Three headliners who were planning to perform at a SeaWorld music series have canceled, citing a recent documentary that raises questions about the effects of captivity on whales.
The group Heart is the latest act to cancel an appearance at SeaWorld Orlando's Bands, Brew & Barbecue music series in February.
The series is held over several weekends and features top classic rock and country acts.
Heart joined country singer Willie Nelson and rock group Barenaked Ladies in canceling their performances.
A posting on Heart's official Twitter page over the weekend said the decision was influenced by the recently-released documentary "Blackfish."
The documentary raises questions about the effects of captivity on killer whales at marine parks such as SeaWorld.
A SeaWorld spokesman didn't immediately return phone calls or an email Monday.