Mercury contamination of seabird and sea duck eggs from high Arctic Greenland

Mercury (Hg) levels in the environment have substantially increased over the past century leading to increased concentrations in many high trophic level predators, including Arctic seabirds. From the Canadian high Arctic, research on seabird eggs has documented some of the greatest concentrations of egg Hg anywhere in the Arctic. Farther east, in high Arctic Greenland, no similar data on Hg concentrations in eggs exist, making spatial comparisons unfeasible. To address this paucity of data, we collected whole eggs from Thick-billed Murre Uria lomvia (n = 11), Black-legged Kittiwake Rissa tridactyla (n = 9), and Common Eider Somateria mollissima (n = 12) in the high Arctic of northwest Greenland in the summer of 2014 and assessed their concentration of total Hg. Thick-billed Murre eggs had the highest mean total Hg concentrations (1.32 +/- 0.42 mg g(-1) dw) followed by kittiwakes (0.64 +/- 0.19) and eiders (0.23 +/- 0.10). When compared with murre and kittiwake egg samples collected in high Arctic Canada during the same time period, total Hg concentrations from northwest Greenland were higher, but not significantly. Based on what is known about lethal Hg concentrations in murre eggs, these results indicate that some murre eggs may be at risk for increased embryonic mortality and further monitoring is suggested to determine long-term trends in egg Hg concentrations.