Surrogate Moms Raise Orphan Pups at Aquarium of the Pacific

Before last month, a young southern sea otter named Rey could never have imagined she’d be a mother. But that changed when she met Sunny, a pup ─ about two weeks old ─ found orphaned and alone on Asilomar State Beach in February. Rescued and brought to the Aquarium of the Pacific in Long Beach, California, the two otters now live as mother and daughter. Arriving at the facility last month, they were successfully paired as part of the facility’s surrogacy program that runs in partnership with the Monterey Bay Aquarium.

A Brilliant "Out of the Box" Idea

The program, created in the 1990s, was launched in 2024, and it pairs maternal-age female otters with young, motherless pups who would otherwise not survive on their own in the wild.

Megan Smylie, the sea otter program manager, says the operation has since rehabilitated and released nine otters into their natural habitat, with three others expected to leave by the summer.

Sunny and Rey cannot be released into the wild, because they are both too used to being around people and lack the survival instincts to make it on their own in the ocean. Instead, the two are destined for motherhood in captivity. For Rey, Sunny will be the first pup she raises into adulthood. And it’s a full-circle moment for her ─ about two-and-a-half years old, Rey was found stranded herself in July 2023.

“Rey has far surpassed my expectations of what I thought was going to happen,” Smylie said. “She’s fantastic.” The aquarium can handle 11 otters at a time, with up to seven in the main tank with rehabilitation pools that can each house two otters. They currently have five otters, including two other females that are preparing to be surrogate mothers.

Incredible Success Story

As a surrogate mom, Rey is teaching her adopted baby everything she needs to know, such as manipulating an imitation crab shell and foraging for food. Young otters, because of the thickness and buoyancy of their fur, don’t have the strength to get their furry bodies to the bottom of the water tank so they need mom’s help to feed themselves. Otters have the thickest coat of any mammal, with as many as a million hairs per square inch. The hairs trap air, which acts as insulation and helps keep the otters buoyant.

In time, Rey may also teach the pup how to use tools. Sea otters are known to be crafty creatures, able to use rocks to crack clam shells, take nuts off bolts and open doors on their own. When it’s time to calm down, she’ll groom the pup, and when it’s time for a nap, Rey will pull Sunny to her chest and roll onto her back. The maternal bond is a strong one, and sea otter pups require constant attention.

An Important Conservation Strategy

Experts say this quick-forming connection, between that of surrogate-raised otters and their wild offspring, has played a significant role in growing the population along California’s Central Coast.

The animals, which once boasted a population of more than 300,000 along the Northern Pacific Rim from Japan to Baja California, were prized for their fur and hunted down to about 2,000 by the early 19th Century. Officials say they were thought to have been exterminated until a colony of otters was discovered nearly a decade later.

Now a federally threatened species, California’s southern sea otter population has rebounded to about 3,000. Despite efforts to aid their comeback, the species faces a low survival rate for pups and constant threats of parasites, shark attacks, and human-caused catastrophes. This makes the work of every mothering otter like Rey all the more important, as she is tasked with not only providing pups the childhood she never had, but also ensuring the preservation of her species.

And while Sunny may never see the ocean again, aquarium staff hope she can grow into a mom herself, giving the next generation of young pups another shot at life.

“That is kind of a happy ending, if maybe a little bittersweet,” Smylie says. Fingers crossed that it will help California’s sea otters survive and even thrive over time.