# Barat Daya Islands

The Barat Daya Islands (Indonesian: Kepulauan Barat Daya) are a group of islands in the Maluku province of Indonesia. The Indonesian phrase barat daya means 'south-west'.

## Geography

These islands are located off the eastern end of East Timor. Wetar is the largest island in the group. To the west, the Ombai Strait separates Wetar from Alor Island, part of East Nusa Tenggara. The Wetar Strait separates Wetar from Timor to the south.
Even though included in the Indonesian Maluku province political division, the southwestern islands are geographically part of the Lesser Sunda Islands. Rainfall is limited with a dry season between October and December when some of the islands appear as dry savannah. The Barat Daya Islands except Wetar are part of the Banda Sea Islands moist deciduous forests ecoregion. Wetar and Timor comprise the Timor and Wetar deciduous forests ecoregion. Most of the islands are barren, infertile and minimally forested.
Together with Timor, Nusa Tenggara, Sulawesi, and most of Maluku, the Barat Daya Islands are part of Wallacea, the group of Indonesian islands that are separated by deep water from both the Australian and Asian continental shelves. The islands of Wallacea have never been linked by land to either Asia or Australia, and as a result have few mammals and a mix of flora and fauna from both continents.

### Islands

Among the islands within the archipelago are (from west to east):
* Liran
* Wetar
* Kisar
* Nyata
* Romang
* Leti Islands (Leti, Moa, Lakor)
* Sermata Islands
* Damer
* Babar Islands

### Populated places

* Layoni (Teun Island)

## Geology

The islands are part of the Inner Banda Arc, a volcanic island arc created by the collision of the Indo-Australian Plate and the Eurasian Plate. Romang and Damar are volcanic; Wetar consists mostly of oceanic crust that was pushed to the surface by the colliding plates. The Barat Daya and Banda islands constitute an inner arc; the outer arc, which includes Timor, the Tanimbar Islands, and the Kai Islands, is mostly made up of oceanic crust lifted up by the collision, and wraps around south and east of the inner arc.

## History

Unlike much of the rest of the Maluku Islands, the Barat Daya Islands did not participate in the inter-island trade over the centuries. Damar was the region's only island to have produced spice. Too remote from the centre of the Malukan spice trade, the Dutch destroyed the nutmeg trees on Babar. Bugis and Makarassarese annually sailed to coral-rich Luang to purchase reef products such as trepang and mother of pearl.

## Administration

The Maluku Barat Daya Regency is administratively composed of seventeen districts (kecamatan), whose areas (in km$^2$) and 2013 officially estimated populations are listed below.: The districts are formally grouped into three archipelagoes – the Terselatan Group (including Wetar, as well as Kisar and Romang Islands), the Lemola Group (Letti, Moa and Lakor) and the Babar Group (including the Damer and Sermata Islands). The areas (in km$^2$) and the populations at the 2010 census and 2020 census, together with the official estimates as at mid 2023, are listed below. The table also includes the locations of the district administrative centres, the number of administrative villages in each district (totaling 117 rural desa and 1 urban kelurahan – the latter being Tiakur on Moa Island), and its post code.
| Kode Wilayah | Name of district (kecamatan) | comprising | Area in km$^2$ | Pop'n census 2010 | Pop'n census 2020 | Pop'n estimate mid 2023 | Admin centre | No. of Villages | Post Code |
| 81.08.06 | Wetar Selatan | southern part of Wetar Island | 1,157.60 | 7,916 | 2,359 | 2,830 | Ilwaki | 6 | 97446 |
| 81.08.14 | Wetar Barat | western part of Wetar Island, plus Lirang Island, and other islands west of Wetar | 345.70 | $^{(a)}$ | 2,181 | 2,732 | Ustutun | 5 | 97447 |
| 81.08.13 | Wetar Utara | northern part of Wetar Island, plus Reong Island | 677.60 | $^{(a)}$ | 2,365 | 3,421 | Lurang | 6 | 97449 |
| 81.08.15 | Wetar Timur | eastern part of Wetar Island | 470.90 | $^{(a)}$ | 1,717 | 2,126 | Arwala | 6 | 97448 |
| 81.08.07 | Kisar Selatan | southern part of Kisar Island | 65.40 | 17,899 | 10,027 | 10,803 | Wonreli | 6 | 97445 |
| 81.08.17 | Kisar Utara | northern part of Kisar Island | 18.59 | $^{(b)}$ | 3,185 | 3,274 | Putihair Timur | 3 | 97441 |
| 81.08.16 | Kepulauan Roma | Romang Islands | 194.30 | $^{(b)}$ | 4,146 | 4,430 | Rumkuda | 3 | 97440 |
| | Totals for Terselatan Group | | 2,930.09 | 25,815 | 25,980 | 29,616 | | 35 | |
| 81.08.08 | Letti | Leti Island | 90.10 | 7,526 | 8,060 | 9,019 | Serwaru | 7 | 97444 |
| 81.08.01 | Moa | Moa Island | 361.60 | 9,138 | 16,294 | 18,953 | Weet | 8 | 97442 |
| 81.08.12 | Lakor | Lakor Island | 112.60 | $^{(c)}$ | 2,516 | 2,865 | Wewawan | 5 | 97443 |
| | Totals for Lemola Group | | 564.30 | 16,664 | 26,870 | 30,837 | | 20 | |
| 81.08.02 | Damer | Damer, plus uninhabited Nus Leur, Terbang Utara and Terbang Selatan | 201.80 | 5,560 | 5,718 | 6,362 | Wulur | 7 | 97128 -97652 |
| 81.08.03 | Luang Sermata | Sermata Islands | 125.50 | 5,269 | 5,116 | 6,365 | Lelang | 11 | 97652 |
| 81.08.04 | Babar Barat | Babar Island (western half), Dai | 359.70 | 7,752 | 6,491 | 7,234 | Tepa | 9 | 97451 |
| 81.08.05 | Babar Timur | Babar Island (eastern half) | 281.30 | 9,654 | 6,012 | 6,759 | Letwurung | 11 | 97654 |
| 81.08.09 | Pulau Masela | Masela Island | 46.71 | $^{(e)}$ | 2,322 | 2,705 | Latalola Besar | 11 | 97653 |
| 81.08.10 | Dawelor Dawera | Dawelor Island and Dawera Island | 27.06 | $^{(e)}$ | 1,294 | 1,476 | Watuwey | 6 | 97651 |
| 81.08.11 | Pulau Wetang | Wetang Island | 44.60 | $^{(d)}$ | 2,125 | 2,412 | Rumah Lewang Besar | 8 | 97652 |
| | Totals for Babar Group | | 1,086.679 | 28,235 | 29,078 | 33,313 | | 63 | |
Notes: (a) the 2010 populations for the four districts which comprised Pulau Pulau Wetar District are listed under Wetar Selatan District. (b) the 2010 populations of Kisar Utara and Kepulauan Roma Districts are included under the figure for Kisar Selatan District (formerly called Pulau Pulau Terselatan District), from which they were split off. (c) the 2010 population of Lakor District is included in the figure for Moa District, from which it was split off. (d) the 2010 population of Pulau Wetang District is included in the figure for Babar Barat District (formerly called Pulau Pulau Babar District), from which it was split off. (e) the 2010 populations of Pulau Masela and Daweloor Dawera Districts are included under the figure for Babar Timur District, from which they were split off.