Jeff Sharick – Masters student

I am interested in the trade-off between reproductive effort and survival, a key concept in life-history theory. Many studies support the existence of this trade-off but the underlying physiological mechanisms are not well-understood. I am interested in researching this trade-off through the scope of oxidative stress. Oxidative stress has been proposed as a potential mechanism underlying the observed inverse relationship between reproductive investment and lifespan. Prolonged fasting and elevated metabolic rates are associated with oxidative stress by increasing the production of reactive oxygen species which can cause oxidative damage and inflammation. My masters work is looking at oxidative stress as a cost of breeding in the model capital breeding system of northern elephant seals. Being capital breeders, elephant seals represent the physiologically extreme side of prolonged fasting with elevated metabolic rates among some of the highest measured in nature. I am measuring the changes in concentration of markers of oxidative damage, inflammation, pro-oxidants and antioxidants across the l breeding fast for both male and female northern elephant seals. This research will help understand some of the mechanisms behind trade-offs in the life-history theory.

Derek Somo – Masters student

extreme nature pic

I am interested in the unique opportunity marine mammals provide for investigating the impacts of physiological limitation on behavior and the implications of these limitations for demographics in the context of life history theory. Plus marine mammals are pretty cool.

Using northern elephant seals as a model system, for my masters thesis I am looking at how individual variation in pup body reserves at weaning and dive activity across the post-weaning fast impact the rate of development of physiological dive capacity as well as the biochemical mechanisms driving this  development. I intend to pursue my doctorate in additional work on the physiological, biochemical, and behavioral mechanisms which direct development and maintenance of dive capacity.

When I’m not in the field or lab I’m usually dancing Argentine Tango! (An amazing dance everyone should at least give a try).

David Ensminger – Masters student

13185_10151511717191341_366401149_nI am interested in anthropogenic effects on marine life and marine life’s ability to adapt and tolerate changes. I am interested in marine ecology, biology, and comparative physiology. I am currently studying the effect of stress on hormone and metabolite concentrations in male adult northern elephant seals. I am simulating the stress response by conducting an ACTH challenge.



Sarah Codde – Masters student

OI am interested in the ecology and behavior of marine mammals. I have been working at Point Reyes National Seashore for the past 4 years, coordinating the monitoring programs for Pacific harbor seals and northern elephant seals. For my master’s thesis, I will look at how ambient temperature affects the skin temperature and behavior of adult female and pup elephant seals during the breeding season.