Mercury accumulation in mink fed fish collected from streams on the Oak Ridge Reservation

This study evaluates effects of feeding mercury (Hg) contaminated fish collected from streams on the Oak Ridge Reservation (ORR) on mink. Diets composed of 25, 50, or 75% fish collected from streams on the ORR were fed to mink beginning 3 months prior to breeding and ending 6 weeks following whelping. Mercury concentrations in diets, tissues of adult mink and their offspring, and physiological and reproductive effects were recorded and compared to concentrations and effects observed in mink fed diets composed of 75% fish collected from the Clinch River above the ORR or from the ocean. Mercury concentrations in prepared diets and in tissues of adult mink and their offspring increased progressively with increased percentage of ORR fish in the diets. Female mink fed diets containing 75% ORR fish had reduced body weight and a decreased number of kits compared to those fed diets containing 75% fish collected above the ORR or from the ocean. However, based on previously reported Hg concentrations associated with adverse effects in mink, the observed adverse effects are not thought to result from exposure to Hg.