Pollock Conservation Cooperative Research Center
2009 Awarded Research Projects
Project title: Impact of health and maternal investment on survival of endangered Steller sea lion pups
Principal investigator: Shannon Atkinson
Award: $66,609
Abstract
There is a well-established link between the mammalian immune and endocrine systems. These finely tuned interactions are required for the survival and health of an individual and are regulated by circulating hormones, which are in turn influenced by nutrition, body condition and a host of environmental factors. The overall goal of this project is to determine if changes in maternal investment, body condition, and circulating hormone levels results in measurable changes in the health and survival of Steller sea lion (SSL) pups, as measured through the immune system. As part of an ongoing long-term monitoring and research effort, researchers observe the Chiswell Island rookery via a remotely-operated video system, which provides an in-depth assessment of maternal investment as well as pup well-being and survival. During three breeding seasons (2005, 2007, and 2008) pups ranging in age from 5 to 38 days old were measured, weighed, and permanently marked allowing for identification of mother-pup pairs, determination of exact pup ages, and assessment of maternal investment. Blood samples were collected from 61 pups (24 female, 37 male) for the measurements of a suite of blood-borne components, including complete blood cell counts, lymphocyte proliferation, serum chemistries, contaminants, and circulating levels of IL-6. Some of these measurements have been made, however this proposal requests funding for the remaining endocrine and immune assays. Serum will be used to determine circulating levels of adrenocorticotropic hormone (ACTH), ghrelin, cortisol, aldosterone, leptin, and thyroid hormones. The complete suite of measurements will allow a comprehensive evaluation of health parameters that will be used to compare with the level of maternal investment and survival of SSL pups.
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