Back With a Splash: Sea Lions Return to Denver Zoo Upon Completion of New Habitat

A crowd of children gripped the fence barricading them from a large pool of saltwater before a backdrop of small coastal houses, shuffling to get a glimpse of the open doorway from which the act of the hour would soon emerge.

The much-anticipated personality turned out to be Gunnison, a 300-pound sea lion who is one of four pinnipeds recently brought back to the Denver Zoo Conservation Alliance after the completion of the zoo’s new, $19 million state-of-the-art sea lion habitat, which replaced the one that began housing the animals in 1987.

"At that time, it was state-of-the-art, it was great, but they did not realize the importance of salt water for marine animals," says Denver Zoo carnivore animal care specialist Meryt Schumacher. "Our facility needed to be renovated so that we could have salt water in all of our pools. Previously, our exhibit pools were freshwater, and our holding pools were manually salted by us."
After the upgrades, all of the sea lions' pools are saltwater, and the pools' new saltwater filtration system will save an estimated 8 million gallons of water a year, according to the zoo's sustainability team. "Our holding pools are so much larger than what they were before, so if animals have to be inside for an extended period of time, they have a lot more space to be able to swim," Schumacher adds.

But those are just the behind-the-scenes upgrades. A viewing area with ample seating gives guests a place to relax and watch the sea lions as they glide and dive deep beneath the surface of the new pool.
Technically, the animals now live at "Schlessman Shores," a beach area with a vibrant façade of homes reflecting the real-life communities where sea lions and people coexist.

According to Jake Kubié, the zoo's director of communications, the sea lion habitat upgrade was the bookend to the zoo's Great Wild Open campaign, a fundraiser started in 2019 that just reached its $75 million goal. "That campaign has helped us build an animal hospital and a lot of other upgrades throughout the campus. Donor and community support is a big part of it," Kubié says.

Nearly 30 percent of the $19 million bill for the new facility was covered by donors, including the Koelbel Family Foundation, the Anschutz Foundation and the Schlessman Family Foundation.

The renovations took almost two years to complete; the sea lions had been away from the Denver Zoo since October 2023. "They’re very charismatic animals, and I think a lot of people missed seeing them while they were gone, so I think it’s exciting to have them back," Schumacher says.

While the facility was being upgraded, the pinnipeds were moved to different zoos around the country, which was no small task. Prior to their relocation, Schumacher's team began training the sea lions — Luci, Ady, Gunnison, Maverick and Nick — to be comfortable going into a crate and having the door shut. "Everybody went into their own special crate, and we have a transport company that moved them," Schumacher explains.

Maverick went to Hogle Zoo in Salt Lake City, Luci and Ady went to Brookfield Zoo in Chicago, Gunnison went to the Seneca Park Zoo in Rochester, and Nick went to National Zoo in Washington, D.C.

Denver Zoo staffers traveled with each of the sea lions to their temporary homes to help them transition to the new keeper who would be working with them. Schumacher says that her team continued to keep in close communication with the other keepers while the sea lions were away.

Luci, Ady, Gunnison and Maverick returned to the Denver Zoo and their new-and-improved habitat this May. Nick is slated to return in the fall, as he is currently in rut, a breeding season that sea lions go through in the summer that can make intact males (like Nick) more distracted and territorial. "We thought it would be in his best interest to stay there for the season and then come back in the fall when he was out of rut," Schumacher says. "It helps us to be able to help our animals get used to the space without a distracted boy in the mix."

The four other sea lions have been settling in well. "They’ve been doing great," Schumacher says. "All of our training is positive reinforcement-based. Previous to them leaving, we had spent many years working with them and had a great relationship with them. Everybody came back and they were eating and participating. It kind of felt like they never left."
Sea lions are social creatures who like learning new things, but most of the "tricks" they perform in the twice-daily demonstrations really just aid in their own health checks. Luci, the Denver Zoo's oldest sea lion, is 24 years old. "They have really great health care, a constant diet and don’t have to worry about predators," Schumacher says. "They have it pretty good." 

In April and May, Schumacher and others from the Denver Zoo traveled to California to help sea lions that don't have it as good. The Marine Mammal Rescue Center in San Pedro saw an extreme influx of patients due to a domoic acid event that typically happens in the summer; Schumacher says that this year's event happened earlier than she's ever seen it.

"Basically, ocean waters get warm, there’s a bacteria that blooms, you have fish that eat the bacteria and then larger animals that eat the fish," Schumacher explains. "That neurotoxin creates a lot of health issues with the animals, so they saw a lot of streaming sea lions and some other mammals like dolphins and whales."

The center had eighty patients when Schumacher was there. The team from Denver helped feed and clean the animals, and Schumacher says that on her last day, the center was able to release fifteen sea lions.

"They’re fun, they’re so smart, easy to train, and I love being able to do training and learn with them as we’re teaching them new behaviors," Schumacher says of her work with sea lions. "It’s very rewarding, and they all each have their own individual personalities."

Maverick, for example, is very inquisitive and loves toys and puzzle feeders. "All of us are super excited that they’re back," Schumacher says.

Sea lion demonstrations are held at 10 a.m. and 3 p.m. every day at the Denver Zoo, 2300 Steele Street.