Sperm abnormalities associated with high copper levels in impala (Aepyceros melampus) in the Kruger National Park, South Africa
The morphology of spermatozoa may be affected by very low concentrations of pollutants in the environment, and sublethal effects of toxic substances can be detected by studying the sperm of an animal. Sperm were collected from 50 impala (Aepyceros melampus) from a conservation area in South Africa and studied ultramicroscopically. Thirty-two samples were obtained from animals close to a copper mine, while 18 represented animals from an unpolluted area and held in captivity. Liver samples from all these animals were analyzed for their copper content. The findings from 12 animals kept in captivity and fed on a diet to which copper was added correlated with the findings from the field study. The general condition of the animals as expressed by the fat content of the bone marrow from the area exposed to copper contamination was affected detrimentally in comparison to the animals from the uncontaminated area. High percentages of sperm with neck vacuoles were found in all animals with high liver copper levels. A statistically significant correlation is demonstrated between the percentage of impala sperm with vacuoles in the neck region and the copper concentrations in this group of animals.