Body and blubber relationships in antarctic pack ice seals: implications for blubber depth patterns

Area of Science:

• Marine Mammal Physiology
• Antarctic Ecology
• Physiological Ecology

Background:

• Investigating physiological adaptations of Antarctic seals is crucial for understanding their survival in extreme environments.
• Data on morphometrics and blubber depth across multiple Antarctic seal species from a single location and season are scarce.

Purpose of the Study:

• To compare morphometrics and blubber depths across four high Antarctic seal species (Weddell, Ross, crabeater, leopard).
• To determine variances in blubber depth related to species, sex, and age.
• To differentiate the influence of species, sex, and age on blubber mass by controlling for location and season.

Main Methods:

• Collected morphometric and blubber depth data from Weddell, Ross, crabeater, and leopard seals during a midsummer research cruise in the Ross Sea.
• Measured absolute blubber depth and the ratio of blubber depth to body core diameter.
• Analyzed data to identify differences related to species, sex, and age.

Main Results:

• Adult and younger seals exhibited differences in blubber depth.
• No significant differences in blubber depth were found between male and female seals within any species.
• Adult Weddell seals showed a distinct ratio of blubber depth to body core diameter compared to the other three species.

Conclusions:

• Blubber depth is influenced by age, but not sex, across these Antarctic seal species.
• Weddell seals appear to utilize blubber differently than Ross, crabeater, and leopard seals.
• This unique blubber pattern in Weddell seals is likely linked to nutritional demands during the breeding season, outweighing thermal regulation needs.