SeaWorld, together with the Humane Society of the United States, announced a landmark agreement Thursday to drastically alter practices at its theme parks, which have come under increased scrutiny for their treatment of animals.

The company confirmed that it will end orca breeding. The animals currently in captivity at the parks will live out the remainder of their lives there.

The agreement, which SeaWorld CEO Joel Manby and Humane Society President Wayne Pacelle announced in a joint statement, would fundamentally change SeaWorld's business model.

"My intent is to show a new direction for young people who want to be more conservation-minded," Manby said in a call with reporters.

SeaWorld is also set to end theatrical shows at its parks in San Diego, San Antonio and Orlando, Florida, instead focusing on educational programs as well as animal rescue and restoration work.

"These two organizations have been long-time adversaries, but we’re excited now to see the company transforming its operations for the better on animal welfare," Pacelle said. "Today’s announcement signals that the era of captive display of orcas will end and that SeaWorld will redouble its work around rescue and rehabilitation of marine mammals in crisis and partner with us to tackle global threats to marine creatures."

Pacelle said he was excited about the partnership with SeaWorld and hopeful about the joint mission to "make progress for animal welfare."

Together, he added, he hopes the organizations can broaden the scope of their work. "We have the largest network of direct care for animals but the safety net [for] marine creatures is quite limited," he said.

Manby said SeaWorld would work with its staff and millions of visitors to create "an army of advocates to protect animals and wild places.”

Orcas, while often called "killer whales," are actually a species of dolphin. They are powerful and intelligent mammals, and can live for up to 50 or even 100 years in the wild.

SeaWorld has been under growing pressure to change its business model in recent years. In 2010, an orca named Tilikum fatally injured a trainer at the company's Orlando park while visitors looked on. That incident was explored in Death at SeaWorld, a 2012 book by Huffington Post blogger David Kirby that attributed the aggression of Tilikum and other orcas to their captivity. The 2013 documentary "Blackfish" also cast a critical eye on SeaWorld, reporting on Tilikum's treatment and raising the question of whether orcas should be confined in marine parks.

The company has made a series of half-steps toward better orca care since the release of "Blackfish," which many have credited with launching the eponymous "Blackfish effect": Profits at the entertainment giant have plummeted and attendance has collapsed.

Animal rights groups have called on SeaWorld to free the orcas currently in captivity. While Thursday's agreement isn't expected to go that far, it would nevertheless represent a major shift for the 57-year-old company.

"A lot of people just don't realize that without facilities like SeaWorld, there are no places for these creatures to go," Manby added, noting the company cares for many sick and injured animals as part of its conservation initiative.

The company has made some previous attempts to change its practices. In November, SeaWorld committed to ending theatrical orca shows at its San Diego park by 2016 and said it will focus instead on educational presentations. But those presentations themselves won't be changed until sometime in 2017, and they'll take place in the same arenas with similar jumps that've been deemed more "natural."

The company has also shown a reluctance to change, suing the state of California last year over its restriction on breeding orcas in captivity. The company also admitted last month that it had sent employees to infiltrate animal rights groups critical of SeaWorld's practices.

This article has been updated with additional comments from Manby and Pacelle.