Humans are not well adapted physiologically for oxygen deprivation, which increases our vulnerability to the long-term effects from any disease that disrupts the body’s oxygen supply pathway, such as COVID-19. But marine mammals are very well-adapted to low oxygen levels, since they routinely perform strenuous activities while holding their breath for long periods under water, using up the oxygen in their circulatory system as they dive.
To learn more about this cutting edge research, check out an article by Dr. Terri Williams at UC Santa Cruz.