(CNN) -- Country star Trace Adkins has decided not to sing at SeaWorld to avoid controversy over how the Orlando, Florida, theme park treats its orcas.
Adkins joins a long list of musical acts who have canceled shows that were scheduled as part of SeaWorld's "Bands, Blues & BBQ" in February and March.
"Trace prefers that the focus of his performances be on music, not on controversy," Adkins' representative said in a statement e-mailed to CNN on Thursday. "Therefore, he has decided not to proceed with this show in the midst of this debate."
The entertainers' exodus from SeaWorld's calendar begin soon after CNN broadcast the documentary "Blackfish" in October. The film tells the story of the killing of a SeaWorld trainer 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.
Only Justin Moore and Scotty McCreery remain from the original list of acts on the event calendar. Their representatives have not responded to CNN's repeated requests for comment.
A promoter could put together a whale of a concert series with the acts that have canceled SeaWorld shows, including Trisha Yearwood, Willie Nelson, Cheap Trick, Heart, Barenaked Ladies, Martina McBride and 38 Special.
SeaWorld spokesman Nick Gollattscheck confirmed Adkins' cancellation, which CNN was initially alerted to through Twitter postings Thursday.
"While we're disappointed a small group of misinformed individuals was able to deny fans what would have been great concerts at SeaWorld, we respect the artists' decisions," Gollattscheck said in an e-mailed statement nearly identical to what was sent to CNN when others canceled last month. "We expect that other artists will be targeted in this campaign."
Adkins' show was never officially announced, but it later appeared on his own online schedule for March 2, 2014.
The park's six-week concert scheduled disappeared from SeaWorld's website last month. It now simply promises "incredible concerts with top artists in classic rock and country music."
SeaWorld is working to book replacement acts, Gollattscheck said. "We'll announce the full lineup of bands when all artists have been confirmed."
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 December 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."
"We're disappointed a small group of misinformed individuals was able to deny fans what would have been great concerts at SeaWorld," Gollattscheck said.
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."
CNN's Jane Caffrey contributed to this report.