My research focuses on the comparative physiological ecology of vertebrates, specifically, on developmental biochemistry, physiology, morphology, and whole animal energetics, with an emphasis on the respiratory, cardiovascular, and musculature systems. My aim is to elucidate the effect of ontogeny on the diving, thermoregulation, and swimming performance of immature animals in “extreme environments” using marine mammals as models. In light of habitat degradation we must understand the physiological limitations of the immature segments of populations because these groups are the most vulnerable to environmental perturbations.