Concentrations of mercury in otters (Lutra lutra L.) in Scotland in relation to rainfall

Concentrations of mercury (Hg) were measured in 112 livers of otters from various areas in Scotland during 1986–1992. Mercury concentration varied from 0.3–44.7 ppm (dry). There was a significant positive correlation between Hg in otters and annual rainfall, consistent with an atmospheric origin of mercury pollution. Mercury concentration was higher in animals with lower body condition. Concentrations were shown to increase with the age of the animal, but not everywhere, and the correlation was weak. It appeared unlikely that during the study period otter numbers were affected by mercury.