Variation in organochlorine and mercury levels in first and replacement eggs of a single-egg clutch breeder, the thick-billed murre, at a breeding colony in the Canadian Arctic

Contaminant concentrations may vary among sequentially-laid eggs in multi-egg clutches, and this variation has implications for the interpretation of contaminant concentrations in monitoring programs. The thick-billed murre (Uria lomvia) is a key species for monitoring contaminants in the Canadian Arctic and lays only a single egg per year. Therefore, the potential issue of intra-clutch variation in contaminant concentrations is avoided....