Sir David Attenborough addressed his mortality as he reflected on his life in his powerful new documentary about the world's oceans. The broadcaster turns 99 on May 9, and as he prepares to celebrate the milestone birthday, he admitted he is "nearing the end of his life." Animal enthusiast Sir David has been on TV screens for eight decades and spoke about his future while filming a new show about the ocean, which comes out on Disney+ later this year.

TV presenter shared his fears for the future in new film Ocean with David Attenborough, sharing: "When I first saw the sea as a young boy, it was thought of as a vast wilderness to be tamed and mastered for the benefit of humanity. Now, as I approach the end of my life, we know the opposite is true. After living for nearly a hundred years on this planet, I now understand that the most important place on Earth is not on land, but at sea.”

He added: "Today, it is in such poor health I would find it hard not to lose hope were it not for the most remarkable discovery of all."

He did say that the sea can "bounce back to life", saying: "If we save the sea, we save our world. After a lifetime of filming our planet, I’m sure nothing is more important.’

The film shows Attenborough looking back at 1957 footage of his first attempt at scuba diving on the Great Barrier Reef.

Although he says we are “almost out of time”, Attenborough remains optimistic that we can protect marine reserves where fishing is banned and allow the ocean’s ecosystem to recover.

Sir David's shows have raised awareness of environmental issues impacting the world for many years and helped develop systems to protect endangered species.

The 98-year-old shared: "The world would be in a far, far worse situation now had there been no broadcasting of natural history. People have found it a source of fascination, beauty, and interest, which has become key to looking after the world."

Sir David told the Telegraph a few years back that he was “coming to terms” with the idea that when finding the right words takes longer, you can “run into problems" as he forgot the name of a plant in front of him.

Ocean with David Attenborough is releasing as a Global Cinema Event from May 8. It will also be made available on National Geographic, Disney Plus, and Hulu later this year.