In a major concession to critics and animal welfare groups, SeaWorld Parks & Entertainment Inc. says it will stop breeding captive killer whales.

SeaWorld's treatment of its killer whales, or orcas, was put in the spotlight three years ago by Blackfish, a documentary that examined the death of SeaWorld trainer Dawn Brancheau, who was killed by an orca named Tilikum. Since then, in a steady campaign on social media, critics have demanded SeaWorld end its orca breeding program.

In an agreement with the Humane Society of the United States, SeaWorld says it now will do so. In a news release, HSUS President and CEO Wayne Pacelle said, "Today's announcement signals that the era of captive display of orcas will end."

SeaWorld President and CEO Joel Manby said in the same news release, "As one of the largest rescue organizations in the world, we will increase our focus on rescue operations — so that the thousands of stranded marine mammals like dolphins and sea lions that cannot be released back to the wild will have a place to go."

The director of Blackfish, Gabriela Cowperthwaite, called it "a defining moment. The fact that SeaWorld is doing away with orca breeding marks truly meaningful change."

For SeaWorld, the agreement resolves an issue that has held up expansion of the company's San Diego theme park. Last year, the company announced it would phase out theatrical orca shows at SeaWorld, San Diego.

Plans for a new, expanded orca habitat were submitted for approval to a state regulatory body, the California Coastal Commission. The commission gave its approval, but only if the theme park agreed to end captive breeding of orcas. SeaWorld went to court, arguing in a lawsuit that the commission doesn't have the authority or the expertise to make such a demand.

But with today's announcement, SeaWorld is now agreeing to end captive breeding, not just in San Diego, but also at its two other SeaWorld parks, in San Antonio, Texas, and Orlando, Fla. It is a major concession that also signals a change in SeaWorld's business model.

On the company's blog, SeaWorld announced it is phasing out over the next three years theatrical performances featuring orcas.

"We will introduce new, inspiring, natural orca encounters rather than theatrical shows, as part of our ongoing commitment to education, marine science research and the rescue of marine animals."

SeaWorld has seen attendance decline at its three parks since the release of Blackfish. The company says the decline, in part, is because of the film. The stock price of the publicly traded company has dropped by more than half in the past three years.

Industry analysts say SeaWorld needs new attractions to compete with other theme parks, such as Walt Disney Parks & Resorts and Universal Studios Theme Parks. SeaWorld has several new roller coasters in the works and recently unveiled images of a new signature submarine ride it's planning in San Diego.

By ending captive breeding, SeaWorld is moving toward a future that eventually will no longer include orcas.

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