Abstract
The possible effects of human activities (such as the release of pollutants, exploitation, and disturbance) on the reproductive performance of pinniped populations (especially of certain seals) are discussed. While there are documented cases of reproductive rates increasing in exploited seal populations, the effects of disturbance on reproduction have only been suggested on the basis of rather incidental observations. In a number of cases the decline of a pinniped population has coincided with an elevation in the level of various contaminants. In some animals, reproductive failure has been associated with high levels of contaminants in their tissues; but even in these cases, no cause-and effect relation between pollutants and altered physiological processes has been established. Clearly, far more research will be needed to elucidate these problems.