SeaWorld will stop breeding killer whales in captivity, bowing to years of pressure from animal rights activists.
But the orcas already at its three parks will continue performing as they live out their remaining years.
SeaWorld Entertainment Inc's decision came after it pledged in November to replace its signature "Shamu" killer whale shows in San Diego with modified presentations of the animals that focused on conservation.
"We don't need all these theatrical 'tricks,'" SeaWorld President Joel Manby told reporters on a conference call. He said the parks will use birth control to halt reproduction among its killer whales, also known as orcas.
SeaWorld, which operates marine parks in San Diego, Orlando and San Antonio, has a total of 29 killers whales, including six on loan to a park in Spain. Five of them were captured in the wild, but it has not caught orcas at sea for almost 40 years.
The parks have been criticised for their treatment of the captive marine mammals, with some activists seeking an end to public exhibition of killer whales altogether.
The criticism intensified after three marine mammals - an orca, a beluga whale and a white-sided dolphin - died at SeaWorld San Antonio within four months in late 2015 and early 2016.
The life span of a killer whale in the wild is typically 30 years for males and 50 for females, with some females living as long as 100 years, according to the website of the National Oceanic and Atmospheric Administration. SeaWorld's oldest killer whale, Corky, is 51.
SeaWorld, whose shares rose 9.4 per cent on Thursday, also said it will scrap plans for a $US100 million ($A134 million) project called "Blue World" to enlarge its orca habitat at SeaWorld San Diego.
Under the new plan, the orcas will still be shown to visitors at set times but re-designed viewing areas will "reflect the natural world" with a program focusing on "orca enrichment, exercise and overall health," according to the SeaWorld website.
SeaWorld faced mounting criticism after the release of the 2013 documentary "Blackfish," which depicted the captivity and public exhibition of killer whales as inherently cruel.
