Meeting Abstract
Seals must store and efficiently use oxygen while diving and foraging at depth. Like all mammals, they store oxygen in their lungs, blood, and muscle, but the physiological properties of skeletal muscles play a disproportionately large role in defining diving capacities. Further, pups are not born with the same physiological abilities as adults, with muscle oxygen stores typically beginning to develop at the onset of independent foraging. Bearded seals (Erignathus barbatus) are large ice-dependent Arctic seals. They dive to the seafloor to search for and consume benthic fish and invertebrates, and use sea ice as a platform to rest between foraging bouts. In this study, we examined the physiological development of bearded seal locomotor muscle (longissumus dorsi). Samples were obtained from subsistence harvested bearded seals (n = 37) of different ages collected at Point Hope, Alaska. All muscle samples were analyzed for both myoglobin content and non-bicarbonate buffering capacity. We found clear and progressive ontogenetic trends in skeletal muscle physiology, which indicate that young bearded seals are at a physiological disadvantage in diving and foraging ability when compared to adults. These data provide insight into potentially sensitive life-stages, during which individuals are likely constrained in their behavior. Ultimately, defining age-specific diving capacities and physiological limitations can inform understanding of bearded seal habitat use and aid in predicting behavioral responses to environmental change.
