Marine mammals, including seals and whales, possess a remarkable diving reflex that is so potent that they do not drown. It’s fascinating to note that if a seal, for instance, were forcibly held underwater, it would perish due to asphyxiation rather than drowning, as water does not enter their lungs. However, it is important to acknowledge that certain ethically questionable experiments were conducted in the past during the study of diving physiology.

Another intriguing observation is that marine mammals do not seem to possess flawless control over their limits. In the case of deep-diving species like sperm whales, we have discovered individuals with indications of decompression sickness, such as bone pitting. This suggests that some individuals may be exceeding their physiological limits, which raises questions about the reasons behind such behavior. Potential factors include evading noise pollution (e.g., seismic testing), engaging in extended foraging when faced with food scarcity, and the accumulation of effects over time, possibly linked to age.

The precise motivations behind these behaviors are not entirely understood, but they provide an intriguing avenue for further research and exploration.