The demonstrators with the group People for the Ethical Treatment of Animals were dressed in orca costumes and laid in the middle of Sea World Drive for at least an hour, causing traffic problems in the area.

The four demonstrators, whose names were unavailable, were protesting a new Shamu show opening at the marine park around Memorial Day.

The upcoming whale show, "One Ocean," is themed around the idea that humans have to share the ocean with its natives. It will replace the show "Believe," which ran for five years, according to park officials.

Lindsay Rajt of PETA called the demonstration successful and said PETA plans more activism in San Diego and other SeaWorld parks.