production	180,817	20,352	4,981

 

• Number of domestic animals in the catchment area

Cattle 68,000, sheep 34,000, swine 54,000, poultry 1,908,000, goat 1,700, horse 900, mink 102,000, polar fox 3,400, fox 1,000.

G3 POPULATION IN THE CATCHMENT AREA

 

1989
	Population	Population density [km-2]	Major cities (population)
Urban	305,000	-	Petrozavodsk,
Rural	194,000	-	Kondopoga
Total	499,000	9.7

 

 

H. LAKE UTILIZATION (Q)

H1 LAKE UTILIZATION

Source of water, navigation and transportation (tonnage of cargo in 1989: 10 million tons), sightseeing and tourism (no. of visitors: 300,000 per year), recreation (sport-fishing, yachting) and fisheries.

H2 THE LAKE AS WATER RESOURCE

 

1988
	Use rate [mill. m3 yr-1]
- Domestic	26.9
- Irrigation
Agriculture	0.2
- Industrial	27.0
- Total	54.1

 

 

I. DETERIORATION OF LAKE ENVIRONMENTS AND HAZARDS (Q)

I3 EUTROPHICATION

• Nitrogen and phosphorus loadings to the lake [t yr-1]

 

1989
Sources	Total
T-N	17,800
T-P	1,040

 

I4 ACIDIFICATION

• Extent of damage: Detected but not serious.

 

J. WASTEWATER TREATMENTS (Q)

J1 GENERATION OF POLLUTANTS IN THE CATCHMENT AREA

c) Limited pollution with wastewater treatment.

J2 APPROXIMATE PERCENTAGE DISTRIBUTION OF NUTRIENT LOADS

 

	[%]
- Non-point sources	10
- Point sources
Municipal	10
Industrial	80
Fish farming	-
- Total	100

 

J3 SANITARY FACILITIES AND SEWERAGE

• Percentage of municipal population in the catchment area provided with

adequate sanitary facilities (on-site treatment systems) or public sewerage: 100%.
• Percentage of rural population with adequate sanitary facilities (on-site

treatment systems): 60%.
• Municipal wastewater treatment systems

No. of secondary treatment systems: 6. No. of primary treatment systems: 0. No. of other types: 0.
• Industrial wastewater treatment systems

No. of industrial wastewater treatment systems: 11.

 

K. IMPROVEMENT WORKS IN THE LAKE (Q)

None.

 

M. LEGISLATIVE AND INSTITUTIONAL MEASURES FOR UPGRADING LAKE ENVIRONMENTS (Q)

M1 NATIONAL AND LOCAL LAWS CONCERNED

• Names of the laws (the year of legislation)
1. Principles of Water Laws for the USSR (1971)
2. RSFSR Water Code (1980)
3. "Measures on ensuring of protection and rational utilization of water and other natural resources in the Basin of Lakes Ladoga, Onego and Ilmen", Council of Ministers of the USSR Decision (1984)
• Responsible authorities
1. Local authorities
2. State sanitary inspection
3. State fish inspection
4. State Committee of Environmental Protection
5. State Committee of Hydrometeorology
• Main items of control
1. Discharge of industrial and municipal sewage
2. Non-point sources of contamination control

M2 RESEARCH INSTITUTESS ENGAGED IN THE LAKE ENVIRONMENT STUDIES

1. Karelian Centre of the Academy of Science of the USSR, Petrozavodsk
2. Northern State Research Institute for Fish Industry, Petrozavodsk

 

N. SOURCES OF DATA

17. Questionnaire filled by Dr. N. N. Filatov, Water Problem Department, Karelian Centre of the Academy of Science of the USSR, Petrozavodsk, based on the following sources.
1. Kauffman, Z. S. (ed.)(1990) The Ecosystem of the Onego Lake and the Trends of Its Changes (in Russian). 263 pp. Publ. House "Nauka", Leningrad.