Measuring and validating levels of steroid hormones in the skin of bottlenose dolphins (Tursiops truncatus)
Abstract
Project summary Marine mammals face a wide range of anthropogenic stressors including underwater noise. In an effort to avoid biases introduced by the handling stress typically associated with sampling blood in wild animals, previous work has demonstrated that it is possible to extract and measure cortisol from cetacean skin. Additional work is currently underway to validate the measurements made by this assay through examining the relationship between blood cortisol and skin cortisol levels in bottlenose dolphins (Tursiops truncates), including any delay between cortisol peaks in the two matrices. This work is using skin sampled non-invasively from dolphins before, during and after a stress test paradigm at the U.S. Navy Marine Mammal Program, located at the Space and Naval Warfare Systems Center Pacific facility in San Diego, California. Results from various other ONR-funded projects discussed at the May 2014 ONR Program Review meeting made it clear that hormones other than cortisol are also important for assessing stress responses in cetaceans, including progestagens, oestrogens, androgens and aldosterone. Accordingly, the work proposed here represents an expansion of the analysis to include these hormones, without the need for additional sampling. The extraction and analysis methodology will be validated for each new hormone. At full undertaking, this work will also determine the relationship between the blood and skin levels of aldosterone, as well as establish any time-lag between spikes in the two matrices. These results will allow validation of the existing analysis method for aldosterone (in addition to the cortisol validation already funded). Finally, a comparison of all measured hormones with the known age and sex of the dolphins will support interpretation of cortisol and aldosterone levels in skin samples where age and sex may not be known. This is a critical step in taking the method to a point where it can be used in the field.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 08, 2016
- Source ID
- N000141512187
Entities
People
- Thea Bechshoeft
Organizations
- Aarhus University
- Office of Naval Research
- United States Navy