Laptev Sea large marine ecosystem

December 1, 2011, 11:23 am
Source: NOAA

 

caption Location of the Laptev Sea LME. (Source: NOAA)

 

The Laptev Sea Large Marine Ecosystem (LME) is a high-latitude marine region located in the Polar Circle in the eastern section of the Siberian shelf. It is topographically defined by the New Siberian Islands in the East, and the Northern Land islands in the West. The coastline of the Laptev Sea is indented by many islands, shallow bays, gulfs and inlets. The LME is characterized by extremely severe climatic conditions with major seasonal and annual changes. It is covered with ice for most of the year. The sea is mostly shallow, with a deeper northern section.

Productivity

The LME is uniquely sensitive to environmental change. Climate, e.g. temperature, is the primary force driving this LME. Climatic conditions have a major influence on the distribution, growth and recruitment of the LME’s fish species and other living marine resources. The LME is characterized by perennial ice cover over extensive regions, water exchange with the Arctic Ocean, and freshwater input from the Yana, Lena, Olenek, Anabar, Khatanga and Kotuy Rivers. Ice cover for a major portion of the year prevents light from penetrating deep into the water column and thus limits production for several months. Increased production occurs after the ice melts in the summer months. The Laptev Sea LME is considered a Class III, low productivity (<150 grams of Carbon per square meter per year (gC/m2-yr)) ecosystem based on SeaWiFS global primary productivity estimates.

Ecosystem diversity is unevenly distributed. For a map and productivity data on surface waters in this LME, see a map of salinity and temperature. The Laptev Sea has many valuable types of fish. The largest stocks are generally concentrated in sub-estuarial zones. The six major Siberian rivers bring millions of tons of nutrients into the Sea every year. The Transdrift IV (1996) expedition studied the Lena River’s influence on the Laptev Sea ecosystem. For more information on physical and biological systems in this region and their response to climate change, see the Arctic Climate Impact Assessment (ACIA).

Fish and Fisheries

Sea birds, seals, walruses, arctic foxes and polar bears make up the varied, rich fauna of this region, especially in the summer months when they can be found at the edge of the drift ice and on the shore. The Laptev Sea LME has many valuable types of fish. Target stocks are generally concentrated in sub-estuarial zones. For information on fisheries and the impacts of humans and their activities, see the Arctic Climate Impact Assessment. The University of British Columbia has detailed fish catch statistics for this LME.

Pollution and Ecosystem Health

This Arctic LME has a unique sensitivity to environmental change. Some hazardous contaminants (for instance oil, hydrocarbons, organochlorine compounds, heavy metals and radionuclides.) can be found in snow, ice, seawater, marine organisms and bottom sediments. The average concentrations of these contaminants appear, however, to be quite low. There is pollution in areas located near mineral resource extraction zones, adjacent to ports or in the vicinity of small coastal settlements. The Siberian rivers discharging into the Laptev Sea LME encompass industrial and agricultural regions within their watershed. In those industrial regions, the air, the water and the soil are polluted with harmful substances. Obsolete technologies and the lack of facilities for processing industrial waste are major ecological problems. Contaminants can be found in regions that are a part of the watershed of these rivers. Some of the rivers are reportedly polluted with PCBs, DDT, heavy metals, and viral contaminants. Pollutants can be transported by coastal currents along the continental shelf. Dissolved pollutants are carried even farther, as the river runoff flows across the central Arctic basin in the Transpolar Drift Stream. Other issues of ecosystem health are endangered marine species; the fragile marine ecosystem that is slow to recover from disruptions or damage; the thinning polar ice pack. For more information on radionuclides in the Laptev Sea LME, see Pavlov and Stanovoy, 1996. For more information on the environmental distribution of pollutants, on UV radiation and on climate change, see the Arctic Climate Impact Assessment (ACIA) web page.

Socioeconomics

Economic activity focuses on fisheries and the exploitation of natural resources (petroleum and natural gas). There are less oil and gas reserves in this LME than in the other Siberian LMEs. Vast coastal areas in this LME remain practically unaffected by human activity. There are relatively low densities of population in the coastal areas. Some parts of the coast are almost uninhabited. The few small settlements are separated by long distances. The anthropogenic impact of these populations is thus considered to be quite low. Since navigation is restricted by heavy ice in the winter, ships carry goods mostly in the summer. There are societal challenges faced by the indigenous peoples of the area.

Governance

This LME is situated on the Northern coast of Russia, where particularly severe climatic conditions and ice conditions increase the danger for shipping and pollution of the marine environment. Some governance issues needing to be addressed are: the fragility of this ecosystem; its endangered marine species; and the thinning polar ice pack. The Soviet era adopted special measures for the protection of the marine environment and the prevention of pollution in the Arctic areas adjacent to its Northern coast. These provided for special navigational rules on that coastline. Other issues are the question pertaining to the legal status of the Arctic areas. During Soviet times, the Laptev Sea was held to be internal waters. For ongoing bilateral science projects, see international science initiative in the Russian Arctic ( ISIRA ).

References

  • Cooper, L., Beasley, T., Dolvin, S., Grebmeier, J., Kelley, J., Scott, M. and Johnson-Pyrtle, A. 1998. The distribution of radiocesium and plutonium in sea ice-entrained Arctic sediments in relation to potential sources and sinks. J. Environmental Radioactivity 39(3): 279-303.
  • Dobrovol’skiy, A.d., Zalogin, B.S., 1982. Seas of the USSR - M. Moscow University, p. 192.
  • Gorshkov, S.G., 1980. World Ocean Atlas, Volume 3, Arctic Ocean.
  • Guieu C., Huang W.W., Martin J.M. and Yoon Y.Y., 1996, Outflow of trace metals into the Laptev Sea by the Lena River, Marine Chemistry, 53 : 255-267.
  • Johnson-Pyrtle, A. 1999. Distribution of Cs-137 in the Lena River Estuary-Laptev Sea System as Evidenced by Marine, Estuarine and Lacustrine Sediments. Ph.D. Dissertation, Texas A&M University, College Station, TX.
  • Kosobokova, K. N., H. Hanssen, H.-J. Hirche, and K. Knickmeier. 1998. Composition and distribution of zooplankton in the Laptev Sea and adjacent Nansen basin during summer 1993. Polar Biology, Vol. 19, 63-76.
  • Pavlov,V.K., and Stanovoy,V.V. 1996. About the Possible Reasons of Increased Concentrations of Radionuclides in the Laptev Sea. Terra Nostra, Heft 96/9, Third Workshop on Russian-German Cooperation: Laptev Sea System, AARI, October 16-19, 1996, p.84.
  • Pivovarov, S.V. and Smagin,V.M. 1994. Hydrochemical studies in the Laptev Sea in summer of 1993, Scientific Results of the expedition LAPEX-93, Gidrometeoizdat, S.Petersburg, 1994, p.210-221 (in Russian).
  • Thiede, J., L. Timokhov, H. A. Bauch, D. Bolshiyanov, I. Dmitrenko, H. Eicken, K. Fahl, A. Gukov, J. Hölemann, H. W. Hubberten, K. v. Juterzenka, H. Kassens, M. Melles, V. Petryashov, S. Pivovarov, S. Priamikov, V. Rachold, M. Schmid, C. Siegert, M. Spindler, and R. Stein. 1999. Dynamics and History of the Laptev Sea and its Continental Hinterland: A Summary. In: H. Kassens et al. (Eds.) Land-Ocean System in the Siberian Arctic: Dynamics and History. Springer-Verlag. Berlin, 695-711. ISBN: 3540656766.
  • Timokhov,L.A. and Churun,V.N. 1994. Cold bottom water in the southern Laptev Sea, Scientific Results of the expedition LAPEX-93. Gidrometeoizdat, S.Petersburg, p.83-90 (in Russian).
  • Vanda,Yu.A. and Yulin,A.V. 1994. Seasonal variability features of ice conditions of the Laptev Sea in 1993, Scientific Results of the expedition LAPEX-93. Gidrometeoizdat, S.Petersburg, p.148-157 (in Russian).

 

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(2011). Laptev Sea large marine ecosystem. Retrieved from http://www.eoearth.org/view/article/51cbee517896bb431f696f61

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