Southern Shelf Waters and Slope Edge of Palau IMMA

Area Size

1 490 km2

Qualifying Species and Criteria

Dugong – Dugong dugon

Criterion A; B (1, 2); C (1, 2); D (1)

Marine Mammal Diversity 

Feresa attenuata, Physeter macrocephalus, Peponocephala electra, Stenella longirostris, Stenella attenuata, Pseudorca crassidens, Globicephala macrorhynchus

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Palau’s dugong population is considered small and vulnerable to extinction. Although the IUCN lists dugongs as vulnerable and decreasing at the global level, recent assessments undertaken at a regional level concluded that Palau’s dugongs were Critically Endangered. The Palau dugong population is very isolated – the closest dugongs are 800 km to the south in Papua Barat and 850 km to the west in the Philippines.

Description of Qualifying Criteria

Criterion A – Species or Population Vulnerability

Dugongs are listed as a vulnerable on the IUCN Red List. However, a regional assessment of dugong by Marsh et al. (2011) concluded the Palau population as Critically Endangered and very isolated.  The closest dugongs are 800 km to the south in Papua Barat and 850 km to the west in the Philippines (Marsh et al. 2002).

Criterion B: Distribution and Abundance

Sub-criterion B1: Small and Resident Populations

An aerial survey conducted in 2012, covered a total area of 292 km2, which is only 4% of the total potential dugong habitat in Palau.  During 192 flights over the course of 140 days, 912 dugong sightings were recorded. One to three dugongs were seen on most flights (Davis, 2004). The abundance estimate was 50-200 individuals (Davis, 2004).

Sub-criterion B2: Aggregations

Most sightings during aerial surveys included 1-3 individuals, there have been at least two recorded sightings of aggregations of 30 individuals or larger around the waters of Palau (Etpison, 2012).

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

During aerial surveys in 2012, during which 912 dugong sightings were made, 53 calves accompanied by their mothers were recorded (on 6% of total flights) (Davis, 2004).  Therefore, the waters of Palau are used by the resident dugong population for reproduction

Sub-criterion C2: Feeding Areas

Dugong in Palau are resident and are observed feeding largely in seagrass beds (Davis, 2004, Etpison, 2012, Holm, 2017 Pers. Comm.).

Criterion D: Special Attributes  

Sub-criterion D1: Distinctiveness

The Palau dugong population is considered one of the world’s most isolated dugong populations, separated by at least 800km from all other known populations (Etpison, 2012, IUCN 2015).

Supporting Information

Davis, P. Z. 2004. Current status of knowledge of dugongs in Palau: A review and project summary report. Koror: The Nature Conservancy.

Etpison, M. 2012. Palau Dugong dugon awareness campaign: 2010-2011. Koror: Coral Reef Research Foundation.

Marsh, H.P. 2002. The dugong (Dugong dugon) status reports and action plans for countries and territories in its range. Early Warning and Assessment Reports. Nairobi: United Nations Environment Programme.

Marsh, H.P. 2011. The ecology and conservation of Sirenia: dugongs and manatees. Cambridge: Cambridge University Press.

Palau National Government. 2001. Increased penalties for illegal taking, possessing or exporting dugongs and turtles. Palau National Government Report (2001, October). RPPL 6-28. Republic of Palau.


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