Concentrations of cadmium, mercury and selenium in blood, liver and kidneyof common eider ducks from the Canadian arctic

We determined concentrations of selected trace elements in livers, kidneys and blood samples from common eiders (Somateria mollissima borealis) from t he eastern Canadian arctic during 1997 and 1998. Concentrations of total me rcury and organic mercury were generally low in the livers of these birds ( less than 6 and 4 mug g(-1) dry wt, respectively). Selenium ranged between 11-47 mug g(-1) in livers. Renal cadmium concentrations were among the high est ever published for this species (range: 47-281 mug g(-1)). The regressi ons of log-transformed concentrations of these trace elements in blood samp les on those in liver or kidney were significant (all P-values < 0.05) and positive. However, except for organic mercury (RM2 = 0.83), the co-efficien ts of determination were low to moderate (range of R-2: 0.26-0.52), suggest ing poor to moderate predictive capability. Furthermore, the relationships between total mercury in blood and liver changed between 1997 and 1998, sug gesting that it would not be possible to predict consistently, concentratio ns of mercury in blood from those in liver based on samples taken in one ye ar. Blood samples can be used to determine concentrations of these trace el ements in common eiders (and probably other sea duck species as well). The use of blood samples is especially warranted when it is undesirable to kill the animal such as when working with rare or endangered sea duck species o r when the objective is to relate trace element exposure to annual survival rates. However, the predictive equations developed here should not be used to predict expected concentrations in one type of tissue from those in the other.