National Geographic : 1966 Jan
when the sea is ice-covered stimulate an amazing growth of plants and animals. Seal-watching proved relatively easy. The animals seemed indifferent to us, and let us approach them in their various moods. We never saw them feed or mate, but we did spot them sleeping directly under the ice. The Weddell will do this at times, the air in its lungs giving it the buoyancy needed to remain securely up against the ice. One marvels at the magnificent metabo lism allowing rest in the coldest environment known on earth, for the thermal conductivity of water at this temperature is 23 times great er than that of air at the same temperature. This means that the human body, for instance, would cool 23 times faster in 28.6° F. water than in air at the same temperature. The un protected body could not produce heat fast enough to survive more than a few minutes. Occasionally we saw seals fighting, at times rather vigorously. I witnessed one such fight 64 from the SOC, while Lavallee and Gimbel were swimming outside. The two seals squared off just five feet under the ice, almost ignoring the divers a dozen feet away. When the seals approached each other, I heard one emit a long descending trill. Then they made loud chugging sounds, their throats pulsating with the power of the "music." They opened their mouths and wagged their heads, circling about counterclockwise. Then they lunged and once or twice made harmless contact. They squirmed and contorted, feinting. This continued for about 30 seconds; then the seals separated and swam away. The struggle seemed to be for dominance, with each seal trying to assert authority over the other. In another fight, the seals were a bit more serious. They circled, each trying to get at the other's throat. They closed and whirled furiously, drawing no blood. This seemed to be a fight to protect a breathing territory and drive away an intruder. Weddell seals kept us amused, amazed, and quite busy for the weeks we watched them.