Terrestrial predators can modulate the energy used for prey capture to maximize efficiency, but diving animals face the conflicting metabolic demands of energy intake and the minimization of oxygen depletion during a breath hold.
During the last century, the areas of oxygendepletion have increased drastically from approximately 5,000 km2 in around 1900 to the present day, where they extend to 60,000 km2 — or about one and a half times the total area of Denmark.