2018 Marine Debris Removal and Assessment in the Northwestern Hawaiian Islands

The Papahānaumokuākea Marine National Monument (PMNM) includes all of the Northwestern Hawaiian Islands (NWHI) and encompasses 1,508,870 km2 (582,578 mi2) of the Pacific Ocean. Within the boundaries of the monument lie coral reefs, atolls, shoals, and seamounts, including 70% of all shallow-water coral reef habitats (<200 m) in the United States. The PMNM was named a World Heritage site in 2010 by the 34th session of the World Heritage Committee in recognition of its cultural and natural values (World Heritage Committee 2010). The extensive coral reefs found in the PMNM are home to more than 7,000 marine species, one-quarter of which are found only in the Hawaiian Archipelago (PMNM Webmaster 2019). Many of the islands and shallow-water environments in the PMNM are important habitats for rare species, such as the green sea turtle (listed as threatened under the U.S. Endangered Species Act) and Hawaiian monk seal (listed as endangered under the International Union for Conservation of Nature Red List and as endangered under the U.S. Endangered Species Act). The PMNM contains only 15 km2 of emergent land, but 14 million seabirds representing 22 species use this land as breeding and nesting grounds (PMNM Webmaster 2019). Land areas provide a home for four species of birds found nowhere else in the world, including one of the world’s most endangered ducks—the Laysan duck (PMNM Webmaster 2019).