What makes Weddell seals such excellent divers, routinely able to forage underwater for food as long as 20 minutes at a time? Did you know they have natural, internal scuba tanks? Weddell seal moms make an extraordinary sacrifice to help prepare their offspring for such extended underwater dives. But how? And could climate change play a role, putting mothers nursing seal pups at great risk? Learn more on NSF’s “The Discovery Files.”