Ecologically or Biologically Significant Areas (EBSAs)
published: 12 Jun 2015
The White Sea, the youngest sea in Europe, has a peculiar oceanographic regime with cold, deep water formation in the Gorlo strait. The Gorlo area is characterized by strong tidal currents creating high turbulence and mixing the water column down to the seabed (Timonov, 1925; Naumov and Fedyakov 1991; Pantyulin 2003; Kosobokova et al., 2004). It spreads cold water to the south and fills the deep areas of the entire White Sea and retains sub-zero temperatures all year round (Timonov, 1950; Pantyulin, 2003; Kosobokova et al., 2004). These specific conditions form a biotic boundary that limits dispersal of fauna from outside the area into the White Sea (Derjugin, 1928; Naumov, 2006; Solyanko et al., 2011). Deep areas filled with cold water provide habitats for pelagic and benthic biota, while upper layers and shallow areas host typical boreal fauna and macrophyte flora (i.e., kelp and seagrass) (Derjugin, 1928; Berger and Naumov, 2001; Naumov, 2001). In certain areas, the number of macrobenthic species exceeds 460 (Spiridonov et al., 2012), while number of phytoplankton species in the White Sea exceeds 440 (Ilyash et al., 2013). The White Sea harbours two endemic subspecies of fish, migration routes of Atlantic salmon and their abundant stocks (Studenov, 1991, 2011). Bays and islands of the White sea provide breeding habitats for 17 species of aquatic birds (Semashko et al., 2012) and serve as nesting areas of common eiders (Somateria molissima). This area overlaps with the East Atlantic flyway and thus has huge importance as a migration corridor and staging area (Lehikoinen et al., 2006). The polynyas that develop in winter are important wintering grounds for several seabird species (Krasnov et al., 2010, 2011). With regards to marine mammals, the White Sea contains important feeding, whelping and moulting areas of harp seals (Pagophilus groenladicus) (Melentyev and Chernook, 2009; Svetochev and Svetocheva, 2011) and extremely important mating grounds of beluga whales (Delphinapterus beluga) (Svetochev and Sveticheva, 2011).
The AMSA IIc report on the Identification of Arctic Marine Areas of Heightened Ecological and Cultural Significance revealed the White Sea as an important area and identified particular areas within the White Sea as having special importance (AMAP/CAFF/SDWG, 2013). The White Sea is a complex area that includes areas that meet the EBSA criteria in different ways; a separate description is provided. The AMSA IIc report considered the northern part of the White Sea, the Kandalaksha and the Onega bays as separate areas (AMAP/CAFF/SDWG, 2013). However, for the purpose of using a comparable spatial scale with other areas discussed in this workshop, the White Sea is addressed as a single area meeting the EBSA criteria. Important differences that exist between the parts of the White Sea are highlighted as well.
This area includes the entire White Sea except the northern part of Voronka, which is oceanographically close to the Barents Sea. It is located entirely within the EEZ of the Russian Federation, but contains international sea routes.
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 White Sea is an inland sea with a complex bottom topography and coastline, and contrasting oceanographic regimes (Voronka Inlet, Mezen Bay, Gorlo Strait, and Kandalaksha, Onega and Dvina bays). Oceanographically, its outermost section, called Voronka, is similar to the Barents Sea. The other outer section is the very shallow Mezen Bay, which is characterized by high tidal energy and the highest tidal magnitude in the western Arctic (up to 8 m). The Gorlo (the Russian word for “throat”) is a relatively narrow (about 40 km wide) and shallow (average depth of 37 m) strait connecting the outer part of the White Sea with its inner part (Berger and Naumov, 2001). It comprises about 10% of the total area of the White Sea (about 90,000 km2) and receives about 20% of the tidal energy entering the White Sea. As a result, the tidal height in the Gorlo is 3 m while the velocities reach 100-120 cm s -1 (Pantyulin 2003). Tidal mixing leads to an unstratified water column in most parts of the Gorlo and in the Mezen Bay (Timonov, 1950; Pantyulin, 2003; Kosobokova et al., 2004). Tidal velocities and heights are greater along the Terskiy Coast (Kola Peninsula) in the west, where the more saline mixed water of the Voronka is transported into the inner White Sea (the flow is called “Derjugin Current” by Naumov and Fedyakov,1991). This water is then transported along the eastern Zimniy (the Russian word for “Winter”)coast, where the fresher water fed by the Dvina Current is advected out of the inner White Sea, predominately from the Dvina Bay (Derjugin 1928, Timonov 1950, Naumov and Fedyakov 1991). The latter flow called “Timonov Current” by Naumov and Fedyakov (1991) is characterized by lower salinity: 26–28 ppt in summer and up to 28.5 ppt in winter compared to 28.5-29 ppt in summer and up to 30 ppt in winter in the Derjugin Current area. The temperature in the mixed water column of the Gorlo increases from extreme sub-zero values (-1.57 ºC) from January to March to about 6-7 ºC from July to August. The most rapid increase takes place in June -early July (Anonymous, 1962-1968). Strong tidal currents, which change their direction, form local circulations, creating high turbulence and mixing the water column generally down to the seabed (Timonov, 1925; Naumov and Fedyakov 1991; Pantyulin 2003; Kosobokova et al., 2004). The Gorlo area is remarkable, owing to its specific role in forming the unique oceanographic regime of the White Sea, (i.e., formation of cold, deep water owing to winter mixing of the unstratified water column). This cold water spreads to the south and fills the deep areas of the entire White Sea at depths from 60-70 m to the maximum depth of about 330 m and retains sub-zero temperatures year round (Timonov, 1950; Pantyulin, 2003; Kosobokova et al., 2004). The sea ice regime of the White Sea is very dynamic and variable. Landfast ice builds up in the bays and inlets, however the landfast ice zone is usually less than 1 km wide. The first stable ice forms in the mouth of the Mezen River as early as in October, with the latest freezing period observed in the highly dynamic areas off the Terskiy Coast. The entire sea is usually ice-free again by late May. An important feature of the sea ice regime of the White Sea is the regular export of the ice flows to the Barents Sea (Krasnov et al., 2011). The riverine discharge of Severnaya Dvina and the pattern of mesoscale water circulation combine to create spiral eddies; this is a prerequisite for the formation of large and stable ice floes in the Basin and the Gorlo of the White Sea. These ice habitats attract harp seals, which arrive in February and March from the Barents Sea and the adjacent North-East Atlantic to breed and moult (Melentyev and Chernook, 2009). Water circulation and wind create a stable system of polynyas along Terskiy Coast. The distribution pattern of wintering birds in the polynyas of the Terskiy Coast depends on sea ice conditions and may considerably change from year to year (figure 2). In periods of heavy ice, most of the seabirds migrate to the northwestern part of Voronka (the outermost part of the White Sea) and to the Murman Coast (Krasnov et al., 2011). Extensive and variable polynyas are formed near Solovki Archipelago and in the southwestern part of the Onega Bay. These polynyas are of critical importance for wintering seabirds (Krasnov et al., 2010; Krasnov et al., 2011; Krasnov et al., 2013). Kandalaksha Bay is the deepest of the bays and basins in the White Sea and is naturally divided into an inner shallow area and an outer deep area. It is bordered by rocky shores of fjord-like inlets (called “fiards”, which are analogous to typical fjords but usually do not have such steep rocky shores). Some of these fjord-like inlets (inlet, cove, fjord =“guba” in Russian) have an internal depression and outer sills, so that there is limited water exchange and enclaves of cold water with Arctic species in the deep parts. Owing to the isostatic rise of the Fennoscandian shield, many such inlets are gradually losing the connection to the sea that makes them participants in an exiting natural experiment and provides extensive material for evolution of sedimentological, oceanographical, chemical and microbiological processes and changes of macrobiotic communities over time (Krasnova, 2013a,b). The deep (to 330 m) Kandalaksha Bay, in connection with the adjacent deep central part of the White Sea, may be considered a giant fjord separated from the outer part of the sea by the Gorlo Strait, the depth of which generally does not exceed 50 m. Owing to winter convection in the Gorlo, the deep depression is filled and ventilated with cold water that retains a temperature below zero degrees Celsius year round. The upper layer warms up in summer so that the water column, in contrast to the northern part of the White Sea and Onega Bay, is always markedly stratified owing to seasonal temperature and salinity differences (Babkov, 1998; Filatov et al., 2005). Deep areas filled with cold water provide habitats for pelagic and benthic biota, while upper layers and shallow areas host typical boreal fauna and macrophyte flora (i.e., kelp and seagrass) (Derjugin, 1928; Berger and Naumov, 2001; Naumov, 2001). Numerous islands in the inner part of the bay and along the Karelian coast build up a variety of shallow-water habitats along the coast and provide nesting grounds for eiders and other aquatic birds (Bianki, 1991; Krasnov, 2011a). Seasonally, Kandalksha Bay is covered with sea ice. The outer area of the bay is used by harp seals as a breeding area (although seals in this area primarily aggregate in the central part of the White Sea and in the Gorlo Strait). The coastal zone and the shoreline of the bay provide conditions for forming particular types of the fast ice used by ringed seals for wintering and breeding (Lukin et al., 2006). Kandalaksha Bay is the most-studied area of the White Sea. Currently there are three research stations in this area (operated by Moscow University, St. Petersburg University and the Zoological Institute of Russian Academy of Sciences) and the Kandalksha State nature reserve. Onega Bay is the largest bay in the White Sea, with an area of 12,800 km2. The depth of the bay is generally less than 50 m, with the exception of northern parts, where depths can reach 87 m. The bottom relief is uneven, especially along the coastline. Particularly complex bathymetry is observed along the bay’s western coast, where numerous islands are concentrated. Onega Bay is characterized by a broad range of sediment types, but coarse and hard sediments with a small percentage of silt are the dominant substrata (Berger and Naumov 2001). Onega Bay is connected to the central part of the sea by two relatively broad straits, to the east and to the west of Solovki Archipelago, and the Western and Eastern Solovetsky Salma. The deep waters of the Salmas enable large volumes of water to enter the bay, generating strong tidal currents that are exacerbated by the shallow depths in the bay (Babkov, 1998; Filatov et al., 2005). Tidal amplitude increases towards the inner part of Onega Bay, from 1.5 to 3.0 m. In particular types of shorelines, tidal flats may extend to about 5 km. The bay is fed by several large rivers (Onega, Vyg and Kem’) that contribute about 20% of its volume. About 1,900 islands are located in Onega Bay, ranging in size from small rocks (< 5 ha) to the large islands of the Solovki Archipelago, the area of which is about 30,000 ha. The complex coastline and variety of islands create complex environmental conditions in the bay. Dvina Bay is also relatively shallow and is a very important part of the White Sea because it includes an extensive area with the greatest freshwater input the basin scale of Severnaya Dvina River.
Characteristics such as sea ice and lithology are highly dynamic (Nevessky et al., 1977; Rybalko et al., 1989; Babkov, 1998; Berger and Naumov, 2001; Filatov et al., 2005) but the main physical features determining conditions in the area are constant: strong tidal currents and deep winter convections in the Gorlo leading to formation of the White Sea deep water. The coastal ecosystems have undergone some notable changes, in particular catastrophic decline of the seagrass population in the early 1960s. There are several indications, however, that it has since recovered (Bukina et al., 2010). In other aspects, the processes in the area appear to be stable, although they may be affected by recent observed changes in the sea ice regime. Economic activity is low in this area, aside from shipping, which presents potential threats, such as fuel and hydrocarbon cargo spills. This area is especially vulnerable to these impacts, as it is home to important biological phenomena, including moulting and wintering of sea ducks and whelping of harp seals (Pagophilus groenladicus).
Anonymous 1968. Marine hydrographical monthly bulletin. White Sea, 1962–1968. Arkhangel (in Russian). Babkov A.V. 1998. Hydrology of the White Sea. St. Petersburg, Belomorskaya biostantsiya. 94 p. (In Russian). Bambulyak A., Frantzen B. 2009. Oil transport from the Russian part of the Barents Region. Status per January 2009. The Norwegian Barents Secretariat and AkvaplanNiva. 97 p. Berger V.Y., Naumov A.D. 2001. General features. In: Berger V., Dahle S. (eds) White Sea. Ecology and environment. Derzhavets, St.Petersburg Tromsø, pp. 9–22. Bianki V.V. 1991. Birds. In: Oceanographic conditions and biological productivity of the White Sea. Annotated atlas. Murmansk, PINRO, Pp. 191–201. Bukina M.V., Ivanov M.V., Shatskikh E.V. 2010. Recovery of seagrass Zostera marina Linnaeus in the White Sea; contemporary stage. In: Problems of studies, rational use and conservation of the natural resources of the White Sea. Presentations of the international conference. St. Petersburg, 9–11 November 2010, pp. 27–29 (in Russian). Cherenkova N.N. (ed). 2013. Ecological and economical justification of the landscape-marine natural reserve on Solovki Islands. Moscow, GEF/UNDP Project “Strengthening of marine and coastal protected areas of Russia” document, 149 p. (in Russian). Chikina M.V., Spiridonov V.A., Mardashova M.V. 2014. Spatial and temporal variability of coastal benthic communities in the Keretsky Archipelago area and in Velikaya Salma Strait (Karelian coast, White Sea). Okeanologia, 54 (1), pp. 60–72 (in Russian; English version forthcoming). Denisenko N.V., Denisenko S.G., Frolov A.A. 2006. Zoobenthos of the Gorlo and Voronka straits of the White Sea: structure and distribution patterns in coastal areas of the Kola Peninsula. Explorations of the fauna of the seas. Zoological Institute of the Russian Academy of Sciences, 56 (64): 15-34 (in Russian). Derjugin K.N. 1928. Fauna des Weissen Meeres und ihre Existenzbedignungen. Exploration des mers d’U.R.S.S Fasc. 7 – 8: 1 - 511 (in Russian with extended German summary). Filatov N.N., Pozdnyakov D.V., Ingebeikin Yu.I., Zdorovenov R.E., Melentyev V.V., Tolstikov A.V., Pettersson L.H. 2005. Oceanographical regime. In: Filatov N.N., Pozdnyakov D.V., Johannessen O.M. (eds) White Sea. Its marine environment and ecosystem dynamics influenced by global change. Chichester, Springer-Praxis, pp. 73–154. Gurvich A.G. 1934. Distribution of animals in the littoral and sublittoral of Babye More. Explorations of the seas of USSR, 20, pp. 15–32 (in Russian). Ilyash L.V., Rat’kova T.N., Radchenko I.G., Ghitina L.S. 2013. Phtoplankton of the White Sea. In: Lisitzin A.P., Nemirovskaya I.A. (eds). The White Sea System. Volume II.Water column and interacting with it atmosphere, criosphere, the river runoff and the biosphere. Moscow, Scientofic World, pp. 605–639 (in Russian). Ivanchenko O.F., Lajus D.L. 1991. Herring. In: Oceanographic conditions and biological productivity of the White Sea. Annotated atlas. Murmansk, PINRO, pp. 116-123 (in Russian). Krasnov Yu.V. 2011a. Seabirds, contemporary state of populations, distribution and trophic relationships. In: Berger V.Ya. (ed.) Biological resources of the White Sea: exploration and exploitation. Explorations of the fauna of the sea, 69(77). St. Petersburg, Zoological Institute of Russian Academy of Sciences, pp. 244–260 (in Russian). Krasnov Yu.V. 2011b. Anomalous migrations of harp seal in the White Sea: ecological and social aspects. In: Berger V.Ya. (ed.) Biological resources of the White Sea: exploration and exploitation. Explorations of the fauna of the sea, 69 (77). St. Petersburg, Zoological Institute of Russian Academy of Sciences, pp. 286–293 (in Russian). Krasnov Yu.V., Gavrilo M.V., Shavykin A.A., Vaschenko P.S. 2010. Sex and age structure of endemic common eider Somateria mollissima population. Doklady Russian Academy of Sciences, 435(4): 568–570 (in Russian). Krasnov Yu.V., Goryaev Yu.I., Ezhov A.V. 2013. Sea birds and waterfowls of the White Sea: seasonal dynamics and distribution features. In: P.V. Makarevich (ed). Birds of the northern and southern Russian seas. Apatity, Kola Science Centre of Russian Academy of Sciences, pp. 124–158 (in Russian). Krasnov Yu.V., Strom H., Gavrilo M.V., Shavykin A.A. 2006. Wintering of seabirds in polynyas near the Terskiy Coast of the White Sea and at East Murman. Ornithology. Issue 31. Moscow, MSU publishers, pp. 51–57. (In Russian). Krasnov Yu.V., Gavrilo M.V., Spiridonov V.A. 2011. Sea ice biotopes of southeastern Barents and the White seas. 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. 30–32. Krasnov Yu.V., Spiridonov V.A., Dobrynin D.V. 2012. Seabirds on the Eastern Murman and northern part of the White Sea in summer: features of distribution and differences in forage resources. In: G.G. Matishov (ed). Apatity, Kola Science Centre of Russian Academy of Sciences, pp. 44–66 (in Russian). Krasnova E.D., Pantyulin A.N., Belevich A.D. et al. 2013a. Multidisciplinary studies of the separating lakes at different stage of ssolation from the White Sea performed in March 2012. Oceanology, 53 (5), pp. 639–642. Krasnova E.D., Pantyulin A.N., Rohatykh T.A.,Voronov D.A. 2013b. Inventory of waterbodies in process of separation from the sea on te Karelian coast of the White Sea. In: Problems of studies, rational use and conservation of the natural resources of the White Sea. Pressentations of the international conference, 30 September – 4 October 2013. Petrozavodsk, pp. 16 –167 (in Russian). Lehikoinen A., Kondratyev A., Asanti T., Gustafsson L., Laminsalo O., Lapshin N., Pessa J., Rusanon P. 2006. Survey of Srctic bird migration and staging at the White Sea, in autumna of 1999 and 2004. Helsinki, The Finnish Environment Institute, 107 p. Lisitzin A.P. 2013. Introduction. In: Lisitzin A.P., Nemirovskaya I.A. (eds). The White Sea System. Volume II.Water column and interacting with it atmosphere, criosphere, the river runoff and the biosphere. Moscow, Scientofic World, pp. 13–18 (in Russian). Lukin L.R., Ognetov G.N., Boiko N.S. 2006. Ecology of ringed seal in the White Sea. Ekaterinburg, Institute of Plant and Animal Ecology of Ural Branch of Russian Academy of Sciences. 165 p. (in Russian). Makarevich P.R., Krasnov J.V. 2005. Aquatic ecosystem profile. In: Filatov N.N., Pozdnyakov D.V., Johannessen O.M. (Eds), White Sea. Its Marine Environment and Ecosystem Dynamics Influenced by Global Change. Chichester, Springer-Praxis Publishing, pp. 155–177 Melentyev V.V., Chernook V.I. 2009. Multi-spectral satellite_airborne management of ice form marine mammals and their habitats in the presence of climate change using a «hot_spot» approach // In:S.A. Cushman, F. Huetmann (eds). Spatial complexity, informatics, and wildlife conservation. Tokyo, Springer, pp. 409–428. Moiseenko T.I. 2010. Pollution of surface waters of the watershed and key antropogenic processes. In: A.P. Lisitzin (ed.) The White Sea System. V. I. Warershed Environment. Moscow, Nauchnyi Mir, pp. 301–303 (in Russian). Naumov A.D. 2006. Clams of the White Sea. Ecological and faunistic analysis. Explorations of the fauna of the sea, 59 (67). St. Petersburg: Zoological Institute of Russian Academy of Sciences: 1–351 (in Russian). Naumov A.D., Fedyakov V.V. 1991. Peculiarities of the hydrological regime of the northern White Sea. Trudy (Proceedings) of the Zoological Institute of the Academy of Sciences of USSR, 233: 127- 147 (in Russian). Nevessky E.N., Medvedev V.S., Kalinenko V.V. 1977. White Sea. Sedimentogenesis and history of development in the Holocene. Moscow: Nauka, 236 p. (In Russian). Pantyulin, A.N. 2003. Hydrological system of the White Sea. Oceanology, 43, suppl. 1: S1-S14. Poulin M., Daugbjerg N., Gradinger R., Ilyash L., Rat’kova T., Quillfeldt C. 2011. The pan-Arctic biodiversity of marine pelagic and sea-ice unicellular eukaryotes: a first-attempt assessment. Marine Biodiversity, 41 (1): 13–28. Romankevich E.A., Vetrov A.A 2001. Cycle of carbon in the Russian Arctic Seas. Moscow: Nauka, 302 p. (in Russian). Rat’kova T., Savinov V. 2001. Phytoplankton. In: Berger V., Dahle S. (eds) White Sea. Ecology and environment. St.Petersburg – Tromsø, Derzhavets, pp. 23–28. Rybalko A.E., Spiridonov M.A., Kropachev Yu.P., Moskalenko P.E.,Nechaev M.G., Takki D.F., Khan Yu.V. 1989. Processing and interpretation of the data of side scan sonar data for identification of material composition of shelf surface structures. Guidelines. Leningrad, A.P. Karpinsky All- Union Geologological Institute, (in Russian), 80 p. Sazhin A.F., Mosharov S.A., Romanova N.D., Mosharova I.V. 2009. Primary and bacterial production in ice layer and under-ice water of the White Sea in early spring. In: Proc. 20th IAHR International Symposium on Ice. Lahti, Finland, June 14 to 18. ISBN 978-952-10-5979-7. Paper # 23, pp. 1–13. Sazhin A.F., Rat’kova T.N., Mosharov S.A., Romanova N.D., Mosharova I.V., Portnova D.A. 2011. Biological components of seasonal ice. In: In: Berger V.Ya. (ed.) Biological resources of the White Sea: exploration and exploitation. Explorations of the fauna of the sea, 69(77). St. Petersburg, Zoological Institute of Russian Academy of Sciences, pp. 97–117 (in Russian). Sergienko L.A. 2011. Marsh biotopes and plant communities of the White, Barents and the Kara Seas. 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. 42–43. Semashko V. Yu., Cherenkov A.E. Tertitski G.M. Current breeding population of sea birds on islands of the Onega Bay of the Whitea Sea and and its trend. In: Ecology of marine birds of the White Sea. Apatity, Kola Science Centre of Russian Academy of Sciences, pp. 140–168 (in Russian). Shoshina E.V. Macrophytes. In: Berger V.Ya. (ed.) Biological resources of the White Sea: exploration and exploitation. Explorations of the fauna of the sea, 69(77). St. Petersburg, Zoological Institute of Russian Academy of Sciences, pp. 132–148. Solyanko K., Spiridonov V., Naumov A. 2011a. Benthic fauna of the Gorlo Strait, White Sea: a first species inventory based on data from three different decades from the 1920s to 2000s. Marine Biodiversity, 41 (3): 441-453. DOI 10.1007/s12526-010-0065-9. Solyanko K., Spiridonov V., Naumov A. 2011b. Biomass, commonly occurring and dominating species of macrobenthos in Onega Bay (White Sea, Russia): data from three different decades. Marine Ecology, 32 (Suppl. 1): 36–48. Speer L. and 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. Spiridonov V.A., Bogoslovskaya L.S., Suprunenko Yu.S. 2010. Maritine and coastal cultural landscapes of the White Sa and Chukotka as components of natural-cultural heritage of Russia. In: Study and conservation of marine heritage of Russia. Presentations of the First Scientific-Applied Conference, St. Petersburg, 27-30 October 2010. Kaliningrad, Terra Baltica, pp. 442–453 (in Russian). Spiridonov V.A., Mokievsly V.O., Solynako E.Yu. 2012. Chronicle of field work and some results of the hydrobiological and oceanological investigations on board R.V. “Professor Vladimir Kuznetsov” in July 2006. In: Mokievsky V.O., Spiridonov V.A. Tzetlin A.B. and Krasnova E.D. (eds) Integrated study of the bottom landscapes in the White Sea using remote methods (Proc. N.A. Pertsov White Sea Biological Station. V. 11), Moscow, KMK Sci Press, pp. 112–120 9in Russian). Stasenkov V.A. 1991. Smelt, plaice, capelin, walfish, cod, navaga, episodic migrants from the Atlantic. In: Oceanographic conditions and biological productivity of the White Sea. Annotated atlas. Murmansk, PINRO, pp. 134–151 (in Russian) Studenov I.I. 1991 Semga (Atlantic salmon). In: Oceanographic conditions and biological productivity of the White Sea. Annotated atlas. Murmansk, PINRO, pp. 124–125 (in Russian). Studenov I.I. 2011. Semga (Atlantic salmon). In: Stasenkov V.A. (Ed). Pomor fisheries. Arkhangel, SevPINRO, pp. 135–158 (in Russian). Svetochev V.N., Svetocheva O.N. 2011. Marine mammals: biology, feeding, stocks. In: Berger V.Ya. (ed.) Biological resources of the White Sea: exploration and exploitation. Explorations of the fauna of the sea, 69(77). St. Petersburg, Zoological Institute of Russian Academy of Sciences, pp. 261–287 (in Russian). Terzhevik A.Y., Litvinenko A.V., Druzhinin P.V., Filatov N.N. (2005) Economy of the White Sea watershed. In: Filatov N.N., Pozdnyakov D.V., Johannessen O.M. (Eds), White Sea. Its Marine Environment and Ecosystem Dynamics Influenced by Global Change. Chichester, Springer-Praxis Publishing, pp. 241–301. Timonov, V.V. 1925. On hydrological regime of the Gorlo of the White Sea. Issledovaniya russkikh morei (Investigations of the Russian Seas), 104(1): 1-56 (in Russian). Timonov, V.V. 1950. The principal characteristics of the hydrological regime of the White Sea. In: To the memory of Yu.M. Shokalsky. Moscow – Leningrad, Part. 2, p. 206-235 (in Russian).
Areas described as meeting EBSA criteria that were considered by the Conference of the Parties
C1: Uniqueness or rarity High
The entire White Sea is unique as it is the youngest sea in Europe and has a peculiar oceanographic regime with cold, deep water formation in the Gorlo. Specific conditions of the Gorlo provide an example of a biotic boundary partly preventing dispersal of the outside fauna into the White Sea (Derjugin, 1928; Naumov, 2006; Solyanko et al., 2011). The White Sea also harbours two endemic subspecies of fish: the White Sea herring (Clupea pallasii marisalbi), which originated from the Pacific herring species in the Holocene time, and the non-migrating White Sea cod (Gadus morhua marisalbi). Some rare and distinct habitats are present, namely semi-isolated inlets containing enclaves of cold-water biota of Arctic origin, including the largest basin of its kind, Babye More (Gurvich, 1936) and Dolgaya Guba on Solovetsky Archipelago, which has been studied since 1889. The co-existence of Arctic and boreal organisms, mosaic intergradations of benthic communities or temporal succession of the cold water and temperate water assemblages of plankton is a distinctive feature. Furthermore, peculiar meiofauna (nematodes) were described in the Kandalaksha Bay sea ice, which are different from sea ice nematodes of the High Arctic (Tschesunov, 2006). A residual population of harp seal is present near the town of Kandalaksha, where this species maintains unusual shore hauling-out behaviours in summer (Krasnov, 2011b). There is an endemic sedentary White Sea population of common eider.
C2: Special importance for life-history stages of species High
Onega, and to a lesser extent, Kandalkasha Bay are important for maintaining rich benthic communities dominated by quahog (Arctica islandica), horse mussel (Modiolus modiolus) and Iceland scallop (Chlamys islandica) (Solyanko et al., 2011; Chikina et al., 2014). The Tersky coast in the Voronka, southern coast of Mezen Bay and the Gorlo Strait are the only migration routes of Atlantic salmon (Salmo salar) into the White Sea, while the Ponoi, Kuloi and Mezen rivers in the northern part of the White Sea and Varzuga River in Kandlaksha Bay possess abundant salmon stocks (Studenov, 1991, 2011). In the past, there were abundant stocks of Atlantic salmon in Severnaya Dvina, Onega, Vyg, in smaller rivers of the Onega Bay, and in Keret’and Umba in Kandalaksha Bay. The stocks have declined recently, but nevertheless these areas are critical for the recovery of salmon populations (Studenov, 2011). Mezen Bay and the coastal waters of Kanin Peninsula and Onega and Dvina bays are the main spawning grounds of navaga (Eleginus navaga) (Stasenkov, 1991). Kandalaksha Bay is the most important part of the White Sea for the population of the White Sea cod (Gadus morhua marisalbi). Onega and Dvina bays are the most important spawning ground of the White Sea herring (Clupea pallasii marisalbi) some other fishes (Ivanchenko and Lajus, 1991). 67% of about 1,900 islands of the entire Onega Bay and 84% of the islands of Solovki archipelago are nesting areas of common eiders (Somateria molissima) and provide breeding habitats for another 17 species of aquatic birds (Semashko et al., 2012). The polynyas that develop in winter in the northern and the western parts of the bay are important wintering grounds for the common eider (including most of theWhite Sea population of common eider) and several other seabird species (Krasnov et al., 2010, 2011). Onega Bay has tremendous importance as a migration corridor and staging area of the East Atlantic Flyway (Lehikoinen et al., 2006). With regards to marine mammals, Onega Bay is a feeding area for the highest proportion of the ringed seal (Phoca hispida) population, hosting population densities of more than 10 individuals per 100 km2 (Lukin et al., 2006). The islands of Kandlaksha Bay (in particular those within the Kandalaksha State Nature Reserve) are important nesting and moulting areas for the White Sea population of common eider, herring gull and several other aquatic birds (Bianki, 1991; Krasnov, 2011a) and are of comparable importance to the islands of Onega Bay. Similarly to Onega Bay, the coastal zone of Kandalaksha Bay is an important migration corridor and staging area for aquatic birds migrating between Kola Peninsula and Bothnia Bay in the Baltic Sea (Bianki, 1991). Kandalaksha Bay is also the most important wintering and breeding ground for ringed seal in the White Sea (Lukin et al., 2006). The Terskiy coast, from the mouth of the Strelna River to Sviatoi Nos Cape, is the most important moulting area for eiders: common eider of the Murman coast population, king eider (Somateria spectabilis) and Steller eider (Polysticta stelleri). This is the largest and most important moulting area for the migratory Atlantic population of king eider (Krasnov et al., 2006). Three species of eider spend the winter in the polynyas along the Terskiy coast (Krasnov et al., 2011). Finally, the sea ice flows in the northern part of the deep White Sea Basin and the Gorlo are the most important whelping and moulting areas of the Barents Sea population of harp seals, Pagophilus groenladicus (Melentyev and Chernook, 2009; Svetochev and Svetocheva, 2011).
C3: Importance for threatened, endangered or declining species and/or habitats Medium
The area has some importance for maintaining populations of endangered shorebirds of prey, such as white-tailed sea eagles (Haliaeetus albicilla). The area is extremely important as mating grounds of beluga whales, Delphinapterus beluga (Svetochev, Sveticheva, 2011) (IUCN near threatened). The coastal waters of Terskiy Coast are the principal moulting area and an important wintering ground of Steller eider (Polysticta stelleri) (Krasnov et al., 2006) (Krasnov et al., 2011).
C4: Vulnerability, fragility, sensitivity, or slow recovery High
The ecosystems of the northern part of the White Sea function in a severe environment, and many processes are strongly physically driven. The scale and impact of human activity cannot be compared to the force of the climatic, oceanographical and lithogenic processes that permanently affect habitats and biotopes of marine species (e.g., dynamics of sea ice biotopes, sediment transport). In this way, they can be called sensitive but the environmental impact largely remains within the normal variation and functioning of marine communities and ecosystems in the area. However, the coastal concentrations of sea ducks at moulting grounds in the near shore zone of the Terskiy coast in summer, and wintering concentrations in polynyas in the same area are vulnerable in two important ways. First, these aggregations and their habitats are extremely vulnerable to oil spills, which may cause significant declines in the entire regional populations of common, king and Steller eiders (Krasnov et al., 2006, 2011). Secondly, whelping concentrations of harp seals on sea ice in the Gorlo are highly vulnerable to sea ice conditions, and their breeding success is affected by changes in climate and sea ice regime and may be worsened by shipping (which destroys suitable ice flows) and oil spills. In Onega and Kandlaksha bays, benthic communities dominated by long-lived bivalves (i.e., quahog, horse mussel and scallop) are currently stable, but are most likely slow recovering and susceptible to eutrophication and the impact of active fishing gears (Solyanko et al., 2011b). The other potential threat to the entire ecosystem would be introduction of alien species, i.e., comb jellies, clams or crabs associated with decreasing sea ice cover, although this is not expected in the near future, taking into account the current low intensity of shipping. Nesting grounds of aquatic birds on the islands are increasingly impacted by the development of unregulated tourism (Semashko et al., 2012), as are reproductive aggregations of beluga whales (Cherenkova, 2013). Wintering grounds of seabirds, in particular common eiders in the polynyas around Solovetsky Archipelago and in the western part of the bay are extremely vulnerable to oil spills in sea ice conditions.
C5: Biological productivity Medium
Primary production in different parts of the White Sea strongly varies but is generally lower than in the coastal waters of the Barents Sea (Rat’kova and Savinov, 2001; Romankevich and Vetrov, 2001) and so does benthic biomass as an indicator of long-term productivity conditions (Naumov, 2001; Solyanko, 2010). Onega Bay appears to be the most productive area of the White Sea; the existing observations indicate a moderate to high 0.1 – 0.2 g C m-2 day-1, and high— but not the highest — levels of phytoplankton biomass (Rat’kova and Savinov, 2001; Makarevich and Krasnov, 2005; Ilyash et al., 2011) (figure 3). The data for particulate organic matter indicate the concentration to be the highest for the region (Kravchishina, 2009). There is a very high patchiness of phytoplankton distribution, and probably numerous spots of high production associated with oceanographical phenomena, i.e., tidal and river plume fronts. Onega Bay harbours the richest kelp area in the White Sea, and the standing stock of kelp algae (Sacharina sacharina and Laminaria digitata) is an order of magnitude greater than in the Dvina Bay and about twice greater than in Kandalaksha Bay (Shoshina, 2011). The higher primary productivity of Onega Bay is reflected in the highest benthic biomass of the White Sea (Solyanko et al., 2011b). In Kandalaksha Bay, primary production in the water column is at a moderate level (Rat’kova and Savinov, 2001), however proximity of deep areas facilitates maintenance of abundant stocks of zooplankton consisting of Arctic species, i.e. Calanus glacialis. Sea ice algae are particularly abundant and increasingly productive as daylight increases in late winter - spring; this production is likely consumed in the coastal ecosystem in spring (Sazhin et al., 2009, 2011). It is not yet known if the situation in other parts of the White Sea is much different.
C6: Biological diversity High
The number of phytoplankton species in the White Sea amounts to 449 (Ilyash et al., 2013). This is little less than in the Barents Sea and currently higher than in any other sea of the Russian Arctic (Poulin et al., 2011; Ilyash et al., 2013). The White Sea probably contains the highest diversity of species of different biogeographical origin, communities and habitats existing in proximity within a limited area in the Western Arctic. Onega Bay contains the greatest number of habitat types in the entire White Sea: extensive saltmarshes, wadden shores and beaches (Sergienko, 2011), habitats typical of abrasive-accumulative coasts, rocky shores, fjord-like inlets with sills and inner deep depressions (Troitskaya and Dolgaya inlets at Solovki Islands). The number of species of macrobenthic fauna is the highest in the White Sea: 464 species (Spiridonov et al., 2012). The number of nesting aquatic birds (17) is comparable to that of Kandalaksha Bay and is among the highest for the region (Semashko et al., 2012). In spite of the harsh conditions, the macrobenthic fauna of the Gorlo is thus generally rich (over 350 species) but consists mostly of rarely occurring species (Solyanko, 2010; Solyanko et al., 2011a). The distribution of different types of benthic communities is highly mosaic, and this mosaic is clearly seen on all spatial and temporal scales (Naumov, 2001; Denisenko et al., 2006; Solyanko, 2010).
C7: Naturalness High
The White Sea, Onega Bay in particular, was used by traditional and artisanal fishers and hunters for millennia, and a characteristic maritime cultural landscape has formed (Spiridonov et al., 2010) that is especially remarkable at Soloetskyi Archipelago with its famous monastery, a UNESCO World Heritage site (Cherenkova, 2013). With regard to land-based pollution and other kinds of contamination, the White Sea is likely exposed to lower levels of anthropogenic impacts than many other North-Eeast Atlantic seas, as the industrial activity in the area has never been particularly high and has decreased recently (Terzhevik et al. 2005; Moiseenko, 2010). The area has also experienced practically no impacts from active fishing gears and has shown relative stability of dominant species in benthic communities over decades (Solyanko et al., 2011). The nesting areas of aquatic birds located on islands that are close to coastal towns have been strongly impacted, while other parts of the islands are accessible to terrestrial predators, i.e., foxes; about 19% of the islands still provide good, protected natural habitas. Currently, the greatest actual threat is unregulated tourism (often associated with illegal hunting and the use of boats with powerful engines) (Semashko et al., 2012). Shipping and oil transportation along the Gorlo Strait and to Arkhangelsk and Kandlaksha has recently intensified (Bambulyak and Frantzen, 2009), but fortunately has not yet significantly impacted the naturalness of the area.