After thousands of emails protesting SeaWorld Entertainment's orca whale captivity, authorities have finally prohibited the theme park to breed more whales in their tanks.

BBC reports the Californian Coastal Commission have heard the plea of animal rights groups to stop Sea World's practice. The company requested for an approval to build new tanks in San Diego - which the commission signed "under a condition that would prohibit captive breeding, artificial insemination, and the sale, trade or transfer of any animal in captivity."

The Californian commission released the ruling on Thursday after receiving more than 120,000 emails opposing the proposed expansion.

SeaWorld released a statement saying the company is "disappointed" with the commission's decision. "Breeding is a natural, fundamental and important part of an animal's life and depriving a social animal of the right to reproduce is inhumane", said SeaWorld's San Diego Park President John Reilly.

The park's Florida and Texas locations, however, are not under the same ruling.

Meanwhile, the People for the Ethical Treatment of Animals (PETA) expressed its relief, saying, the ruling would finally cease SeaWorld's maltreatment.

This "ensures that no more orcas will be condemned to a nonlife of loneliness, deprivation and misery," the animal rights group wrote on its statement.

Protests against the theme park broke out when the documentary Blackfish was released in 2013. The film exposed SeaWorld's irresponsible orca imprisonment which prompted the whales to become more aggressive towards their trainers.

Other celebrities such as Jackass star Steve-O, Matt Damon, and Russell Brand have also spoken out their rage.

The company reported an 84% drop on profit for the second quarter this year and a 2% drop in audience.

To revive its public image, SeaWorld announced it will no longer accept whales captured in the wild. Now, the recent ruling threatens the business as it could no longer add more whales to exhibit.