Region 1. Large Marine Ecosystems (LMEs) of the Eastern Arctic
- Inventory and archive data
- ime series of water temperature and salinity
- Time series of ice conditions
- Fisheries time series
Climatic changes in the Arctic are characterized by the greatest differences and lead to significant consequences for ecosystems and maritime activities. The Arctic region was formed in the post-glacial period, which lasted for more than 10 thousand years. The natural anomalies that are deviations of the statistically reliable standards and patterns may be discussed only in relation to this post-glacial period. The warmest period in history was the period of the Atlantic optimum – around 6 thousand years ago (Matishov, Pavlova, 1990). Cyclic changes of climate and ice cover conditions were registered during the last centuries. Among them ‘the little glaciation period’ of the middle of the last millennium was characterised by cooling in Europe, worsening of ice conditions in the Western Arctic seas, and the destruction of settlements of Europeans in Greenland.
Approximately 150 years ago, the Dutch conducted surveys near the Novaya Zemlya, which laid the foundation of research with respect to climate fluctuations in the Arctic. Knowledge about the Eastern Arctic region broadened considerably at the end of the 19th century and beginning of the 20th century due to numerous efforts of outstanding researchers and explorers (Figure 1).
A network of meteorological stations and regular ice surveys were deployed in the Arctic seas at the end of the 19th century. Based on the data received, information databases were developed, allowing conclusions to be drawn regarding the trends of the last century. Among climatic indicators, the changes in water temperature and ice cover are important for practical relations. The state/status of bioresources and conditions of fishery, as well as possibilities of shelf oil and gas resource development depend on them. The ice conditions determine the navigation possibilities along the Northern Sea Route (NSR).
A generally accepted index of climate regime changes is a series of water temperature observations (1898-present) at the Kola Transect in the Barents Sea (along 33°30' E.L.).
One major anomaly was “the warming of the Arctic” in the 1920-1930s. This phenomenon resulted in an increase in air temperature near coastal areas and islands as well as a reduction of ice cover in the Arctic seas(Frolov et al., 1997). There were no regular data collection systems on ice conditions of the seas at the time, however, regular cruises along the NSR took place before the appearance of effective icebreakers. For example, the expedition of 1914–1915 by the ice-breaking steamers Taimyr and the Vaigach failed to navigate the NSR during one navigation period.
In 1878, Nils Nordenskjold on board the Vega covered almost the entire Northern Sea Route from Stockholm to the Bering Strait in one summer period.
The end of the 20th century was characterized by warming events, which significantly impacted the state of atmosphere, ocean, sea and terrestrial ice in the northern polar area (Frolov et al., 1997 ; Levitus et al., 2005; Levitus et al., 2009; Alekseev et al., 2010 , Matishov et al., 2011 1, Matishov, Dzhenyuk, 2012).
The reasons for climatic fluctuations in various areas of the Arctic are different. The most significant factors in the Barents Sea are the transfers in the atmosphere (zonally and meridionally) and the inflow of warm Atlantic waters. The intensity depends on the global oceanic circulation and the Gulfstream current. In the case of the Eastern Arctic seas, changes in water discharge and thermal advection of the great Siberian Rivers are most influential. The increased discharge causes a freshening of the surface layer of seas, which fastens the formation of ice cover. At the same time, the increased freshwater runoff contributes to early ice melt due to its higher content of heat.
There is a wide range of views on the nature of climate change - from the unconditional acceptance of the hypothesis of global anthropogenic warming to its complete denial. Hence, there are opposite political strategies. In one case, urgent concerted measures are needed to reduce greenhouse gas emissions, in another - we can rely on the stability and self-regulation of the climate system (which does not exclude its anomalous conditions like the Quaternary glaciation) and not limit economic development by environmental prohibitions. Among the world leaders of the first position are the EU countries, Japan and, with some reservations, Russia, the second - the US, China, India, to which in December 2011 Canada joined.
Marine and terrestrial ecosystems in the Arctic are more sensitive to climate change and the impacts of anthropogenic factors than ecosystems of other natural areas. The effects of warming for most species are rather favorable, but the anomalies of the ice cover disrupt food interactions in the foothills, the ecological situation worsens for a number of animal species.
In the absence of reliable forecasts of the global climate, it is necessary to be ready for the following options for the development of processes in the marine Arctic:
- the first is the continuation of warming in accordance with the trend of the last two decades;
- the second is stabilization at the level reached by the middle of the last decade;
- the third is the return to the norm, for which the conditions of the second half of the 20th century were adopted;
the fourth - a change in the sign of the anomaly in the direction of lowering the temperature and deterioration of ice conditions.
The databases and graphics of marine environment observations presented in the sections (Inventory and archive data)provide grounds for reliable prognoses of possible climatic trends.
This part of the Atlas considers large marine ecosystems (LMEs) of the Eastern Arctic, covering the Barents and White Seas, the Kara Sea, the Laptev Sea, the East Siberian Sea, and the Chukchi Sea. This section also includes the East and West Bering Sea LMEs (Figure 2).
The part of the database of the Atlas, focusing on the northern (Arctic) seas, The northern Arctic component of the database in this Atlas includes data from 337 618 stations. Their distribution by seas is given in Table 1, by years and months see Figure 3.
|Large Marine Ecosystems||Number of stations||Period|
|Barents Sea (including the White Sea subarea)||238 286||1870-2013|
|Kara Sea||38 445||1870-2013|
|Laptev Sea||6 570||1878-2009|
|East Siberian Sea||3 459||1878-2008|
|Chukchi Sea||50 858||1849-2012|
ВFor a long time, the non-freezing seas of the Western Arctic were the arena for marine expeditions due to their importance in fisheries. Ice-covered seas – from the Kara Sea to the Chukchi Sea – have always been of interest but were accessible by navigation for a short period of time, usually from July to September. Biological processes of the winter stillness were weakly studied until recently, and it was considered that they have minimal influence on bioproductivity and species diversity.
MMBI KSC RAS has conducted a range of marine and coastal expeditions and cruises. It is also responsible for the organization of research stations in the Arctic. MMBI KSC RAS activities along the Northern Sea Route on board nuclear icebreakers have become a new stage of studies in areas that are otherwise difficult to access.
The first MMBI KSC RAS expedition along the Northern Sea Route took place in February – March 1996 on board the Taimyr and Vaigach nuclear icebreakers. Its main task was to assess the possibilities of using cruises of passing vessels for research. The results of the expedition confirmed that it was possible to collect unique scientific material during ice shipping seasons. Consequently, research on cruises became a permanent component of the Institute expeditions.
СSince then the Institute conducts two to four expeditions on an annual basis. From 1996-2013, 61 cruises were carried out with scientific data collected at 2 379 stations (Figure 4).