Exposure of stranded harbour porpoises to trace elements along the coastline

The total concentrations of 31 metals and metalloids were determined in the liver of 101 harbour porpoises stranded along the Scottish coastline using CV-AFS, ICP-MS and MP-AES techniques. The proportion of male to female animals was 44:57, with an age range of 0.1 to 15-yr. Principal component analysis showed significant differences by sex (p < 0.01) in the concentrations of 42 % of the elements and were higher in male animals. Higher liver content of elements were observed in the adult age group than in the juveniles. Age-related bioaccumulation of Hg (p < 0.0001) was observed similar to what had also been found in the liver of pilot whales stranded on the coast of Scotland. A strong and positive correlation (p < 0.0001) was shown between Hg and Se, R_S = 0.93. A similar correlation (p < 0.0001) was observed between Al and Ga in males, R_S = 0.85 and females, R_S = 0.91. There was limited information on the interrelationships found between B, Li and Sr. Adult mammals had significantly higher Hg:Se molar ratios than the juveniles (p < 0.0001). However, Se was found in molar excess to Hg in all individuals.