Temporal trends of cadmium and mercury in Greenland marine biota

Data for cadmium and mercury in Greenland marine biota (blue mussels, polar cod, shorthorn sculpin, glaucous gull and ringed seals) over a period of 2 0 years has been analysed in order to assess temporal changes. Most of the comparisons were conducted between tissue samples collected in the mid-1980 s and mid-1990s. Cadmium data from a few time series obtained at reference sites during monitoring of mining activities were also included. No overall temporal trends in cadmium or mercury concentrations were found within the 20-year period assessed. However, cadmium concentrations in ringed seals t ended to increase in the period from late-1970s to the mid-1980s. From the mid-1980s to the mid-1990s cadmium concentrations in ringed seals decreased again, whilst mercury concentrations showed a tendency to increase in the same period. The observed changes may reflect natural fluctuations caused b y factors such as a shift in feeding behaviour, rather than changes in anth ropogenic exposure. (C) 2000 Elsevier Science B.V. All rights reserved.