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1 . Northern Mariana Islands     Northern Mariana Islands
The Marianas Archipelago encompasses 15 islands and numerous banks oriented on a north-south axis stretching over 460 nmi from Santa Rosa Reef south of Guam, to Uracas Bank north of the island of Uracas, or Farallon de Pajaros. Approximately 120 nmi west of the main island chain exists a succession of seamounts also oriented on a northsouth axis, referred to as the west Mariana Ridge.

The Commonwealth of the Northern Mariana Islands (CNMI) is a political subset of the Mariana Archipelago that includes Rota Island in the south, extending northward to Uracas Bank. The 14 islands of the archipelago are geologically divided into two types; the southern arc characterized as raised limestone plateaus overlying volcanic cores, and the more recent northern islands are basaltic and volcanically active.

Prior to receiving U.S. Commonwealth status in 1978, CNMI was part of the Pacific Trust Territories under the administration of the United States, along with the Marshall Islands, Palau, and the Federated States of Micronesia. During the U.S. administration of the islands, economic development was limited, there were few commercial enterprises, and the population relied primarily on subsistence agriculture and fisheries, and Federal aid.

The population in the islands has increased 57.2% over the past ten years to 69,200 in 2000 (U.S. Bureau of Census 2002). In 1995, about 90% of the CNMI population was in Saipan, 6% was in Rota, 5% was in Tinian, and less than 1% was in the Northern Islands (Stewart 1997).

As with most tropical islands, marine-related tourism is an important part of the island economy (Fig. 285). In the early 1980s, Japan invested heavily in tourism development, bringing in large numbers of foreign workers for facility construction and operation (Stewart 1992), creating a period of dramatic economic growth. In 1996, the CNMI received 737,000 visitors who spent over $587 million (Stewart 1997).

Commercial fish landings generate around $1 million annually (NMFS 2001). In addition to invoice data presented in Western Pacific Regional Fisheries Management Council Plan Teams, numerous DFW Technical Reports have been published over the past eight years specifically addressing fishery resources based on data collection programs.
Source: Starmer, J., M.S. Trianni, and P. Houk , 2002 , Status of coral reefs in the commonwealth of the Northern Mariana Islands. . In: Rogers, Z. et al., 2002. The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2002. National Oceanic and Atmospheric Administration/National Ocean Service/National Centers for Coastal Ocean Science, Silver Spring, MD. 265 pp. (See Document)

2 . Northern Mariana Islands     Northern Mariana Islands
The 290 km long Mariana Islands Archipelago encompasses 14 islands of the U.S. Commonwealth of the Northern Mariana Islands (CNMI), the U.S. Territory of Guam, and numerous offshore banks (Figure 15.1). From a geological perspective, the islands can be divided into two groups: a southern and a northern island arc region. Although the islands of the older southern arc, which includes Rota, Tinian, Saipan, and Farallon de Mendinilla (FDM), are volcanic in origin, they are nearly all covered with uplifted limestone derived from coral reefs. The West Mariana Ridge (WMR) is a series of seamounts, lying 145 to 170 km west of and parallel to the main island chains. Some of these mounts rise to within 13 m of the surface. The WMR is intermediate in age, as it is being younger than the southern island arc and older than the northern island arc. The southern arc islands have the oldest and most developed reefs in the CNMI, which are predominantly located along the western (leeward) sides. The majority of the CNMI’s residents live on Rota, Tinian, and Saipan, the capital.

Southern Mariana Islands
Rota is 117 km southwest of Saipan and 76 km north of Guam, is the southernmost island in the Mariana Island Chain (Figure 15.1 and 15.2). It has a land area of 85.5 km2 and is approximately 17 km long and 5 km wide. The principal communities are Sinapalo and SongSong. As Rota was neither developed extensively by the Japanese nor invaded during World War II (WWII), it still has much of its native vegetation. However, the island is becoming more of a tourist destination and development is increasing, which may impact the existing fringing reefs. Fringing reef surrounds the island and modern reef development is most significant on the northwest coast, west of Teteto Beach, and in the Sasanhaya Bay on the southwest coast. Continuous reef is found inside Sasanhaya Bay and an area along the western shore. Erosion along the Talakaya cliffline on the southern coast is causing sedimentation problems on adjacent reefs.

Aguijan (Goat Island) is an uplifted limestone island with a land area of 7.3 km2 (Figure 15.1). It is presently uninhabited, although it was populated during WWII. The island is now under the management of the Tinian Municipal Council. The neighboring islet, Naftan Rock, was used as a bombing target prior to the U.S. Navy’s use of FDM and unexploded ordnance remains in the surrounding waters. The island is now home to nesting seabirds. The reefs just off the northwest coast are the largest and most developed.

Tinian, with a land area of 102 km2, lies 4.4 km south of Saipan, across the Saipan Channel (Figure 15.1 and 15.2). The principal community is San Jose. Nearly two-thirds of Tinian is leased to the U.S. Military. Tinian’s coral reefs are more developed on the western side, most notably in the vicinity of the Tinian Harbor, an area likely to be negatively affected by future development.

Saipan, the largest of the Northern Mariana Islands, has a land area of 22km2 and is approximately 20 km long and 9 km wide (Figure 15.1 and 15.2). The island consists of a volcanic core enveloped by younger coral reefderived limestone formations. The island has the most diverse types of coral reefs and associated habitats in the Commonwealth. A fringing and barrier reef system protects the majority of the beaches along the western and coastal plains. The western side of the island is the most populated and the coral reefs along these areas are negatively affected by human activity. Continuing sediment and nutrient pollution combined with sporadic stressors such as outbreaks of crown-of–thorns starfish (COTS) (Acanthaster planci) and temperature-induced bleaching affect many of Saipan’s western and southeastern reefs. Furthermore, coral habitat on two large offshore banks (18 km x 22 km) in water depths between 30 m and 60 m on the western side of Saipan are negatively affected by the anchorage of commercial and naval vessels.

FDM is a steep-sided, raised limestone island with a land area of 0.8 km2 (Figure 15.1). The island supports one of the largest breeding colonies of Masked Boobies (Sula dactylatra) in the western Pacific along with several other species of seabirds. The island is surrounded by a fringing reef. Deeper habitat consists of pavement dotted with various sized boulders, some spur and groove formation, and sandy flats. A submerged platform reef with high coral cover exists off the center island lee. Shoal reefs, with a minimum depth of 6 m, occur approximately 1-2 km north of the northern tip of FDM. These reefs consist of complex channels and ridges with a biotic structure similar to that of the windward side of the island.

FDM is presently leased to the U.S. Military as a bombing range. A significant amount of controversy has arisen, especially in the past 10 years, with regard to the U.S. Navy’s use of this island. The effects of bombing are causing accelerated erosion of the landmass.

A variety of fish species that have become uncommon around the populated islands of Saipan and Tinian are more abundant around FDM. Over 350 species of fish have been identified. In addition, survey teams have observed numerous sea turtles (including green and hawksbill) and numerous pods of whitebelly spinner dolphins. In addition, terrestrial wildlife surveys following military live-fire exercises have observed species of whale including Brydes, Sperm, and Humpback whales in the vicinity of FDM.A variety of fish species that have become uncommon around the populated islands of Saipan and Tinian are more abundant around FDM. Over 350 species of fish have been identified. In addition, survey teams have observed numerous sea turtles (including green and hawksbill) and numerous pods of whitebelly spinner dolphins. In addition, terrestrial wildlife surveys following military live-fire exercises have observed species of whale including Brydes, Sperm, and Humpback whales in the vicinity of FDM.A variety of fish species that have become uncommon around the populated islands of Saipan and Tinian are more abundant around FDM. Over 350 species of fish have been identified. In addition, survey teams have observed numerous sea turtles (including green and hawksbill) and numerous pods of whitebelly spinner dolphins. In addition, terrestrial wildlife surveys following military live-fire exercises have observed species of whale including Brydes, Sperm, and Humpback whales in the vicinity of FDM.

Northern Mariana Islands
Anatahan is a small volcanic island (32.4 km2; Figure 15.1 and Figure 15.4). Prior to this island’s eruption on May 6, 2003, feral goats were creating severe erosion problems and the resulting sediment runoff was impacting the nearshore environment. A feral animal control program was started by the U.S. Fish and Wildlife Service (USFWS) and the Northern Island Mayor’s Office, with financial support from the U.S. Navy. Ash fallout from the 2003 eruption caused extensive damage to nearshore reef habitats, especially on the northern side (Figure 15.3). Although all surveyed locations during the 2003 National Oceanic and Atmospheric Administration (NOAA) Marianas Research and Monitoring Program (MARAMP) cruise contained a layer of ash covering the substrate (Figure 15.3), portions of the south shore and southeastern corner had only a veneer layer. Anatahan provides a unique opportunity to observe recovery and development of reef communities over the next several decades.

Sarigan ,is an uninhabited volcanic cone with a land area of 4.9 km2 (Figure 15.1 and Figure 15.4). Sarigan has experienced no terrestrial impacts since the removal of feral animals, although fishery resources continue to be harvested. Since the elimination of feral animals on this island (1997-1998), the vegetation has dramatically recovered, presumably reducing sediment runoff. According to the NOAA MARAMP towed-diver surveys, continuous reef areas along the east and south shores contained roughly 50% live coral cover. The MARAMP dive at Sarigan revealed a layer of sediment that had been deposited from the 2003 Anatahan eruption.

Guguan has a land area of 4.1 km2 (Figure 15.1) and is an active volcano with two cones, one of which is dormant. It is protected from development by the CNMI Constitution as it has been declared a wildlife conservation area, with large seabird colonies of Sooty Terns (Sterna fuscata), Gray-backed Terns (S. lunata), Brown Noddies (Anous stolidus), Black Noddies (A. minutus), and Red-footed Boobies (Sula sula). The reef communities observed around most of Guguan are as well developed as any seen in the northern islands, except for Maug. Unlike the exposed southeast shores of other northern islands, Guguan’s southeast shore has developed reef communities.

Alamagan with a land area of 11.2 km2, is an active volcano (Figure 15.1). Feral pigs, goats, and cattle are causing extensive damage to terrestrial ecosystems (T. de Cruz, pers. Obs.). These terrestrial effects are likely linked to the marine environment through runoff and sedimentation. The reef communities at Alamagan are noticeably less developed than those observed at Guguan Island, which lies only 26 km to the south.

Pagan has a land area of 48.2 km2 (Figure 15.1) and a volcanically active northern portion that is connected to a dormant southern portion byva narrow isthmus. A major eruption in 1981 caused the evacuation of residents and the ashfall negatively affected reefs (Eldredge and Kropp, 1985). Continuing erosion of unconsolidated ash is having unknown effects on the near shore environment. Large numbers of feral pigs and cattle are present. Cattle have been observed walking on the eastern fringing reef flats (T. de Cruz, pers. Obs.). Fish surveys conducted by the CNMI Division of Fish and Wildlife (DFW) in the late 1990s found the nearshore fish resources to be in good condition.

Agrihan is a dormant volcanic cone, with a land area of 47.4 km2 (Figure 15.1). The impact of feral goats and pigs is most evident on the eastern side of the island where resulting sedimentation and runoff is thought to have a significant effect on the marine environment. This is presently the only northern island that supports a permanent population, which currently stands at seven people.

Ascuncion Island is an active volcanic cone and has a land area of 7.3 km2 , which is protected from development by the CNMI Constitution, as it has been declared a wildlife conservation area (Figure 15.1). It is home to nesting colonies of Sooty and Gray-backed Terns (Sterna fuscata and S. lunata, respectively).

Maug consists of three small islands (Higashi, Kita, and Nishi), with a total land area of 2.1km2 (Figure 15.1) surrounding a flooded caldera that is considered to be a dormant volcano (Figure 15.5). The presence of countless seabirds on the three pinnacles that form the island of Maug provides a steady source of nutrients and organic matter into the caldera waters (Embley, 2004).

Maug is uninhabited and is protected from development by the CNMI Constitution. It has been declared a wildlife conservation area. Fisheries resources are currently harvested, although there has been some interest within the CNMI government to extend conservation to the coastal areas. Results from the 2003 and 2004 NOAA surveys (MARAMP and Ring of Fire) show that Maug, with 73 species recorded, is the most coralrich island in the northern islands.

Farallon de Pajaros (Uracas) is an active volcano, with a land area of 2.1 km2 (Figure 15.1 and Figure 15.5). A major eruption and lava flow in 1943 affected coastal habitats. Very steep, sloping, boulder habitats surround Uracas, but provide little suitable habitat for corals. The reef is most developed on the southwest (leeward) side. Uracas was found to have the highest density of large predatory fish in the northern islands based on the MARAMP surveys.

Uracas is protected from development by the CNMI Constitution and has been declared a wildlife conservation area. Although Farallon de Pajaros translates to "the Island of Birds," only those Terns and Noddies that can nest on bare lava have established colonies. Seabird colonies were last surveyed in 1992.
Source: Starmer, J., (ed.) , 2005 , The State of Coral Reef Ecosystems of the Commonwealth of the Northern Mariana Islands. . p.399-441 in Waddell, J. (ed.), 2005. The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2005. NOAA Technical Memorandum NOS NCCOS 11. NOAA/NCCOS Center for Coastal Monitoring and Assessment’s Biogeography Team. Silver Spring, MD. 522 pp. (See Document)

3 . Northern Mariana Islands     Northern Mariana Islands
Offshore Banks and Reefs
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Tatsumi Reef
Tatsumi Reef is a steep-sided, flat-topped submerged bank approximately 2 km southeast of southern Tinian Island and is oriented in a northeast to southwest alignment. It is approximately 5.5 km long by 2 km wide, with a small secondary peak about 1.5 km to the west-southwest (Figure 15.6). The shallowest point on Tatsumi is approximately 6 m. In 2003, Tatsumi was surveyed using multibeam sonar and the R/V Acoustic Habitat Investigator (AHI; Figure 15.6). Two towed-diver surveys during the NOAA MARAMP cruise showed carbonate pavement to be the dominant habitat with low to moderate coral cover. Tatsumi is a popular fishing location, easily accessible from Tinian.

Esmeralda Bank
Esmeralda Bank is located approximately 37 km west of Tinian. There are two shallow banks plotted near Esmeralda Bank and NOAA’s Nautical Chart 81004 shows four soundings less than 80 m in depth. One of these is a kidney-shaped area labeled "Active Sulphur Boil (1945)" with a depth of 30 fathoms (55 m) indicated on the chart. This bank does not exist, while the other bank and Esmeralda Bank are smaller than indicated on the chart. A multibeam survey of Esmeralda Bank was carried out during the NOAA Ring of Fire cruise in April 2004 (NOAA, 2003, 2004). Esmeralda Bank appears to have experienced recent volcanic activity and shows signs of current hydrothermal circulation (Embley, 2004).

Marpi Bank
Marpi Bank is a steep-sided, flat-topped submerged bank approximately 28 km north of Saipan. It is approximately 9 km long by 4 km wide and is oriented in a northeast to southwest alignment similar to Tatsumi Reef; the shallowest point shown on NOAA’s Nautical Chart 81067 is 26 fathoms (53 m). Marpi Bank is also a popular fishing location. In 2003, Marpi Bank was surveyed using multibeam sonar and the R/V AHI (Figure 15.6).

Arakane Bank
Arakane Bank is located approximately 325 km west-northwest of Saipan. On NOAA’s Nautical Chart 81004, it is identified by a single sounding of 5 fm (9 m). It is smaller than indicated on the chart and its true center is approximately 1 km southeast of the center of the charted bank. It was mapped in September 2003 using single-beam sonar and an underwater video camera (Figure 15.7) during the NOAA MARAMP cruise. Encrusting and fleshy algae, hard and soft corals, and sand were seen on hard substrate ridges.

Pathfinder Bank
Pathfinder Bank is located approximately 275 km west of Anatahan in the West Mariana Arc. Pathfinder Bank is 3 km southeast of its plotted position on NOAA’s Nautical Chart 81004 and includes areas shallower than 10 m, rather than the 8 fathoms (15 m) shown on the chart. It was mapped in September 2003 using single-beam sonar and an underwater video camera during the NOAA MARAMP cruise (Figure 15.7). Hard and soft corals were found on ridges of carbonate pavement, separated by channels containing rubble.

Zealandia Bank
Zealandia Bank is located approximately 20 km north of Sarigan Island (Figure 15.4). This flat-topped bank with two pinnacles is surrounded by vertical walls. Rhodoliths, calcareous nodular bodies produced by algal accretion, and Halimeda algae beds were seen by video camera at depths of 115 m.
Source: Starmer, J., (ed.) , 2005 , The State of Coral Reef Ecosystems of the Commonwealth of the Northern Mariana Islands. . p.399-441 in Waddell, J. (ed.), 2005. The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2005. NOAA Technical Memorandum NOS NCCOS 11. NOAA/NCCOS Center for Coastal Monitoring and Assessment’s Biogeography Team. Silver Spring, MD. 522 pp. (See Document)

4 . Northern Mariana Islands     Northern Mariana Islands
Supply Reef
Supply Reef is located approximately 18.5 km northwest of Maug Island and identified as two 5 fathom (9 m) soundings on NOAA’s Nautical Chart 81004. Brief surveys were conducted from the NOAA ship Oscar Elton Sette in 2003. Hard and soft corals and rock were seen at this volcanic pinnacle during a video camera tow.

Stingray Shoals
Stingray Shoals is located approximately 275 km west of Uracas in the West Mariana Ridge. Stingray Shoals is a steep-sided pinnacle that has well-developed continuous reef on the small summit (~300 m x 500 m).Evidence of fishing activity is present, including anchors and long-line gear on the reef.

Socioeconomic Context
Population levels(Figure 15.8), habitation patterns, and the related impacts on reefs have varied tremendously over time. There is evidence of at least temporary settlement on all of the southern Mariana Islands, from Guam to FDM (Fritz, 1986).

In the 17th century, the entire population of the Mariana Islands was removed to Guam and Rota during the Spanish domination of the archipelago. It was not until the end of the 19th and beginning of the 20th century that the foundations of the modern communities in the CNMI returned from Guam and Rota (Spoehr, 2000).

Although some of the islands north of Saipan have held small permanent and seasonal communities, most permanent residents were evacuated in 1981 after the eruption of Pagan. A volcanic eruption also resulted in the evacuation of a small community on Anatahan in 2003. A community of seven individuals remains on Agrihan.

As the population of the CNMI continues to grow and diversify, its effects on adjacent reefs become more pronounced and complex. Fishing appears to have been at subsistence levels until at least the 1950s (Spoehr, 2000). More recently,fishing has grown in importance as a commercial venture with numerous permanent and roadside vendors evident around Saipan.
Source: Starmer, J., (ed.) , 2005 , The State of Coral Reef Ecosystems of the Commonwealth of the Northern Mariana Islands. . p.399-441 in Waddell, J. (ed.), 2005. The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2005. NOAA Technical Memorandum NOS NCCOS 11. NOAA/NCCOS Center for Coastal Monitoring and Assessment’s Biogeography Team. Silver Spring, MD. 522 pp. (See Document)

5 . Northern Mariana Islands     Northern Mariana Islands
The 14 islands that make up CNMI lie on a north-south axis in the western Pacific basin and stretch approximately 600 km with the Pacific Ocean to the east and the Philippine Sea to the west. The southern islands of the archipelago are uplifted limestone, whereas the northern islands are volcanic.
Source: Goldberg, J., K. Adams, J. Albert, J. Asher, P. Brown, V. Brown, D. Burdick, B. Carroll, P. Craig, D. Fenner, C. Fillmed, V. Fread, M. Gawel, A. George, Y. Golbuu, L. Goldman, C. Graham, A. Hall, M. Hasurmai, L. Jacob, D. Jacobson, E. Joseph, J. Kenyon, W. Kostka, T. Leberer, M. Luckymis, E. Lundblad, S. Malakai, J. Maragos, A. Marcus, S. Marino, D. Mathias, J. Mcilwain, J. Miller, D. Minton, M. Nadon, S. Palik, N. Pioppi, L. Raymundo, B. Richards, M. Sabater, R. Schroeder, P. Schupp, E. Smith, T. Zgliczynski and B. Zgliczynski , 2008 , Status of Coral Reef Resources in Micronesia and American Samoa: 2008 . In: Wilkinson, C. (ed.). Status of Coral Reefs of the World: 2008. Global Coral Reef Monitoring Network and Reef and Rainforest Research Center, Townsville, Australia. p199-212. (See Document)

6 . Northern Mariana Islands     Northern Mariana Islands
This report is the third in a series of assessments of the current status of coral reef ecosystems in the U.S. Commonwealth of the Northern Mariana Islands (CNMI) and complements other previous assessments. The focus of this report is primarily on data collected during the period 2004 through 2007, with a greater emphasis on oceanographic data than was found in prior reports (Figure 14.1). For general overview of individual islands, please reference Starmer et al., 2005 (http.ccma.nos.noaa.gov/ecosystems/coralreef/ coral_report_2005).



The fourteen islands that make up CNMI lie in the western Pacific basin, stretching approximately 600 km (375 miles) on a north-south axis, with the Pacific Ocean on the east side and the Philippine Sea on the west (Figure 14.2). The southern islands of the archipelago, Saipan, Tinian, Aguijan and Rota, are uplifted limestone whereas the northern islands are volcanic. Active volcanoes exist on Anatahan, Pagan and Agrihan where most recently an eruption was noted on Anatahan in 2003. The archipelago has a peak elevation of 965 m (3,166 ft) on Agrihan.



The primary ocean current that influences this region is the North Equatorial Current, flowing east to west in the tropical Pacific Ocean (Figure 14.1). Persistent trade winds (10-15 mph on average) from the eastnortheast create wind driven waves that bathe the exposed shores for the majority of the year. The CNMI has a hot and humid tropical climate, with a mean annual temperature of 83°F (28.3°C) and mean annual rainfall of 84 inches (213 cm). The dryer, winter season generally extends from December through June while the wetter summer season begins in July and ends in November. The seasonality of this region varies from year to year and is influenced by El Niño Southern Oscillation (ENSO) events in the Pacific.
Source: Starmer, J., J. Asher, F. Castro, D. Gochfeld, J. Gove, A. Hall, P. Houk, E. Keenan, J. Miller, R. Moffit, M. Nadon, R. Schroeder, E. Smith, M. Trianni, P. Vroom, K. Wong and K. Yuknavage , 2008 , The State of Coral Reef Ecosystems of the Commonwealth of the Northern Mariana Islands. pp. 437-464 . In: J.E. Waddell and A.M. Clarke (eds.), The State of Coral Reef Ecosystems of the United States and Pacific Freely Associated States: 2008. NOAA Technical Memorandum NOS NCCOS 73. NOAA/NCCOS Center for Coastal Monitoring and Assessment's Biogeography Team. Silver Spring, MD. 569 pp. (See Document)

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