Focus Area: Archipelagoes of the Barents Sea
Even though this site aims to cover the entire Arctic, the presented material concentrates on the European Arctic. Examples from the three archipelagoes that delineate the Barents Sea are used: Svalbard, Franz Josef Land and Novaya Zemlya. Of those three archipelagoes, by far the most detailed studies of invertebrate fauna are available for Svalbard. Hence, the focus lies primarily there. Wherever possible, the less well described archipelagoes of Franz Josef Land and Novaya Zemlya are included.
The three archipelagoes considered here share generally similar environmental characteristics hence comprising a natural geographic unit. This is a region of convergence for the Palaearctic and Nearctic biota re-colonising following the ice retreat that commenced approximately 10,000 years before present (YBP) subsequent to the Last Glacial Maximum (LGM) (Brochmann et al., 2003; Alsos et al., 2007; Ávila-Jiménez & Coulson, 2011).
Map of the focus area of this web site – Svalbard, Franz Josef Land, Novaya Zemlya – surrounding the Barents Sea. Map kindly provided by Malin Dase
Arctic climate and light climate
All three archipelagoes in the Barents Sea have an Arctic climate and the particular high Arctic feature of extreme variation in photoperiod with polar night and midnight sun throughout the year. For the settlement of Longyearbyen on Spitsbergen, Svalbard, this is between October 27 and February 15. Conversely, during the period of the midnight sun, the sun remains constantly above the horizon – in Longyearbyen from April 19 until August 23 (www.timeanddate.com). Even though the sun is permanently above the horizon from mid-April, the ground is not released from snow and ice until later in the season. When this happens varies between years, but may be as late as mid-June on Svalbard (Coulson 2013) and the growing season in vegetated reagions, if measured from the approximate period the ground begins to clear of snow until the end of the midnight sun, may be less than 70 days. For Franz Josef Land the period of the midnight sun is approximately from April 15 until August 24 with polar night extending from October 19 until February 21. With a north-south axis the photoperiod of the islands of the Novaya Zemlya archipelago varies considerable. In the south the period of the midnight sun is only from May 21 – July 22 while in the north this period is extended, beginning around April 25 and ending August 17. The polar night is similarly shorter in the south commencing on November 22 with the sun returning on January 20 while in the north the period lasts from October 29 to February 13 (Alaska Public Lands Information Centre, 2013).
Svalbard lies between 10° and 35° E and 74° and 81° N and consists of four main islands, Spitsbergen, Nordaustlandet, Edgeøya, Barentsøya, and the ‘outlier’, Bjørnøya (Bear Island). It covers an area of approximately 63,000 km2 of which 60% is permanently covered by ice and snow (Hisdal, 1985). The archipelago is under Norwegian sovereignity and governed under the terms of the “Svalbard Treaty” (Treaty of Spitsbergen, 1920; pdf can be found here).
In Svalbard the annual mean air temperature recorded at the official meteorological station at the airport in Longyearbyen in the west of the archipelago is -4.6 (mean summer temperature +5.2ºC), with 191 mm precipitation for the period 1981-2010 (Førland et al., 2011). Precipitation is particulary variable across this archipelago, decreasing rapidly from the west coast towards the interior.
Barentsburg and Isfjord Radio, approximately 50-80 km to the west of Longyearbyen and on the coast, receive 525 and 480 mm respectively per year (Norwegian Meteorological Institute, 2013). Air temperature is also heavily influenced by the surrounding ocean and in particular the dominant local current systems. To the west, a northwards branch of the North Atlantic Drift carries relatively warm water, approximately +3°C (Skogseth et al., 2005), past the archipelago. The east coast, however, is influenced by the cold water of the East Spitsbergen Current carrying polar water south at between 0.5° and -1.0°C (Skogseth et al., 2005). Hence air temperatures in the north and east of Svalbard are generally lower than in the west. Throughout the archipelago, soils may be snow-covered and frozen for at least nine months of the year (Coulson et al., 1995).
Novaya Zemlya lies to the north of the Nenetsia Russian coast and includes two main islands separated by the Matochkin Shar strait and numerous lesser islands lying between 70° to 77°N and 51 to 69°E. The main island stretches almost 900 km along a north-east axis and is 145 km in its widest point (Aleksandrova, 1977). Novaya Zemlya extends over an area of 81,280 km2 of which 27% is permanently glaciated (Zeeberg, 2002). During the Cold War, this archipelago was used as a nuclear test site, resulting in a closed military region difficult for biologists to visit (Zeeberg and Forman, 2001).
The latitudinal span of Novaya Zemlya results in a considerable climatic gradient (Zeeberg and Forman, 2001). Annual mean temperature decreases from -5.4°C on the south-west coast to -10.3°C at the northern extremity. While winters (December, January) are cold, averaging around -15°C, the summers are relatively mild with July/August mean air temperature around +6°C. Precipitation also varies, decreasing south to north from 386 mm per year to 283 mm per year. However, as with Svalbard, the climate of Novaya Zemlya is heavily influenced by the surrounding marine environment with advected warm North Atlantic water on the west coast while the east coast adjoins the cold Kara Sea which is ice-bound during the winter.
Franz Josef Land
Franz Josef Land lies to the north-east of Svalbard, 79°73’ and 81°93N and 37° and 65°50’E, and consists of approximately 190 largely ice-covered islands extending over a total area of 12,334 km2, 85% of which is permanently glaciated (Aleksandrova, 1977; Zeeberg and Forman, 2001). As with Novaya Zemlya, Franz Josef Land was a closed military area for much of the Twentieth Century, and although that is no longer the case, access today still requires permission from the Russian authorities, including the Federal Service of National Security and Administration of Reserves and Protected Areas.
Franz Josef Land has the most extreme climate of the three archipelogoes mentioned above. The mean temperature in July (mid-summer) varies between -1.2 and +1.6ºC depending on the specific island considered (Aleksandrova, 1977). Cloudy skies occur approximately 90% of the time, reducing solar heating of the ground. Annual precipitation amounts to 300 mm, most falling as snow (Aleksandrova, 1983).
Svalbard as research location
This increasing interest in Arctic areas is clearly evident in Svalbard, with the establishment of research platforms and collaborative ventures; e.g. the Kongsfjorden International Research Base (KIRB) at Ny-Ålesund, the development of a Norwegian agenda to establish the eastern regions of Svalbard as a “reference area for research” (Ministry of Justice and the Police, 2009), the launching of the Svalbard Integrated Arctic Earth Observing System (SIOS) as part of the European Strategy Forum on Research Infrastructures (ESFRI) program (European Commission, 2012). However, these initiatives have not yet been included within the existing international frameworks aimed to coordinate research activities at the pan-Arctic level.
Svalbard represents an unique platform to study post- glacial colonization patterns, not only due to its level of isolation from the closest land, but also for the wide range of studies regarding climatology, geology, glacial history and ecosystems existing for this archipelago (for example Hjelle et al. 1993, Førland et al. 1997, Hodkinson et al. 1998, Coulson et al. 2000, Coulson 2007, Kubischta et al. 2010). The location of Svalbard, on the edge of the diminishing Arctic sea ice, also makes its terrestrial ecosystems particularly vulnerable to environmental change, and could potentially represent an extremely sensitive indicator of its consequences. Therefore, many of the examples discussed in this book are focused in this region of the Arctic. Most terrestrial ecology knowledge from Svalbard comes from only a few locations along the west coast of Spitsbergen, in particular, Longyearbyen, Ny-Ålesund and Hornsund; however, these are different to the eastern part of Svalbard due to climatology, putative dispersal routes (Alsos et al. 2007) and the extent of possible ice-free areas during LGM (Landvik et al. 2003).