Since announcing their decision to cancel a planned performance at Orlando's SeaWorld, Heart's Ann and Nancy Wilson have had some time to think about their position on the park's treatment of its captive animals -- and they're still pretty steamed.

The sisters opened up about the cancellation during a recent interview with Rolling Stone, with Ann explaining that a viewing of the recent documentary 'Blackfish' helped open her eyes to the way orcas are forced to live in captivity. "Before seeing the movie, I always imagined the orcas got to live in a big extended oceanic area when they weren't performing, but they live in a steel swimming pool and it basically drives them insane," she argued. "Not to mention that somebody died."

Comparing the SeaWorld concert series to the lucrative offers artists received to perform at the Sun City resort in South Africa during the apartheid regime, Ann continued, "I've never been to Sea World. I've seen the photos of people getting splashed and it looks fun, but when you look underneath, you see the dark side. What they do is slavery, plain and simple. It's like people saying, 'OK, let's go to Africa and bring a bunch of people back here.' There's never any way to make that OK. Granted, this is a different species, but it still has a lot of similarities."

For Nancy, the SeaWorld decision may have been even more personal. "I watched the documentary and could barely get through it," she told Rolling Stone. "It was so upsetting and heartbreaking. I was also freaked out because I had made music for a nature documentary about orcas in the Northwest called 'Baby Wild.' It was railing against whales in captivity in general."

Ultimately, added Nancy, the Wilsons' goal is now to help further raise awareness of the orcas' plight. "When this first came up I thought, 'Should I feel guilty about making things hard for SeaWorld?' I've decided I don't have to feel guilty about this," she concluded. "We do hate to rain on anybody's parade, especially if it's someones livelihood, but if it's at the expense of these animals that deserve so much better. If us doing this raises awareness, then it it's worth a little scuffle."