Ecologically or Biologically Significant Areas (EBSAs)
published: 12 Jun 2015
Great Siberian Polynya
The system of polynyas in the Laptev Sea and specific conditions of the waters of New Siberian Islands form an ecologically and biologically significant area with a high degree of naturalness, with limited shipping as the only human activity. Its most remarkable feature is the Laptev walrus. It was previously considered an endemic subspecies (Odobenus rosmarus laptevi), but the latest molecular genetic studies have failed to prove its isolation from the Pacific subspecies (O. rosmarus divergens) (Lindquist et al., 2008). However, the Laptev walrus is indeed a peculiar population differing from the neighbouring Pacific populations by the absence of long seasonal migrations and the location of wintering grounds. This area plays an important role in the recruitment of polar cod (Boreogadus saida), which is a key food item for most of the top predators in the High Arctic ecosystem. Laptev polynyas support a chain of colonies dominated by thick-billed murre (Uria lomvia) and black-legged kittiwake (Rissa tridactyla). These polynyas are used by birds, in particular, Steller’s eider, during the spring migration period (Solovieva, 1999; Gavrilo et al., 2011). The Laptev polynya network also sustains stable, high populations of seals, which in turn draw its main predator: the polar bear (Gavrilo et al., 2011).
Polynyas in the Russian Arctic have been recognized as extremely important for ecosystem processes and maintaining biodiversity (Spiridonov et al., 2011). The report on identifying Arctic marine areas of heightened ecological significance (AMSA IIc) identified the “Great Siberian Polynya” as an area that corresponds to most of the EBSA criteria (AMAP/CAFF/SDWG, 2013, fig. 7). The IUCN/NRDC Workshop to Identify Areas of Ecological and Biological Significance or Vulnerability in the Arctic Marine Environment also highlighted the importance of this area (Speer and Laughlin, 2011).
This area is located in the Laptev Sea and corresponds to the maximum extent of the polynyas developing in the middle shelf of the Laptev Sea between East Taymyr and the area north of New Siberian Islands (on the boundary with the East Siberian Sea). This area is located entirely within the EEZ of the Russian Federation.
DISCLAIMER: The designations employed and the presentation of material in this map do not imply the expression of any opinion whatsoever on the part of the Secretariat concerning the legal status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries.
The area occupies the central part of the Laptev Sea shelf. Near the Asian shore of the Laptev Sea, depth varies between 10 m and 40 m. Seabed topography of the Laptev Sea shelf is relatively smooth in contrast with western Arctic seas. It gently slopes to the north of the accumulative-denudation plain, which is disrupted by three trenches of approximately 40 m depth. On the shelf muddy sediments dominate that are substituted by sand around the River Lena delta (Nikiforov, 2006). Sediments largely determine the distribution of benthic communities and thus together with seabed topography can be regarded as an important driver that shapes composition and biomass of benthos (Pogrebov et al., 2002; Petryashov et al., 2004), which in turn are critical factors affecting walruses and semi-anadromous fish populations. The Laptev Sea is covered with ice for nearly nine months of the year, from October to June. Owing to the system of flaw polynyas the Laptev Sea plays a major role in production of drifting ice in the Arctic Ocean (Popov and Gavrilo, 2011). One of the remarkable features of the Laptev Sea shelf region is a constant, to a varying degree, stratification of the water column regardless of its shallow depth. In summer a warm intermediate layer is formed and can persist until the beginning of next summer. It can be observed under the colder and fresher water layer from the River Lena discharge. Around polynyas, this intermediate layer is degraded and substituted by a different structure due to cooling and salinization during constant ice formation (Bauch et al., 2009). Polynyas are very dynamic (figure 2) but develop in particular areas with high regularity. At present, six flaw polynyas have been identified in the Laptev Sea (Zakharov, 1996; Popov and Gavrilo, 2011; Gavrilo et al., 2011). Mean monthly occurrence frequency of the Laptev polynyas is high over the entire cold period (57 to 100%). As a result, all these polynyas are classed as either recurring or stable depending on the month. In November the frequency of occurrence is generally lower than in other months, and all polynyas are considered stable. The Great Siberian Polynya developing in the south and east of the Laptev Sea occurs most frequently (not less than 65-70%). The Anabar-Lenskaya and the Western Novosibirskaya polynyas are least stable in early winter, while in February their frequency of occurrence reaches its maximum (96-100%). The western Novosibirskaya polynyas have a second maximum of occurrence in April. The appearance of the northern Novosibirkskaya polynyas is at its minimum in January and at its maximum in April-May (96%). Phytoplankton distribution values calculated by Vetrov et al. (2008) have shown significant seasonal fluctuations. In April-May there is an increase in primary productivity (up to 200-300 mg C day-1), which can be observed in areas where flowing polynyas can be found (Anabar-Lenskaya and Novosibirskaya polynyas) (figure 3).
The Laptev Sea is affected by a general trend towards decreasing of summer sea ice and average thickness of ice (Frolov et al., 2009; Gavrilo and Spiridonov, 2011; http://www.nasa.gov/content/goddard/arctic-sea-ice-minimum-in-2013-is-sixth-lowest-onrecord/#. Uvf3p4U1W5U), and increasing intrusion of the Atlantic water that even penetrates to the 20 m depth contour (Dmitrenko et al., 2010). However for developing scenarios of environmental changes in the region winter processes appear to be not less important. Flaw polynyas of the Laptev Sea and their spatial-temporal inter-annual variability are a product of the interaction of processes associated with three atmospheric centres: the Icelandic Minimum, the Arctic and the Siberian Maxima. Deepening of the Icelandic Minimum intensifies the Atlantic cyclones, which receive their energy from the Kara Sea polynyas, to cross the Taymyr Peninsula and form a wind system which facilitates the development of polynyas in the western Laptev Sea (Popov, Gavrilo, 2011; Gavrilo et al., 2011). Strengthening of the Arctic Maximum leads to the development of polynyas in the eastern Laptev Sea. Comparison of the characteristics of the Laptev Sea polynyas during the period 1936–1970 with the modern day indicates that the frequency of occurrence and the numbers of recurring polynyas in the last two decades have increased. In particular, the episodic (30–40%) Eastern Severozemelskaya (in May) and the Eastern Taymyrskaya polynyas (in April and May) have now become stable (Gavrilo et al., 2011). Trends in productivity changes throughout 2003–2007 were considered in the Kara, Laptev, and East Siberian seas using satellite and field data. According to the MODIS data, slight positive trends of average and total phytoplankton production were revealed in the Laptev Sea, i.e. 4.1 and 2.5% respectively in relations to the average values over the observation period. On the other hand total ice algae production has shown a slight decrease, and thus the resulting overall production remains almost unchanged (Vetrov and Romankevich, 2009; 2011).
AMAP/CAFF/SDWG, 2013. Identification of Arctic marine areas of heightened ecological and cultural significance: Arctic Marine Shipping Assessment (AMSA) IIc. Arctic Monitoring and Assessment Programme (AMAP), Oslo. 114 pp. Bauch D., Dmitrenko I., Kirillov S., Wegner S., Hölemann J., Pivovarov S., Timokhov L., Kassens H. 2009. Eurasian Arctic shelf hydrography: exchange and residence time of southern Laptev Sea waters. Continental Shelf Research, 29: 1815-1820. Belikov S., Boltunov A., Belikova T., Belevich T., Gorbunov Yu. 1998. Marine mammals //The distribution of marine mammals in the Northern Sea Route area // INSROP Working Paper No 118-1998. Oslo: The Fridtjof Nansen Institute. – 49 p. Belikov S.E., Boltunov A.N., Gorbunov Yu.A. 2002. Seasonal distribution and migration of cetaceans in the Russian Arctic according to the results of multiyear observations of the sea ice recoinassance and drifting stations “Severnyi Polyus”. A.A. Aristov, V.M. Belkovich & V.A. Zemsky et al. (eds) Marine Mammals (Results of research in 1995-1998). Moscow, Marine Mammals Council, pp. 21-50 (in Russian). Bouchard C., Fourtier 2008. Effects of polynyas on the hatching season, early growth and survival of polar cod Boreogadus saida in the Laptev Sea. Marine Ecology Progress Series, 355: 247–256. Chapsky K. 1941. Marine mammals of the Russian Arctic. Leningrad, Glavsevmorput’ Pulishing House, 187 p. (in Russian). Dmitrenko I.A., Kirillov S.A., Tremblay L.B., Bauch D., Hölemann J.A., Krumpen T., Kassens H., Wegner C., Heinemann G., Schröder D. 2010. Impact of the Arctic Ocean Atlantic water layer on Siberian shelf hydrography. Journal of Geophysical Research, 115, C08010, 17 PP., doi:10.1029/2009JC006020/. Frolov S.V., Fedyakov V.Ye., Tretiakov V.Yu, Klein A.E., Alekseev G.V. 2009. New data on changes in ice thickness in the Arctic Basin // Doklady RAN, 425 (1): 104–108. (In Russian). Gavrilo MV, Popov AV, Spiridonov VA (2011) Sea ice biotopes and biodiversity hotspots in the Laptev Sea. In: V. Spiridonov, M. Gavrilo, N. Nikolaeva, E. Krasnova (eds) Atlas of the Marine and Coastal Biodiversity of the Russian Arctic. Moscow, WWF Russia Publication, pp. 36-37. Gavrilo M.V., Spiridonov V.A. Sea ice habitats and associated ecosystem. In: V. Spiridonov, M. Gavrilo, N. Nikolaeva, E. Krasnova (eds) Atlas of the Marine and Coastal Biodiversity of the Russian Arctic. Moscow, WWF Russia Publication, pp. 25-26. Gilg O., Strøm H., Aebischer A., Gavrilo M.V., Volkov A.E., Miljeteig C., Sabard S. 2010. Post-breeding movements of northeast Atlantic ivory gull Pagophila eburnea populations. Journal of Avian Biology, 41:1–11. Gukov A.Yu. 1999. Ecosystem of the Siberian polynya. Moscow, Nauchnyi Mir, 344 p. (in Russian). Ilyash L.V., Zhitina L.S. 2009. Comparative analysis of the species composition of sea ice diatoms in the Russian Arctic. Zhurnal Obschei Biologii, 70(2): 143-154 (in Russian). Kosobokova K. N., Hanssen N, Hirche H. J.1998. Composition and distribution of zooplankton in the Laptev Sea and adjacent Nansen Basin in the summer 1993. Polar Biology,19: 63-76. Lindqvist C., Bachmann L., Andersen L. W., Born E. W., Arnason U., Kovacs K. M., Lydersen C., Abramov A. V., Wiig Ш. 2008. The Laptev Sea walrus Odobenus rosmarus laptevi: an enigma revisited. Zoologica Scripta, 38: 113–127. Mironov A.N., Dilman A.B. 2010. Influence of the East Siberian Barrier on the dispersal of echinoderms in the Arctic Ocean. Okenologiya, 50 (3): 371-386 (in Russian). Nikiforov S.L. 2006. Bottom relief of the Russian Arctic Seas Shelf. Dr. of Science Dissertation Thesis, Moscow, Institute of Oceanology of Russian Academy of Sciences, 34 p. Petryashov V.V., Golikov A.A., Schmid M., Rachor E. 2004. Macrobenthos of the Laptev Sea shelf. Explorations of the Fauna of the Seas, vol. 54(2). St. Petersburg, Zoological Institute of the Russian Academy of Sciences, pp. 9-26 (in Russian). Pogrebov V.B., Panteleimonov T.V., Negulayeva S.V. 2002. Ecological factors forming the structure of benthos in the marine coastal zone and estuaries of the Russian Arctic: analysis of impact based on the results of self-organizing modeling. Problem of Arctic and Antarctic, issue 73: 117-134 (in Russian). Popov A.V., Gavrilo M.V. 2011. Flaw polynyas. In: V Spiridonov, M Gavrilo, N Nikolaeva, E Krasnova (eds) Atlas of the Marine and Coastal Biodiversity of the Russian Arctic. Moscow, WWF Russia Publication, pp. 28-29. Romankevich E.G., Vetrov A.A. 2001. Carbon cycle in the Arctic seas of Russia. Moscow, Nauka, 300 p. (in Russian). Schmid M., Piepenburg D., Golikov A.A., Juterzenka K. von, Petryashov V. V., Spindler M. 2006. Trophic pathways and carbon flux patterns in the Laptev Sea. Progress in Oceanography, 71: 314- 330. Speer L., Laughlin T. (eds) 2011. IUCN/NRDC Workshop to Identify Areas of Ecological and Biological Significance or Vulnerability in the Arctic Marine Environment, La Jolla, California. 02-04 November 2010. 37 p. Sirenko B., Denisenko S., Deubel H., Rachor E. 2004. Deep water communities of the Laptev Sea. Explorations of the Fauna of the Sea, St. Petersburg: Zoological Institute of the Russian Academy of Sciences, 54 (62): 28-73. Sirenko B.I. 2001. Introduction. In: B.I.Sirenko (ed).List of species of free-living invertebrates of Eurasian Arctic seas and adjacent deep waters. Explorations of the Fauna of the Seas, vol. 51 (59), St. Petersburg. Zoological Institute of Russian Academy of Sciences, pp. 5-10. Skjoldal H.R., Chrisnesen T., Ericksen E., Gavrilo M., Mercier F., Mosbech A., Thurston D., Andersen J., Falk K. 2012. Identifying Arctic Marine Areas of Heightened Ecological Significance. A follow up project to Recommendation IIC of the Arctic Marine Shipping Assessment, 2009. Prepared for PAME by national experts with assistance from AMAP, CAFF, and SDWG. 181 p. Solovieva D.V. 1999. Spring stopover of birds on the Laptev Sea polynya. In: Kassens H. et al. (eds) Land-Ocean Sysyem in the Siberian Arctic. Dymamica and history. Berlin, Heidelberg, Springer Verlag, pp. 189–195. Spiridonov V.A., Gavrilo M.V., Nikolaeva N.G., Krasnova E.D. (eds) 2011. Atlas of the Marine and Coastal Biodiversity of the Russian Arctic. Moscow: WWF Russia, 78 p. Vetrov A.A. Romankevich E.A., Belyaev N.A. 2008. Chlorophyll, primary production, fluxes, and balance of organic carbon in the Laptev Sea, Geokhimiya, 2008, No. 10, 1122–1130 [Geochemistry International, 46 (10): 1055–1063]. Vetrov A.A., Romankevich E.G. 2009. Production of phytoplankton in the Arctic Seas and its response on recent warming. In: J.C.J. Nihoul & A.G. Kostianoi (eds). Influence of Climate Change on the Changing Arctic and Sub-Arctic Conditions NATO Science for Peace and Security Series, 2009, 95-108, DOI: 10.1007/978-1-4020-9460-6_8. Vetrov A.A., Romankevich E.G. 2011. Primary production and fluxes of organic carbon to the seabed in the Russian Arctic seas as a response to the recent warming. Oceanology, 51: 255–266. Zakharov V.F. 1996. Sea ice in the climate system. St. Petersburg, Gidrometeoizdat, 213 p. (in Russian).
Areas described as meeting EBSA criteria that were considered by the Conference of the Parties
C1: Uniqueness or rarity High
The Great Siberian Polynya is the most persistent and largest polynya system in the Eurasian Arctic and is comparable to North Water Polynya. Walruses that winter in the polynyas from East Taymyr to the north of the New Siberian Islands have been long time considered as an endemic subspecies Odobenus rosmarus laptevi. The latest molecular genetic studies have failed to prove its isolation from the Pacific subspecies (O. rosmarus divergens) (Lindquist et al., 2008). However, the Laptev walrus is indeed a peculiar population differing from the neighbouring Pacific populations by the absence of long seasonal migrations and the location of wintering grounds.
C2: Special importance for life-history stages of species High
Polynyas play a particularly important role in the recruitment of polar cod, Boreogadus saida, which is a key food item for most of the top predators in the high Arctic ecosystems. If polynyas open up early, polar cod could start spawning as early as January. Open water provides the first-feeding larvae with the minimum light necessary to detect and capture plankton prey and thereby obtain better nutrition. Thus they grow to larger pre-winter sizes and provide protection against predators. On the whole, years with well-developed polynyas tend to be characterized by the highest levels of polar cod recruitment (Bouchard and Fortier, 2008). Laptev polynyas support a chain of colonies dominated by Thick-billed murre (Uria lomvia) and Black-legged kittiwake (Rissa tridactyla) that stretches from Preobrazheniya Island in Khatanga Gulf across Stolbovoy and Belkovsky islands through to De Long islands in the Novosibirsk archipelago. All polynyas are used by birds during the spring migration period (Solovieva, 1999; Gavrilo et al., 2011). The Laptev polynyas network also sustains stable, high populations of seals which in turn draw in its main predator: polar bear (Gavrilo et al., 2011).
C3: Importance for threatened, endangered or declining species and/or habitats Medium
Laptev Sea polynyas support the regional non-migrating population of walruses which are listed in the Russian Red Book and the IUCN Red List (Chapsky, 1941, Belikov et al., 1998; Gavrilo et al., 2011). Polynyas are also migration areas for Steller’s eider.
C4: Vulnerability, fragility, sensitivity, or slow recovery High
Sea ice habitats and communities are extremely vulnerable to climate changes. Polynyas as corridors that are shared by both wildlife and vessels susceptible to all threats associated with intensive ship traffic, including noise pollution, and, of course catastrophic oil spills which consequences can hardly be underestimated.
C5: Biological productivity High
In ice-covered seas, polynyas are often regarded as oases. Early, for the Arctic, and lasting through the growing season in the Laptev Sea, polynyas support high productivity, substantial zooplankton growth and population stability at high trophic levels (Gavrilo et al., 2011). Due to strong vertical circulation and organic matter inflow into the near bottom water layers and sediments, benthic communities in polynya regions also have high productivity and species richness (Gukov, 1999; Petryashov et al., 2004; Schmid et al., 2006).
C6: Biological diversity Medium
With regard to the number of species in marine fauna and sea ice flora, the Laptev Sea holds an intermediate position among the Arctic seas of Eurasia. The species richness is lower than in the Barents and Chukchi seas because the latter two are open either to the Atlantic or to the Pacific species inflow. On the other hand, it is higher than in the Kara and East Siberian Seas (Sirenko, 2001; Petryashov et al., 2004; Ilyash and Zhitina, 2009; Spiridonov et al., 2011). Similar trends can be observed in marine vertebrate species (fish, shore-nesting seabirds and marine mammals) richness from the Barents Sea towards the seas of the Siberian shelf. At Kara Sea, it is half what it was in the Barents Sea; it remains more or less similar in the Laptev Sea (54 species of fish, 13 species of obligate- and facultative colonial seabirds and 8 mammals). Most of these fish species and nearly all seabirds and marine mammals are associated with the polynya system.
C7: Naturalness High
The area holds high degree of naturalness, with limited shipping as the only human activity.