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Ecoregion Description


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Species Richness


# of Endemic Species


Threats

409: Lake Onega - Lake Ladoga

Major Habitat Type:

large lakes

Author:

Nina Bogutskaya

Countries:

Finland; Russia

Boundaries:

The rivers in the Gulf of Finland are excluded by the ecoregion’s south and southwest borders.  Together, the northern and westerly borders exclude the lakes of Karelian Lakeland [406].  The northern border also marks the divide between the Lake Onega basin and White Sea basin river catchments.  There are several channels and canals in the region—both natural and manmade—and the borders reflect historical conditions before large-scale human intervention.

Beloye [410] and Onega lakes are connected by the Volgo-Baltiyskiy Canal, and Lake Onega is artificially connected to the White Sea. The ecoregion’s southeastern border runs along the divide between the Volga catchment and Ladoga-Onega basin in the Vepsovskaya Upland.  The same border cuts through the Volkhov River, excluding the Ilmen Lake [404] in the Baltic Lowlands.

Drainages flowing into:

Ladoga and Onega lakes lie in the Neva drainage area near the Baltic Sea. Lake Onega has been connected to the White Sea (Onezhskaya Guba Bay) by the Belomorsko-Baltiyskiy Kanal (White Sea-Baltic Canal) since the 1930s. Three main waterways connect Ladoga and Onega lakes to the Volga drainage. The Volga-Baltic system (formerly Mariinskaya Systema) connects the Sheksna, Vytegra, Svir, and Neva rivers with Beloye and Onegra lakes and Priladozhskiy Canal.

Tikhvinskaya Systema has connected the Mologa, Chagodoscha, and Syas rivers with Ladoga Lake and the Tikhvinskiy Canal since 1811.

The oldest waterway—Voshnevolotskaya Systema (est. 1703)—connects the Tvertsa and Msta rivers with Lake Ladoga, as well as several smaller canals and lakes. 

Main rivers or other water bodies:

Lake Onega (connected with the Suna, Vodla, and Shuya rivers); Syamozero Lake; Lake Ladoga  (connected with the Svir, Vuoksa, and Volkhov, and Neva rivers).

Topography:

With a length of 1,570 km, a volume of 908 km3 and an area of 17,680 km2, Lake Ladoga is not only the largest lake in Europe, but one of the largest in the world.  The quadrilateral lake widens in the south, and is marked by several small, skerry-like bays along its northern shoreline.  Islands dominate the northern coast, while rocky archipelagos—like the Valaam—take over in the south. The southeastern and southern coasts contain three large, open bays: Petrokrepost, Volkhovskaya Guba and Svirskaya Guba.  Despite the fact that Lake Ladoga plummets to 228 m in its deepest region, depths of roughly 100 m are more characteristic of the northern part of the lake.  The lake’s mean depth is 51 m, and it deepens with proximity to the southern shore, where the lake bottom evens out significantly.

Lodoga Lake is fed by three main tributaries—the Svir, Vuoksa, and Volkhov rivers— while the Neva River allows the lake to drain into the Baltic Sea.

Lake Onega is the second largest lake in Europe, with an area of 9,690 km2. Its depth ranges from 30 to 120 m, and its three main tributaries—the Suna, Vodla, and Shuya rivers—keep its total volume around 292 km3. The Svir River connects Onega and Ladoga lakes.

Freshwater habitats:

Both lakes contain deep waters that remain cold (1 to 4°C) year-round, yet the coastal waters heat relatively quickly during spring.  A distinct thermal bar between warm and cold water often separates water masses by roughly 20°C.  Despite unrelentingly cold temperatures in the lake’s central regions, cold-loving whitefishes and paliya still inhabit the areas during most of the year.

Terrestrial Habitats:

Both lakes’ shores appear particularly indented in the north. The southern shore of Lake Ladoga is extremely high and rocky.

Fish Fauna:

The ecoregion’s large, deep lakes support unique fish fauna derived from river-dwelling ancestors of Atlantic-Baltic origin. In contrast to the nearby Northern European [407] ecoregion, Ladoga and Onega lakes are marked by a total absence of Siberian species and genera. By some estimates, the region contains nearly 50 fish species in 14 families.

Lake Ladoga shares connections with Baltic Sea basin fauna, and contains a number of the species found in the north and south Baltic Lowlands (from genera Coregonus and Cottus). Other European representatives—mostly from Black Sea drainage areas—include members of the family Cyprinidae. These carps and minnows fall under the genera Alburnus, Abramis, Ballerus, Aspius, Blicca, Leucaspius, Rutilus, Vimba, Tinca, and Gobio. Wels catfish (Silurus glanis), pike-perch (Sander lucioperca), European perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus) are also found in the Lake Ladoga region. The most typical and abundant representatives of the ecoregion’s fish fauna are local endemic lacustrine whitefishes (genus Coregonus).

The ecoregion’s fauna includes stenothermic, psychrophilic (cold-loving) fish like Atlantic salmon (Salmo salar), sea trout (Salmo trutta), grayling (Thymallus thymallus), and fourhorn sculpin (Triglopsis quadricornis lonnbergi). Heat-loving fish from the south, like Silurus glanis, rudd (Scardinius erythophthalmus), and zope (Ballerus ballerus), also inhabit the species-rich ecoregion.

With less than 40 species, Lake Onega’s ichthyofauna is less varied than LakeLadoga; Lake Onega lacks the Ponto-Caspian species found in the Ladoga ecoregion (asp [Aspius aspius], tench [Tinca tinca], belica [Leucaspius delineates], white-eye bream [Abramis sapa], vimba [Vimba vimba]).

Description of endemic fishes:

There are two strict endemic species in the ecoregion: Salvelinus lepechini and Valaam whitefish(Coregonus baerii).

Valaam whitefish (Coregonus baerii)—a unique form of endemic whitefish—displays declining numbers, but still claims the highest growth rate among Lake Ladoga’s whitefishes. This species inhabits Lake Ladoga’s southern region, typically near estuaries of the rivers Volkhov and Svir. Lake Ladoga’s western and southern tributaries—the Syas, Pasha, and Svir rivers—once served as spawning grounds for the species. The Volkhov River was dammed in 1926, preventing C. baerii’s historic migration up the river to Lake Ilmen and its tributaries—the Msta (most popular spawning area on the way to Lake Mstina), Lovat, Pola, and Shelon rivers. Today, C. baerii exclusively inhabits the lower reaches of the Volkhov River. Commercial fishing on Lake Ladoga—which exploits C. baerii along with other lake whitefishes—looms as a threat to the species’ survival.

Coregonus lutokka—a near-endemic (and purportedly abundant) lake whitefish that lives in stony areas—embarks on an upstream summer migration in search of zooplankton. During this summer feeding session, large numbers of C. lutokka mass along the western, southern and eastern coasts Lake Ladoga’s southern half. During winter, the fish tend to gather along the eastern and western coats of the lake’s northern half.

Coregonus ladogae is also considered endemic in Lake Lodoga, though some scientists include the fish as part of C. albula. This proposed species differs from C. albula in spawning area size and other specific coloration and morphological features.

Coregonus kiletz is believed to be endemic to Lake Onega. It’s described as a large relative of C. albula, though—like C. ladogae—further research is required to confirm its status as a separate subspecies. Another subspecies of the Coregonus genus (name unavailable, but vernacular name is Ladozhskiy lake whitefish) may be one additional endemic subspecies, but further research is needed.

Other noteworthy fishes:

Local fourhorn sculpin subspecies Triglopsis quadricornis onegensis (and one other possible unknown) appears to have marine origins, though these freshwater sculpins are smaller in size.  It’s known that the deep-dwelling fish maintain winter spawning patterns, though population sizes and other biological factors remain unclear.

Atlantic sturgeons have inhabited the Ladoga Lake basin since before the 19th century.  This local lacustrine form once travelled up the Volkhov River for spawning, but purportedly never reached the Baltic Sea.  Some authors say the Baltic and Ladoga sturgeon specimens are actually the American Acipenser oxyrinchus, yet extremely scarce (and possibly locally extinct) remaining sturgeons make this difficult to confirm or reject.

Other noteworthy aquatic biotic elements:

The lakes contain some relict crustacean species.

Evolutionary phenomena:

Ladoga and Onega lakes hold unique examples of speciation in large, deep, and cold northern lakes.  These postglacial lake species demonstrate remarkably fast rates of diversification and adaptation to ecological niches. Both lakes have at least two subspecies of C. albula.  Further genetic and morphological studies are required to explore the lakes’ true species diversity.

Justification for delineation:

Though, geographically, Ladoga and Onega lakes lie within the Neva drainage region (Baltic Sea basin), certain characteristics may warrant them a spot in a different ecoregion. Both lakes support several fishes and crustaceans that exist in large lakes of Sweden and North America.

As previously mentioned, the lakes are home to relict freshwater forms of the fourhorn sculpin—a species with marine origins. In general, the ecoregion supports unique fish fauna (which mostly share riverine ancestors of Atlantic-Baltic fish forms), whereas it completely lacks Siberian species and genera. Similar to the Barents Sea Drainages [407], this ecoregion formed postglacially and contains many forms of lacustrine whitefishes (Coregonus genus), making its reasons for delineation a bit more difficult to discern.

Level of taxonomic exploration:

Relatively good, but of the taxonomic status of local Coregonus subspecies requires further study.

References/sources:

Bogutskaya, N. G. (2001)"A revision of Altai osmans of the genus Oreoleuciscus (Cyprinidae: Leuciscinae) with a description of a new species, O. angusticephalus, from River Kobdo (Hovd) system, West Mongolia" In New contributions to freshwater fish research. ((Vol. 287, pp. 5-44) St. Petersburg: Proc. Zool. Inst. RAS.

Bogutskaya, N. G.,Naseka, A. M. (2004). "Catalogue of agnathans and fishes of fresh and brackish waters of Russia with comments on nomenclature and taxonomy" Moscow: KMK Scientific Press.

Feodorova, G. V. (1997). "Transformation of fish assemblages of Ladoga Lake under pollution and antropogenous eutrophication" Voprosy Ikhtiologii [J. Ichthyol.] 37(2) 272-275.

Ivanter, E. V.,Kuznetsov, O. L. (Ed.) (1995). "Red data book of Karelia" Petrozavodsk: Karelia.

Kitaev, S. P., Pervozvanskiy, V. Ya, et al. (2000)"Fishes" In Inventories and research of biological diversity in the terrtiory of Zaonezhskiy Peninsula and Northern Priladozh'ye [Ladoga Region]. (pp. 189-192) Petrozavodsk: Institute of Forest Karelian Scientific Centre of RAS.

Kotiranta, H., Uotila, P., et al. (Ed.) (1998). "Red data book of East" Helsinki: Fennoscandia.

Kuderskiy, L. A.,Pechnikov, A. S. (2002)"Dinamics of fish assemblage" In Rumyantsev, V.A.;Drabkova, V.G. (Ed.). Ladoga Lake: the past present, future. (pp. 224-237) St. Petersburg: Nauka.

Kvasov, D. D. (Ed.) (1990). "History of Ladoga, Onega, Pskovsko-Chudskoye, Baikal and Khanka lakes" Leningrad: Nauka.

Kvasov, D. D. (1975). "Late Quaternary history of large lakes and continental seas of eastern Europe" Leningrad: Nauka.

Podushka, S. B. (1999). "Finding of Atlantic sturgeon Acipenser sturio in Ladoga Lake" Scientific Bulletin of Laboratory of Ichthyology of INENKO RAS 1 5-10.

Pravdin, I. F. (1954). "Whitefishes of Karelo-Finskaya SSR" Mosow-Leningrad: Izdatel'stvo Academy of Sceince of USSR.

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