President Obama recently signed a proclamation designating the largest marine reserve in the world and declaring it off limits to commercial resource extraction including commercial fishing.

According to an announcement from the White House, the Sept. 25 proclamation expands the existing Pacific Remote Islands Marine National Monument, one of the most pristine tropical marine environments in the world, to six times its current size, resulting in 370,000 square nautical miles (490,000 square miles) of protected area around the tropical islands and atolls in the south-central Pacific Ocean. Expanding the monument will more fully protect the deep coral reefs, seamounts, and marine ecosystems unique to this part of the world, which are also among the most vulnerable areas to the impacts of climate change and ocean acidification, the White House says.

The expanded monument will include over 130 newly protected sea mounts, which are hotspots of biodiversity that harbor uncounted numbers of new and unique marine species. The expansion will better protect the habitat of animals with large migration and foraging ranges that stretch throughout the area, including sea turtles, marine mammals, and manta rays.

Commercial fishing and other resource extraction activities, such as deep-sea mining, are banned. Recreational and traditional fishing that is consistent with the conservation goals of the monument will still be allowed.