 Seals as biomonitors of radionuclides in the Arctic
Seals are high trophic level feeders that bioaccumulate many
contaminants to a greater degree than most lower trophic level
organisms. Their trophic status in the marine food web and wide-spread
distribution make seals useful sentinels of arctic environmental change.
This investigation was carried out to document the levels and
bioaccumulation potential of radiocaesium in high latitude seal species
for which data have not previously been available. Studies were carried
out on harp, ringed, and hooded seals caught along the northeast coast
of Greenland (75-80° N), north of the island archipelago of Svalbard
(82° N), and along the Kola peninsula in Northwest Russia.
Mean concentrations of 137Cs in muscle and liver samples were very
low (0.36±0.13 Bq/kg fresh weight and 0.26±0.08 Bq/kg fresh weight
respectively). The results are consistent with previous studies
indicating low levels of radiocaesium in Arctic seals in response to a
long term trend of decreasing levels of 137Cs in the Barents Sea region.
Illustration: Monitoring of radioactivity in
seals. Levels of 137Cs (Bg/kg) content of muscle tissue collected from
harp, ring, and bearded seals (Carroll et al., 2002, 2006).
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