WASHINGTON — (CNN) President Barack Obama plans to designate on Thursday an undersea range of canyons and peaks off the US Eastern seaboard as the country’s first Atlantic marine national monument.

The move, in the works for more than a year, will further Obama’s conservation efforts in the final months of his presidency, an initiative he views as a major component of his environmental legacy.

The Northeast Canyons and Seamounts Marine National Monument, situated 130 miles southeast of Cape Cod on the southern edge of George’s Bank, will protect 4,913 square miles of ocean from commercial activity and development, the White House said.

That includes barring undersea drilling and mining, as well as commercial fishing activity. An administration official downplayed the effect on local fisherman, describing a “limited number of vessels” who regularly operate in the newly protected area.

Some fishing groups had protested the long-rumored designation of the canyons and seamounts as a national monument, saying the move could harm the region’s economy and impede the work of existing fishery management groups.

The White House says it designed the new designation to “recognize the unique role that fishing plays in the region’s economy and culture.” Red crab and lobster fisheries will have seven years before they’re required to cease commercial activity within the monument, while other types of commercial fishing enterprises will have 60 days to exit.

Recreational fishing will still be permitted within the monument’s boundaries.

Obama was set to make the announcement during remarks at a State Department-sponsored conference focused on marine protection. The decision was hailed by environmental groups.

“Teddy Roosevelt had the foresight to protect the treasures of America’s landscape. With that same boldness, President Obama is conserving the crown jewels of our nation’s seascape,” said Rhea Suh, president of the Natural Resources Defense Council. “This historic act will make our ocean more resilient to climate change. By preserving this rich diversity of marine life, it will also support New England’s coastal and ocean economy.”

The creatures who populate the protected area range from unique types of coral to several species of mammals, including sperm, fin, and sei whales. Some of the specimens exist only in that particular ecosystem.

Responsibility for managing the area will fall to the departments of Interior and Commerce.

Earlier this month Obama traveled to Midway atoll in the Pacific to view the expanded Papahanaumokuakea Marine National Monument, which he quadrupled in size in August. While there he argued for the importance of using his conservation powers to protect vulnerable environments.

“There are countries that now are at risk and may have to move as a consequence of climate change. There are enormous effects on the human presence in the ocean that creatures are having to adapt to and, in some cases, cannot adapt to,” Obama said on Midway. “I look forward to knowing that 20 years from now, 40 years from now, 100 years from now, this is a place where people can still come to and see what a place like this looks like when it’s not overcrowded or destroyed by human populations.”

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