Current view: Text account
Site description (2008 baseline):
Site location and context
Helen Reef is an atoll located in the Southwest Islands. It is a largely submerged coral reef and contains a small island in its northern section. Helen is a sandy, atoll island and therefore is flat and rises only a few feet above sea level. It is inhabited by two to four individuals at a time who man a small marine research and ranger outpost. Helen Atoll and Tobi Island (which is about 80 km to the northwest) comprise the state of Hatohobei. Hatohobei is Palau’s southernmost state, and is closer to Indonesia than it is to the main islands of Palau. Access to this IBA is extremely limited with a single state boat providing service to the six islands of the Southwest as weather and sea conditions allow. Helen is owned and managed by the state of Hatohobei.
This island is one of only two IBAs in Palau that qualifies under the A4 criteria for significant congregations of seabirds. Helen Island qualifies as an IBA because of the A4 (iii) congregations of nesting Black Noddies. Recent studies have estimated 20,000-24,000 nesting birds (Helen Reef 2004; Knecht 2005). The island also has nesting populations of Sooty Terns (16,000-80,000 birds) and Great Crested Terns (5,000-7,000). Thousands of Red-footed Boobies and Brown Boobies used to nest on the island, but have moved to an abandoned barge on the nearby reef because of past human disturbance.
Non-bird biodiversity: Helen Island and the surrounding lagoon is one of Palau’s most outstanding atoll complexes. The lagoon and surrounding reef have about 270 species of hard coral. Significant marine species include trochus, large numbers of humphead wrasse, bumphead parrotfish, green and hawksbill turtles, groupers, and many others. Helen is one of Palau’s most significant green turtle nesting sites. Vegetation on the island is characteristic of beach strand, and consists mostly of velvet-leaf soldier bush (riirs) and grasses. There are a few coconut palms and Casuarina trees.
Pressure/threats to key biodiversity
Helen Reef Conservation Area which includes the island, entire lagoon and surrounding reefs, covers an area of 262 km2 and is protected under Hatohobei state legislation, which created a board that oversees management of the area. Helen has been the target of illegal fishing by mostly foreign boats, due to its isolation and proximity to Indonesia. The area has also suffered from coral bleaching. The low-lying island is susceptible to storms and other natural disasters. The presence of resident rangers on the island has had significant impact on improving enforcement and monitoring of this protected area. Access to the main archipelago for human resources and supplies remains the greatest management challenge. The Singapore ant was introduced to Helen by confiscated fishing canoes from Indonesia and the Philippines. This ant presents one of the biggest threats to the island’s biodiversity, especially to the nesting seabirds. Other introduced species which may threaten the islands’ birds and biodiversity are introduced dogs and chickens. Climate change and storms are significant threats to the low-lying sandy island.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Helen Island, Hatohobei (Palau). Downloaded from
https://datazone.birdlife.org/site/factsheet/helen-island-hatohobei-iba-palau on 23/11/2024.
