Prince William gave his groundbreaking address on Sunday at Monaco's Blue Economy and Finance Forum, which was attended by world leaders.
The Prince of Wales, founder and president of The Earthshot Prize, praised the work of his initiative's finalists for providing hope for rescuing the plant despite the ocean floor "diminishing before our eyes".
In his passionate address, William stated that "healthy oceans are essential to all life on earth" because they "generate half of the world's oxygen, regulate our climate, and provide food for more than three billion people".