TITOV O.V., PEDCHENKO A.P., AND YU.M. .LEPESEVICH
Polar Research Institute of Marine Fisheries and Oceanography (PINRO), Russia

The state of the Barents Sea ecosystem is mostly specified by climate variations in warm Atlantic and cold Arctic waters.

According to scientists viewpoint (Knipovich, 1938; Zenkevich, 1963 et al.), geographic position and relationship between Arctic and boreal waters of the Barents Sea provide with a large biological productivity and stocks of commercial fishes (about 5% from the global catch of marine and oceanic fishes).

The increase in the air temperature above the Barents Sea area and adjacent seas, anomaly high enthalpy indexes of Atlantic waters in the last decade and, as a consequence, the decrease in the square of the sea ice cover in 2004-2008 describe the current warming period in the system “ocean-atmosphere”.

It should be noted that the duration of the current warm period is lesser than the previous one, and the values of climatic index in the beginning of XXI c are lower than its extreme values in 1930-1950 (Boytsov, 2006). Researches, conducted in the period of Arctic extreme warming, revealed appearance of thermophilic species, which previously did not occur here, the decrease in the abundance of typical cold water inhabitants, displacement of the fishing areas in the northern and eastern directions (Zenkevich, 1963). The climate variations are accompanied by the activation of fishery of cod and haddock at the western coast of Spitsbergen, by-catches of herring, mackerel, haddock and saithe at the coastal Novaya Zemlya, haddock, saithe and redfishes in the White Sea and Atlantic herring and cod in the Kara Sea.

Current climate variations have already been influenced the biological resources of the Barents Sea and adjacent areas. The increase in the transition of warm waters to the Barents Sea and the decrease of its ice character stipulate the increase in the total biological productivity, which favors a higher survival rate for young boreal fishes, the increase of their stocks and areas in future.

PINRO scientists have found a remarkable geographic redistribution of fishing objects in the sea area and appearance of new fish species, traditionally inhabiting warm Atlantic waters (Smirnov et al. 2000; Rusyayev, Shatsky, 2001; Dolgov, 2004; PINRO researches…, 2004; Pedchenko et al., 2006). Alongside with warming, acclimatization and extension of the red king crab area have been actively occurred. The blue whiting appearance in the Barents Sea, observed since the middle of 90-s of the XX c, and the transition of the foraging areas of cod northwards can change this situation and influence the recruitment of many commercial fishes and the abundance of traditional food objects for other predators - capelin and Arctic cod.

If anthropogenic impact related to the pollution in the Barents Sea waters probably increases, the most “vulnerable zones” will suffer from a negative effect (Novikov, Plotitsina, 2003). As resulted from domestic researches (Israel, Tsyban, 1989), the highest concentrations of pollutants in the Barents Sea water are observed in the areas of convergence of different water masses (frontal zones) and zones of quasi-stationary circles. This causes a certain concern regarding possible pollutant emissions in the exploitation process of Belosneghka (Snovit) and Goliaf (Goliat) fields in the Norwegian sector of the sea and in the course of development of Shtokman field (SGKM) on the Russian shelf of the sea, located in the areas of frontal zones.

Resulted from redistribution of fishing objects in the Barents Sea area influenced by climate variations, spawning and foraging areas of the most valuable fish species can occur in the “vulnerable zones”. This requires the development of preventative measures for conservation of stocks and the Barents Sea ecosystem.

Long-term forecasts, conducted by PINRO, do not give ground to speak about climate warming for the nearest decade. However, scenarios of climate variations, supposed by foreign experts should be taken into account, according to which remained will be a tendency to warming in the Barents Sea. In this case, there is a strong possibility that areas of active fishery will transmit to the areas of license square SGKM and to the northern part of main pipelines, connecting the field and the Kola Peninsula. In this regard, current variations in the Barents Sea ecosystem and adjacent waters should be studied and possible scenarios of the impact from climate variations on the fishery should be prepared taking into account the development of oil-and-gas raw material production on the Arctic shelf.

References
Boytsov V.D. 2006. Variability of the Barents Sea water temperature and its forecasting. Murmansk: PINRO Press. p.292
Dolgov A.V. 2004. Species composition of ichtyofauna and structure of the Barents Sea ichtyocenes. In: Izvestiya TINRO. Selected papers. Vladivostok: TINRO- center. V.137. p. 177-195.
Zenkevich L.A. 1963. Biology of USSR seas. Moscow: ZOAN USSR Press. p. 738.
Israel Yu.A., Tsyban A.V. 1989. Anthropogenic ecology of the ocean. Leningrad: Hydrometeoizdat. p. 528.
Knipovich N.M. 1938. Hydrology of seas and saltish waters (supplemented to the commercial file). Moscow- Leningrad. p. 513
Novikov M.A., Plotitsyna N.F. 2003. Ecological-fishery atlas of the Barents Sea (electronic resource). Murmansk: PINRO Press. (1CD-ROM).
Pedchenko A.P., Borovkov V.A., Guzenko V.V., Karsakov A.L., Sentyabov Ye.V. 2006. Space-time variations of abiotic factors and their influence on the distribution of basic commercial fish species of the Northern basin in 2005. In: Voprosy promyslovoy okanology. Moscow: VNIRO Press. № 3. p.50-74.
Rusyaev S.M., Shatsky A.V. 2001. New data on the distribution of Eutrigla gurnardus (Triglidae) in the Barents Sea. In: Voprosy ihtiology. V.41. № 2. p. 265-267.
Smirnov O.V., Dolgov A.V., Guzenko V.V., Lepesevich Yu.M., Ozerov Yu.B. 2000. New data on hydrological regime and ichtyofauna of Spitsbergen and France Joseph Land archipelagoes. Materials of PINRO report session on the results of research works in 1998-1999. Murmansk: PINRO Press. P.1. p.79-92.

Oil and gas of Arctic shelf 2008