Study Finds Grey Seals Can Track Blood Oxygen to Prevent Drowning

Scientists at the University of St Andrews wanted to understand how gray seals manage their time underwater without relying on carbon dioxide buildup as a signal. The researchers placed six adult gray seals in a controlled environment to study their diving patterns. The study further revealed that the seals where only allowed to surface at a designated chamber, where the researchers adjusted the levels of oxygen and carbon dioxide to study the responses from the seals. 

According to the study published in Science, different air compositions were tested to measure their effect on dive times. The researchers adjusted the air in the chamber to create four different scenarios: normal air, increased oxygen, reduced oxygen, and heightened carbon dioxide levels. When oxygen levels were increased, seals stayed underwater for longer, while when oxygen was reduced, they surfaced sooner. Moreover, the level of Carbon dioxide did not altered their behaviour. This simply suggests that oxygen, and not carbon dioxide, was the crucial factor for the seals to come up for air.

Unique Adaptation in Marine Mammals

The report further highlighted that the grey seals have an internal system to track oxygen levels, which allows them to surface before reaching dangerous limits. The report further added that this ability help them prevent from drowning. The researchers also noted that since deep-diving mammals must manage oxygen carefully, one could expect a similar style of management might be present in other mammals species, including whales, dolphins and more.

Lucy Hawkes from the University of Exeter and Jessica Kendall-Bar from the University of California, San Diego noted that the understanding of this adaptation might sheds some light on how marine mammals survive in extreme underwater conditions.