Radiocaesium (137Cs) in marine mammals from Svalbard, the Barents Sea and the North Greenland Sea

Abstract

Specific activities of the anthropogenic radionuclide, 137 Cs, were determined in marine mammals from Svalbard and the Barents and North Greenland Seas. Muscle samples were collected from 12 polar bears, 15 ringed seals, 10 hooded seals, 7 bearded seals, 14 harp seals, one walrus, one white whale and one blue whale in the period 2000-2003. The mean concentrations (F SD) of 137 Cs were: 0.72 F 0.62 Bq/kg wet weight (w.w.) for polar bears; 0.49 F 0.07 Bq/kg w.w. for ringed seals; 0.25 F 0.10 Bq/kg w.w. for hooded seals; 0.22 F 0.11 Bq/kg w.w. for bearded seals; 0.36 F 0.13 Bq/kg w.w. for harp seals; 0.67 Bq/kg w.w. for the white whale sample; 0.24 Bq/kg w.w. for the blue whale; and below detection limit for the walrus. Significant differences in 137 Cs specific activities between some of the species were found. Ringed seals had higher specific activities than the other seal species in the study. Bearded seals and hooded seals had similar values, which were both significantly lower than the harp seal values.The results in the present study are consistent with previous reported results, indicating low specific activities of 137 Cs in Arctic marine mammals in the Barents Sea and Greenland Sea region during the last 20 years. The species specific differences found may be explained by varying diet or movement and distribution patterns between species. No age related patterns were found in specific activities for the two species (polar bears and hooded seals) for which sufficient data was available.Concentration factors (CF) of 137 Cs from seawater were determined for polar bears, ringed, bearded, harp and hooded seals. Mean CF values ranged from 79 F 32 (SD) for bearded seals sampled in 2002 to 244 F 36 (SD) for ringed seals sampled in 2003 these CF values are higher than those reported for fish and benthic organisms in the literature, suggesting bioaccumulation of 137 Cs in the marine ecosystem. D

137Cs, 40K and 210Po in marine mammals from the southern Baltic Sea

“…More recent studies reported low levels 137 Cs in marine mammals from Svalbard and North Greenland Sea collected in the period [2000][2001][2002][2003]. Mean values (±SD) were from 0.22 ± 0.11 Bq kg − 1 for bearded seals to 0.72 ± 0.62 Bq kg − 1 w.w. for polar bears (Ursus maritimus) (Andersen et al, 2006). Similar low average concentrations of 137 Cs in muscle were reported in Pacific walruses (Odobenus rosmarus divergens) (0.07 Bq kg − 1 w.w) and bearded seal (Erignathus barbatus) (0.17 Bq kg − 1 w.w.) from St. Lawrence Island, Alaska (Hamilton et al, 2008).…”

“…Thus, data are available from other regions, including the Arctic, Asian and European coastal waters, Lake Baikal and the Caspian and Black Seas. These studies reported average levels of 137 Cs that varied between 0.2 and 17 Bq kg −1 wet weight (w.w.) (Cooper et al, 2000;Yoshitome et al, 2003;Gwynn et al, 2005;Andersen et al, 2006;Malta & Carvalho, 2011). Cesium-137 levels in tissues of marine mammals have been suggested as chemical marker for radioactive pollution in the marine environment, and correlations between tissue levels and seawater levels have been reported (Yoshitome et al, 2003).…”

Barents Sea polar bears (Ursus maritimus): population biology and anthropogenic threats

“…Numerous local sources of potential radionuclide contamination are known in the region, for example, nuclear reactor dump sites and atmospheric nuclear bomb testing sites on Novaya Zemlya. It appears from the data reported by Andersen et al (2006) that these potential sources have had little impact on marine mammals in the European Arctic. In general, pollution acts across large temporal and spatial scales, potentially having negative effects on polar bear reproduction and survival in several populations.…”

“…The low 137 Cs levels observed in the marine mammals studied by Andersen et al (2006) (Hallstadius et al 1982;Kershaw and Baxter 1995;Strand et al 2002). Numerous local sources of potential radionuclide contamination are known in the region, for example, nuclear reactor dump sites and atmospheric nuclear bomb testing sites on Novaya Zemlya.…”

Radionuclide activities in sediments on the northern coast of Spitsbergen

“…Different radioactivity levels of anthropogenic 137 Cs in soils, bottom sediments and living organisms have been also noted (Gwynn et al 2004;Andersen et al 2006;Stepanets et al 2007;Zaborska et al 2010). Measurements of radioactive isotopes appearing after nuclear tests in the near-bottom waters were performed intensively in the 1950s and at the beginning of the 1960s.…”