What Oceanographers Can Learn From Their Animal Colleagues
A gulp of air, a kick of flippers, and the elephant seal dives. Sunlight slants through the Southern Ocean’s melting roof of sea-ice, its solid dome shattered by the arrival of Antarctic summer. The seal—Mirounga, we’ll call her—descends many times each day to snatch fish and squid in her toothy jaws; she spends 90 percent of her life below the surface, thinks nothing of a thousand-foot foraging plunge. But now she’s diving deep, truly deep, galvanized by the clicks and squeals of an approaching pod of orcas. Mirounga can go places where killer whales can’t follow.
Two thousand feet below the surface. Three thousand. Four. The light fades to twilight, then to virtual black. The water grows colder, heavier, saltier. Mirounga barely feels it. Her thousand-pound body is insulated by blubber; her muscles themselves store oxygen; intricate vascular networks funnel warmth to her heart. She’s a mile below the surface now, the orcas a distant memory, swimming hard through the dense layer of seawater that creeps along the ocean’s floor and powers the planet’s currents, its weather, its climate. She joins this circumpolar flow, a red blood cell in the circulatory system of the Earth.
