Oxygen uptake and temperature regulation of young harbor seals ( Phoca vitulina richardi) in water

Abstract

Abstract o 1. Oxygen uptake and body temperatures were measured in two young harbor seals at water temperatures between 5 and 37°C. 2. Basal metabolic rates of both animals were approximately 0·74 u O2g−1hr−1 or about 2·6 times the value expected for an adult terrestrial mammal of the same weight. Lower critical temperature was 12°C in one animal and 19°C in the other. 3. A surprising tolerence to high water temperatures was demonstrated and thermal and metabolic equilibrium could be established with only a 2°C difference between deep body and water temperature. 4. It is concluded that water at temperatures typically encountered by newborn of the northern harbor seal imposes only a modest cold stress requiring, at most, a 2-fold increase in metabolism over the basal rate.