Inside the Monterey Bay Aquarium’s incredible surrogacy program for otters
A crowd has gathered around the otter exhibit at the Monterey Bay Aquarium, watching the animals do somersaults in the water and paddle on their backs while clutching toys.
“Aren’t they fun?” asks one of the women. “Bonk,” a tiny observer says as one otter collides with another. “Bonk, bonk.”
But upstairs, past locked doors and a SORAC — Sea Otter Research and Conservation — office, a different kind of otter action is taking place. Three otters are wrangled from a tank into plastic kennels by aquarium staffers using nets to remove mussel shells and other food debris from their enclosure. These aren’t the popular otters from downstairs. These are wild animals that were brought in as puppies after becoming stranded or sick. They were raised at the aquarium with little human interaction and fiercely dodge the nets.
“We actually want them to associate this (process) with a negative interaction with humans,” says Sandrine Hazan, the aquarium’s sea otter stranding and rehabilitation manager. She assists in the capture of one otter, remarking, “We got the problem child first, that’s good.” She simply enjoys climbing onto the nets and making it that much more difficult to capture her.”
The aquarium hopes to return these otters to the wild soon, where they will join an estimated 3,000 southern sea otters living off the coast of California. The fact that there are so many attests to the species’ remarkable recovery.
Eighteenth-century fur traders seeking their lush pelts decimated the population to the point where the otters were thought to be extinct by the early 1900s. It wasn’t until 1914, when a few dozen otters were spotted off the coast of Big Sur, that people realized, against all odds, the otters were still alive.
Since then, conservationists working with the government have protected and increased the otter population, perhaps none more effectively than the folks at the Monterey Bay Aquarium. The aquarium has been rearing otter pups found stranded or sick in the wild since the 1980s, initially using methods best described as “learning by doing.”
“Young pups are so reliant on their mother’s care that when they strand and you care for them as their mother would, they bond with you that strongly,” Teri Nicholson, senior research biologist at the aquarium, says. “They consider you as their mother, and they’ll follow you anywhere.”
This maternal connection was used by Nicholson and others to guide young animals around their natural environment. They took the pups on free-diving swims through kelp forests, collecting urchins and crabs and feeding them to the hungry kids. They practiced staying afloat on the surface, opening clams while floating in the waves, and pounding shells against rocks to crack them open (otters like to use tools).
The pups were raised by the researchers in inflatable kiddie pools and on waterbeds. A staffer had one living in their bathtub for a while. “The caretakers became quite familiar,” the aquarium’s historical literature observes dryly, “with the piercing scream a young otter makes.”
Despite its good intentions, direct human-to-otter contact came at a cost.
“Often a strong bond would endure in the wild after release – especially as our coastlines became more crowded – resulting in persistent interactions with humans,” Nicholson said. “So the minute we had an opportunity to try other methods, we pivoted.”
Today, a staff member is dressed in a poncho and a darkened face shield, similar to a welder’s mask. She enters an ICU room, looking like a B-movie psychopath, and begins fluffing an orphaned pup’s fur with her fingers, mimicking the grooming behavior a mother would do at this age.
“The idea with the disguise is it creates this amorphous shape that masks the human form,” Hazan said. “We don’t want them to form a bond, because then you have to deal with separation anxiety, and it can be difficult for them.”
It turns out that allowing wild otters to become acquainted with humans is not a good idea.
“What we don’t want is when they’re released back into the wild, they’re approaching humans, jumping on kayaks,” Hazan says. “If that were to happen, they would potentially have to be recaptured and (be) unable to be released back into the wild.”
Despite how entertaining it may sound, you do not want an otter on your kayak. When handling otters, aquarium employees wear heavy Kevlar gloves. Despite this, Hazan’s hands have bite marks.
“Otters are very charismatic and adorable, but they’re also dangerous,” she says. If they want something, they’ll try to get it with their teeth or paws. And the way they play or roughhouse can cause injury even if they are not aggressive.”
As a result, the program’s rescued otters are effectively blinded to the sight, sounds, and smells of humans, raising the question of who is actually doing the hard work of raising the pups.
Naturally, there are other otters.
In the 1990s, aquarium workers in the field observed adult female otters caring for young otters who were not biologically related. They had the opportunity to observe this behavior in a controlled setting in 2001, when an otter mother lost a pup to stillbirth and they received an orphaned pup from a nearby beach.
“Both animals were in distress – the female at the aquarium was vocalizing for her dead pup, and the orphaned pup we’d picked up was vocalizing for its mother,” Nicholson says. “So we introduced them and within minutes, the two resembled a natural mother-pup pair.”
That quickly became the new standard procedure. When a helpless pup is discovered in the wild, the aquarium often pairs it with one of the public exhibit’s captive otters. The two enter a private tank together, where the surrogate otter mother teaches the pup how to survive outside. When the pup is released into local waters, the mother is returned to the exhibit until the next time duty calls.
Some surrogates have raised over a dozen wild pups. But do they have fun doing it?
“Each female is unique, and each introduction between mom and pup is unique.” “Just as we all feel differently on different days,” Nicholson says. “On some occasions, the bond is instant, while on others, it may take some time. We’ve had mother-puppy pairs switch pups.”
Otter fathers are not involved because, as in the wild, they are not required at this time.
“Not unlike many mammal populations, the female is the primary caregiver, and the male contributes his sperm,” Nicholson said. “The males are holding territories, mating with other females, while females are just rearing their young.”
Seventy-five percent of pups raised in the surrogacy program went on to establish themselves in the wild and contribute to population growth (compared to only 31 percent without surrogates). The results can be seen in the Elkhorn Slough, a 7-mile-long body of water north of Monterey. The aquarium used to release otters here because it is safe and free of sharks, but the slough is now full.
Southern sea otters spanned all sides of the water on a recent afternoon, doing somersaults to remove parasites and clean their fur, sticking their paws up to warm in the sun, and wrapping themselves in eelgrass to take little naps. Some otter mothers, distinguishable by nose scars caused by mating, could be seen demonstrating behaviors to their pups such as grooming and cracking clam shells.
Surrogate otters and their offspring are thought to have contributed to more than half of Elkhorn’s population growth. And the presence of otters has benefited the slough by preventing other species from overpopulating and causing damage, as well as increasing the growth of native seagrass beds, which act as carbon sinks.
“We saw a lot of improvements in ecosystem health in just that area as that population grew in Elkhorn Slough,” says Cara Field, medical director at the Marine Mammal Center in Marin.
“There is a lot of enthusiasm for assisting in the restoration of our entire (Pacific) coastline to a more healthy ecosystem.” And otters may have a significant role to play in this. At least, that’s what those of us interested in otter reintroduction believe.”
Surrogate mothers never get to see the benefits they’ve brought to the Monterey Bay ecosystem from their permanent homes at the aquarium. They do, however, have their little pleasures. Take Rosa, a surrogate mother who has successfully raised 15 puppies.
“She was a phenomenal surrogate, very consistent from pup to pup in how maternal she was,” Hazan said.
Rosa has retired at the age of 23. And how does an otter spend his or her retirement?
“I mean, luxury,” Hazan clarifies. “You can have whatever you want, as much crab as you want.” You don’t have to deal with any annoying puppies, and you don’t have to look after anyone. You can be grumpy and irritable one day and decide you don’t want to eat something, then like it the next. Everything will be catered to you, which is pretty incredible.”
