of the Shallow-Water 

hic Habitats of the 

stern Hawaiian Islands

DRAFT

U.S. Department of Commerce

National Oceanic and Atmospheric Administration

National Ocean Service

March 2003
NOS held two workshops in Hawai̒i where experts were provided access to draft maps of the shallow-water coral 

reef ecosystems of the NWHI. These workshops resulted in important information that was incorporated into the draft maps in this Atlas.The U.S. Fish and Wildlife Service (FWS), NOAAís National Marine Fisheries Service (NMFS), and the Hawai̒i Department of Land and Natural Resources (DLNR) provided permits for access to the marine and terrestrial environments of the NWHI. Alex Wegman participated in the mission to ensure no disturbance of any threatened or endangered animals.The Coral Reef Ecosystem Investigation (CREI) of the Honolulu Laboratory of the National Marine Fisheries Service (NMFS-HL) provided copies of more than 100 underwater video tapes and 300 georeferenced photographs collected in the NWHI for use in habitat characterization.Dan Basta, Robert Smith and many others in NOS contributed to the development of this Atlas. Numerous people who have worked extensively in the NWHI reviewed and provided valuable comments to the draft benthic habitat maps depicted in this Atlas. They also provided valuable comments on this Atlas.Earth Satellite Corporation of Rockville, Maryland, and GeoData Systems of Fairfax, Virginia, were involved in the processing of the IKONOS and Landsat satellite imagery used as the basis for the maps presented in this Atlas.The maps presented in this Atlas were derived from IKONOS and Landsat satellite imagery. These derived maps can be provided without redistribution restrictions. For further information about the maps in the Atlas, please contact Richard Stumpf (Richard.Stumpf@noaa.gov; 301.713.3028). For general information about the Atlas, please contact Steve Rohmann (Steve.Rohmann@noaa.gov; 301.713.3000).All photography in this Atlas was taken during the AugustSeptember 2001 GPS and benthic characterization mission to the NWHI. The photography is printed with the permission of the Hawaiian Islands National Wildlife Refuge and the Midway Atoll National Wildlife Refuge, U.S. Fish and Wildlife Service, Department of the Interior. The photograph of a Hawaiian monk seal is printed with the permission of the National Marine Fisheries Service-Honolulu Laboratory.

Uses of this AtlasThe maps in this Atlas provide baseline information about the locations and distributions of the shallow-water (0ñ30 m) benthic habitats in the NWHI. These maps can be used manually or digitally in comparative analyses with other data sets. Such comparative analyses can reveal patt erns and indicate where changes have occurred in the mapped NWHI habitats resulting from natural or anthropogenic infl uences. In addition to serving as a valuable management tool, these maps are a useful source of information for managers, analysts, and scientists in both the public and private sectors. All of the maps in this Atlas are oriented with North at the top. All of the maps, except the index maps, are presented with a one (1) kilometer grid overlay. All of the maps also have longitude and latitude tic marks along their peripheries. Related Products In addition to this Atlas, a set of two CD-ROMs are available. These CDs contain the digital, high resolution, detailed benthic habitat maps, the digital, aggregated habitat cover maps, and the digital, detailed estimated depth maps in GeoTIFF. These digital maps can be incorporated into a computerized GIS or other soft ware for further use and analysis. The CDs also contain the metadata, associated fi eld benthic characterization data, and other information related to mapping the benthic habitats of the Northwestern Hawaiian Islands. The data on the CD-ROMs also are available on the Internet at htt p://biogeo.nos.noaa.gov/projects/pacifi c/nwhi/data. Citation Please use the following citation when referring to this Atlas: National Oceanic and Atmospheric Administration. 2003. Atlas of the Shallow-Water Benthic Habitats of the Northwestern Hawaiian Islands (Draft ). 160pp.

i
ii

Map Development 9 Satellite Technologies 9 Imagery Positioning 10 Image Analysis 11 Estimating Depth 11 Classifi cation Scheme 12 Map Validation 12Literature Cited 12Unit Conversion Table 14The Classifi cation Scheme Used to Map

 the NWHI 14Map Legends 27Kure Atoll 28Midway Atoll 34Pearl and Hermes Atoll 40Lisianski Island 52Laysan Island 68Maro Reef 76Gardner Pinnacles 98French Frigate Shoals 102Necker Island 126Nihoa Island 140Pioneer Bank 148Raita Bank 151Brooks Banks and St. Rogatien Bank 155Bank West of Nihoa 158
iii
shaped this area. These diverse natural resources are complemented by the areaís rich historic signi

fi cance. Numerous artifacts found on Nihoa and Necker Islands in the NWHI establish a close relationship with the Hawaiian culture in the main 

Hawaiian Islands, as well as to early Polynesian cultures. With its diverse history and signi

fi cant natural resources, this shallowwater coral reef ecosystem also provides outstanding research 

opportunities for biologists, oceanographers, archaeologists and historians.Table 1 provides the best available estimates of the extent of shallow-water coral reef ecosystems in the NWHI. With the exception of Gambia Shoals for which no satellite imagery is available, IKONOS high-resolution satellite imagery or Landsat 7 Enhanced Thematic Mapper Plus (ETM+) satellite imagery was used to generate the maps depicted in this Atlas. In most cases, features in water up to 30 meters deep can be seen in the IKONOS or Landsat 7 ETM+ imagery. The IKONOS satellite imagery was used to generate the detailed benthic habitat maps, estimated depth, and aggregated habitat cover maps. The Landsat 7 ETM+ satellite imagery was used to characterize the extent of the shallow-water bank. No a

tt empt was made 

to derive any habitat maps from the Landsat 7 ETM+ imagery. Shallow-water bank maps were not made using IKONOS imagery primarily because the cost of purchasing such large amounts of imagery was prohibitive.The detailed benthic habitat maps in the Atlas are presented at 1:40,000 scale (1 cm = 0.4 km). The aggregated habitat cover maps and the estimated depth maps in the Atlas are presented at 1:80,000 scale (1 cm = 0.8 km). The bank areas are presented at scales ranging from 1:80,000 to 1:200,000 scale.

Formation and GeologyBeginning about 30 million years ago, a series of volcanic land masses emerged from a stationary geologic ìhot spotî in the Paci

fi c Ocean to form the Hawaiian Archipelago, which stretches 

for 2,579 kilometers from South Point on the island of Hawai̒i 

to the west-northwest tip of Kure Atoll. Kure Atoll is the oldest island in the Hawaiian Archipelago (Grigg and Dollar, 1980). However, the Emperor Seamounts, located north and west of Kure Atoll, mark the western extent of the chain of islands. As the Paci

fi c Plate crosses over the ìhot spotî at a rate of approximately 10 cm. per year, a new shield volcano is created. The 

most recent shield volcanoósubmerged Lo̒ihi volcanoóis still forming (Grigg, 1982; Rauzon, 2001).The NWHI are very small islands, most less than 1.6 square kilometers in area. At the southeastern end is Nihoa Island, 210 km. from Ni̒ihau, the western most of the main Hawaiian Islands. Moving northwest, the 1,920-kilometer stretch of emergent lands are characterized as small rocky islands, atolls, coral islands and reefs, which become progressively older and generally smaller (Wells, 1988).Kure Atoll lies at a latitude of approximately 29 degrees North. It is at this latitude that the so-called Darwin Point is reached. Named a

ft er Charles Darwin, this position on the earth marks 

where the slow growth rate of shallow-water coral reef ecosystems almost perfectly matches the slow erosion and subsidence of the shield volcano on which the reefs are growing (Grigg and Dollar, 1980). Because of their active volcanism, isolation, and linear progression, the NWHI, together with the main Hawaiian Islands, represent an excellent example of the evolution of island biogeography (MacArthur and Wilson, 2001; Gulko, 1998).

1

Diagram of a shield volcano.

Dolphins at Midway Atoll.
This codependent relationship between coral polyps and symbiotic zooxanthellae algae is critical for the survival and maintenance of shallow-water coral reef ecosystems. Major changes in water temperature, the presence of sediment, and the introduction of pollutants in the water can threaten this delicate symbiotic relationship, thereby weakening or killing the polyps and algae, and eventually destroying the living shallow-water coral reef ecosystem itself (National Geographic Society, 2000).The healthy and extensive shallow-water coral reefs of the NWHI encompass over 11,550 square kilometers of shallowwater coral reef habitat, or about 65 percent of all shallow-water coral reefs in U.S. waters (Miller and Crosby, 1998). Pearl and Hermes Atoll, French Frigate Shoals, Maro Reef, and Lisianski Island have the most extensive near-shore reefs. Gardner Pinnacles, Lisianski Island, Maro Reef, and Necker Island have the most extensive shallow-water bank areas (see Table 1).

The reefs support 47 species of hard coral and eight species of soft coral (Maragos and Gulko, 2002), a diversity and species 

richness that rivals that of the main Hawaiian Islands. But compared to other regions, the diversity of coral species is low and is oft en att ributed to the biogeographic isolation of this island 

chain (Grigg, 1983; Maragos, 1977). This low diversity is thought to account for the exceptionally high numbers of endemic Hawaiian marine species.Within the NWHI, the reefs diff er in coral cover and species 

organization. Diff erences in the amount of coral cover within the 

NWHI are the result of natural variations between fringing reefs and atolls, and variations in latitude (Grigg, 1983; Maragos and Gulko, 2002). In the past, mean coral cover was thought to range from 8 percent to 69 percent among the islands (Green, 1997). This vast, shallow-water coral reef ecosystem supports a dynamic system of marine species. Maragos and Gulko (2002) report that up to 25 percent of the shallow-water organisms found in the Hawaiian Islands are endemic, or found nowhere else on earth. The NWHI act as stepping stones and reservoirs for organisms found in the main Hawai̒i Islands. The shallow-water coral reefs are the foundation of an expansive ecosystem that hosts an interdependent association of vertebrates (monk seals, reef and bott om fi sh, turtles, birds, sharks), invertebrates (corals, anemones, jellyfi shes, mollusks, shrimps, crabs, lobsters, sea 

urchins, sea stars, sea cucumbers) and extensive areas of algae.Coral species in the NWHI generally are slower-growing than in areas closer to the equator. Climatic events, on an inter-annual scale, may play an important role in the ecosystem productivity of the northwestern chain. Declines in the productivity of sea2

Debris at Pearl and Hermes Atoll. Wreck at Kure Atoll.
ate the status and trends in monk seal populations; survival, reproduction, growth, behavior, and feeding habitats; and the success of various activities aimed at supporting population growth. Since the mid-1980s, adults have comprised a growing percent- age of the total monk seal population, estimated to be about 375 seals (excluding those at Midway Atoll). This trend has resulted in fewer young females reaching reproductive age and more older females aging past reproductive age. The overall impact of this trend cannot be predicted reliably at this time. High mortal- ity of immature seals appears to be a leading factor in this trend, especially at two important pupping locations, French Frigate Shoals and Laysan Island. Starting in 1997, NMFSís marine mammal research program initiated three management activities in an att empt to increase the survival rate of immature seals. First, a program to remove debris in which seals could become entangled was initiated in all NMFS study sites. While conducting this debris removal activity, 13 seals were disentangled. Second, debris was removed from several areas of fringing reef at French Frigate Shoals and Pearl and Hermes Atoll to assess the feasibility of conducting a more extensive debris-removal activity. Third, weaned monk seal pups were redistributed at several suitable locations on French Frigate Shoals (Johanos and Ragen, 1999). Hawaiian spinner and bott lenose dolphins also are year-round resident species. Numerous other dolphin and whale species (e.g., spott ed and striped dolphins, humpback, beaked, killer and false killer whales) occur seasonally within the NWHI archi- pelago. This ecosystem also is important nesting habitat for the threat- ened green sea turtle. Major nesting sites are found on French Frigate Shoals and, to a lesser extent, on Laysan Island, Lisianski Island, and Pearl and Hermes Atoll. The green sea turtle oc- cupies three habitat types: open beaches, open sea, and feeding grounds in shallow, protected waters. Upon hatching, the young turtles gradually work their way from the beach, over shallow reef areas and extensive shoal areas to the open ocean. When their shells grow 8 to 10 inches long, they move to shallow feed- ing grounds over shallow-water coral reefs and rocky bott oms (U.S. Fish and Wildlife Service, 2000). Sexual maturity generally is reached between ages 20 and 50. The green sea turtle was listed as threatened in 1978. Although the population has increased signifi cantly since the 1970s, the total number of nesting females is still well below the histori- cal levels of the late 1800s (NMFS, 2000). Scatt ered, low-level nesting occurs throughout the Hawaiian archipelago. However, more than 90 percent occurs at French Frigate Shoals. The shal- low waters within French Frigate Shoals have been identifi ed as inter-nesting habitat for adult females. Adult males also migrate to this area to breed (Dizon and Balazs, 1982). This amounts to approximately 200 to 700 females nesting annually (FWS, 2001). Research indicates that the range of adult green turtles using French Frigate Shoals is limited to the 2,457-kilometer stretch of the Hawaiian Archipelago (Balazs, 1976; 1983) and to Johnston Atoll, which lies south of the Hawaiian Archipelago (Balazs, 1985). While the green sea turtle is a resident species, the leath- erback, olive ridley, and loggerhead sea turtles are considered transient species that occur seasonally in this expansive area.

3

Red-footed boobies at Laysan Island.

Rock-boring urchins at Midway Atoll.
Birds 

The NWHI provide vital habitat for 14 million nesting seabirds and breeding species, many of which rely on the shallow-water coral reefs for food. Ninety-nine percent of the worldís Laysan albatross and 98 percent of the worldís black-footed albatross nest in these islands (Midway Atoll National Wildlife Refuge, 2000).The Laysan fi nch is listed by the FWS as an endangered species. The Laysan fi nch, common only on Laysan Island, is a highly 

inquisitive bird that constantly inspects and probes all types of items. It does not appear to be innately wary of human-made items. As a result, the FWS has established special visitor restrictions on Laysan Island and Pearl and Hermes Atoll to eliminate the chance of accidental drowning, entanglement, and entrapment of the birds.Similarly, most NWHI seabirds exhibit a lack of wariness toward human visitors. Most NWHI seabirds nest either under the ground, on the surface, or in the low trees and shrubs. Petrels and shearwaters nest in burrows that can be collapsed easily, trapping the adults, chicks or crushing the eggs. Grey-backed terns and brown noddies nest on the ground and can be easily forced off their nests. Thermal stress may also aff ect the chick 

and eggs. Any disturbance of the nest may cause the adults to leave the nest unatt ended, exposing the eggs or chicks to extreme temperatures, or overly wet conditions.Frigate birds will take chicks and nest material from booby nests and other frigatebird nests when the nests are unatt ended. Also, 

One of the few large benthic predators found on Hawaiian coral reefs is the Hawaiian Grouper. This species is rarely found at SCUBA depths in the main Hawaiian Islands, but it is frequently observed on the forereef at Kure and Midway Atolls. Many species, such as the endemic spectacled parrotfi sh, the endemic 

Hawaiian Hogfi sh, and the bigeye emperor, are quite abundant and can grow to a large size in the NWHI. These species are heavily exploited for commercial, subsistence and recreational use in the main Hawaiian Islands. Their reduced numbers and size in the main Hawaiian Islands likely is the result of overfi shing (Friedlander and DeMartini, 2002).

Several species that are rare in the main Hawaiian Islands are commonly found in the NWHI (Friedlander, 1996). The butt erfl yfi sh lives closely with the coral Acropora, which is 

common at French Frigate Shoals and Maro Reef, but rare or absent in the remainder of the Hawaiian Archipelago. Temperate and subtropical species exist on the shallow reefs of the northern portion of the archipelago, but they occur at much greater depths southward. These include two species of knifejaws, thespinyface soldierfi sh, the thicklipped jack, the Hawaiian 

Morwong and the boarfi sh. All of these species are found in both 

hemispheres but not in equatorial regions. They are thought to have established themselves here when surface waters were cooler in the NWHI (Randall, 1981).The masked angelfi sh is a highly prized species in the ornamental fi sh trade. It is extremely rare in the main Hawaiian Islands, and is usually encountered at depths greater than 70 m (Hoover, 1993). This species is relatively common on reefs at Midway, Kure, and Pearl and Hermes in the 20- to 30-m depth range (Hobson, 1984; Friedlander and DeMartini, 2002).

4

Algae at Laysan Island.

Lobe coral at Laysan Island
5

are estimated to have lived there during prehistoric times. Evidence of habitation, religious ceremonies, agriculture, and burials at 88 archaeological sites on Nihoa Island has been found. Artifacts on Necker Island suggest that the island was used in prehistoric times, primarily for religious ceremonies. Of the 52 known archaeological sites, 33 are religious shrines. Many of the temple sites closely resemble those of the Marquesas Islands and Tahiti, establishing a possible link to early Polynesian cultures. Oral history and identifi ed artifacts demonstrate that these islands have also served as fi shing grounds for the people of 

Hawai̒i for centuries. Both Nihoa and Necker Islands are on the National Registry of Historic Places (Rauzon, 2001).The NWHI played a signifi cant role in U.S. history during World 

War II. In June 1942, the famous Batt le of Midway took place in 

the seas to the north of Midway Atoll. Midway Atoll, now part of the FWS National Wildlife Refuge System, is the only remote island National Wildlife Refuge open to the public (Hawai̒i Department of Land and Natural Resources, 2000).

Preserving the EcosystemThe NWHI ecosystem remains relatively pristine. Much of the NWHI has been protected from human visitation since 1909, when President Theodore Roosevelt signed an Executive Order establishing the Hawaiian Islands Bird Reservation. In 1940, President Franklin D. Roosevelt established the Hawaiian Islands National Wildlife Refuge in the area. Nine of the islands and bank areas in the NWHI are managed by the FWS as part of the Refuge System: Nihoa Island, Necker Island, French Frigate Shoals, Gardner Pinnacles, Maro Reef, Laysan Island, Lisianski 

Island, Pearl and Hermes Atoll, and Midway Atoll. Kure Atoll is managed by the Hawai̒i Department of Land and Natural Resources.Several islands within the Refuge Complex are especially pristine and, as a result, are rich in rare and special plants and animals. Nihoa Island has 13 potential candidate endangered insect species, numerous endangered plants and two endangered birds. Necker Island has endangered plants and seven endemic insects that are candidates for inclusion on the Endangered Species list. Endangered plants, fi ve potential candidate endangered insect species, and the endangered Laysan fi nch and Laysan 

Duck live on Laysan Island.Other islands in the Refuge Complex, such as Lisianski Island, Pearl and Hermes Atoll, and French Frigate Shoals provide habitat for a variety of endemic or endangered species and require special protection from alien species of plants, insects and animals. In 1902, rabbits were introduced on Laysan Island and caused the extinction of numerous plants and insect species and three endemic land bird species. The introduction of rats to Laysan Island has caused the extirpation of many burrowing seabird colonies. The introduction of exotic grasses to Laysan Island has crowded out the native grasses and eliminated nesting habitat for the endangered Laysan fi nch.

Marine DebrisSurveys of the NWHI from 1979 to 1983 reported relatively pristine reefs, but by 1996 the reefs were suff ering from 

substantial anthropogenic damage, primarily due to the eff ects 

Galapagos shark at Kure Atoll.

Leopard blenny at Laysan Island.
2001, activities included marine debris survey and removal work 

at Pearl and Hermes Atoll and Kure Atoll. In FY 2002, detailed reef surveys for derelict fi shing gear have been conducted at fi ve NWHI sites: French Frigate Shoals, Pearl and Hermes Atoll, Lisianski Island, Kure Atoll, and Midway Atoll. Satellite and aircraft remote sensing technologies are being used to evaluate the feasibility of locating and effi ciently removing concentrations of marine debris before shallow-water coral reefs and protected species are adversely impacted. ManagementThe NWHI are managed by several federal and state agencies. These are described briefl y below.The Shallow-water Coral Reef Ecosystem ReserveOn December 4, 2000, the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve was created by Executive Order 13178. The Reserve encompasses an area of the marine waters and submerged lands of the NWHI extending approximately 2,222 kilometers long and 185 kilometers wide. The Executive Order contains conservation measures that restrict some activities throughout the Reserve, and establishes Reserve Preservation Areas around certain islands, atolls and banks where all consumptive or extractive uses are prohibited. A 30-day public comment period was initiated to receive comments regarding whether to make permanent the Reserve Preservation Areas. Comments also were requested on the conservation measures for the Reserve.

On January 18, 2001, aft er the close of the 30-day comment period, the process and establishment of the Reserve was fi nalized by issuance of Executive Order 13196. This Executive Order modifi ed Executive Order 13178 by revising certain conservation 

measures and making permanent the Reserve Preservation Areas with modifi cations. With this action, the establishment of the 

Reserve, including the conservation measures and permanent Reserve Preservation Areas, was completed.The Executive Orders can be downloaded at:htt p://hawaiireef.noaa.gov/PDFs/EO13178.pdfhtt p://hawaiireef.noaa.gov/PDFs/EO13196.pdfhtt p://hawaiireef.noaa.gov/PDFs/AmendmentSummary.pdf

The Reserve CouncilIn managing the Northwestern Hawaiian Islands Coral Reef Ecosystem Reserve, the Secretary of Commerce was directed to establish a Coral Reef Ecosystem Reserve Council, in accordance with the National Marine Sanctuaries Act. The role of the Council is to provide advice and recommendations to NOAA on the Reserve Operations Plan and the designation and management of the sanctuary.The Council, which was offi cially established on December 5, 2000 plays an important role in helping shape the initiatives that will provide lasting protection to the marine resources of the Reserve and sanctuary. The Council operates under a charter developed by NOAA, which prescribes the frequency of meetings, objectives and roles, and operation of the Council. Council meetings are open to the public.

Rice coral at Midway Atoll.

Spectacled parrotfi sh at Kure Atoll.

6
the benefi t of future generations. The DLNR is the stateís lead 

agency in protecting the natural and cultural resources of the islands. The DLNR strives to balance use of resources with the long-term social, environmental and economic well-being of Hawai̒iís people.DLNR has aquatic resource trustee responsibility out to three nautical miles throughout the NWHI, with the exception of Midway Atoll. DLNR may share these responsibilities with other agencies. Also, DLNR supports pioneering research and programs that enhance ocean resources. Information collected by DLNR is used in planning for the future. The DLNR works with agencies, civic and non-profi t organizations, community groups, residents and visitors to protect the resources of the NWHI.The DLNRís Division of Aquatic Resources manages the Stateís marine and freshwater resources through programs in commercial fi sheries and resource enhancement; aquatic resources protection, enhancement and education; and recreational fi sheries. Major program areas include managing or enhancing fi sheries for long-term sustainability of the resources, protecting and restoring the aquatic environment, protecting native and resident aquatic species and their habitat, and providing facilities and opportunities for recreational fi shing 

consistent with the interests of the state.

Kure Atoll State Wildlife RefugeKure Atoll State Wildlife Refuge is managed by the DLNR Division of Forestry and Wildlife. Numerous research and invasive species removal activities are conducted at Kure Atoll by DLNR in partnership with NMFS, FWS and NOS. The removal of invasive plants from Kure Atoll is a high priority for DLNR. Also, DLNR has ongoing surveys to assess the extent of seabed habitats along the back reef portion of the atoll (Walsh et al., 2002).Hawaiian Islands National Wildlife Refuge The Hawaiian Islands National Wildlife Refuge (HINWR) was designated in 1909 by President Theodore Roosevelt. This refuge consists of the following remote Pacifi c islands: Nihoa Island, Necker Island, French Frigate Shoals, Gardner Pinnacles, Maro Reef, Laysan Island, Lisianski Island, and Pearl and Hermes Atoll.The HINWR consists of a chain of islands, reefs and atolls extending about 1,287 kilometers in a northwesterly direction from the main Hawaiian Islands. This refuge has a total of 13.4 sq. km of emergent lands, and 2,469.2 sq. km of submergent lands.The HINWR is home to millions of seabirds, such as sooty terns and albatrosses, and provides a rich habitat for marine life. 

7

Prehistoric remnants of early Polynesian cultures are found on Nihoa and Necker Islands.Except for fi eld stations on Tern and Laysan Islands, these remote islands are uninhabited by humans and are protected by the U.S. Fish and Wildlife Service. Even scientifi c research is limited and closely scrutinized to minimize unnecessary disturbance. Entry to the refuge is permitt ed by Special Use Permit 

only.For more information:U.S. Fish & Wildlife ServiceRefuges Division300 Ala Moana BoulevardRoom 5-231, Box 50167Honolulu, Hawai̒i 96850(808) 541-1201Hawaiian Islands National Wildlife Refuge Administrative BoundariesThe FWS has established certain administrative boundaries within the HINWR. Recreational and commercial activities are not allowed in the HINWR. The area has been set aside by the director of the FWS as a Research Natural Area. Authority for promulgation of Refuge Regulations is found in 16 U.S.C. 668dd, 50 CFR Parts 25ñ28. The boundaries are as follows:

 Pearl and Hermes Atollóthe atoll and reef as defi ned by the 10 fathom isobath.

Lisianski Islandóthe island and shoal (Neva) as defi ned by the 10 fathom 

 isobath.

Laysan Islandóthe island and atoll as defi ned by the 10 fathom isobath.

Soft coral at Laysan Island.
around the Territory of American Samoa, Territory of Guam, 

State of Hawai̒i, the Commonwealth of the Northern Mariana Islands and US Pacifi c island possessionsóan area of nearly 3,885,000 sq. km. The Council is one of eight regional councils in the United States that were established under the Magnuson Fishery Conservation and Management Act of 1976. This act as amended is known as the Magnuson-Stevens Act. The Western Pacifi c Council consists of 13 voting and three nonvoting members. Half of the members are appointed by the US Secretary of Commerce to represent fi shing and related community interests in the region. The others are designated state, 

territorial and federal offi cials with fi shery management responsibilities.

The main task of the Council is to protect fi shery resources while maintaining opportunities for domestic fi shing at sustainable levels of eff ort and yield. To accomplish this, the Council 

monitors fi sheries within its region and prepares and modifi es 

fi shery management plans as needed. The regulations are enforced jointly by the NMFS, the US Coast Guard and deputized state and territorial agents. The Council encourages cooperative fi shery management among the island and distant-water fi shing 

nations throughout the the Pacifi c.

The Western Pacifi c Regional Fishery Management Council has developed several management plans relevant to the NWHI. To obtain these documents, please visit: htt p://www.wpcouncil.org/

about.htm.

Staghorn coral at French Frigate Shoals.

8

U.S. Navy manage the atollís unique wildlife and resources. Aft er 93 years of U.S. Navy administration, Midway Atoll was 

transferred to the FWS on October 31, 1996. As part of the base closure and realignment process, the Navy completed its environmental cleanup and pulled out of Midway in June 1997. With the closure of Midwayís Naval Air Facility, the FWS is charged with restoring its biological diversity, conserving its historic and natural resources, and providing opportunities for compatible public education and enjoyment on the refuge.The FWS is committ ed to maintaining the historic spirit of Midway Atoll, and sharing its vital roles in the mid-Pacifi c with its visitors in a manner respectful of the past and as a reminder for the future. Remnants from Midwayís military history tell of the atollís strategic signifi cance to the United States, including the supposedly ìbombproofî Sand Island power plant, which was struck by a shell lobbed from a Japanese destroyer on December 7, 1941; ammunition storage huts; and gun emplacements. Several historic monuments commemorating the courageous soldiers who fought and died during World War II have been erected on Sand and Eastern Islands.From November though July, Midway is alive with albatross, boasting the largest colony of Laysan albatross in the world and the second largest colony of black-footed albatross. At other times of the year, red-tailed tropicbirds may perform their aerial acrobatics overhead, curious white terns will fl utt er above, black and brown noddies may nod their greetings, and wedge-tailed shearwaters and Bonin petrels may serenade visitors to sleep. Midwayís only native mammal is the endangered Hawaiian monk seal. Adults and immature monk seals are frequently seen basking on the beaches of all three islands in the atoll. Midway Atollís lagoon is an important feeding area for threatened green sea turtles, and they are frequently spott ed within the harbor 

area of Sand Island or basking on Midwayís beaches. Hawaiian spinner dolphins frequent Midwayís shallow lagoon waters during the day and forage outside the atoll at night. Midwayís lagoon and surrounding nearshore waters support more than 250 species of fi shes, including many colorful reef fi shes.For more information contact: Midway Atoll National Wildlife RefugeP.O. Box 29460Honolulu, Hawai̒i 96820-1860

The Fishery Management CouncilThe Western Pacifi c Regional Fishery Management Council determines the management policies of fi sheries in the exclusive economic zone (EEZ, generally 4.8 km to 320 km off shore) 
Map Development

The maps found in this Atlas were derived from satellite imagery. IKONOS high-resolution satellite imagery was used to derive the draft benthic (seabed) habitat maps, estimated depth, and the color images. Landsat moderate-resolution satellite imagery was used to derive the maps of banks.Generally, features (habitats) on the seabed to a depth of approximately 30 m can be seen in the satellite imagery. In some areas, such as portions of the southeastern part of Pearl and Hermes Atoll, turbidity in the water limited visibility to 12 m into the water column. In other areas, such as the southern part of Laysan, seabed features could be clearly identifi ed in water 25ñ30 m 

deep.

Satellite TechnologiesThe IKONOS satellite provides commercially available panchromatic (black and white) and multispectral (blue/green/red/nearinfrared) imagery. The panchromatic imagery has a 1-m pixel dimension (meaning features as small as 1 m square can be seen in the imagery). The multispectral imagery has a 4-m pixel dimension (meaning features as small as 16 sq. m can be seen in the imagery). IKONOS imagery is purchased under strict licensing agreement. Only licensed users can have access to the imagery. Derived products, such as the habitat maps presented in this Atlas, can be openly distributed.The Landsat 7 Enhanced Thematic Mapper Plus (ETM+) satellite imagery has a 28.5 m multispectral pixel dimension (mean9

CREI conducts Rapid Ecological Assessments and towed diver surveys in water depths of 0-30 m in the NWHI and other Pacifi c 

islands. The results of these activities are used to groundtruth aerial and remote sensing data for benthic habitat mapping; create a species inventory: provide a baseline assessment of species abundance and distribution; and evaluate reef health, including coral bleaching, predation, algal overgrowth and breakage. Habitat mapping and characterization research in water depths of 20ñ400 m employs single- and multibeam acoustic technologies, bott om classifi cation research, towed 

camera systems, and towed-diver surveys. CREI coordinates marine debris mitigation on shallow-water coral reefs and employs divers on multiple ships in multi-agency campaigns.An array of tools and methods is used to determine the oceanographic processes that infl uence shallow-water coral 

reef ecosystems. These include the use of instrumented oceanographic moorings and buoys, oceanographic research vessels, and satellite remote sensing technologies. The oceanographic information collected in the NWHI provides time series of high resolution sea surface temperature, salinity, photosynthetically available radiance, ultraviolet-B, air temperature, barometric pressure, and wind direction and speed. These data help us bett er understand the infl uences of local environmental conditions on the health of the surrounding shallow-water coral reef. Data telemetry helps monitor the imminent or occurring shallow-water coral reef bleaching or other natural events (e.g., hurricanes, storm damage, heating/cooling) so that additional fi eld observation and data collection 

eff orts can be initiated. To learn more about CREI, please visit: htt p://crei.nmfs.hawaii.edu.

Sponge at French Frigate Shoals.

Linckia starfi sh at Pearl and Hermes Atoll.
10

Imagery PositioningAll of the IKONOS imagery was purchased in National Imagery Transmission Format with the associated Rational Polynomial Coeffi cients (RPCs or satellite ephemeris data). When using image analysis soft ware capable of reading NITF fi les with associated RPCs, the horizontal positioning error never exceeded 15 m (for locations where there is litt le or no vertical relief to aff ect image pixel displacement).NOS mosaicked the IKONOS imagery swaths, both panchromatic and multispectral, to within one pixel. In the case of the 1-m panchromatic imagery, the swaths overlap to within 1 m. For the 4-meter multispectral imagery, the swaths overlap to within 4 m.NOAAís National Geodetic Survey (NGS) recently gathered very accurate ground control data (horizontally accurate to within 15 cm of its location on the earth) on nine locales in the NWHI. The only locale that was not successfully ìoccupiedî was Maro Reef, where no permanent site could be found above sea level. Where available, NOS used these ground control data in its eff orts to improve the geopositioning of IKONOS imagery.Working with NGS, NOAAís Offi ce of the Coast Survey will be 

publishing revised nautical charts for the NWHI. The revision of these charts included obtaining satellite imagery from sources not available to the public. NGS compiled vector shoreline for all but one NWHI locale (Maro Reef) using a combination of IKONOS and restricted-access imagery. Where available, NOS used this vector shoreline in its eff orts to improve the geopositioning of IKONOS imagery. However, because the restricted-access imagery used to compile vector shoreline for some areas has 

a diff erent resolution and was acquired at diff erent times from 

the IKONOS imagery, complete superimposition is not possible.For Kure Atoll, Midway Atoll, Pearl and Hermes Atoll, Laysan Island, Lisianski Island, and French Frigate Shoals, NOS used a combination of ground control data and vector shoreline data to further geoposition the IKONOS panchromatic and multispectral imagery. As a result, the mean horizontal positioning error at sea level of this imagery is less than 4 m (one pixel).NGS successfully gathered ground control data and compiled vector shoreline for Necker Island, Nihoa Island and Gardner Pinnacles. However, the islands have considerable vertical relief. As a result, both the restricted access imagery and IKONOS imagery for these islands are aff ected by parallax (the displacement 

of an object as seen from two diff erent points not on a straight line from the object). This parallax results in less accurate positioning of the imagery. NOS used a combination of ground control data and vector shoreline data to improve the geopositioning of IKONOS panchromatic and multispectral imagery. NOS believes the IKONOS imagery of Necker Island, Nihoa Island, and Gardner Pinnacles to be within 15 m of their actual locations at sea level.For Maro Reef, neither supplemental ground control data nor vector shoreline data are available. However, trackline bathymetry with accurate GPS data was recently gathered at Maro Reef.These data were used to correct the position of the imagery. Using these data, the mean horizontal error at sea level for Maro Reef was 11 m.

Landsat ETM+ multispectral image of a portion of Midway Atoll.

IKONOS panchromatic image of a portion of Midway Atoll.
the att enuation of light by the water column during analysis of satellite imagery. It also is used in the analysis to help determine seabed features such as patch reefs, linear reefs, and micro-atolls. Bathymetry provides valuable information for organism habitat use, where both structure and water depth aff ect distribution patt erns. Estimated depth is being examined for use in vessel navigation, and this Atlas includes estimated depth for many areas in the NWHI. Estimated depth can be determined in clear water to between 20 m and 35 m, depending on the bott om type and absolute water clarity. The absolute accuracy of estimated depth varies with water depth. The error is generally 0.3 m for water less than 1 m deep. In water up to 15 m, deep the error is plus or minus 15 percent. In water 15 or more meters deep, the error is plus or minus 30 percent. The estimated depth maps in this Atlas depict structural features larger than 8 m in diameter. Using the estimated depth and water refl ectance, bott om albedo (bott om refl ectance) is computed. The image analysis to identify and characterize seabed features (i.e., map) is performed on the bott om refl ectance. Bott om refl ectance is the approximate re- fl ectance of bott om features when the water column is removed. Approximations of light att enuation are computed, based on real or estimated water depth, and ìaddedî to the actual refl ectance signal received from the bott om. The result is a ìnormalizedî bott om feature refl ectance. The seabed habitat maps are generated using digital image analysis of the color and depth information. The analysis uses methods originally developed for land classifi cation. The computer-based image identifi es seabed features in the imagery based on spectral and spatial characteristics of seabed Chubs at Midway Atoll.

11

tance (or at-satellite refl ectance) converts DNs into standardized, 

satellite-independent, comparable values. First developed for Landsat satellite imagery, the algorithm used to perform this conversion was modifi ed for IKONOS image processing. As part of the conversion from DNs to at-satellite refl ectance, the following equation is used (Green et al., 2000):

R = pi * L/ (Eo cos(theta0) 1/r^2) L = radiance (from calibration provided by Space  Imaging). theta0 = the solar zenith angle. r = earth-sun distance in Astronomical Units. Eo = the mean solar exo-atmospheric irradiance in each  band. (A convolution of the spectral response and  solar radiation from Neckel and Labs (1984) was  used to get Eo.)The acquisition angles (ephemeris data) of the satellite relative to the ground at the time of image acquisition were also used. Calibration coeffi cients for the satellite, provided by Space Imaging, were used to calculate at-satellite radiance, which was then 

transformed to refl ectance.The normalized refl ectance imagery was then transformed into water refl ectance (or the signal < 10 cm above the water surface). Water refl ectance uses the near-infrared band to remove radiance att ributable to atmospheric and surface eff ects (Stumpf et al., in press). Water refl ectance estimates how the signal (photons) received by the satellite is diminished as it passes through 

the atmosphere on the way down to the water-atmosphere boundary and on the way back up to the satellite aft er the signal leaves the water-atmosphere boundary. Water refl ectance also 

estimates how the signal at the satellite is diminished by water vapor, clouds, specular eff ects at the water surface (wave surface glint), and other signal-absorbing and diff using materials in the air and at the water surface (Green et al., 2000).

Estimating DepthWater depth, in the form of estimated depth, is derived from the satellite imagery following the procedure of Stumpf et al. (in press). Knowing the depth of the water is important because water att enuates (absorbs) light. As the water depth increases, less and less light reaches the bott om and even less light is refl ected off the bott om back up through the water column. Mapping relies on identifying and characterizing seabed features based on their spectral and morphologic characteristics. Due to water att enuation, the spectral characteristics of a seabed feature in 2 m of water is diff erent than that same seabed feature in 10 m or 15 m of water. The estimated depth is used to compensate for 
12

mapping activity. Information gathered during several research cruises, including videotapes and Rapid Ecological Assessments by the NMFS Coral Reef Ecosystem Investigation program, the 2000 NOW-RAMP cruise, and information collected from personal communication also were used to support the mapping e

ff ort.

Map ValidationOnce generated, the dra

ft benthic habitat maps were evaluated 

for accuracy. Two types of validation were employed to validate the maps in this Atlas. First, two workshops were held in Hawai̒i to enable locally-knowledgeable, shallow-water coral reef experts to review the dra

ft maps and provide comments. 

The comments from these workshops were incorporated into the dra

ft benthic habitat maps in this Atlas.

Participants in the dra

ft habitat map review workshops include:

Alan Friedlander, Oceanic InstituteEd Carlson, NOS, NGSRusty Brainard, NMFS, CREIJean Kenyon, NMFS, CREIJoyce Miller, NMFS, CREIStephanie Holzwarth, NMFS, CREIFrank Parrish, NMFS-Honolulu LaboratoryRay Boland, NMFS-Honolulu LaboratoryMichael Parke, NMFS-Honolulu LaboratoryDave Foley, NMFS-Honolulu LaboratoryJim Maragos, FWSRon Salz, FWSMiles Anderson, Analytical Laboratories of Hawai̒iDave Gulko, DLNRDave Smith, DLNRWill Smith, University of Hawai̒iPaul Jokiel, University of Hawai̒iEric Brown, University of Hawai̒iIsabelle Abbo

tt , University of Hawai̒i

Fenny Cox, University of Hawai̒iCelia Smith, University of Hawai̒iJennifer Smith, University of Hawai̒iEric Hochberg, University of Hawai̒i

Second, statistical analysis to compute a ìuserî and ìproducerî error was performed using a subset of the 1,100 site-speci

fi c habitat characterization data available for the NWHI. This analysis 

quanti

fi ed the di

ff erences, i.e., the error, between what a habitat 

was in reality and what it was interpreted to be using rule-based image analysis. ìUserî accuracy is the probability that a habitat polygon interpreted from the image actually represents that habitat in the 

fi eld. ìProducerî accuracy is the probability that 

any polygon of a particular habitat is correctly classi

fi ed (Green 

et al., 2000). The major habitat categories depicted on the dra

ft

maps will be evaluated for both ìUserî and ìProducerî error.A Kappa Statistic is computed as part of the accuracy assessment. A Kappa Statistic of 0.59 (59 percent) implies that the classi

fi cation process is avoiding 59 percent of the errors that a 

completely random classi

fi cation would generate (Congalton, 

1991; Green et al., 2000).In addition, a Tau Coe

ffi cient is computed. The Tau Coe

ffi cient 

measures the accuracy of the entire map across all major categories. The Tau Coe

ffi cient is valuable because it indicates how 

many more habitat polygons (groups of pixels) were correctly classi

fi ed than would be expected by chance alone (Ma and Redmond, 1995). 

Literature CitedAbbo

tt , I. A. 1989. Marine algae of the Northwestern Hawaiian 

Islands. Paci

fi c Science 43(3): 223ñ233.

Balazs, G. H. 1976. Green turtle migrations in the Hawaiian Archipelago. Biological Conservation 9: 125ñ140.Balazs, G. H. 1983. Recovery records of adult green turtles observed or originally tagged at French Frigate Shoals, Northwestern Hawaiian Islands. U.S. Dept. of Commerce., NOAA Technical Memo. NMFS, NOAA-TM NMFS-SWFC-36. 42pp.Balazs, G. H. 1985. Status and ecology of marine turtles at Johnston Atoll. Atoll Resource Bulletin 285: 1ñ46.Seajelly and jack at Maro Reef.
13

Coral Reefs 1: 29ñ34. Grigg, R. W. 1993. Precious coral fi sheries in Hawai̒i and the 

U.S. Pacifi c Islands. Marine Fisheries Review 55(2): 50ñ60.

Grigg, R. W. and S. Dollar. 1980. The status of reef studies in the Hawaiian Archipelago. (In) R. Grigg and R. Pfund (eds.) Proceedings of the Symposium on Status of Resource Investigation 

in the Northwestern Hawaiian Islands. Sea Grant report 80-04. Honolulu. 280 pp.Gulko, D. 1998. Hawaiian Coral Reef Ecology. Honolulu: Mutual Publishing.Hawai̒i Department of Land and Natural Resources. The Northwestern Hawaiian Islands Exhibit. July 2000. State Government of Hawai̒i. 28 Oct. 2000.<htt p://www.state.hi.us/dlnr/exhibits/nwhi/NWHI_1.htm>Hobson, E. S. 1984. The structure of reef fi sh communities in the 

Hawaiian archipelago. In ìProceedings of the Second Symposium on Resource Investigations in the Northwestern Hawaiian Islandsî (R. Grigg and K. Tanoue, eds.), University of Hawai̒i 

Sea Grant MR-84-01 Volume 1:101ñ122.Hoover, J. P. 1993. Hawai̒iís fi shes. A guide for snorkelers, divers 

and aquarists. Honolulu: Mutual Publishing. 183 pp.Johanos, T. C. and J. D. Baker. 2000. The Hawaiian monk seal in the Northwestern Hawaiian Islands, 1998. U.S. Department of Commerce, NOAA Technical Memorandum, NOAA-TM-NMFSSWFSC-292, 107 pp.

Johanos, T. C. and T. J. Ragen (eds.) 1999. The Hawaiian Monk Seal in the Northwestern Hawaiian Islands, 1997. NOAA-TMNMFS-SWFSC-262. 100 pp.Ma, Z. and R. L. Redmond. 1995. Tau Coeffi cients for Accuracy Assessment of Classifi cation of Remote Sensing Data. Photogrammetric Engineering and Remote Sensing. 61:435ñ439.MacArthur, R. H. and E. O. Wilson. 2001. The Theory of Island Biogeography. Princeton: Princeton University Press. 224 pp.Maragos J. E., M. P. Crosby and J. W. McManus. 1996. Coral reefs and biodiversity: a critical and threatened relationship. Oceanography 9(1): 83ñ101.Maragos, J. and D. Gulko (eds.) 2002. Coral Reef Ecosystems of the Northwestern Hawaiian Islands: Interim Results Emphasizing the 2000 Surveys. Honolulu: U.S. Fish and Wildlife Service and the Hawai̒i Department of Land and Natural Resources, HI. 46 pp.Midway Atoll National Wildlife Refuge Home Page. 2000. U.S. Fish and Wildlife Service. 10 Nov. 2000.<htt p://www.r1.fws.gov/midway/intro/default.htm>Miller, S. L. and Crosby, M. P. The Extent and Condition of US Coral Reefs. NOAAís State of the Coast Report. 1998. National Oceanic and Atmospheric Administration. 4 Nov. 2000.<htt p://state-of-coast.noaa.gov/bulletins/html/crf_08/crf.html> National Geographic Society. 2000. Coral World. A map of the Worldís coral reefs.

Rice coral at Lisianski Island.

Lobe coral at Lisianski Island.
The habitat scheme is hierarchical, descending from the broad 

substrate category (level 1), followed by structure (level 2), cover (level 3) and cover modifi er (level 4). This format allows for fl exible classifi cations; characterization of levels can be validated at a 

given time, and updated later as additional information becomes available (see Diagram 1). The structure of the classifi cation scheme for NWHI is presented in the table below, with the class numbers designating the classifi cation level (e.g., 1000 represents 

a fi rst-level class, 1100 a second, 1110 a third, and 1111 a fourth).A total of 30 unique classes of benthic habitat were included in the NWHI classifi cation scheme. Of these independent classes, 23 have been identifi ed and mapped at one or more atolls in the NWHI. Including both unique and upper level classes, a total of 45 separate habitat classes are identifi ed on the maps included in the Atlas. For more information on the NWHI mapping eff ort, 

please visit: htt p://biogeo.nos.noaa.gov.

Descriptions of the detailed benthic habitats mapped in the NWHI can be found starting on page 16. Descriptions of the aggregated benthic cover habitats mapped in the NWHI can be found starting on page 21.

14

 = 0.39 square statute miles1 kilometer = 3,281 feet = 1,094 yards = 0.54 nautical miles = 0.62 statute miles

The Classifi cation Scheme Used to Map the NWHIA hierarchical benthic habitat classifi cation scheme was used to defi ne and delineate habitats in the NWHI. The scheme was developed with extensive input from shallow-water coral reef experts in Hawai̒i. The structure of the classifi cation scheme was initially based on schemes developed by NOS for shallowwater coral reef ecosystems in the Caribbean (Kendall et al, 2001) and main Hawaiian Islands (Coyne et al, 2001). Modifi cations were required to adapt these schemes to NWHI habitats and to characterization methods using satellite imagery.The IKONOS satellite provided the imagery used for mapping the aggregated cover and detailed benthic habitats. The Landsat satellite provided the imagery for mapping the bank areas. Digital processing of the imagery to produce maps made it possible to establish a minimum mapping unit (MMU) of approximately 100 sq. m (1/40 acre). The spatial and spectral information from the satellite imagery was used to characterize detailed and aggregated benthic habitats and estimated depth. Combining digital image processing and establishing a small MMU enabled benthic features to be characterized that would not otherwise have been mapped.Site-specifi c benthic feature characterization data and towboard data collected in the NWHI by CREI and NOS were used extensively to develop and validate the digital image analysis procedures. These data also provided information used to bett er defi ne several of the categories of habitat found in the classifi cation scheme, particularly the macroalgae subcategory. The classifi cation scheme was reviewed by shallow-water coral reef experts during a workshop held in Hawai̒i and at several follow-up meetings and discussions.The classifi cation scheme is designed to categorize benthic habitat by substrate category (unconsolidated and hardbott om), structure (e.g., linear reef or pavement) and cover (e.g., coral or macroalgae). Shallow-water coral reef ecosystems also can be grouped into larger geomorphological systems such as atoll and bank, and geographic zones such as lagoon and back reef. However, this Atlas focuses only on grouping by substrate, structure and cover.

Diagram 1. Hierarchical classifi cation scheme.
15

 Sca

tt ered Coral/Rock in sand with live coral (>10% cover)*

 (2610) Pavement* (2700) Pavement with sparse (10ñ50% cover) algae* (2701) Pavement with dense (>50% cover) algae* (2702) Pavement with live coral (>10% cover)* (2710) Pavement with live coral (>10% cover) and dense (>50% cover) algae* (2712) Pavement, uncolonized* (2720) Pavement, uncolonized with dense (>50% cover) algae* (2722) Pavement with crustose coralline algae (>10% cover)* (2730) Pavement with Sand Channels* (2800) Pavement with sand channels and live coral (>10% cover)* (2810) Pavement with sand channels, uncolonized* (2820) Volcanic Rock* (2900) Volcanic Rock with dense (>50% cover) algae* (2902) Volcanic Rock with live coral (>10% cover)* (2910) Volcanic Rock, uncolonized* (2920)Other Delineations* (3000) Deep water* (3010) Reef crest* (3020) Dredged channel* (3030) Land* (3100) Arti

fi cial* (3110)

 Flags* (3200) Cloud cover* (3210) Shadow* (3220) Surf* (3230) Missing Data* (3240) Unclassi

fi ed* (3300)

No Data* (4000)

The Aggregated Cover Benthic Habitat of the Northwestern Hawaiian Islands. This classi

fi cation scheme combines numerous detailed habitat 

categories into more general cover habitat categories.

Hardbo

tt om with >10% live coral

 Hardbo

tt om with live coral (>10% cover)* (2010)

 Linear Reef with live coral (>10% cover)* (2110) Aggregated Coral Heads with live coral (>10% cover)* (2210) Patch Reef with live coral (>10% cover)* (2410) Aggregated Patch Reef with live coral (>10% cover)* (2510) Sca

tt ered Coral/Rock in sand with live coral (>10% cover)* (2610)

 Pavement with live coral (>10% cover)* (2710) Pavement with live coral (>10% cover) and dense (>50% cover) algae* (2712) Pavement with sand channels and live coral (>10% cover)* (2810) Volcanic Rock with live coral (>10% cover)* (2910)Hardbo

tt om with >10% crustose coralline algae

 Hardbo

tt om with crustose coralline algae (>10% cover)* (2030)

 Linear Reef with crustose coralline algae (>10% cover)* (2130) Patch Reef with crustose coralline algae (>10% cover)* (2430) Pavement with crustose coralline algae (>10% cover)* (2730)Hardbo

tt om (uncolonized)

 Hardbo

tt om, uncolonized* (2020)

 Linear Reef, uncolonized* (2120) Patch Reef, uncolonized* (2420) Pavement, uncolonized* (2720) Pavement with sand channels, uncolonized* (2820) Volcanic Rock, uncolonized* (2920)Hardbo

tt om with >10% macroalgae

 Hardbo

tt om with sparse (10ñ50% cover) algae* (2001)

 Linear Reef, uncolonized with sparse (10ñ50% cover) algae* (2121) Patch Reef, uncolonized with sparse (10ñ50% cover) algae* (2421) Pavement with sparse (10ñ50% cover) algae* (2701) Pavement with dense (>50% cover) algae* (2702) Pavement with live coral (>10% cover) and dense (>50% cover) algae* (2712) Pavement, uncolonized with dense (>50% cover) algae* (2722)Hardbo

tt om with indeterminate cover

 Hardbo

tt om* (2000)

 Linear Reef* (2100) Spur and Groove* (2300) Individual Patch Reef* (2400) Aggregated Patch Reef* (2500) Pavement* (2700) Pavement with Sand Channels* (2800) Volcanic Rock* (2900)Unconsolidated with 10% or less macroalgae or seagrass Unconsolidated sediment* (1000) Sand* (1100) Unconsolidated rubble* (1300) Sand and rubble* (1400) Groove* (1500)Unconsolidated with >10% macroalgae or seagrass Sand with macroalgae (1120) Sand with patchy (10ñ50% cover) macroalgae* (1121) Sand with dense (>50% cover) macroalgae* (1122) Unconsolidated Rubble with sparse (10ñ50% cover) algae* (1301) Unconsolidated Rubble with dense (>50% cover) algae* (1302)(* - This habitat category or other delineation was identi

fi ed on a map.)
macroalgae (e.g., Microdictyon spp.) found on hardbott om substrates (level 4 classes).

Turf algae is commonly found on both unconsolidated rubble

and hardbott om substrates. Habitat features that cover areas smaller than the MMU were not mapped as separate features, but described as a class that aggregates them into larger areas (e.g., Scatt ered Coral/Rock in Sand). Similarly, some habitat classes were included that combine substrate types, where the combination has particular biological and/or structural signifi -

cance (e.g., Pavement with Sand Channels).Other Delineations includes features identifi ed in the imagery, 

but are not benthic habitat, such as deep water, intertidal reef crest, dredged channels, and land, as well as areas that are obscured by cloud, shadow or surf. Areas of imagery that were not obscured, but which were not conclusively classifi ed (typically deep areas where the bott om was marginally visible) are listed 

as ìunclassifi ed.îThe Detailed Benthic Habitat Classifi cation Scheme of the Northwestern Hawaiian Islands.Unconsolidated sediment* (1000): Mobile substrate that varies in coarseness (from mud to sand to rubble), and which is characterized by some degree of instability in response to water motions.

Five habitat subcategories exist within the Unconsolidated sediment habitat category. These Level 2 subcategories include:Sand* (1100): Coarse sediment typically found in areas exposed to currents or wave energy. See Figures 1, 15 and 16. Calcareous Mud (1200): Fine sediment associated with buildup of organic material in areas sheltered from high-en- ergy waves and currents. This habitat category is not found in the NWHI. Unconsolidated Rubble* (1300): Dead, unstable coral rubble that appears predominantly pebble- and cobble-sized. This habitat oft en occurs landward of well-developed reef crest formations or in the back reef, as well as at the base of patch reef and linear reef formations. See Figures 2 and 15. Sand and Rubble* (1400): Sediment composed of approxi- mately even amounts of sand and rubble that cannot be sepa- rately distinguished in the imagery for the given area. Groove* (1500): Narrow, linear sand feature that alternates with coral formations in spur and groove habitat (see Figure 6), and which is oriented perpendicular to the shore or bank/ shelf escarpment. Groove is delineated as an individual cat- egory when the channel is clearly larger than the MMU. A Level 3 subcategory describes the type of algae found on the Unconsolidated sediment substrate. Two Level 3 subcategories have been defi ned: Sand with seagrass* (1110): Sand with 10 percent or great- er cover of seagrass, where percent cover refers to coverage of the substrate by the bed, rather than shoot density. Note that this habitat is very uncommon in NWHI. Representa- tive species: Halophila sp.

16

Figure 2. Unconsolidated rubble at Midway Atoll. Figure 3. Sand with macroalgae at Midway Atoll.
or result in isolated patches of macroalgae that are too small (smaller than the MMU) to be mapped individually as dense beds.Sand with dense (>50 percent cover) macroalgae* (1122): Macroalgae covering 50ñ100 percent of the sand substrate. May include blowouts (no coverage) of less than 10 percent of the total area that are too small (less than the MMU) to be mapped independently.Unconsolidated Rubble with sparse (10ñ50 percent cover) algae* (1301): Rubble with 10ñ50 percent cover of macroalgae or turf algae. Turf algae is the most frequent cover type.Unconsolidated Rubble with dense (>50 percent cover) algae* (1302): Rubble with greater than 50% cover of macroalgae or turf algae. See Figure 15.

Hardbott om* (2000): Hardened substrate of unspecifi ed relief 

formed by the deposition of calcium carbonate by reef building corals and other organisms (relict or ongoing) or existing as exposed bedrock or volcanic rock. Habitats within this category typically have some colonization by live coral. If no coral colonization is present, habitats would be categorized as Uncolonized.

Nine habitat subcategories exist within the Hardbott om

habitat category. The Level 2 subcategories generally describe structural features found within shallow-water coral reef ecosystems. These nine Level 2 subcategories include:Linear Reef* (2100): Linear coral formations that oft en are 

oriented parallel to shore or the shelf edge, but which are also found within NWHI atolls, without a particular axis relative to the shore/shelf edge. This category includes habitat structures that are commonly referred to as fore reef, fringing reef, and shelf edge reef. See Figures 4 and 15.Aggregated Coral Heads* (2200): Coral formations that are 

composed of relatively monotypic coral colonies, typically isolated from other shallow-water coral reef formations by unconsolidated sediment, where the hardened substrate is larger than the MMU. This habitat can include large individual coral heads and clusters of coral heads that are too small (less than the MMU) or too close together to be mapped separately. Small, individual coral heads that are isolated from each other by larger areas of sediment normally will be classed as scatt ered coral/rock (see below), rather than as aggregated coral heads. Representative species: Porites spp.; Montipora spp.; Acropora spp. See Figures 5 and 15.Spur and Groove* (2300): Habitat having alternating sand 

and coral formations that are oriented perpendicular to the shore or bank/shelf escarpment. The coral formations (spurs) of this feature typically have a high vertical relief relative to pavement with sand channels (see below) and are separated from each other by 1ñ5 m of sand or bare hard bott om 

(grooves). The height and width of the spurs and grooves may vary considerably. This habitat type typically occurs in the fore reef or bank/shelf escarpment region and is frequently found seaward of breaks in the barrier reef. The spur and groove habitat is important for dissipating wave energy. See Figures 6, 15 and 16.

17

Figure 5. Aggregated coral heads at Kure Atoll. Figure 6. Spur and groove at Midway Atoll.
dicular to the shore, fringing reef or bank/shelf escarpment. 

The sand channels of this feature have low vertical relief relative to spur and groove formations. This habitat type occurs in areas exposed to moderate wave surge such as the bank/shelf zone or areas just landward of breaks in the barrier reef. See Figure 16.Volcanic Rock* (2900): Substrate of exposed basalt rock, which frequently includes large boulders and blocks. This habitat is typically found in nearshore environments around small basalt islands. See Figure 10.

A Level 3 subcategory describes the type and percentage of coral and/or crustose coralline algae found on the Hardbott om substrate. Three Level 3 subcategories have been 

defi ned. These second-level subcategories may apply to more than one Level 2 subcategory.Hardbott om with live coral (>10 percent cover)* (2x10): 

Substrates formed by the deposition of calcium carbonate by reef-building corals and other organisms. Habitats within this category have greater than 10 percent colonization by live coral. Representative species: Porites compressa, 

Porites lobata, Montipora spp., Pocillopora meandrina. See Figure 8.Hardbott om, uncolonized* (2x20): Hard substrate composed of relict deposits of calcium carbonate or exposed volcanic rock. Habitats within this category have 10 percent or less coverage of hard coral or crustose coralline algae, but total coverage from both cover types may exceed 10 percent. See Figure 11.

18

Scatt ered Coral/Rock in sand with live coral* (2600): Sand or 

rubble substrate with scatt ered rocks, or small, isolated coralheads that are too small to be delineated individually (i.e., too small to be identifi ed as individual patch reef or aggregated 

coral heads).Pavement* (2700): Flat, low-relief, solid carbonate rock. See Figures 9, 15 and 16.Pavement with Sand Channels* (2800): Habitat with alternating sand and pavement substrates that are oriented perpen

Figure 10. Volcanic rock at Nihoa Island.Figure 9. Pavement with macroalgae at Kure Atoll.

Figure 11. Uncolonized hardbott om at Midway Atoll.
19

Figure 13. Hardbott om with dense macroalgae at Kure Atoll.

based supplemental information was lacking were labeled ìunclassifi ed.îReef crest* (3020): The fl att ened, emergent or nearly emergent segment of a reef. This feature typically is found along barrier reef lines in NWHI and is frequently covered with dense macroalgae. Breaking waves are typically found at or just seaward of the reef crest and are delineated as surf (see below) if present in the imagery. See Figures 14, 15 and 16.Dredged channel* (3030): Area where excavation or dredging has occurred.

Land* (3100): Areas determined to be above the water line in the imagery at the time the imagery was acquired. See Figure 16.

Artifi cial* (3110): Human-made habitats such as dredged channels, large piers, submerged wrecks, submerged portions of rip-rap jett ies, and the shoreline of islands created from dredge spoil.

Flags* (3200): Areas where the water or land surface in the imagery is obscured. The types of fl ags include:

Cloud cover (3210)Shadow (3220)Reef crest or Surf (3020; 3230) See Figures 15 and 16.Missing data (3240; data dropouts in the imagery)

Unclassifi ed* (3300): Areas where the bott om type is unclassifi ed because of turbidity in the water, surface glint, or other 

Figure 14. Reef crest at Kure Atoll.

types of interference. This category also includes areas where the seabed cannot be classifi ed due to a lack of supplemental 

fi eld-based information, or for other reasons.

No data* (4000): Refers to areas within the geographic bounds of the habitat map that lie outside the bounds of the acquired imagery. This is not a habitat category in the classifi cation scheme.

(* ñ This habitat category or other delineation was identifi ed on a 

map within this Atlas.)
20

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21

Example detailed class: Linear Reef with crustose coralline algae (>10 percent cover) (2130).Hardbo

tt om (uncolonized): Included all classes in the 

hardbo

tt om substrate category that had less than 10 percent 

live coral cover, crustose coralline algal cover or macroalgal cover. Example detailed class: Pavement with sand channels, uncolonized (2820).Hardbo

tt om with >10 percent macroalgae: Included all classes 

in the hardbo

tt om substrate category that had more than 10 

percent macroalgae, but not more than 10 percent live coral cover or 10 percent crustose coralline algal cover. Typically, these habitats also had a high percentage of turf algal cover. Example detailed class: Hardbo

tt om with sparse (10ñ50 percent cover) 

algae (2001).Hardbo

tt om with indeterminate cover: Included all classes in 

the hardbo

tt om substrate category for which a speci

fi c bo

tt om 

cover was not identi

fi ed. Included were all areas classi

fi ed only 

to the 

fi rst or second level of the detailed classi

fi cation scheme. 

Example detailed class: Aggregated Patch Reef (2500).Unconsolidated with 10 percent or less macroalgae or seagrass: Included all classes in the unconsolidated substrate category with not more than 10 percent cover of live submerged vegetation (macroalgae/seagrass). Example detailed class: Sand (1100).Unconsolidated with >10 percent macroalgae or seagrass:Included all classes in the unconsolidated substrate category with more than 10 percent cover of live submerged vegetation (macroalgae/seagrass). Seagrass was very uncommon in NWHI (only a small area was found at Midway during the 

fi eld 

survey) and was not identi

fi ed on any of the habitat maps. 

Example detailed class: Sand with patchy (10ñ50 percent cover) macroalgae (1121).
22

ge of a portion of Kure Atoll showing typical benthic habitats. 

bitats are described in the classifi cation scheme.

Pavement with sparse

(10ñ50% cover) algae (2701) Spur and Groove (2300)

Sand (1100)

Reef crest with Surf (3020; 3230)

Pavement, uncolonized (2720)Unconsolidated Rubble (1300)
23

vement with sand channels

live coral (>10% cover) (2810)

al Patch Reef (2400)

Land (3100) Reef crest with Surf (3020; 3230)

of a portion of Pearl and Hermes Atoll showing typical benthic 

hic habitats are described in the classifi cation scheme.
24

abitat Cover Type and Geographic Locale (sq. km)

arl & 

ermes 

Atoll

20.3

0.0

13.762.249.3

226.2

19.9

391.6

Lisianski 

Island

 16.4 0.0 0.9 6.1 183.5 231.8 0.0 438.7

Laysan 

Island

 5.8 0.5 2.9 0.1 81.7 36.2 0.0 127.2

French 

Frigate 

Shoals

 48.3 4.7 49.9 3.7 46.1 241.5 23.4 417.6

Necker 

Island

 0.0 0.0 0.0 0.0 208.1 19.5 0.0 227.6

Maro 

Reef

 14.8 1.3 6.8 0.4 180.1 295.7 19.6 518.7

Nihoa

Island

 <0.1 0.0 0.7 4.5 58.9 10.0 0.0 74.1

TOTAL

 108.8 7.3 101.4 105.2 822.8 1149.6 65.8 2360.8

ober 2002

mapped within the Northwestern Hawaiian Islands 

ates derived from NOAA nautical charts and remotely 

hom 

th

d from 

hart)

km

10-fathom 

isobath

(digitized from 

NOS chart)

in sq. km

Landsat

(visible

bott om)

in sq. km

IKONOS

(mapped

habitat)

in sq. km

ithin:

 ñ 99 ñ ñ ñ 387 ñ ñ ñ 211 ñ ñ 26 189 16 1 ñ ñ ñ ñ ñ 2 464 ñ 3 9 3 6 ñ 1,416 0.4

 ñ ñ ñ ñ ñ ñ ñ ñ ñ 972 369 269 453 1,648 503 1,934 315 ñ ñ 85 65 11 712 ñ ñ 1,314 247 487 91 10,045 3.0

 70 96 ñ ñ ñ 392 ñ ñ ñ 439 ñ ñ 127 519 ñ ñ ñ ñ ñ ñ ñ ñ 418 ñ ñ 228 ñ 74 ñ 2,363 0.7

NOTES:1. Approximiate area of entire Reserve (as currently defi ned) = 340,000 sq. km 

2. All areas digitized from charts include all polygons within the respective  isobath contours, and so include small amounts of land area.3. The 100-, 20-, and 10-fathom areas are based on digitized isobaths depicted  on nautical charts and obtained from several sources. They should be  considered approximations of actual area.4. Landsat areas were calculated using computerized image analysis of  polygons drawn around bott om habitat visible in the imagery.5. Areas shown for IKONOS refl ect actual mapped habitat, rather than the 

 amount of visible bott om. 6. Total area includes 70 sq. km for Kure Atoll, 96 sq. km for Midway Atoll,  and 389 sq. km for Pearl and Hermes Atoll mapped using IKONOS; and 15  sq. km for Gambia Shoal estimated from a nautical chart. 

ank areas found in the NWHI. 
f Aggregated Habitat Cover for all NWHI Islands

The accuracy assessment was performed on the aggregated cover benthic habitat maps only. This was due to the relatively few site-speci

fi c benthic characterization data (1,130 points) available for the NWHI. The overall accuracy of the aggregated cover 

maps was 72 percent, and ranged from 94 percent accuracy for unconsolidated sediment with li

tt le or no algae or seagrass to 

9% for unconsolidated sediment with seagrass present. [Note: A subset of the 1,130 points (376) was used in the accuracy assessment]Correctly classifying benthic habitats that include algae and live coral was challenging. For example, it is di

ffi cult to separate Unconsolidated Rubble with dense (>50 percent cover) algae from 

Pavement with dense (>50 percent cover) algae. Also, it is diffi cult to separate Unconsolidated Rubble and Sand and Rubble from Pavement habitats. These challenges also were encountered when di

ff erentiating between the various habitats with live coral 

cover.The aggregated cover category Hardbo

tt om with indeterminate 

cover was not included in the accuracy assessment. The aggregated Hardbo

tt om with indeterminate cover includes those 

detailed habitat categories where a speci

fi c cover was not identifi ed on the map, and no comparison to the 

fi eld-based benthic 

characterization information could be performed.An assessment of the overall accuracy of the hardbo

tt om and 

unconsolidated was performed (see the bo

tt om of Table 5). That 

analysis included habitat catgories with indeterminate cover and their associated 

fi eld-based benthic characterization data. That 

analysis revealed that these two habitats were correctly identifi ed 82 percent and 90 percent of the time, respectively.The Kappa Statistic is a measure of map accuracy relative to a map with classi

fi cations randomly assigned, expressed as a 

percent.The Tau Coe

ffi cient measures the accuracy of the entire map 

across all major categories. The Tau Coe

ffi cient is valuable because it indicates how many more habitat polygons were correctly classi

fi ed than would be expected by chance alone.

Tau Coe

ffi cients were not generated for the individual detailed 

habitat maps because only a small number of 

fi eld-based benthic 

characterizations were available at each NWHI locale.

25

Actual Habitat Type

ardbo

tt om 

ncolonized)

Hardbo

tt om 

with >10%

macroalgae

Unconsolidated with 

10% or less 

macroalgae 

or seagrass

Unconsolidated with 

>10%

macroalgae 

or seagrass

Row 

Total

User

Accuracy

5 5 0 0 63 79%

0 0 1 0 12 92%

33 2 3 0 44 75%11 16 3 6 39 41%18 14 161 6 209 77%

1 13

1 9 11%

68 38 171 13 376

45% 42% 94% 9%

e Type

d Row Total User Accuracy

239 92%218 78%

457
26

tat Cover Type and Geographic Locale (sq. km)

way 

oll

.0.2.2.0.0.0.0.0.0.7.0.0.6.5.1.2.0.0.0.0.0.9.4.1.0.0.0.0.0.0.9.4.0.6.0

7.5

.0.0.2.1.8.0.0.0.0.0

7.8

.1.4.0.4.0.5.2

Pearl & 

Hermes Atoll

 141.9 60.4 0.0 0.0 0.0 14.5 14.2 5.6 7.0 2.5 8.3 52.3 0.0 0.0 0.0 2.9 6.7 0.0 0.0 0.0 0.0 6.8 11.0 0.5 0.0 0.0 0.0 6.2 0.0 0.0 13.8 3.5 1.3 7.9 5.1 13.7 0.0 0.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 156.7 0.0 0.0 0.5 19.2 0.0 391.6 562.9

Lisianski 

Island

 75.4 72.3 0.0 0.0 0.0 16.9 0.0 0.0 67.2 0.0 155.7 6.0 7.1 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 18.4 8.7 0.0 9.4 0.0 <0.1 0.5 0.0 0.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 59.3 0.0 0.0 1.5 93.3 0.0 438.7 592.8

Laysan 

Island

 0.0 35.0 0.0 0.0 0.0 1.1 0.0 0.0 0.0 0.0 81.7 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.4 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.1 <0.1 5.4 0.0 2.9 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.7 33.0 0.0 0.0 3.5 7.6 0.2 127.2 172.2

Maro 

Reef

 245.4 43.4 0.0 0.0 0.0 6.9 19.6 0.0 0.0 0.0 176.4 0.0 1.0 <0.1 <0.1 0.1 10.5 1.6 0.2 0.2 0.0 0.0 3.4 3.4 5.2 0.2 0.1 0.0 0.0 0.0 0.2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100.4 0.0 0.0 0.0 60.4 0.1 518.7 679.6

French Frigate 

Shoals

 0.0 98.4 0.0 22.3 1.0 0.3 0.0 0.0 142.8 0.0 0.0 0.0 0.0 0.0 0.0 3.9 0.0 5.3 3.4 1.3 1.6 0.0 8.5 0.0 0.0 0.0 0.3 0.0 0.0 2.0 21.2 0.0 0.3 27.8 0.0 44.5 0.0 3.1 12.4 16.9 0.0 0.0 0.0 0.0 0.0 0.0 196.7 0.0 0.0 0.2 90.7 113.3 417.6 818.3

Necker 

Island

 0.0 19.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 205.5 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 2.7 <0.1 0.0 0.0 0.0 78.3 0.0 0.0 0.1 11.1 0.0 227.6 317.2

Nihoa

Island

 7.2 2.8 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 58.3 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.5 0.0 0.0 0.0 0.0 0.0 4.5 3.1 12.4 16.9 0.0 <0.1 0.0 <0.1 0.7 0.0 39.1 0.0 0.0 0.7 6.3 0.0 74.1 120.2

TOTAL

 469.9 406.5 0.2 22.3 1.0 52.3 33.8 8.3 217 3.9 685.9 58.3 9.7 16 0.6 7.4 17.4 6.9 3.6 1.5 2.1 14.8 28.3 4.4 5.2 0.2 0.4 24.6 8.7 2.0 46.1 9.9 23.5 42.3 5.1 71.6 4.5 6.9 25.4 33.9 0.8 2.7 <0.1 <0.1 0.7 0.7 852.8 <0.1 0.4 13.4 303.7 113.6 2360.8 3640.4
27

Legend for the detailed benthic habitat maps of the Northwestern Hawaiian Islands. Refer to the classifi cation scheme for habitat descriptions.

Unconsolidated sediment (1000)Sand (1100)Sand with macroalgae (1120)Sand with patchy macroalgae (1121)Sand with dense macroalgae (1122)Unconsolidated Rubble (1300)Unconsolidated Rubble with sparse algae (1301)Unconsolidated Rubble with dense algae (1302)Sand and Rubble (1400)Groove (1500)Hardbott om (2000)Hardbott om with sparse algae (2001)Hardbott om with live coral (2010)Hardbott om, uncolonized (2020)Hardbott om with crustose coralline algae (2030)Linear Reef (2100)Linear Reef with live coral (2110)Linear Reef, uncolonized (2120)Linear Reef, uncolonized with sparse algae (2121)Linear Reef with crustose coralline algae (2130)Aggregated Coral Heads with live coral (2210)Spur and Groove (2300)Individual Patch Reef (2400)Patch Reef with live coral (2410)Patch Reef, uncolonized (2420)Patch Reef, uncolonized with sparse algae (2421)

Patch Reef with crustose coralline algae (2430)Aggregated Patch Reef (2500)Aggregated Patch Reef with live coral (2510)Scatt ered Coral/Rock in sand with live coral (2610)

Pavement (2700)Pavement with sparse algae (2701)Pavement with dense algae (2702)Pavement with live coral (2710)Pavement with live coral and dense algae (2712)Pavement, uncolonized (2720)Pavement, uncolonized with dense algae (2722)Pavement with crustose coralline algae (2730)Pavement with Sand Channels (2800)Pavement with sand channels and live coral (2810)Pavement with sand channels, uncolonized (2820)Volcanic Rock (2900)Volcanic Rock with dense algae (2902)Volcanic Rock with live coral (2910)Volcanic Rock, uncolonized (2920)Other Delineations (3000)Deep water (3010)Reef crest (3020)Dredged channel (3030)Land (3100)Unclassifi ed (3300)No data, cloud cover (3210), cloud shadow (3220), surf (3230), missing data (3240), and no image data (4000)