Lake Baikal ecology
Lake Baikal, located in southeast Siberia, Russia, is recognized as the world's oldest and deepest freshwater lake, with an estimated age of 25 million years and a depth of 1,700 meters (5,580 feet). It holds approximately one-fifth of the Earth's unfrozen freshwater, making it a critical resource for biodiversity. The lake is home to a unique ecological system, with over 1,500 species of plants and animals, two-thirds of which are endemic, meaning they are found nowhere else on Earth. Notable species include the Baikal sturgeon and the tiny epischura, which plays a vital role in maintaining the lake's water clarity. The surrounding region features diverse habitats, including coniferous and deciduous forests, supporting a rich array of wildlife, including various mammals and over 200 bird species.
Despite its ecological importance and UNESCO World Heritage designation, Lake Baikal faces significant threats from industrial pollution, particularly from the Baikalsk Pulp and Paper Mill, which has been a source of environmental concern since its establishment. The mill has discharged large quantities of wastewater into the lake, prompting ongoing debates about its environmental impact. Efforts to protect Lake Baikal continue amid challenges posed by industrial development, climate change, and the need for effective conservation strategies. The lake also offers valuable insights into historical climate variations through sediment core sampling, contributing to our understanding of ecological and geological history.
Lake Baikal ecology
- Category: Inland Aquatic Biomes.
- Geographic Location: Southeast Siberia, Russian Federation.
- Summary: Lake Baikal is a UNESCO World Heritage Site in Siberia that is among the world's oldest, largest, and deepest freshwater lakes; it is home to many unique species, but under threat from anthropogenic pollution.
At 25 million years old and 5,580 feet (1,700 meters) deep, Lake Baikal is the world's oldest and largest freshwater lake. With a volume of 5,500 cubic miles (23,000 cubic kilometers), this isolated lake in southeast Siberia is estimated to contain one-fifth of the world's unfrozen freshwater, making it the largest single-liquid freshwater reservoir. Its isolation and age give Lake Baikal and the surrounding shores a unique ecology with tremendous biodiversity and unique freshwater species. Lake Baikal is designated as a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site. Despite its unique environmental qualities and irreplaceable value, the lake is at risk from industrial pollution.
The lake is situated in southeastern Siberia near the Mongolian border, along a continental rift valley. The surrounding terrain is mountainous; some 300 streams and rivers flow into the lake, including these major rivers: the Selenga, the Barguzin, and the Upper Angara.
Drainage is into the Angara, a tributary of the Yenisei, which ultimately flows into the Arctic Ocean. Lake Baikal is approximately 396 miles (640 kilometers) long and 49 miles (80 kilometers) wide. It is considered the deepest lake in the world; in most places, the shoreline plunges deeply into the lake, and there are very few coastal plain areas or islands—a striking exception being the 45-mile-long (72-kilometer-long) Olkhon Island. Thermal vents found deep in the lake produce heated, oxygenated water that helps Lake Baikal circulate oxygen more thoroughly than many other deep lakes.
Mosaic of Endemic Species
Many endemic (evolved specifically to a biome and not found elsewhere) species of plants and animals are found in Lake Baikal. Of more than 1,500 plant and animal species living in the lake and its environs, as many as two-thirds are thought to be endemic. From phytoplankton, diatoms, and protozoa to bacterial mats, sponges, worms, shrimp, fish, seals, chipmunks, moose, elk, and bears, the lake area teems with a rich mosaic of biodiversity.
Baikal sturgeon (Acipenser baerii baicalensis) is one of the endangered species endemic to the lake. The Baikal sturgeon preys upon mollusks—there are more than 100 species here—as well as sponges, which live at depths up to 3,280 feet (1,000 meters).
The transparent, tiny, shrimplike epischura (Epischura baikalensis) enjoys the dominant position among all zooplankton in the lake; its feeding upon microscopic life and algae helps filter and purify the lake's water. Much of the cold-water bacteria in the lake also helps break down organic matter and decomposing entities. This filtering action accounts for the extreme clarity of Baikal waters.
Among and across the rugged mountains that surround Lake Baikal, a rich biota inhabits the areas of light coniferous forests, pine forests, and deciduous forests. Characteristic plants include Siberian fir (Abies sibirica), alpine bearberry (Arctostaphylos alpina), dwarf birch (Betula divaricata), and Siberian larch (Larix sibirica), as well as mountain pine, aspen, and Adam's rhododendron (Rhododendron Adamsii).
Signature mammal species include European roe deer (Capreolus capreolus), red deer (Cervus elaphus), wolverine (Gulo gulo), Siberian chipmunk (Tamias sibiricus), brown bear (Ursus arctos). Eurasian lynx (Lynx lynx), and sable (Martes zibellina). Over two hundred species of birds are found around the lake region. Among the avian notables are black stork (Ciconia nigra), red grouse (Lagopus lagopus), spotted nutcracker (Nucifraga caryocatactes), grey partridge (Perdix perdix), and the peregrine falcon (Falco peregrinus).
Protection and Threats
Lake Baikal's UNESCO World Heritage Site designation came in 1996 due to its valuable and unique natural qualities according to four UNESCO criteria: (1) The lake is an exceptional natural phenomenon with aesthetic value for its natural beauty, (2) the age of the lake places it as a valuable example of Earth's history, (3) the isolation and biodiversity of the lake make it an example of significant ecological and biological processes in the evolution of ecosystems and plant and animal life, and (4) Lake Baikal and the surrounding area also contain important and significant natural habitats needed for conservation of biodiversity, including threatened species. In 2010, the organization considered removing Lake Baikal from the World Heritage list because of concerns about the adverse environmental effects of industrial pollution tied to a pulp and paper mill. As of 2024, the organization still had serious concerns about the pollution, large-scale tourism development, and poor sewage treatment. However, Lake Baikal was not yet removed from the World Heritage list.
The most significant threat to the health of Lake Baikal is industrial development, including two pulp mills, as well as logging and a hydroelectric dam. One contentious source of pollution has long been the Baikalsk Pulp and Paper Mill on the lake's southwestern tip. The mill has been under continued pressure from Russian ecologists and environmental activists to close operations since its opening in 1966. Ecologists have argued that the plant pollutes Lake Baikal through its discharge of wastewater into the lake; mill operators argue that the wastewater is adequately treated before discharge and poses no harm. The mill discharges around 50,000 tons of wastewater into the lake each year.
Biologist and ecologist Marina Rikhvanova received a Goldman Environmental Prize in 2008 for her efforts to preserve Lake Baikal from such threats. Her research showed that the water near the mill is polluted, resulting in decreasing populations of crustaceans, genetic mutations, and disoriented fish unable to find food or spawning grounds. Among the mill's wastes are dioxins, extremely toxic and known to affect hormones and weaken immune systems. The people and animals who eat fish with dioxin contamination can suffer from ill health effects. The plant was closed in 2008 due to environmental contamination concerns, and had gone bankrupt, but was allowed to reopen in 2010 with permission from Russian Prime Minister Vladimir Putin and with the Russian government owning 49 percent of the company. By summer 2021, the mill was shuttered, but environmentalists still considered it a hazard because its reservoirs were filled with 6.5 million tons of lignin sludge. This is waste from pulp and paper production. Officials in Moscow planned to dispose of it correctly by 2024, however, they have not yet done so. Instead, Russia dismantled some of its environmental standards, worrying environmentalists that the hazard may be discarded into the lake.
Lake Baikal is unique in another way, related to global climate change. Sampling of sediment cores has the potential to provide a detailed historical record of climate variation. Most long-term historical climate data is taken from oceanic marine environments; there is little comparable data available from continental interiors. Core sampling from Lake Baikal can provide such data. Scientists can use that core sampling to provide climatic, environmental, and geological history reaching back millions of years.
Bibliography
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