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 archipelagos that delineate the Barents Sea are used: Svalbard, Franz Josef Land and Novaya Zemlya. Of those three archipelagos, 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 archipelagos of Franz Josef Land and Novaya Zemlya are included.
The three archipelagos 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 recolonising following the ice retreat that commenced approximately 26,000-15,000 YBP, reaching the most recently deglaciated areas about 10,000 YBP (Brochmann et al., 2003; Alsos et al., 2007; Ávila-Jiménez & Coulson, 2011).
Map of Svalbard, Franz Josef Land, Novaya Zemlya and the surrounding Barents Sea. Map provided by Malin Dase
Arctic climate and light climate
All three archipelagos in the Barents Sea have an arctic climate and feature extreme variation in photoperiod with polar night and midnight sun throughout the year.
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, 60% of which is permanently covered by ice and snow (Hisdal, 1985). The archipelago is under Norwegian sovereignty 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 ºC (mean summer temperature +5.2 ºC), with 191 mm precipitation from 1981-2010 (Førland et al., 2011). Precipitation is particularly variable across the 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 laying between 70° to 77°N and 51 to 69°E. The main island stretches ~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, and as a closed military region it was difficult for scientists to obtain access (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 all three archipelagos mentioned above. The mean temperature in July (mid-summer) varies between -1.2 and +1.6 ºC depending on the specific island considered (Aleksandrova, 1977). The skies are cloudy approximately 90% of the time, reducing solar heating of the ground. Annual precipitation amounts to 300 mm, mostly falling as snow (Aleksandrova, 1983).
Svalbard as research location
The increasing interest in Arctic areas is 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); and 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 in the existing international frameworks aimed to coordinate research activities at the pan-Arctic level.
Svalbard represents a unique platform to study post-glacial colonisation patterns. This is not only due to its level of isolation from the closest land, but also the wide range of studies regarding climatology, geology, glacial history and ecosystems that already exist on 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). As Svalbard is located on the edge of diminishing arctic sea ice it makes its terrestrial ecosystems particularly vulnerable to environmental change, potentially representing an extremely sensitive indicator of the consequences of climate change. Therefore, many of the examples discussed on this website are focused on this region. 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 locations 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).