President Obama will declare the first fully protected area in the U.S. Atlantic Ocean when he addresses the Our Ocean conference on Thursday.
He will designate 4,913 square miles off the New England coastline as a new marine national monument.
This follows President Obama's latest declaration to protect the Pacific.
Three weeks ago, Barack Obama created the world’s largest marine protected area by expanding an existing ocean reserve off Hawaii to cover 582,578 square miles.
It quadruples the size of the Papahānaumokuākea marine national monument, which was originally designated by George W Bush in 2006 and was declared a World Heritage site in 2010.