FOOD-REQUIREMENTS OF WHALES IN THE SOUTHERN-HEMISPHERE

Feeding data for small and medium sized cetaceans parallel the basal metabolism predicted for mammals. Heat loss calculations, a consideration of feeding volumes, and the feeding data indicate the energy requirements of the large whales can be expressed as 1.5 times the calculated basal metabolism. Comparing the energy requirement calculated for fin whales to the energy available from storage indicates that fin whales must feed, though at a reduced level, while away from the Antarctic. A summation of the food requirements for both the initial and recent populations of whales in the southern hemisphere indicate that whales are major oceanic consumers. The reduction in their numbers through hunting has reduced their food requirements by about 50% in the open ocean and by 75% in the Antarctic, leaving approximately 96 × 106 tons per year of 'unconsumed' food. © 1979.