Yenisei River

Category: Inland Aquatic Biomes.

Geographic Location: Asia.

Summary: Supporting rich fish communities amid its taiga and tundra environment, the Yenisei is threatened by industrialization and development.

As the largest river system flowing into the Arctic Ocean, the Yenisei River drains a large part of Asia and is considered to be one of the three great Siberian rivers. The Yenisei River ecosystem provides a rich habitat for a variety of flora and fauna.

As with many large rivers, however, the Yenisei has been heavily dammed so that a system of hydroelectric generating stations could be installed for human needs. This has affected the Yenisei River ecosystem and the species that rely on habitats throughout its watershed. Climate change effects in Siberia and the Arctic region, especially the thawing of permafrost lands here, are of mounting concern to many and portend further disruption of the river environment.

With a length of more than 3,400 miles (5,472 kilometers), the Yenisei is the world’s fifth-largest river, exceeded only by the Nile, Amazon, Yangtze, and Mississippi. The Yenisei River’s maximum depth is 80 feet (262 meters), and it has an average depth of 45 feet (148 meters). With more than 97 percent of its drainage basin located within Russia, the Yenisei also includes some areas of Mongolia in its drainage area.

The Yenisei River is fed by many tributaries, chief among them the Angara and Selenge Rivers. The Yenisei empties into the Kara Sea in the Arctic, which is icebound for more than half the year. Much of the river runs through sparsely populated areas, usually featuring taiga, also known as boreal forest. Taiga is the world’s largest land biome and represents almost 30 percent of the planet’s forest cover. After permanent ice caps and tundra biomes, taiga represents the ecosystem with the next lowest average temperatures, although during the depths of winter, taiga can be colder on a regular basis than tundra regions.

The short summer in the taiga ecosystem lasts one to three months on average, and winter extends five to seven months. Temperatures across the Siberian taiga vary greatly, from minus 65 to 86 degrees F (minus 54 to 30 degrees C). The Yenisei River watershed is not particularly moist; it experiences average annual precipitation of 7–30 inches (178–762 millimeters).

Soil supporting the taiga tends to be poor in nutrients. Lacking the deep, organically enriched supplements provided by temperate deciduous forests, taiga soil is relatively thin and young. Cool temperatures discourage the contribution of fallen leaves to the soil, and evergreen needles make the soil acidic.

Flora and Fauna

Taiga forests are largely coniferous and are dominated by fir, larch, pine, and spruce. The southern parts of the taiga have some small-leaved deciduous trees, including alder, birch, poplar, and willow, although in the Yenisei River ecosystem, the most common species of tree is the larch, which can thrive in extremely low temperatures. Coniferous trees do better in this climate because the low sun in the region inhibits photosynthesis for much of the year, and evergreens are able to photosynthesize even in very low temperatures.

A large variety of wildlife thrives in the Yenisei River ecosystem, including many species that are endemic, or found only in this region, such as the Siberian thrush.

The region is especially varied in fish, with the ecosystem supporting more than 55 species in 14 families. Despite the huge geographic area covered by the Yenisei River, the distributional pattern of species is relatively the same along the river and among its tributaries. The fish found in the region can be categorized into four main ecological groups.

The first of these four groups includes cold-loving species that originated in the Arctic but now mostly inhabit lower reaches and adjacent sea areas; they tend to be anadromous. This group includes such fish as the Arctic cisco (Coregonus autumnalis), charr (Salvelinus alpinus), migratory tugun (C. tugun), muksun (C. muksun), inconnu (Stenodus leucichthys), peled (C. peled), and round whitefish (Prosopium cylindraceum).

The second group represents boreal river species, both resident and migratory, some anadromous, including the common dace (Leuciscus leuciscus baikalensis), European perch (Perca fluviatilis), ide (Leuciscus idus), lake minnow (Phoxinus percnurus), northern pike (Esox lucius), Prussian carp (Carassius gibelio), roach (Rutilus rutilus lacustris), Siberian sculpin (Cottus sibiricus), and Siberian sturgeon (Acipenser baerii).

The third group consists of a piedmont complex, such as Arctic grayling (Thymallus arcticus), East Siberian grayling (T. palasii), Eurasian minnow (Phoxinus phoxinus), lenok (Brachymystax lenok), and taimen (Hucho taimen).

The final group is comprised of originally marine species that have entered the lower reaches of the river, such as Arctic flounder (Liopsetta glacialis), Atlantic rainbow smelt (Osmerus mordax), fourhorn sculpin (Triglopsis quadricornis), and sardine cisco (Coregonus sardinella).

Lake Baikal, sometimes referred to as the Jewel of Siberia, is listed as a World Heritage Site by the United Nations Educational, Scientific, and Cultural Organization (UNESCO). The deepest and oldest lake in the world, Lake Baikal drains into the Angara tributary of the Yenisei River. The lake has a rich and diverse number of species, including more than two thousand species of plants and animals, approximately 65 percent of which are endemic. These include the Baikal seal (Pusa siberica), also known as the nerpa, and the Baikal omul (Coregonus migratorius), a whitefish species of the salmon family. The richness of the Baikal system helps ensure that the Yenisei watershed retains the capacity to recover and regenerate species diversity following harsh climatic intervals.

Environmental Threats

For much of its history, the Yenisei River ecosystem was sparsely populated, save for intermittent visits by the nomadic indigenous peoples who lived throughout the central-southern area of Siberia near the river’s banks. During the Soviet era, a tremendous amount of work was done, sometimes by gulag labor, to develop a series of dams in the middle section of the Yenisei River. These dams provide a tremendous amount of hydroelectric power—but also have produced industrial contamination, vast erosion and inundation, and other threats to the area’s ecosystem.

Conservation efforts in the region seek to protect it from industrial pollution and other threats. Lake Baikal was home to the Baikalsk Pulp and Paper Mill (BPPM), which opened in 1966 and spent almost five decades producing toxic particulates settled into the forests and grasslands that drain into the Yenisei system. Water tainted by the plant threatened the upper reaches of the watershed. The plant was eventually shut down in 2013, but the Russian government and the people in the surrounding area continue to deal with the cleanup into the 2020s.

During the 1990s, the Russian national pipeline company Transneft announced plans to build the East Siberia-Pacific Ocean Oil Pipeline within 1 mile (1.6 kilometers) of Lake Baikal. This announcement caused a great deal of protest from environmental groups, which feared a pipeline spill would endanger the sensitive ecosystem in the area. After negotiation with the Russian government, resulting in an edict from president Vladimir Putin to move the pipeline at least 25 miles (40 kilometers) north of Lake Baikal, Transneft agreed to alter the proposed route for its construction. The pipeline became fully operational in 2012.

In 2006, the Russian government made public its plans to build an International Uranium Enrichment Center at an existing nuclear facility in Angarsk, less than 60 miles (97 kilometers) from Lake Baikal, and to store in the region radioactive and other toxic materials generated as part of the process. Although this announcement caused outcry from many quarters, by 2011, the center was operational.

Environmental threats to the Yenisei River ecosystem are not new, and they are not likely to disappear. Because Siberia is in need of economic development, there is some hesitation on the part of Russian authorities to pursue policies that fully protect the Yenisei River ecosystem, despite the great benefits that the region presents to scientists, future generations, and, of course, the natural inhabitants.

Bibliography

Goebel, Ted and I. Buvit. From the Yenisei to the Yukon: Interpreting Lithic Assemblage Variability in Late Pleistocene/Early Holocene Beringia. College Station: Texas A&M Press, 2011.

"International Uranium Enrichment Centre." International Atomic Energy Agency, 2022, www.iaea.org/topics/international-uranium-enrichment-centre. Accessed 8 Aug. 2022.

McCully, Patrick. Silenced Rivers: The Ecology and Politics of Large Dams. New York: Zed Books, 2001.

"What Can Be Done With the Legacy of the Baikalsk Pulp and Paper Mill?" Key to Baikal, 27 Sept. 2019, 1baikal.ru/en/ekologiya/what-can-be-done-with-the-legacy-of-the-baikalsk-pulp-and-paper-mill. Accessed 8 Aug. 2022.

Woods Hole Research Center. “Investigating the Changing Arctic.” http://www.whrc.org/global/arctic‗system/index.html.