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(214) Increasing trends in mercury concentrations in Atlantic and Arctic seabird eggs in Canada. Burgess, Neil1, Braune, Birgit2, 1 2 ABSTRACT- Seabird eggs are commonly used to monitor temporal and spatial trends in marine contamination. Concentrations of total mercury were measured in eggs of three species of seabirds collected from three areas of the Atlantic Coast of Canada between 1972 and 2000. Similarly, mercury concentrations were measured in eggs of three species of seabirds collected at one location in the Canadian Arctic, Prince Leopold Island, from 1975 to 1998. On the Atlantic Coast, mercury levels increased significantly in Leach's Storm-Petrel (Oceanodroma leucorhoa) eggs collected in the Bay of Fundy and Newfoundland between 1972 and 2000. Storm-petrel eggs from Newfoundland contained 0.37 ug/g (wet wt) mercury in 1972 and increased 73% to 0.64 ug/g in 2000. Mercury concentrations in Atlantic Puffin (Fratercula arctica) eggs collected in Newfoundland increased significantly between 1968 and 2000 by 22%. No linear trend was observed in mercury levels in Double-crested Cormorant (Phalacrocorax auritus) eggs collected from the Bay of Fundy and the St. Lawrence River. In 2000, mercury concentrations were highest in Leach's Storm-Petrel and lower in cormorants and puffins (0.28 and 0.22 ug/g respectively, in the Bay of Fundy). In the Arctic, an increasing trend was found in mercury in Thick-billed Murre/Brünnich's Guillemot (Uria lomvia) eggs; concentrations increased 65% from 0.20 ug/g (wet wt) in 1975 to 0.33 ug/g in 1998. Similarly, mercury levels increased 43% in Northern Fulmar (Fulmarus glacialis) eggs from 0.25 ug/g in 1975 to 0.36 ug/g in 1998. No trend was observed in mercury levels in Black-legged Kittewake (Rissa tridactyla) eggs. The relation between mercury contamination and each species' feeding habits and year-round distribution will be discussed. These increasing trends in Atlantic and Arctic mercury contamination confirm the need to reduce global mercury emissions in order to protect marine ecosystem health. Key words: seabirds, mercury, Atlantic Ocean, Arctic Ocean |
