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The Republic of Palau (Belau)

Geography

The Republic of Palau, also called Belau, located between 5o 53' and 8o 12' north and 134o 07' and 134o 39' east, is part of the Caroline Islands group. It is the westernmost archipelago in Oceania, lying at the far western end of Micronesia in the Philippine Sea. Palau is located approximately 460 miles (741 km) east of the island of Mindanao in the southern Philippines and about 808 miles (1,300 km) southwest of Guam. The archipelago extends over l50 miles (241 km) and has about 177 square miles (458 km2) of dry land and approximately 203 square miles (525 km2) of coral reef habitat. Numerous volcanic islands, atolls, raised limestone islands, and low coral islands comprise Palau. Tropical forests cover much of the islands with ironwood, banyan, breadfruit, coconut, and pandanus making up the bulk of the greenery. Mangrove forests and grassy savannas are also present. Palau's highest point, Mt. Ngerchelchuus on Babeldaob Island, is 715 feet (215 m) above sea level.

Palau is composed of approximately nine inhabited islands and more than 700 islets stretching 435 miles (700 km) from Ngeruangel Atoll in the Kayangel Islands in the north to Helen Reef in the south. The archipelago consists of a clustered island group of four high islands (Babeldaob, Koror, Peleiu, and Angaur), two low coral atolls (Kayangel and Ngeruangel), and the famous karst-weathered, forested limestone Rock Islands. Six isolated Southwest Islands (Helen Reef, Tobi, Merir, Pulo Anna, Sonsorol, and Fana) lie approximately 211-372 miles (339-599 km) to the southwest. Babeldaob is the largest island in the Palauan chain and the second largest island in Micronesia; only Guam is larger. Babeldaob and its reefs are separated from Koror and the southern islands of the group by Toachel El Mid, a deep east-west pass. All the islands are enclosed within a 104 km-long reef, except for Angaur in the south and several small atolls in the north.

The Rock Islands are a small collection of relic coral reefs. They surfaced in Palau's Southern Lagoon to form approximately 250 islands, most of which are uninhabited, small, mushroom-shaped, and topped with vegetation, although some are large enough to have beaches. Tourists are attracted to the Rock Islands for their white sandy beaches, blue lagoons, and marine lakes, which invite snorkeling, scuba diving, fishing, and kayaking. A portion of the Rock Islands, known as Seventy Islands, has been set aside as a marine turtle conservation area. Turtle hatchlings are taken to a mariculture center, where they are raised to nearly six inches and are then released into Palauan waters.

Map of the Republic of Palau
Map of the Republic of Palau courtesy of Waddell, J.E. and A.M. Clarke (eds.), 2008. 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 Assessmentís Biogeography Team. Silver Spring, MD. 569pp. (Click on the image for large view)

IKONOS satellite image of Palau
IKONOS satellite image of Palau (Click on the image for large view)

Palau is home to about 70 marine lakes, which are connected to the ocean through fissures in the islands’ porous limestone. One of the most famous marine lakes, Jellyfish Lake, is found among the Rock Islands. It provides habitat for millions of “stingless” jellyfish, which snorkelers can swim among without fear of being stung. Before the recent introduction of a predator anemone into Jellyfish Lake, the two species of jellyfish that live there had had no predators and had, over time, lost the potency of their principal defensive and prey-catching weapons (stinging cells). These jellyfish became completely “stingless”. As with their coral relatives, they host symbiotic, photosynthesizing algae in their tissues which provide food energy. The greatest number of jellyfish ever recorded in the lake was 31 million (accuracy ± 8 million) in January 2005.

The Southwest Islands are small oceanic islets that sit atop flat-topped seamounts, except for one islet that sits on a perimeter reef surrounding a lagoon.

Ngeruangel and Velasco Reefs are the northernmost reefs in Palau and share the same reef formation. Ngeruangel is a small atoll that has only one small coral islet at the southwest side. The reef that forms the barrier of Ngeruangel atoll is nearly continuous except for some small passes in the west and the north facing Velasco Reef.  Velasco Reef is a sunken atoll north of Ngeruangel Reef, rising abruptly from the surrounding deep seafloor. 

Surface view of Jellyfish Lake
Surface view of Jellyfish Lake (Photo: Julian Sachs/Sachs Lab/University of Washington)
Jellyfish in Jellyfish Lake
Jellyfish in Jellyfish Lake have tiny stinging cells that do not affect swimmers, hence the term "'stingless"

 

 

 

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