15: Variability of Hormonal Stress Markers and Stress Responses in a Large Cross-sectional Sample of Elephant Seals

The Office of Naval Research recently funded a multi-year, collaborative research project to investigate baseline hormone variations in northern elephant seals (Mirounga angustirostris) and studies of the hypothalamus-pituitary-adrenal (HPA) and hypothalamus-pituitary-thyroid (HPT) axes (grant # N000141110434). These investigations described natural variation in corticosteroid, thyroid, and catecholamine hormones in northern elephant seals across multiple matrices, and assessed the sensitivity of HPA and HPT axes. Using the large sample bank from this project a number of opportunities to better understand the stress response in pinnipeds, and marine mammals overall, are available. These include the relatively low cost ability to better understand the role the binding globulins play in modulating the bioavailability of stress hormones and the mechanisms by which stress hormones interact with energy metabolism, salt balance, reproductive and immune systems. These research goals will increase our understanding of when stress has biologically significant effects on animals and identify potential mediators and mechanisms of those effects.