Boundaries

This ecoregion includes river drainages and lakes of the White Sea, Barents Sea, and the western part of the Kara [Karskoye] Sea from the Kola Peninsula (including lakes Iesjav’ri and Inarijarvi in Norway and Finland) in the northwest to the Kara River in the east. The ecoregion also includes the islands of Svalbard, Vaigach [Vaygach], Kolguyev, Novaya Zemlya, and Franz Josef Land archepelago. The eastern border runs along the main ridge of the Ural Mountains [Ural’skiye Gory] south to about 62º N latitude. The southeastern part of the ecoregion includes the headwaters up to the Severnyye Uvaly Hills (bordering ecoregion 410). In the southwest, the ecoregion includes headwaters of the Kubena and Sukhona rivers (with lakes Lacha, Vozhe, and Kubenskoye) that are tributaries to the Severnaya [Northern] Dvina River. Further north, the ecoregion wraps around the Onega Lake basin and Mansel’kya Uplands in east Laplandiya.

Topography

The Northern [Severnaya] Dvina River is 744 km long, and has the largest drainage area (357,000 km²) in northern Russia in Europe. It is formed from the confluence of the Sukhona and Yuga rivers, originating in the Vologda Region. It then flows through the Komi Republic and Arkhagelsk Region, and drains into Dvina Bay of the White Sea. The upper portion of the river is called the Malaya Severnaya Dvina, whereas the lower portion is called the Bolshaya Severnaya Dvina. The Northern Dvina has relatively short slopes and a wide valley, with the width of its floodplain more than 10 km. Only around the Vaga and Pinega rivers does the character of the valley and river channel change somewhat; high steep banks composed of limestone approach the outflow, and the floodplain disappears completely in some areas. At its mouth, the Northern Dvina forms a large delta with numerous branches over an area of approximately 900 km². The delta formed under conditions of pronounced tidal currents, which can travel 90 km upstream to the outflow of the Pinega. Only for a short time in spring a pronounced current toward the sea is established.

The Pechora River, 1809 km long, is the largest river by volume, and the second largest in catchment area (322,000 km²) in northern Russia. It originates on the slopes of the Northern Urals at an altitude of 677 m above sea level, and flows into Pechora Bay in the Barents Sea. From its riverhead up to the confluence with its largest tributary, Usa, the Pechora travels through mountainous terrain with  large slopes, stony river channels with rapids, and a narrow valley. Downstream from the confluence with the Usa River, the Pechora River becomes deep and flows through a plain several kilometers wide, with channels that split into branches. Where the outflow reaches Pechora Bay, the river forms a delta divided by many islands and anabranches.

The Kara River, 287 km in length, originates on the western slopes of the Polar Urals and flows into Baidaratskaya Bay in the Kara Sea. The middle and lower reaches of the Kara River cut through the Pai Khoi Range, which is separated from the northern ranges of the Ural Mountains by a low, swampy tundra.

The glacier that covered the entire territory of the Kola Peninsula in the Quaternary Period played an important role in the formation of the modern landscape of the western part of the ecoregion. The peninsula is covered by numerous lakes and swamps alternating with hills and forests. Khibin tundras are separated by deep depressions of tectonic origin occupied by Lake Imandra (west) and Lake Umbozera (east). Lake Imandra’s area exceeds 13,000 km², its length is 109 km, and width ranges from 9 to 19 km.

Freshwater habitats

Along the northern border, the ecoregion includes coastal waters, shallows, bays, and brackish or freshwater estuaries (main foraging areas for migratory – anadromous and semi-anadromous – fishes). The cold climate ensures that rivers are covered by solid ice for over 5-7 months of the year.  During floods, when ice is absent, river water levels can rise significantly. From the second half of the summer until winter, the catchment’s rivers are fed only by scanty subsoil waters below permafrost. Swampy rivers cross the area’s lowlands and form a complex system of reaches and lakes connected by fast-moving anabranches. Many of the rivers running through the swampy lowlands (particularly in the Kola Peninsula) have sources in the mountains. The ecoregion’s rivers are often described as “dirty” and “very polluted.”

Terrestrial habitats

The ecoregion’s numerous lakes are surrounded by extensive swamps, meadows, and low rolling plains.  The area also contains many bays, often called “lakhtas.” The lakes are relicts of the past—they inhabit depressions that were previously occupied by glaciers.

Description of endemic fishes

Some scientists believe a small whitefish, currently referred to as Coregonus nelmushka, deserves its own species status. It’s thought to be endemic to Lake Kubenskoye , a refuge on the periphery of a glacier, and appears isolated from other populations of Coregonus in the ecoregion. Due to human encroachment, overfishing, and effects of climate change, this population is considered highly endangered.

Other noteworthy fishes

There is speculation that the group of fish referred to as “Paliya” (Salvelinus lepechini, S. alpinus lepechini , or a lake form of S. alpinus by different authors) may not stem from a single evolutionary origin, but rather a few convergent forms of an ancestor to the local migratory char.  This deepwater lake fish has a larger head and darker color than local chars, and only journeys near shallow, rocky banks for spawning.

Though further research is needed, it is believed that there are over 15 subspecies of lacustrine whitefishes in the Kola Peninsula region.

Ecological phenomena

Migratory species form the core of the ecoregion’s fish fauna.  After spawning in rivers, these migratory species journey downstream to deltas and adjacent sea shallows for foraging during winter months or periods between spawning events.

Spawning patterns in different rivers and tributaries are clearly defined for separate populations; migratory routes (both before and after spawning) differ in length and rate of travel. 

Justification for delineation

The ecoregion encompasses river and lake drainages from the White Sea, Barents Sea, and the western part of the Kara Sea. Brackish or freshened coastal waters, shallows, bays, and river estuaries are main foraging areas for migratory—both anadromous and semi-anadromous—fish. In a geological sense, the ecoregion is relatively young, with hydrographic systems formed after glaciers vanished from the landscape.  The landscape is punctuated by several postglacial lakes of varying size. The fish fauna is formed from immigrants of Atlantic and Siberian origins with only a weak assemblage of primary freshwater European species; thus, a "mixed" nature of the fish fauna is its main distinguishing feature. Few of the ecoregion’s fish populations share origins with freshwater European species; the majority of the area’s fish fauna come from mating events between Atlantic and Siberian migratory fish.

The ecoregion is home to many diverse trout populations from the genus Salmo (i.e.: S. salar, S. trutta).  Depending on the area, these fish are migratory marine trouts, migratory or non-migratory lacustrine trouts, or stream trouts.

Level of taxonomic exploration

Good