A petition filed by SeaWorld asking a federal appeals court to overturn a safety violation issued by the Occupational Safety and Health Administration (OSHA) has been denied -- meaning that the park's trainers will not be allowed to interact with killer whales during performances -- a move that is seen as a major step forward for both animal and trainer safety at the marine parks.

Animal advocates have applauded the decision, saying that not only are trainers safer, but the whales are free from the stress that comes along with having humans constantly interacting with and touching them.

The ruling is the culmination of a three-year legal battle that began after the February 2010 death of trainer Dawn Brancheau at the SeaWorld's Orlando park, the central incident of the documentary "Blackfish." OSHA alleged that SeaWorld had violated safety standards, and ordered that trainers maintain a minimum distance or a physical barrier between themselves and orcas. The violation was issued under the "general duty clause" of the Occupational Safety and Health Act -- usually used in citing industries without established safety standards.

SeaWorld appealed this violation, as David Kirby of TakePart reported back in November, when Eugene Scalia (son of United States Supreme Court Associate Justice Antonin Scalia) represented the marine park in court:

Scalia also argued that physical contact with killer whales is as critical to his client's core business as blocking and tackling are to professional football. By banning trainer-to-orca contact at SeaWorld, he argued, the government was irreparably changing and undermining the "premise of its business model." OSHA's restrictions were akin to telling "the NFL that close contact would have to end," Scalia said, adding that the NFL saw more player injuries on any given Sunday than had occurred at SeaWorld in the past 22 years.

Now, SeaWorld's appeal has been denied by the U.S. Department of Labor, which issued this notice on Friday: