Influence of Environmental Pollution on Wildlife Health, Reproductive Performance, and Ecosystem Functioning

Abstract

Environmental pollution, such as endocrine-disrupting chemicals and pesticides used in agriculture, among other consequences for invertebrate prey bases, is another pervasive cause of wildlife decline that differs from habitat destruction by its mechanism. The present paper is devoted to reviewing evidence on the ways in which pollutants influence wildlife individuals' health and reproduction and, further on, influence population and ecosystem functioning as well. It was demonstrated through fundamental toxicological studies that a wide range of human-derived chemicals disrupt the hormone function in wildlife species, causing certain reproductive and developmental problems in birds, fish, reptiles, and mammals. Field data from agricultural systems have, however, connected a particular and common family of insecticides with population reductions in insectivorous birds due to surface water pollution; studies on agricultural intensification, on the other hand, demonstrate that the use of pesticides has a negative influence on biodiversity at various trophic levels, even after controlling for other aspects of intensification. Individual and population-level impacts are related to the functioning of ecosystems by severe reductions in the biomass of flying insects found in nature reserves within agricultural landscapes. This suggests that pollution affects the prey base and ecological functioning of even formally protected habitats. In sum, this information demonstrates that pollution represents a multi-level threat to wildlife from individual endocrine disruption to landscape-level reductions in insect biomass, which cannot be dealt with through area-based conservation measures.