President Barack Obama announced the expansion of the Papahānaumokuākea Marine National Monument last Friday, creating the world’s largest protected marine area.

Papahānaumokuākea was designated a Marine National Monument by President George W. Bush in 2006. It was also named a UNESCO World Heritage Site in 2010. This area encompassed about 140,000 square miles of remote islands and atolls of Northwestern Hawaiian Islands. At the time it was the largest marine protected area on the planet. Having now quadrupled in size to more than 580,000 square miles, it has regained the title.

The monument was created under the Antiquities Act of 1906 — the United States’ first program for protecting its natural resources — and is protected from commercial fishing and mining. However, recreational fishing and scientific research are still allowed under permit, as is the removal of fish and other resources for Native Hawaiian cultural practices. This is different from a National Park, which can only be created by acts of congress. Under the law the president can designate any federal land containing objects of “historic or scientific interest” as national monuments — both of which can be found in Papahānaumokuākea.

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Scientifically speaking, the isolated region is a biological as well as geological hotspot and provides refuge for more than 7,000 marine species. Among them are 24 species of whales and dolphins — three of which are critically endangered, five of the seven species of sea turtle, endangered Hawaiian monk seals and numerous sharks and seabirds.

The area also features seamounts and a non-volcanic ridge that provides a habitat for many deep-sea sponges and invertebrates — including endangered black coral. NOAA recently released some video of the deepest corals found inside the Papahānaumokuākea Marine National Monument.

“As ocean acidification, warming, and other impacts of climate change threaten marine ecosystems, expanding the monument will improve ocean resilience, help the region’s distinct physical and biological resources adapt, and create a new natural laboratory that will allow scientists to monitor and explore the impacts of climate change on these fragile ecosystems,” said White House officials in a statement.

Papahānaumokuākea is also a source of historical and cultural interest as this region holds sacred significance to native Hawaiians. The area is used to participate in traditional island practices like long-distance voyaging and wayfinding.

The adjacent waters hold the remains of many World War II shipwrecks. About 3,000 people lost their lives during the Battle of Midway in 1942, and the remains of the naval conflict are still being discovered. A U.S. Naval aircraft carrier, the USS Yorktown was found 16,000 feet below the surface, and many other vessels have yet to be found and identified.

Other shipwrecks have been discovered there as well, such as the Gledstanes, a 19th-century British whaling ship discovered in 2008.

Between newly discovered species and rediscovered wrecks, Papahānaumokuākea Marine National Monument is a wealth of important underwater resources that will be further protected thanks to this expansion.