These data represent the marine and terrestrial areas designated as critical habitat for the Hawaiian monk seal on August 21, 2015 (80 FR 50926). The official NMFS critical habitat (SealHawaiianMonk_20150821) for the Hawaiian monk seal is comprised of both polygon data (marine and terrestrial areas in the MHI and Northwestern Hawaiian Islands) and line data (coastal segments in the MHI); together the polygons and lines represent the entire final critical habitat designation.

Northwestern Hawaiian Islands (NWHI): Hawaiian monk seal critical habitat includes all beach areas, sand spits and islets, including all beach crest vegetation to its deepest extent inland, lagoon waters, inner reef waters, and habitat through the water's edge (mean lower low water line), including the seafloor and all subsurface waters and marine habitat within 10 meters of the seafloor, out to the 200 meter depth boundary in the following 10 areas: Kure Atoll, Midway Islands, Pearl and Hermes Reef, Lisianski Island, Laysan Island, Maro Reef, Gardner Pinnacles, French Frigate Shoals, Necker Island, and Nihoa Island.

Main Hawaiian Islands (MHI) polygon data: Hawaiian monk seal critical habitat areas surrounding Kauai, Oahu, Maui Nui (including Kahoolawe, Lanai, Maui, Molokai), and Hawaii are defined in the marine environment from the water's edge (mean lower low water line) seaward to a 200 meter depth boundary, including the seafloor and all subsurface waters and marine habitat within 10 meters of the seafloor. Niihau critical marine habitat includes the seafloor and all subsurface waters within 10 meters of the seafloor, from a 10 meter depth boundary seaward to a 200 meter depth boundary. Kaula Island critical marine habitat includes the seafloor and all subsurface waters within 10 meters of the seafloor, from a 3 nautical mile boundary seaward to a 200 meter depth boundary. Seven islets (near Oahu and Maui Nui) and numerous coastal locations (identified as lines in a separate dataset) around the MHIs have critical habitat designated from the water's edge into the terrestrial environment where the boundary extends inland 5 meters (in length) past the shoreline. The shoreline is described by the upper reaches of the wash of the waves, other than storm or seismic waves, at high tide during the season in which the highest wash of the waves occurs, usually evidenced by the edge of vegetation growth or the upper limit of debris. In locations where critical habitat does not extend inland to the terrestrial environment, the designation boundary is the mean lower low water line.Areas ineligible for designation as critical habitat and areas that were excluded from critical habitat were clipped out of this dataset. The final rule (August 21, 2015 80 FR 50926) describes ineligible and excluded areas. Critical habitat does not include the following particular areas where they overlap with the areas described above: all cliffs and manmade structures, such as docks, seawalls, piers, fishponds, roads, pipelines, boat ramps, platforms, buildings, ramparts and pilings existing within the legal boundaries on September 21, 2015.

Main Hawaiian Islands (MHI) line data: Hawaiian monk seal critical habitat in the terrestrial environments of Kauai, Lehua, Oahu, Maui Nui (including Kahoolawe, Lanai, Maui, Molokai), and Hawaii extends from the water's edge (mean lower low water line) inland 5 meters (in length) past the shoreline. The shoreline is described by the upper reaches of the wash of the waves, other than storm or seismic waves, at high tide during the season in which the highest wash of the waves occurs, usually evidenced by the edge of vegetation growth or the upper limit of debris. Areas ineligible for designation as critical habitat and areas that were excluded from critical habitat were clipped out of this dataset. The final rule (August 21, 2015 80 FR 50926) describes ineligible and excluded areas. Critical habitat does not include the following particular areas where they overlap with the locations described above: all cliffs and manmade structures, such as docks, seawalls, piers, fishponds, roads, pipelines, boat ramps, platforms, buildings, ramparts and pilings existing within the legal boundaries on September 21, 2015.