The 39-year-old 'Wolf of Wall Street' star had already made a USD 3 million grant to a sea wildlife charity February 2014 through his charity foundation 'The Leonardo DiCaprio Foundation.'
In addition to that, he is making another donation of USD 7 million to help conserve the oceans.
"Thru my foundation today I'm pledging USD 7 million to ocean conservation projects over the next 2 years. #OurOcean2014," DiCaprio tweeted.
DiCaprio says he has seen the environmental devastation of the ocean firsthand and has pledged the money "as a concerned citizen of this planet" to raise awareness as much as possible.