Laptev Sea ecosystem
The Laptev Sea is a marginal sea of the Arctic Ocean, situated between the northern coast of Siberia and neighboring seas, including the Kara Sea to the west and the East Siberian Sea to the east. This frigid environment is predominantly frozen for most of the year, creating challenges for flora, fauna, and human habitation. One of the most significant rivers flowing into the Laptev is the Lena River, contributing both freshwater and nutrients that shape the ecosystem, including a diatom flora with a notable proportion of freshwater species. The sea’s shallow continental shelf, with average depths around 164 feet (50 meters), contrasts sharply with deeper areas reaching nearly 0.6 miles (1 kilometer) in the north.
Biodiversity in the Laptev Sea is limited, with few fish populations due to ice cover and low sunlight availability, although some new species, like halibut, have recently been observed. Historically, the region has been inhabited by indigenous groups such as the Yukaghirs, Evens, and Evenki, who have relied on fishing and reindeer herding. While pollution levels are currently low, primarily from chemical spills and river runoff, there are concerns about potential impacts from increased human activity due to climate change. Navigational routes and mining represent the area’s primary commercial activities, but the harsh winter conditions restrict extensive fishing and industrial development. Understanding the Laptev Sea ecosystem is becoming increasingly important in the context of global environmental changes.
On this Page
Subject Terms
Laptev Sea Ecosystem
Category: Marine and Oceanic Biomes.
Geographic Location: Arctic Ocean.
Summary: A mostly frozen sea north of Siberia, the Laptev is considered to be a high-productivity ecosystem despite the seasonally limited availability of sunlight and nutrients.
A marginal sea of the Arctic Ocean, the Laptev Sea lies between the Arctic Ocean and the northern coast of Siberia, with the Kara Sea to its west and the East Siberian Sea to its east. Like those seas, it is frozen for most of the year, leading to limited populations of flora, fauna, and humans.
The Lena River, which begins in the Baikal Mountains and is one of the longest rivers in the world, is the largest river flowing into the Laptev. The craggy shores are full of gulfs and bays, and the coast becomes mountainous in places. Half the sea is shallow, resting on the continental shelf, which keeps average depths around 164 feet (50 meters). In the north, the sea bottom drops suddenly, and almost a quarter of the sea has a depth of 0.6 mile (1 kilometer). The large freshwater inputs of the Lena and other rivers have significant effects on the ecosystem: About 60 percent of the diatom flora consists of freshwater species transported here from Siberian lakes.
Because of its proximity to the North Pole, polar night on the Laptev lasts three months in the south and five months in the north The sun disappears entirely for the winter. The midnight sun of summer is as lengthy. As elsewhere in the Arctic region, this affects the life cycles and available sunlight for what local life there is. Even in the warmest months, temperatures are only slightly above 32 degrees F (0 degrees C), except on the coasts. Winter’s coldest months drop to minus 29 degrees F (minus 34 degrees C).
The Laptev contributes more sea ice than the Barents, Kara, Chukchi, and East Siberian seas combined, with the outflow of ice varying considerably—from 96,912 square miles (251,000 square kilometers) in 1985 to 282,627 square miles (732,000 square kilometers) in 1989, for example. Ice formation begins in October in the coastal south, and September in the Arctic north, creating a continuous sheet of ice covering about 30 percent of the sea.
Biodiversity
Fish populations in the Laptev are scanty because of the ice and the poor availability of sunlight. The lack of commercial fishing in the area diminishes the body of available data, but most of the pelagic fish in the region are whitefish species of genus Coregonus. In the 2010s researchers discovered the presence of fish not previously seen in the Laptev, including halibut.
Pollution in the sea is slight and results principally from chemical spills in coastal areas. River runoff contributes some industrial pollution because of the lack of local facilities in the coastal settlements for processing waste, but because the human population and industrial activity are so sparse in the first place, this is not a problem of nearly the same magnitude that it would be in a more urban or industrialized area. It could become a serious concern should the Siberian coast become more populous in the future.
Human Impact
The Laptev shores were inhabited for millennia by the indigenous Yukaghirs, Evens, and Evenki, who herded reindeer and fished the frigid waters. It was previously known as the Tatar Sea, the Lena Sea, the Siberian Sea (from whence the East Siberian Sea was disambiguated), the Icy Sea, and the Nordenskjold Sea. Mammoth remains are well preserved on many of the sea’s islands, and may have been hunted by the Yukaghirs’s prehistoric ancestors. Russian explorations began in the 17th century along rivers like the Lena, Anabar, Olenyok, and Khatanga that empty into the Laptev Sea.
There is little commercial activity in the area other than navigation along the Northern Sea Route, which passes through, and mining on the shore. The lengthy winter prevents the feasibility of commercial fishing. Ice typically melts only in August and September in this remote part of the world. Global climate change is expected to increase redistribution of mercury found in rivers in Siberia to the Arctic Ocean and research was being conducted to examine the degree of contamination in the sediment of the Laptev Sea.
Bibliography
Alexandrov, Vitaly Y., Thomas Martin, Josef Kolatschek, Hajo Eiken, Martin Kreyscher and Alexandr P. Makshtas. “Sea Ice Circulation in the Laptev Sea and Ice Export to the Arctic Ocean: Results from Satellite Remote Sensing and Numerical Modeling.” Journal of Geophysical Research 105, no. C7 (July 2000).
International Hydrographic Organization. Limits of Oceans and Seas, Special Publication No. 28. Monte Carlo: International Hydrographic Organization, 1953.
Kassens, H., H. A. Bauch, and Heidemarie Kassens, eds. Land-Ocean Systems in the Siberian Arctic: Dynamics and History. New York: Springer-Verlag, 1999.
Liem-Nguyen, Van, et al. "Spatial Patterns and Distributional Controls of Total and Methylated Mercury Off the Lena River in the Laptev Sea Sediments." Marine Chemistry, vol. 238, 2022. DOI: 10.1016/j.marchem.2021.104052. Accessed 24 Aug. 2022.
Staalesen, Atle. "Marine Researchers Find a Dramatic Ecosystem Shift in Russian Arctic Waters." The Barents Observer, 26 Nov. 2019, thebarentsobserver.com/en/ecology/2019/11/marine-researchers-find-dramatic-ecosystem-shift-russian-arctic-waters. Accessed 24 Aug. 2022.