ORLANDO, Fla. -

SeaWorld on Wednesday announced that music superstars Kid Rock and Alan Jackson will perform this weekend at its Bands, Brew and BBQ event, which came under fire after the release of the controversial documentary "Blackfish."

Jackson opens the SeaWorld festival, which features six weekends of concerts, with a concert at 5 p.m. Saturday.  Kid Rock will follow with a show at 4 p.m. on Sunday.

Both concerts will be held at the park's Bayside Stadium.

Nine other acts previously canceled their appearances at the event, including Willie Nelson, Barenaked Ladies, Cheap Trick, Trace Adkins and Martina McBride.

Of the originally announced acts, country singers Scotty McCreery and Justin Moore remain on board.

Earlier this week, Central Florida country singer Patrick Gibson signed on with SeaWorld and saw immediate backlash through social media.

In a picture posted to his Facebook fan page, Gibson told his fans he supports "all that [SeaWorld does]" and invited his fans to come to the concert and support the park.

Following Gibson's post, "Blackfish" supporters flooded the singer's Facebook page, criticizing his decision.

"I hope you educate yourself more before performing there," wrote Teresa Wagner. "It's hard to imagine that you would intentionally support cruelty."

However, Gibson's fans countered the criticism, thanking the singer for his "courage."

"Thanks for taking a stand for Sea World," wrote Barb Nefer.

"Good for you," wrote Terri Sullivan. "Stand behind your decision to play at Sea World! Ignore this negativity from others."

"I've seen a lot of people coming out of the woodwork that do support SeaWorld that I've never met that are just grateful to see somebody like myself standing up," Gibson told Local 6. "And my fan base and my friends and family, they're very encouraging at this time."

'Blackfish' backlash

The entertainers' exodus from SeaWorld's calendar began soon after "Blackfish" aired in October. The film tells the story of the killing of SeaWorld trainer Dawn Brancheau by an orca in 2010. It raises questions about the safety and humaneness of keeping killer whales in captivity.

Online petitions and social media postings targeted the acts who had signed on to play at the park.

The Canadian rock band Barenaked Ladies was the first to cancel, reacting to a petition posted on Change.org.

"This is a complicated issue, and we don't claim to understand all of it, but we don't feel comfortable proceeding with the gig at this time," the band said on its Facebook page.

"I don't agree with the way they treat their animals," Willie Nelson said on Dec. 6 when he canceled. "It wasn't that hard a deal for me."

Sisters Nancy and Ann Wilson of Heart did not elaborate last month when they announced their decision to cancel at SeaWorld, although they acknowledged it was "due to the controversial documentary film."

SeaWorld's defense

SeaWorld said it would like the musical artists to learn for themselves about SeaWorld.

"The bands and artists have a standing invitation to visit any of our parks to see firsthand or to speak to any of our animal experts to learn for themselves how we care for animals and how little truth there is to the allegations made by animal extremist groups opposed to the zoological display of marine mammals," Gollattscheck said.

SeaWorld says the documentary ignores the park's conservation efforts and research.

"More than 11 million people a year visit SeaWorld parks and most will see a killer whale presentation during their visit," Gollattscheck said.  "Over the course of our 50-year history hundreds of millions of people have experienced killer whales in our parks.  There is tremendous appeal in that kind of inspirational and educational experience and we anticipate that killer whale display will continue for generations to come."