Levels of cadmium, mercury and lead in otter and mink faeces from the United Kingdom

Abstract

Over 500 faeces of otter (Lutra lutra) from Britain, with a small sample from northeast Greece, were analyzed for Cd, Hg and Pb. A small sample of mink (Mustela vison) faeces was also analyzed. Mean concentrations of metals (mg kg-1 dry weight) in otter faeces ranged from 1.53 to 3.97 Cd, 0.25 to 0.74 Hg and 12.4 to 20.9 Pb. Mink faeces generally contained less Cd and Hg, but more Pb. Metal concentrations in faeces may reflect both natural and anthropogenic sources. Estimates of daily Cd and Pb intake were made from faecal concentrations and these were in good agreement with concentrations in major fish prey. The estimates of daily Cd and Pb intake are high, but nevertheless most samples came from thriving otter populations. The value of faecal analysis in assessing metal burdens during surveys of otters is discussed.