Photo: All rights reserved.

Jason Momoa

Aquaman star Jason Momoa has bid farewell to his signature beard after seven years of no shaving - and it's all for a good cause.

The actor has filmed himself ditching his thick facial hair for the first time since 2012, after growing the beard to play a number of onscreen roles.

"Goodbye Drogo, Aquaman, Declan, (and) Baba!" he captioned the clip, referencing his respective characters from Game of Thrones, the DC Comics blockbuster, and TV series Frontier, and See.

"I'm shaving this beast off, it's time to make a change."

Reflecting on his new appearance, which revealed his chiseled jawline, he quipped, "Looks pretty good!"

The grooming video was uploaded to YouTube as part of Momoa's collaboration with officials at the Ball Corporation to promote a new line of canned water, which is made of "100 per cent recyclable" aluminum.

The aim of the shoot was to encourage fans to make a major change in their lives and become more environmentally friendly.

"I just want to do this to bring awareness because plastics are killing our planet and I think we have a solution," the actor explained. "I don't want to b**ch about it (but) there's only one thing that will really help our planet and save our planet - as long as we recycle - and that's aluminum.

"About 75 per cent of all aluminum that's ever been used is still in use today. And it's 100 per cent recyclable. You drink the can and in about 60 days, it'll be back. One hundred per cent. Infinitely recyclable."

Momoa revealed he's been working on the passion project for the last two months, so he can set an example to friends, fans, and family and do his part to clean up the oceans.

"It's just water but I feel good about it," the father-of-two shared. "I know I'm going to recycle this and I know that we can recycle it.

"So please, please. There's a change coming. Aluminum. We got to get rid of these plastic water bottles. Aquaman's trying to do the best he can. For your kids, for my kids, for the world. Clean up the oceans, clean up the land."

Momoa isn't the only star trying to convince consumers to move away from water packaged in plastic bottles - Will Smith and his son Jaden founded the JUST company in 2015 to provide boxed spring water in a fully recyclable paper-based carton.