The Geography and History

Ulithi Atoll and Micronesian Outer Islands

Regional Geography

The Federated States of Micronesia (FSM) are an autonomously governed island nation (with autonomous governance by individual island communities) in the Western Pacific, and are a part of the US Compact of Free Association.  The FSM consists of 4 States: Yap, Chuuk, Pohnpei and Kosrae. There are approximately 607 islands with a combined land area of 702 Km2 (271 Mi2), and a population of 103,395 people (2012 census).

The FSM covers more than 2,600,000 square kilometers (over 1,000,000 square miles) of ocean in the Western Pacific (Caroline Islands).

The autonomous nature of governance and traditional land and ocean tenure rights make this a region well suited for locally driven management and conservation.Yap State consists of 138 islands and atolls, 22 of which are populated, extending approximately 800 Km (500 miles) eastward into the tropical western Pacific.

Although the islands encompass over 100,000 square miles of ocean, the state consists of only 45 square miles of land, much of which rises barely above sea level (the main island of Yap is a ‘high’ island).  The 2000 census estimated a population at that time of 11,200 people.  Although Yap State is a collection of islands, ‘outer islanders’ – people from islands other than the largest main island of Yap – often have a strong sense of cultural identity, and in many cases they differ significantly from communities on the main islands, including the language and leadership structure.

Yap State with Ulithi Atoll

Ulithi Atoll is one of the outer island atolls of Yap state, lying approximately 100 miles east of the main island of Yap.  The lagoon,  36 X 24 Km (22 X 15 miles) encompasses  548 Km2, (212 Mi2), and is one of the largest on Earth.

It consists of 40 islets (4 inhabited islands), collectively making up only 4.5 Km2 (1.7 Mi2) of land, most barely more than a meter above sea level.  The total population of Ulithi is about 1000, depending on time of year (it has one of the two high schools in the outer islands, to which youth come during the school year from the neighboring islands).

The 4 inhabited islands are Falalop (which lies just outside the main Atoll) the largest on Ulithi, which has a population of between 500-700 people, Mog Mog, the governance and spiritual center of the outer islands, with a population of approximately 150, Asor, with a population of approximately 70, and Federai to the Southeast, with a population of approximately 150.

History of the Region

 The people of Ulithi and other outer islands rely on subsistence from the sea and the land. Historically their fishing practices involved…

The occupation of Ulithi by US Naval Fleets during World War II, changed the Islanders’ way of life dramatically. Entire islands were razed to the ground to make room for Allied Troops. Imported food, culture and language changed the traditional ways of these remote islands. After the war a surplus of boats, fuel, and new technologies like spear-guns radically altered the effectiveness of the Islanders’ fishing techniques.


Ulithi Atoll, home to the 3rd Fleet in late 1944. The land in the foreground is one of several depot islands surrounding the anchorage. After WWII many battleships were intentionally sunk rather than taken elsewhere to disassemble. These iron behemoths lie at the bottom of the Atoll and as they rust their iron content leaks into the seawater changing the very chemistry of the nutrient-poor tropical waters.

Presently subsistence fishing is done through a variety of techniques including spearfishing, line fishing, and “reef walking”. Most fishing is limited to the range of small boats, and fuel is scarce.

Resource scarcity is a threat, though the causes (such as potential overfishing) have not been established, and likely involves multiple factors including habitat degradation due to climate change, and historical impacts such as from World War 2.

There is a lack of information on reef condition and target food species such as unicorn fish and parrotfish (herbivorous), and grouper and emperors (piscivorous).  We are working to help create a management plan that combines traditional practices and scientific recommendations to protect marine resources to ensure sustainable harvests.