The National Aquarium in Baltimore announced on June 14 plans to move its eight dolphins into a seaside sanctuary by the end of 2020. (National Aquarium)

The dolphin’s name was Spock, and John Racanelli, chief of the National Aquarium at Baltimore, has never forgotten him.

Racanelli was 17 years old, and his job at a San Francisco Bay marine park was to scrub algae off the concrete walls of Spock’s tank. Racanelli said he “wondered what Spock’s previous life in the blue vastness of the open sea must have been like.”

As public opinion about animals in captivity has shifted, Racanelli announced a decision Tuesday to retire the National Aquarium’s eight dolphins and move them to a yet-to-be-built seaside sanctuary in Florida or the Caribbean.

Dolphin experts said research over the years has shown that animals thrive in more natural settings, rather than as part of shows or attractions at aquariums and zoos. The dolphins will remain on display at the aquarium until a new spot is found and a sanctuary is built by 2020, Racanelli said.

In an op-ed published Tuesday in the Baltimore Sun, Racanelli wrote that while baby boomers grew up watching “Flipper,” for the future generation, it was “Free Willy.”

A rendering of what a yet-to-be-built sanctuary in Florida or the Caribbean for the National Aquarium’s dolphins may look like. (Courtesy of the National Aquarium in Baltimore)

“Through feedback painstakingly gathered over 10 years, we have learned that the American public is increasingly uneasy with the notion of keeping dolphins and whales in captivity,” Racanelli wrote. “These beliefs matter to us.”

The decision to shut down the Baltimore exhibit has been five years in the making. Racanelli has served as chief executive of the nonprofit aquarium since 2011, which was about the time aquarium leaders began looking at options for the dolphins.

Racanelli said the aquarium considered rebuilding its aging pools to create a more “naturalistic style” or moving the dolphins to other accredited facilities, but ultimately decided that the best option was to build a sanctuary in a tropical or subtropical area.

He said one of the primary factors was considering what’s best for the dolphins.

“This has not yet been done, and it is not the cheapest or easiest solution,” Racanelli said.

Research shows that dolphins do better in an environment that most closely resembles the ocean in the tropics. Although dolphins have been known to migrate to parts of the Chesapeake Bay seasonally, Racanelli said creating a sanctuary in Maryland wasn’t really an option.

Aquarium officials also wanted to keep the six female and two male dolphins together because they’ve bonded since all but one was born at the aquarium. They range in age from 7 to 44.

Some of the eight dolphins at the National Aquarium that will be moved to a new sanctuary in Florida or the Caribbean. (Heather Moran/National Aquarium)

The National Aquarium’s decision to end its dolphin exhibit comes after other venues and shows have changed how they use animals. SeaWorld in Orlando has stopped its captive breeding program of killer whales. The Ringling Brothers-Barnum & Bailey Combined Shows Inc. recently ended a longtime practice of having elephants in its circuses.

In Baltimore, the aquarium’s dolphin exhibit already had undergone some changes.

A few years ago, the aquarium changed its dolphin exhibit from a performance-based show to more of a display where visitors see the animals swimming in tanks. The aquarium, which attracts more than 1.3 million visitors annually, sits in Baltimore’s Inner Harbor, a popular tourist attraction for the city.

National Aquarium officials are touting the new home for the dolphins as the “first-of-its-kind protected, oceanside habitat.” The dolphins will be cared for full time by a veterinarian and other experts. The aquarium has no plans to breed the dolphins at the sanctuary.

The dolphins’ new home will still have a “digital connection” to the aquarium in Baltimore, officials said, and research will be done at the sanctuary. It will be open to the public, and visitors will be able to watch the dolphins from a viewing deck.

People for the Ethical Treatment of Animals activists have been pushing the National Aquarium and other venues to change or end their exhibits. Dolphins are “highly intelligent, highly social animals,” said Jared Goodman, director of animal law at PETA’s Los Angeles operation.

“When they’re held in tanks, they’re deprived of all of their natural behaviors,” which include taking deep dives and going on long swims, Goodman said. “They can’t swim up to 60 miles a day when they’re held in the equivalent of a bathtub,” he said.

Officials said they will look to donors to help buy land and build the sanctuary, which doesn’t yet have an estimated cost.