How to Dive Deeper and Longer: Air Sac and Lung Volumes of Penguins

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

The principal investigator will obtain direct lung and air sac volume for three species of penguin (Emperor, Adelie, and King), using state of the art medical technology (MRI, CT-scan) available at the UCSD Keck Center. These data are critical to understanding penguin dive physiology because: (1) The respiratory oxygen store is estimated to be a significant fraction of the total oxygen body store in these species, and (2) the ratio of air sac to lung volume is a potential mechanism for the prevention of pulmonary barotrauma (lung squeeze). Direct measurements are needed to evaluate and interpret data obtained using indirect techniques (based on simulated dives in pressure chambers or on buoyancy-swim speed calculations during dives at sea). The data will allow the investigators to test the hypothesis that mass-specific lung volumes are smaller in deeper diving penguins, and that the resulting ratio of air sac to lung air capillary volume will be sufficient to allow for 60-fold compression of air in Emperor penguins without risk of 'lung squeeze'. Adelie and King penguins are already available for participation in the study. The P.I. seeks support to export Emperor penguin chicks from Cape Washington, to be raised at Sea World, to round out the species comparisons. Broader impacts include creation of educational exhibits at Sea World Parks; establishment of a research and conservation fund for penguins; and student training in medical techniques.