Three headliners have canceled their performances at a SeaWorld music series, 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. Country singer Willie Nelson and the rock group Barenaked Ladies also have canceled.
The series is held over several weekends and features top classic rock and country acts.
A posting on Heart's official Twitter page over the weekend says 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.