The model, who is pregnant with her second child will appear naked in posters for PETA's SeaWorldOfHurt initiative.

The U.S. marine park came under fire following the 2013 release of hard-hitting documentary Blackfish, which details the alleged cruelty in keeping marine mammals captive.

In the new photo shoot, Miller proudly shows off her baby belly while lying nude in a bathtub, suggesting the themepark's whales don't have a lot of room to move in enclosures.

Explaining her decision to become the latest pregnant beauty to bare all, Miller tells People magazine, "I've always been an animal lover and I do a lot with ocean conservation. I always see dolphins when I surf, but I didn't have the knowledge about how they (killer whales and dolphins) are acquired. When Blackfish came out, I saw it and I was so upset.

"I was so unaware of the realities about how the whales are captured, how they are separated and their emotional capacity. This is an animal whose babies never leave their mother's side their whole life. So, as a mother, I have a totally different perspective on relating to that."

She continues, "Even the tanks they do their ridiculous tricks in are way bigger than where they actually sleep. They're completely confined... The animals are ripped apart from their family, they have to be drugged to handle the environment they're in.

"There are other ways to experience them. There is a way that you can rehabilitate the animals in an environment that they can swim and you can go check them out. It’s about awareness. Once the public knows, then they can make their own choices."

Miller previously bared all for another nude photo shoot for Allure magazine while pregnant with her now-two-year-old son, Gavin.