Martina McBride is one of many singers that have cancelled shows at SeaWorld because of issues raised in the documentary 'Blackfish'. The documentary follows the 39-year history of killer whales in captivity leading up to the 2010 killing of SeaWorld trainer Dawn Brancheau.McBride posted on Facebook over the weekend, 'I've decided that given all the issues that have been aired recently, the time isn't right for me to play at SeaWorld.'

McBride is the seventh musical act to cancel their shows at SeaWorld.

Other country artists that have cancelled are Trisha Yearwood and Willie Nelson.

SeaWorld is working to book replacement acts.