Metabolism and growth of young harp and grey seals

Metabolic rates and growth rates of juvenile harp and grey seals were monitored during the postweaning period after the onset of feeding. Growth rates varied from 0.03 to 0.32 kg d−1, depending on the level of energy intake and absolute body mass of the seal. Measurements of sculp mass (blubber with attached skin), as a percentage of total mass, indicated low rates of growth in the sculp and preferential growth in the core. When feeding started there was a 1.3- to 2.3-fold increase in standard metabolic rate, which was independent of the heat increment of feeding. Metabolic requirements of feeding seals, measured by indirect calorimetry, were between 1.2 and 7.2 W kg−1 in water and between 1.2 and 6.0 W kg−1 in air, similar to average daily metabolic rates calculated from net energy intake.