East Siberian Sea
The East Siberian Sea is a shallow, ice-filled marginal sea located in the Arctic Ocean, off the northern coast of Siberia. Bordered by the Chukchi Sea to the east and the Laptev Sea to the west, it is characterized by limited organic activity and is predominantly frozen for most of the year, making it navigable only during the summer months of August and September. The sea is relatively obscure and has been less studied compared to other parts of the Arctic, with its distinct name only established in 1935. Major rivers, including the Indigirka and Kolyma, flow into the East Siberian Sea, contributing nutrients that support seasonal marine life.
Climate change is dramatically affecting the region, resulting in significant reductions in sea ice cover, with 2020 marking the first year that the sea was not frozen in late October. This warming trend raises concerns about the future of Arctic ecosystems. Despite its harsh conditions, the East Siberian Sea supports some biodiversity, including populations of gray whales, polar bears, and various fish species. The region, while facing environmental challenges, remains a critical area of interest for understanding the impacts of climate change on Arctic marine ecosystems.
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East Siberian Sea
- Category: Marine and Oceanic Biomes.
- Geographic Location: Arctic Ocean.
- Summary: This shallow, foggy, ice-filled marginal sea in the Arctic Ocean is marked by little activity, either organic or tidal. Global warming is making dramatic changes in sea-ice cover here and is affecting the habitats of the planet's northernmost reaches.
A marginal sea of the Arctic Ocean, located off the northern coast of Siberia, the East Siberian Sea is bordered to the east and west by the Chukchi and Laptev Seas; it is noted for its numerous ice fields, most of which are fully melted for less than two months a year.
An obscure area in many respects, the East Siberian Sea has been less studied than much of the Arctic area, and commercial fishing has been little developed within it. The sea did not even receive a distinct name until 1935, when the government of the former Soviet Union gave the sea its present designation. Before that, the East Siberian Sea was variously called Kolymskoe, Sibirskoe, Ledovitoe, and other names, and sometimes went without specific designation on maps.
Because the shallow sea is frozen for most of the year, it is navigable only in August and September, limiting human presence. Even the coast is the site of several of Siberia's ghost towns, including the former trading post of Logashkino and the abandoned mining town of Valkumey.
Rivers flowing into the sea include the Indigirka, Alazeya, Ujandina, Chukochya, Kolyma, Rauchua, Chaun, and Pegtymel. There are two distinct hydrological zones in the sea: the west, which is influenced most strongly by the water of the Lena River (and marine- and terrestrial-derived sediments), and the east, influenced by Pacific Ocean waters. The main gulfs of the East Siberian Sea are in the south, with the north opening into the Arctic Ocean. It is home to few islands, many of which consist only of gradually eroding sand and ice.
Most of the remaining islands are grouped along the coastal limits, including the tundra island of Ayon off the coast of Chukotka, used by the Chukchi people to pasture herds of reindeer; the small adjacent islands Ryyanranot, Chengkuul, and Mosey; and the uninhabited Medvezhyi Islands in the west of the Kolyma Gulf. The Medvezhyis, the name of which means bears in Russian, are both covered by ice, the proximate sea generally staying frozen even in the summer. Though home to minor seasonal commercial fishing, the islands serve mainly as a breeding ground for polar bears.
Climate and Ice Cover
One reason the ice is so tenacious is because the sea is so shallow. Seventy percent of the area is less than 164 feet (50 meters) deep, and the deepest point is 509 feet (155 meters) deep. The summer air temperature averages just above freezing, 32 degrees F (0 degrees C), and in winter plummets to minus 20 degrees F (minus 29 degrees C). The ice cover prevents sunlight from penetrating far into the sea, and along with the seasonal change of the seawater salinity and chemical content due to the gradual freezing and thawing of the ice, this situation causes considerable complications for the ecosystem.
The entire phytoplankton life cycle takes place during the brief summer, lying dormant the rest of the year. Seasonal coastal erosion and river discharges provide key nutrients, especially in the Kolyma River, which contributes millions of tons (metric tons) to the sea every year.
Climate change appears to have increased the summer period in the East Siberian Sea. In 2007, the National Aeronautics and Space Administration (NASA) satellite imagery confirmed that as early as June 16, melting was well underway, and patches of ocean water had become visible surrounding small slabs of ice in the northeast. By the end of July, the area between the Siberian coast and the New Siberian Islands had become almost entirely ice-free, and throughout the sea, ice was sparse.
While sea-ice loss was detectable throughout the Arctic during summer 2007, the majority of it occurred in the East Siberian Sea—but even this event was just a prelude. The summer melting in 2012 exceeded anything previously seen in the record of Arctic satellite imagery, with the East Siberian Sea especially void of surface ice. In 2020, for the first time ever, the water in the East Siberian Sea was not frozen in late October. Scientists predict that this trend will continue throughout the Arctic into the future. They believe that the entire Arctic will be ice-free in the summer by 2040-2050.
The water in the sea is fairly clean by twenty-first century standards. While the snow and sediment can be found to contain hazardous contaminants, including heavy metals, radionuclides, and hydrocarbons, their concentrations are very low except in areas immediately surrounding mineral-resource extraction zones. The Siberian rivers contribute industrial and agricultural runoff, and coastal currents carry pollutants along the continental shelf, but the levels of these substances are low compared with other parts of the ocean.
Biodiversity
The sea is home to a limited number of gray whales in the summer months, populations of which may migrate between the East Siberian Sea and the western Chukchi Sea, wherever conditions are most favorable and ice conditions permit movement. Gray whales have been spotted in the early fall, before ice coverage is complete. Some scientists have speculated that the whales may be reoccupying habitats that had been abandoned after commercial whaling decimated the whale population.
Other fauna living on the coast and the drift ice include Pacific walruses, polar bears, Arctic foxes, seals, and seabirds. Prominent fish include salmon, pollock, halibut, and crab, mainly in the subestuary zones.
Bibliography
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International Hydrographic Organization. Limits of Oceans and Seas, Special Publication, Vol. 28. Monte Carlo: International Hydrographic Organization, 1953.
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Murdok, Ryan. “Climate Change and Siberia: No Time for Climate Inaction.” Harvard International Review, 28 Jan. 2022, hir.harvard.edu/climate-change-and-siberia-no-time-for-continued-climate-inaction/. Accessed 27 Nov. 2024.
Robinson, Allan R. and Kenneth H. Brink. The Global Coastal Ocean: Regional Studies and Syntheses. Cambridge, MA: Harvard University Press, 2005.