Mercury in components of ecosystems of Western Spitsbergen fijord in summer, 2017

Abstract

The total content of mercury was studied in marine water, sediments and benthic organisms in Billefjord, Isfjord and Gronfjord (Western Spitsbergen) in 2017. The samples were collected between 21 and 24 of July 2017 on-board RV “Dalnie Zelentsy” of Murmansk Marine Biological Institute. Total mercury content was measured at chemical-analytical laboratory of the Russian Scientific Center on Spitsbergen in Barentsburg.Total mercury concentration in the water did not exceed 10 ng/l in all fjords. In the surface sediments the highest concentrations of total mercury were found in Isfjord (median 55 ng/g d.w.) while the Billefjord sediments were characterised by the lowest concentrations (median 10.4 ng/g d.w.). This fact might reflect the differences in water circulation and therefore sediment accumulation peculiarities.Total mercury data were obtained for benthic organisms of various feeding modes. Generally mercury levels were comparatively low (median 12.2 ng/g w.w.), however the highest concentrations were measured in the benthic fauna of Isfjord, specifically in polychaetes Maldania sarsi (max. 49.2 ng/g w.w.). Mercury accumulation in benthic organisms predominantly depended on their trophic level in the ecosystem and location in the fjord: benthic detritus feeders accumulate more mercury (median 25.0 ng/gw.w.).