Lena River Delta

/ ©: WWF-Canon / Peter PROKOSCH
Polygone pond, Lena delta from ground Jakutia, Russia.
© WWF-Canon / Peter PROKOSCH

About the Area

Siberia's Lena River is one of the longest rivers in the world. It rises west of Lake Baikal - a small mountain lake in southern Russia - and eventually flows north for 4,400km (2,800 miles) before emptying into the Laptev Sea, an arm of the Arctic Ocean. At its mouth into the Laptev Sea in northern Siberia, the river forms a huge delta of 32,000 sq km, which is the largest Arctic delta and the most extensive protected wilderness area in Russia.

The Lena River and delta are host to many nature reserves, including the Lena Pillars, Beloozersky, Belyanka, Muna, Ust-Viluisky, Lena Delta Nature Reserve, and Ust-Lensky nature reserve. There is also an International Biology Station - Lena-Nordenskiöld - on the Bykovskaya channel. The whole of the Lena Delta area has been nominated as a UNESCO World Heritage Site.

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Size:
30,000 sq. km (12,000 sq. miles)

Habitat type:
Large River Deltas

Geographic Location:
Northern Asia: northeastern Russia

Conservation Status:
Relatively Stable/Intact
Local Species
The wet tundra in the delta, which floods each spring, is an important area for nesting and migrating birds, and also supports a rich fish population. There are 92 planktonic species, 57 benthic species, and 38 species of fish in the river. Sturgeon, burbot, chum salmon, Coregonus autumnalis (cisco), Stenodus leucychthis (nelma), and C. albula are the most commercially important fish.

This arctic ecoregion experiences 7 months of winter before the snow-covered tundra transforms into fertile wetlands. Swans, divers, geese, ducks, plovers, sandpipers, snipes, phalaropes, terns, skuas, birds of prey, passerines and gulls are just some of the migratory birds that breed in the productive wetland that also supports abundant populations of fish and 5 marine mammals.

Some scientists think that fish of the genus Coregonus, called ciscos, originated here. Spawning fish reported from the delta include the Arctic lamprey (Lethenteron japonicum), burbot (Lota lota), and Arctic cisco (Coregonus autumnalis). Several species of ciscos (Coregonus spp.) are also found in the delta, including C. tugun, C. sardinella, C. peled, C. muskun, and C. nasus.

A few of the many birds that visit or breed in the delta are black brant (Branta bernicla), common and Steller's eiders (Somateria mollissima and Polysticta stelleri), Sabine's and Ross's gulls (Xema sabini and Rhodostethia rosea), and peregrine falcon (Falco peregrinus).

Featured species

Arctic lamprey (Lethenteron japonicum)

The Arctic lamprey is an eel like fish, characterized by a jawless mouth with 2 large teeth on the tongue. Average length is 13-16cm. The dorsal fins arise far back on body, the anterior dorsal lower than the posterior, the fins higher in males. The lower lobe of caudal fin is somewhat larger than upper, the fin joined to both dorsal and anal fins. The anal fin is small, in males represented only by a low ridge. Colour ranges from brown to olive to grayish above, paler below.

Its life cycle consists of a lengthy larval stage followed by metamorphosis in which the lamprey develops eyes and teeth. It then migrates to sea to feed by attaching parasitically to various species of fish. The Arctic lamprey prefers sites with stony or sandy bottoms, shaded by riparian vegetation. It feeds on small aquatic invertebrates, algae and organic matter contained in detritus.

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Threats
The Lena Delta Reserve was expanded in 1995, making it the largest protected area in Russia (61,000km2). However, overfishing, particularly of cisco populations is a concern. Outside of the reserve, mining, forestry, grazing, expanding agricultural activities, water diversion for irrigation, and pollution from fertilizers and pesticides may threaten the water quality and quantity that reaches the delta.
WWF’s work
Freshwater ecosystems are important components of WWF's work on protected areas in the Arctic. WWF is working to strengthen the Circumarctic Protected Areas Network (CPAN) initiative under the Arctic Council by, among other things, including freshwater issues.

WWF works to protect the Lena Delta for the benefit of science and local communities, and to ensure survival of many unique birds and other species.

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