President Barack Obama has announced the expansion of Hawaii’s Papahanaumokuakea Marine National Monument.

Therefore, the monument has become the world’s largest marine reserve, the White House says.

Barack Obama’s announcement on August 26 quadruples in size a monument originally created by President George W. Bush in 2006.

The Papahanaumokuakea Marine National Monument will now span 582,578 sq miles, more than twice the size of Texas.

Photo Flickr

The designation bans commercial fishing and any new mining.

The White House says the marine reserve’s expansion is helping to protect more than 7,000 species and improves an ecosystem affected by ocean acidification and warming.

A fact sheet previewing the announcement also states that the expanded area is considered a sacred place for Native Hawaiians.

The expansion was welcomed by environmental campaigners.

Joshua Reichert, an executive vice president at the Pew Charitable Trusts said: “By expanding the monument, President Obama has increased protections for one of the most biologically and culturally significant places on the planet.”

Greenpeace also hailed what it called a “bold decision” that will ban commercial fishing and mineral extraction in the region.

However, some fishing groups have voiced concerns.

Sean Martin, the president of the Hawaii Longline Association told the Associated Press: “We are disappointed that the president has made a decision to close an area nearly the size of the entire state of Alaska without public process.”

“This action will forever prohibit American fishermen from accessing those American waters. Quite a legacy indeed,” he added.

The area is also known for its many shipwrecks and downed aircraft from the Battle of Midway, which marked a major shift in World War Two.

Barack Obama, who was born in Hawaii, will travel to the Midway Atoll next week.

With this announcement, President Obama will have created or expanded 26 national monuments during his time in office.

In 2014, Barack Obama extended the Pacific Remote Islands Marine National Monument south-west of Hawaii, which now covers 490,343 sq miles.