The Bottlenose Dolphin (Tursiops truncatus) as a Model to Understand Variation in Stress and Reproductive Hormones Measures in Relation to Sampling Matrix, Demographics, and Environmental Factors

: The overarching goal of this research is to develop indicators and methods to quantify chronic stress in bottlenose dolphins. Much research has focused on the stimuli that induce stress in marine mammals, as well as the hormonal mediators of the stress response. Stress may be induced by a variety factors, including noise, pollutant or toxin exposure, presence of predators, loss of prey and/or habitat changes. The stress response is complex and difficult to study experimentally in marine mammals due to ethical and logistical considerations, but it has been well characterized in other laboratory mammal species. Using the bottlenose dolphin as a model species, the specific objectives for this project are as follows: (1) determine the correlation of hormone measures (cortisol, T3, T4, FT4, reproductive hormones) between blood and blubber; (2) develop a comprehensive understanding of factors that influence stress hormone levels and establish reference intervals for blood and blubber measurements, determining necessary stratifications by sex, age, and/or sampling season; and (3) examine relationships among the various hormone measures, and conduct preliminary screening analyses to examine potential relationships between the stress hormones and other health measures, including immune function.