(CNN) -- Rocker Joan Jett warned SeaWorld to stop blasting her music at "sound-sensitive" orcas or they'll see her protesting at their gate.
"I was surprised and upset to see on YouTube that SeaWorld used "I Love Rock 'n' Roll" as the opening music for its cruel and abusive 'Shamu Rocks' show," Jett said in a letter sent this week to SeaWorld President Jim Atchison.
Jett's demand comes as several major artists canceled planned performances at the Orlando, Florida, theme park in response to petition drives by fans who became upset after watching the CNN documentary "Blackfish."
"I'm among the millions who saw 'Blackfish' and am sickened that my music was blasted without my permission at sound-sensitive marine mammals," Jett wrote. "These intelligent and feeling creatures communicate by sonar and are driven crazy in the tiny tanks in which they are confined."
The documentary -- which first aired on CNN in October -- tells the story of the killing in 2010 of experienced SeaWorld trainer Dawn Brancheau by a 12,000-pound orca. The film raises questions about the safety and humaneness of keeping killer whales in captivity over the past 39 years.
"SeaWorld's reliance on cruelty and captivity for commerce has been widely exposed," Jett's letter, obtained by CNN, said. "I hope you'll take the respectable path and release the captive orcas to coastal sanctuaries so that they can live out their lives with other orcas in nature. This move would show that your company is truly family-friendly."
Jett warned Atchison that if she doesn't get it in writing that SeaWorld has stopped using any of her music, "I will be forced to take further action, and you'll find me among the PETA protesters outside your parks."
A SeaWorld spokesman said that Jett's song is no longer used in any of its shows, but that it "was played as walk-in music for the "Shamu Rocks" nighttime show at SeaWorld Orlando and was fully licensed for us to use."
"A new nighttime Shamu show is being designed for SeaWorld Orlando and we had no plans to use any of her music in that show," spokesman Nick Gollattscheck told CNN Wednesday.
Rock band Cheap Trick is the latest act to cancel a show during SeaWorld's six weekends of Bands, Brew & BBQ events starting in February. The group follows in the footsteps of Heart, Willie Nelson and Barenaked Ladies, who announced withdrawals from the park's schedule this month.
"We expect that other artists will be targeted in this campaign," the SeaWorld spokesman said.
The park's concert schedule -- which also previously listed REO Speedwagon, Martina McBride, 38 Special, Justin Moore and Scotty McCreery -- has disappeared from SeaWorld's website. 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. We'll repost the schedule on our site then."
Artists speak up
"I don't agree with the way they treat their animals," Nelson told CNN about his decision to cancel. "It wasn't that hard a deal for me."
The Canadian rock band Barenaked Ladies was the first, 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.
Sisters Nancy and Ann Wilson of Heart did not elaborate last week when they announced their decision to cancel at SeaWorld, although they acknowledged it was "due to the controversial documentary film."
"While we're disappointed a small group of misinformed individuals was able to deny fans what would have been great concerts at SeaWorld by Heart, Barenaked Ladies and Willie Nelson, we respect the bands' decisions," SeaWorld's Gollattscheck told CNN on Sunday. He has not yet responded to news that Cheap Trick joined the exodus.
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.
CNN's Carolyn Sung contributed to this report.