On the background values of heavy metal content in bottom sediments of the Barents Sea

Based on the long-term data the background content in the number of heavy metals in bottom sediments of the Barents Sea has been estimated. For the purpose to estimate the up-to-date state of the geochemical background the contents of heavy metals in bottom sediments of the Barents and the East Siberian Seas have been compared. To solve the problem of separating the natural background from the anthropogenic constituent the methods of mathematical statistics and geospatial analysis have been used. Mapping including geostatistical analysis has been performed in GIS application Arcview 3.2 environment with the use of a special approach. As a base map the bathymetric map of the Barents Sea made on the basis of own PINRO data has been used. The data from 559 stations in the Barents Sea and adjacent areas received from 1998 to 2015 have been processed. As a result of researches, the background content of nickel, copper, chromium, zinc, lead, and mercury in bottom sediments of that region has been suggested. The results of using different methods to estimate the background values including the suggested and Norwegian ones have been compared. It has been shown that the content of Ni and Cu in bottom sediments of the Barents Sea allowed us to speak about the regional negative geochemical anomaly concerning these metals. The distribution of contrast geochemical anomalies of the studied heavy metals in the Barents Sea area has been mapped. The conclusion about steady anthropogenic pollution of bottom sediments in the Western Murman coastal zone and the Kola Gulf mouth has been made. The other revealed geochemical anomalies need to be studied in future.