Nelson, Barenaked Ladies and Heart all canceled performances scheduled in February and March as part of SeaWorld's Bands, Brew and BBQ festival. Petitions urging them and other musicians like Trisha Yearwood to cancel SeaWorld performances are circulating on the website, Change.org.
Joan Jett also is requesting the theme park discontinue playing her song, "I Love Rock 'n' Roll." SeaWorld did not respond to requests for comment.
The protests come after the release of a controversial documentary, Blackfish, about a whale that killed a SeaWorld trainer in 2010.