NBC News said that as SeaWorld marks its fiftieth year as a marine-animal-themed park on the Friday, it is still facing public pressure following its captivity of killer whales and the use of them for shows at the San Diego, California facility.

Pressures from the public have escalated since A South by Southwest 2013 documentary titled "Blackfish" highlighted the dangers of keeping seemingly-behaved wild animals away from their homes. The documentary centers on the death of SeaWorld trainer Dawn Brancheau, who was attacked by her assigned animal, 12,000-pound killer whale named Tolikum, in 2010. NBC News said that Tikikum has been linked previously to two other deaths.

SeaWorld's birthday on Friday could also been the point of the marine park's continuous downhill slide, as a Reuters report said a proposed legislation will require the company to end its killer whale live performances.

State Assemblyman Richard Bloom, who introduced the new measure, said that he got interested with the issue of killer whale captivity when he watched the controversial documentary. The news agency said that the film's conclusion was that SeaWorld had continued the cruel practice against the sea animals in order to continuously take a lion's share in the highly-lucratuve theme park industry. Marine mammal biologist Naomi Rose with the Washington, D.C.-based Animal Welfare Institute, tow ex-SeaWorld trainers, and "Blackfish" director Gabriela Cowperthwaite joined Bloom in the unveiling of his proposal, Reuters said.

In remarks that he prepared for his bill proposal, Bloom said, "There is no justification for the continued display of orcas for entertainment purposes. These beautiful creatures are much too large and far too intelligent to be confined in small, concrete tanks for their entire lives."

In its response to the bill proposa, SeaWorld said, "(The individuals) he has chosen to associate with for today's press conference are well-known extreme animal rights activists, many of whom regularly campaign against SeaWorld and other accredited marine mammal parks and institutions."