SEASONAL CHANGES IN BLUBBER DISTRIBUTION IN ATLANTIC HARBOR SEALS: INDICATIONS OF THERMODYNAMIC CONSIDERATIONS

• Published in: Marine Mammal Science
• Main Authors: ROSEN, DAVID A. S., RENOUF, DEANE
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1997
• Subjects: Aquatic Science; Ecology, Evolution, Behavior and Systematics; Elephant Seals; Southern Elephant Seals
• Online Access: http://dx.doi.org/10.1111/j.1748-7692.1997.tb00630.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1748-7692.1997.tb00630.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1748-7692.1997.tb00630.x

ABSTRACT Among its functions, the hypodermal blubber layer of pinnipeds serves as both an energy reserve and insulation. This study examined seasonal changes in blubber distribution and body morphology in a group of captive changesharbor seals to test whether these changes were designed to maximize insulative effectiveness. Seasonal changes were found in girth, blubber volume, mean blubber depth, and the ratio of blubber depth to body radius (d/r ratio). These changes were more evident in older seals. The d/r ratio demonstrated a smaller relative annual change than mean blubber depth. The d/r ratio also exhibited less variation along the length of the seal than blubber depth at any given time. Similar to reports for ringed seals, and contrary to those for southern elephant seals, the harbor seals preferentially lost blubber from overinsulated areas of the body. These results suggest that core tissue and blubber mass are lost in a manner that maximizes insulative effectiveness.