PETA sues SeaWorld for 'enslaving' orcas.

Killer whale Tilikum, watches as SeaWorld Orlando trainers take a break during a training session at the theme park's Shamu Stadium. Photo / AP

Animal rights group PETA is accusing US marine park SeaWorld of "enslaving" orcas.

People for the Ethical Treatment of Animals (PETA) is taking the marine park to court, accusing the SeaWorld parks of keeping five star-performer whales in conditions that violate the 13th Amendment ban on slavery.

Although SeaWorld said the suit is baseless, PETA is arguing that the 13th Amendment, while prohibiting slavery and involuntary servitude, does not specify that only humans can be victims.

The plaintiffs are the five orcas, Tilikum and Katina based at SeaWorld in Orlando, Florida, and Corky, Kasatka and Ulises at SeaWorld San Diego, California. Tilikum, a six-ton male, made international headlines last year when he grabbed a trainer at the close of a performance and dragged her underwater until she drowned.

The lawsuit asks the court to order the orcas released to the custody of a legal guardian who would find a "suitable habitat" for them.

"By any definition, these orcas are slaves - kidnapped from their homes, kept confined, denied everything that's natural to them and forced to perform tricks for SeaWorld's profit," said PETA's general counsel, Jeff Kerr. "The males have their sperm collected, the females are artificially inseminated and forced to bear young which are sometimes shipped away."

However, SeaWorld said any effort to extend the 13th Amendment's protections beyond humans "is baseless and in many ways offensive."

PETA's legal team, which includes New Zealand marine biologist Ingrid Visser, have spent 18 months preparing the case, which they believe is the first federal court suit seeking constitutional rights for members of an animal species.

The suit will be filed tomorrow.

- HERALD ONLINE