Edward Nortonhas urged his fans to back a campaign calling for the protection of marine life in the Antarctic.
The Incredible Hulk star has filmed a video message in support of the Antarctic Ocean Alliance, outlining the dangers of over-fishing in the southern polar region.
In the clip, he says, "People are a part of nature and everything in our lives and civilization are built on, rely on, healthy eco-systems in the planet. It's about making sure that what we enjoy today is here for other people to enjoy tomorrow. Most populations of fish are in decline. We're fishing our way down the food chain."
Officials at the environmental organization have set up an online petition in a bid to highlight the issues and have the area designated as a protected site, and Norton has called on his followers to sign the form.
He adds, "There's a moment of opportunity here to apply that pressure. You can send a clear signal that millions and millions of people are watching this process - don't let us down. I'm going to be watching - join the watch."