Eco-toxicants: A Growing Global Threat

Ecotoxicology is a constantly evolving discipline, and ecological risk assessments are required to estimate and predict threats and exposures before they occur. There is a critical need to obtain species- and site-specific data to determine toxicological sensitivities under prevailing environmental conditions and so mitigate the potential effects of pollutants on wildlife, particularly on species that are already endangered. Cetaceans are considered one of the most vulnerable organisms with respect to long-term toxicity of chemicals such as organochlorines and metals. Many studies have investigated the factors affecting the accumulation, metabolization, and potential harmful effects of such pollutants, but the question of whether chemical pollution is changing the dynamics of the populations is not yet resolved. In the case of primates, although extrapolations can be made to some extent with humans, the pollution levels and their effects in wild populations are largely unknown. The present chapter examines the main cetacean and primate features that might lead to differential vulnerability among individuals, populations, and species, and evaluates how behavioral patterns can influence exposure potential and outcomes. Furthermore, the role of pollutants as stressors of the ecological health and social systems of cetaceans and primates is explored by two case studies: the first case describes site fidelity of common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay (Florida, USA), despite the cumulative impacts that they face resulting from human activities, and the second case discusses manganese-induced neurotoxicity as a causal agent of cognitive, motor, and behavioral dysfunctions in cynomolgus monkeys (Macaca fascicularis).