The Weddell seal is a relatively large and abundant true seal with a circumpolar distribution surrounding Antarctica. The Weddell seal was discovered and named in the 1820s during expeditions led by British sealing captain James Weddell to the area of the Southern Ocean now known as the Weddell Sea.

Weddell seals can dive up to 2,000 feet down and stay under for up to 45 minutes. But no matter how deep they dive, like all marine mammals, they must surface to breathe. If natural openings are not available, Weddell seals use their teeth to open and maintain air holes in the ice pack.