Pathophysiology of Stress in Wild and Managed-Care Bottlenose Dolphins (Tursiops truncatus)

Abstract

Abstract : Concern for the conservation of marine mammals continues to rise as they are exposed to multiple anthropogenic and natural environmental stressors (Fair and Becker, 2000; Bossart, 2006; 2011). Stress responses play a critical role in allowing animals to cope with environmental perturbations. As such, there remains a large gap in our knowledge about the pathophysiological effects of both acute and chronic stress to guide management decisions on these important species. A paucity of research exists that characterizes basic stress responses required to better understand multiple stressors and biologically significant effects. As top predators, marine mammals can serve as an integrator and intensifier of the diverse stressors and hazards present in the environment. The growing concerns about anthropogenic stress include multiple stressors faced by marine mammals from increased environmental exposures to pathogens, pollution, noise and other acoustic influences. Studies that evaluate these effects in marine mammals are lacking since much of the baseline data related to physiology and health are not available. Given the limited amount of data specific to free-ranging marine mammal populations, our study used managed-care animals to bridge this gap and generate baseline data for stress parameters to ground hypotheses regarding wild populations. The bottlenose dolphin is a particularly relevant species to study stress, as it is the most common cetacean in near coastal waters, with a cosmopolitan distribution, widely represented along the U.S. coast and an important resource for the U.S. Navy.