Isabel Lucas is fighting to preserve Australia's Coral Sea by having it declared a protected marine park.
The Transformers: Revenge of the Fallen star, who was born in Melbourne, is backing a campaign urging government officials to regulate the amount of fishing and seabed mining in the Coral Sea, which lies just off Australia's north-east coast.
Isabel Lucas is also calling for the sea to be made an official marine park in a bid to save its endangered inhabitants.
In a blog for the Huffington Post, she writes, "When I learned that only one per cent of Australia's Coral Sea was protected, I was stunned.
"I've become passionately involved with the Protect Our Coral Sea initiative, which aims to create the largest marine park in the world. It would protect a huge diversity of habitats from tropical coral reefs, to species living in the open ocean, to a huge pool of biodiversity living in the depths of the ocean that we don't even know about yet.
"It would serve as a place for inspiration, enjoyment and where the ocean's species - whales, dolphins, sea turtles, rays - will all have a safe haven forever."
To accompany her article, Isabel Lucas shot a music video with her musician boyfriend Angus Stone to inspire fans to join the eco-friendly cause.