A wild sea otter surprised employees of a California aquarium over the weekend when she gave birth to a pup in the aquarium's open-ocean tide pool Sunday.

Monterey Bay Aquarium announced the birth on the aquarium's Facebook page and blog Sunday afternoon.

"We just have to say it -- squee!" employees wrote on Facebook. "A wild otter mom gave birth to her pup in our Great Tide Pool this morning!"

On the aquarium's blog, staff members said they worried about the wild, female sea otter after noticing she frequented the protected basin of the aquarium's Great Tide Pool, apparently to find respite from recent winter storms.

"It's rare for a healthy sea otter to visit the pool so frequently - we started to wonder if she was doing all right," employees wrote in a blog post titled "the squee heard 'round the world."

The mystery was solved the next day when workers spotted a pup resting on the otter's belly. The pup's umbilical cord was still attached.

The aquarium hailed the birth as a "conservation success story."

"Not that long ago, sea otters were hunted to near extinction," according to the aquarium's blog. "Maybe 50 were left in all of California by the early 1800’s. But now, thanks to legislative protection and a change of heart toward these furriest of sea creatures, the otter population has rebounded to steady levels in the Monterey Bay, and with 3,000 total in central California."

Since Sunday, the otters have been seen going back and forth from the aquarium's open tide pool to Monterey Bay.