Dolphin’s Death at Six Flags Discovery Kingdom Prompts PETA Plea to Free Survivors

For Immediate Release:
August 17, 2026

Contact:
Moira Colley 202-483-7382

Just-released records obtained by PETA reveal that after spending four decades confined in tiny tanks at Six Flags Discovery Kingdom in Vallejo, a bottlenose dolphin named Chelsea—who was taken from her ocean home and family off the Gulf Coast in 1983—was euthanized on July 14 due to “multiple recurring chronic diseases” and a “declining quality of life.” In response, PETA sent a letter today to Six Flags Entertainment Corporation CEO John Reilly, calling on him to move the surviving dolphins to seaside sanctuaries and immediately end all swim-with-dolphins encounters.

Chelsea was used as a breeding machine at Six Flags Discovery Kingdom, where she gave birth to six calves—two of whom died prematurely at marine parks.

“For more than 40 years, Six Flags Discovery Kingdom sentenced Chelsea to a life of misery in a sad, shallow pool, stripping away any semblance of the natural life she was born to and using her up like a disposable prop,” says PETA President Tracy Reiman. “PETA is calling on Six Flags to stop clinging to a cruel, dying industry and send the remaining dolphins trapped in its tanks to seaside sanctuaries, where they could finally feel the ocean before it’s too late.”

In nature, dolphins maintain dynamic relationships with large social networks and can swim up to 60 miles a day. But at Six Flags Discovery Kingdom, they’re housed in tanks so cramped that they can do little more than swim in endless circles. The park forces dolphins to perform in regular shows—during which they may endure trainers standing on their faces—and subjects them to stressful hands-on encounters with visitors in its “swim with dolphins” program. Six Flags Discovery Kingdom’s lengthy history of violations of the federal Animal Welfare Act includes a critical citation for the role of poor water quality in the deaths of two young dolphins.

PETA—whose motto reads, in part, that “animals are not ours to use for entertainment”—points out that Every Animal Is Someone and offers free Empathy Kits for people who need a lesson in kindness. For more information, please visit PETA.org or follow PETA on X, Facebook, or Instagram.

PETA’s letter to Reilly follows.

August 17, 2026

John Reilly

CEO

Six Flags Entertainment Corporation

Dear Mr. Reilly:

I’m writing on behalf of PETA and our millions of members and supporters worldwide with an urgent request following the death of bottlenose dolphin Chelsea at Six Flags Discovery Kingdom. Before another dolphin suffers and dies after a lifetime of being forced into shows and stressful, dangerous encounters with humans, denied everything that’s natural and important to them, we urge you to commit to sending the remaining dolphins to seaside sanctuaries.

Nearly every major travel company, including Airbnb, Booking.com, Expedia, and TripAdvisor, prohibits ticket sales to venues that offer dolphin encounters and shows. Companies and consumers alike are recognizing that dolphins’ complex physical and psychological needs simply can’t be met when they’re used for entertainment, and experts agree that these animals exhibit a range of welfare problems, including stress, disease, health issues, and behavioral abnormalities due to conditions of confinement. Chelsea was torn from her family and ocean home in 1983 and spent the rest of her life in tiny tanks while being used as a breeding machine to create even more dolphins to exploit.

The world now recognizes that dolphins deserve freedom. Canada, France, and Mexico have banned dolphin captivity, and that list will only grow. Two belugas were transferred from a marine park in China to a sanctuary in Iceland, three dolphins confined to tiny pools in Indonesia were rehabilitated and released into the sea, and the Whale Sanctuary Project is creating a sanctuary for orcas and belugas in Nova Scotia. Companies that have profited from confining dolphins should be investing in sanctuaries where they can dive deep, swim far, and regain some semblance of a natural life.

Chelsea deserved a future beyond concrete tanks. It’s too late for her, but there’s still time to do the right thing for the surviving dolphins. Six Flags can become a leader in marine animal welfare rather than a relic of a fading industry. May we please hear that you’ll immediately end all swim-with-dolphin encounters, and commit now to sending the dolphins to seaside sanctuaries?

Thank you for your consideration. I look forward to hearing from you soon.

Sincerely,

Tracy Reiman

President