The 3 areas are North Anglesey Marine, West Wales Marine and the Bristol Channel Approaches.
The Cabinet Secretary has also approved three additional marine areas as Special Protection Areas.
The Cabinet Secretary said:
Ceri Davies, Natural Resources Wales’ Executive Director for Evidence, Policy and Permitting, said:“We are committed to creating a network of marine protected areas in Wales so species and habitats can thrive. A rich and healthy marine environment ensures the sustainable use of our seas now and in the future.“The wide response to Natural Resources Wales’ consultation on the protection of marine porpoises shows the value people place in protecting marine life. I am pleased we are taking steps to provide protection for our harbour porpoise and protect important areas for sea birds.”
"We are proud that the seas around Wales support such a rich diversity of wildlife, which is highly valued by local communities and sustains important businesses such as fishing, tourism and recreation.“NRW looks forward to working with stakeholders to ensure that these sites are appropriately managed to help conserve them for future generations."