The expression of the mother is priceless.
The photo was taken in October by USGS scientist William Link. Link, a statistician, was helping researchers tag newborn seal pups. He confirmed Friday that the adult seal was the baby's mom.
It's hard to know what she was thinking when her baby nuzzled up to her in this photo, but Link said the animals flare their noses when disturbed, "so this Mom was pretty relaxed," Link told CNN Friday. "I have a great shot a few seconds later where Mom yawned hugely. She looked utterly content, to me."
The agency's public affairs department had asked scientists for interesting images to post on social media.
As the Instagram caption notes, the Weddell seals of Erebus Bay have been studied extensively for over 40 years.
"Because of its isolation, this population is undisturbed by human activities. The Weddell seal population is healthy and stable, and thus gives a good example for studies of animal population dynamics."
Link said it was a privilege to see the animals up close.
"I was awed," he said. "It's incredible that animals can live and thrive in such harsh conditions. It's hard to describe the remoteness and isolation of the spot -- bitter cold, high winds, no life to be seen except for the seals, an occasional skua or an emperor penguin."
After a seal pup is born, Link said its mom spends all her time close to her baby in a very small area, with hardly any interaction with other seals.
"Mom doesn't even leave for a swim until the baby is nearly ready to be weaned, and even then doesn't get to eat. So while baby puts on a couple of hundred pounds, Mamma loses about twice that much," he said.
For more information on the seals, visit WeddellSealScience.com