SeaWorld Entertainment Inc announced plans on Monday to phase out the signature "Shamu" killer whale show at its San Diego Park next year, after long-running criticism of its treatment of the captive marine mammals.

The move follows a vote by the California Coastal Commission last month barring the park from continuing to breed killer whales, or orcas, in captivity, was announced during a webcast company presentation to investors and the media.

In place of its centerpiece orca performances, the park plans to open a new killer whale exhibition in 2017 staged in a "more natural setting" with a more conservation-oriented theme, SeaWorld Chief Executive Officer Joel Manby said during the presentation.

SeaWorld executives did not immediately elaborate on how the new attraction would differ from the old shows. And it was not clear whether the same changes would be undertaken at the company's two other aquatic theme parks in Orlando, Florida, and San Antonio, Texas.

SeaWorld has faced heated criticism and declining admissions since release of the 2013 documentary film "Blackfish", which depicted captivity of killer whales as inherently cruel and said the practice has persisted because orcas are the primary attraction at the company's highly lucrative theme parks.

The film, which SeaWorld has criticised as inaccurate and misleading, also explored the circumstances leading to the 2010 death of a top SeaWorld trainer, who was pulled underwater and drowned by an orca she had worked and performed with in Florida.

Trainers have not been allowed back into the water with killer whales during performances at SeaWorld since that incident.

A plan by the San Diego Park to expand its orca pools drew opposition from animal rights groups and their supporters who wanted to see the park's collection of 11 killer whales released into the wild instead.

The state Coastal Commission voted unanimously in October to permit SeaWorld San Diego to expand its orca habitat while requiring the park to cease its captive-breeding programme for the whales. SeaWorld said days later that it intended to challenge that decision.

The commission's decision was seen as a major blow to the park's long-running traditional orca shows, named for Shamu, the original killer whale star of SeaWorld's performances, in the 1960s and early 1970s.