Joe Jonas thinks there are so many little things people can do to make a "big impact" on Earth Day, and the JoBro has pitched in. His [article id="1634657"]duet with Demi Lovato, "Make a Wave,"[/article] is featured on the soundtrack for "Oceans," which opens Thursday (April 22), coinciding with the eco-conscious holiday.

The documentary, which takes a closer look at ocean-dwelling creatures, is narrated by Pierce Brosnan. "It's so cool to be part of it," Joe told MTV News.

The singer was asked by Friends for Change: Project Green to record a song. The organization is a multi-platform environmental initiative that encourages kids to make thoughtful decisions about the environment. "It's a really amazing movie, and also, it's really great to watch, because there's a lot of knowledge [about] the people that are a part of the oceans and that help out with trying to save the coral reefs or ... protect the animals that live in the ocean."

Not only does the doc introduce moviegoers to the often mysterious oceanic world, but, Jonas said, it also encourages fans to participate in looking after those waters. "There [are] a lot of things that people can do to help out that they don't really know about," he said. "The movie really ... helps you understand what you can do Whether it's really taking your time and going to the beaches and helping out or whether it's something at home, there's so many different things that if we all do it together, just like anything else, we can make a big impact."

Joe got more good news when he learned "Make a Wave" would also get screen time in "Oceans."

"It's really cool to be a part of the movie," he said. "I didn't expect that at all when the charity asked us. And Demi and I were like, 'Definitely.' Then to hear it was a part of the movie, it was an even greater thing for us. It's so cool."

Are you looking forward to more duets from Joe and Demi? Tell us in the comments!

Check out everything we've got on "Oceans."

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