Martina McBride, along with six other acts, said she has backed out a SeaWorld Orlando (Fla.) festival due to the documentary "Blackfish." The documentary criticizes the water park's treatment of whales. "I've decided that given all the issues that have been aired recently, that time isn't right for me to play at SeaWorld," McBride said on Facebook Saturday. "I have canceled my scheduled performance." REO Speedwagon, Cheap Trick, Barenaked Ladies, Willie Nelson, Trisha Yearwood and Heart have also canceled their performances, the Orlando Sentinel reported. The concert series is set to run from Feb. 1 to March 9.