US theme park SeaWorld plans to replace its "Shamu" killer whale shows in San Diego with displays focused on conservation, after sagging attendances and criticism over treatment of the captive marine mammals. A highlight of the shows has been a leaping killer whale, or orca, unleashing an enormous splash onto the front rows of spectators. The move announced on Monday followed a vote by California regulators last month barring SeaWorld San Diego from continuing to breed orcas if it proceeds with a planned expansion of their artificial habitat. SeaWorld has faced censure since the 2013 release of the documentary Blackfish, which depicted the captivity and exhibition of killer whales as cruel. SeaWorld called it inaccurate and misleading.