Updated February 5.

The federal government listed a captive orca at a Miami aquarium as an endangered species on Wednesday, though the new designation doesn't mean the killer whale will be released anytime soon.

Animal activists have fought for years to free the orca, known as Lolita, from the Miami Seaquarium.

In response to a petition filed in 2013 by a consortium of animal rights groups, the National Oceanic and Atmospheric Administration (NOAA) Fisheries ruled Wednesday that "captive animals such as Lolita cannot be assigned separate legal status from their wild counterparts." Lolita came from a specific population of orcas that has been listed as endangered since 2005.

The ruling does not affect other captive orcas in the U.S., says Michael Milstein, a public affairs officer with NOAA Fisheries. Lolita is a special case because she is the only known captive orca in the U.S. from the only population of the species that is considered endangered according to the federal Endangered Species Act.

Wednesday's ruling does not have an immediate effect on Lolita, Milstein said, because "the Endangered Species Act does not prohibit keeping of captive animals." In fact, he said that releasing an orca that has been captive so long could put her and wild animals at risk from disease or aggression.

"Our primary concern is with the safety of wild whales," he said, "in addition to the safety of the captive whale itself."

A spokesperson for the Miami Seaquarium said it was not planning to make any changes.

"Just because she was listed as part of the Endangered Species Act does not mean that she is going anywhere," Seaquarium general manager Andrew Hertz said in a statement. "Lolita is healthy and thriving in her home where she shares her habitat with Pacific white-sided dolphins."

Unique Whale

Lolita was caught in Puget Sound and has been on display at the Miami Seaquarium since 1970. NOAA verified through genetic testing and physical characteristics that the whale originated from the population known as the Southern Resident Killer Whales, which spend much of the year in the inland waters of Washington and British Columbia. That population was classified as endangered in 2005 and is thought to include only about 80 whales.

NOAA Fisheries ruled on Lolita's status after receiving 17,000 comments from the public, most of which supported her inclusion in the endangered species designation, Milstein said.

This isn't the first time a government agency has included captive animals in endangered species designations. The government previously listed sturgeon; the U.S. Fish and Wildlife Service is currently considering the status of captive chimpanzees.

Legal Battle to Come?

Animal rights activists hope the new designation moves Lolita a step closer to release.

"Now that Lolita has been given additional protection from 'harm and harassment' (how else can being confined to the smallest orca tank in North America, denied an orca companion or shelter from the sun, and forced to perform stupid tricks be described?), we'll work to ensure that these protections are enforced and continue to push for her retirement and release," the nonprofit group People for the Ethical Treatment of Animals (PETA) said in a blog post on Wednesday.

A government official familiar with the issue said that PETA may try to use the Endangered Species Act as leverage to sue for the release of Lolita, under the legal precedent that endangered animals cannot be "taken" or "harassed."

Under that reasoning the ruling could be used as leverage to sue for Lolita's release.

"There is now significant precedent behind the idea that captive animals need to be protected just as wild members [of the species] are, and we are going to use everything in our power to make sure that Lolita is protected by the harm and harassment provisions of the Endangered Species Act," said Jared Goodman, PETA's director of animal law.

But the Seaquarium argues that it's in Lolita's best interest to stay there.

"There is no scientific evidence that the 49-year-old post-reproductive Lolita could survive in a sea pen or the open waters of the Pacific Northwest," the Seaquarium's Hertz said in his statement. "And we are not willing to treat her life as an experiment."

Wednesday's ruling came in response to a petition filed by the PETA Foundation, the Animal Legal Defense Fund, and the Orca Network.