Daitō Islands Explained

Daitō Islands (Borodino Islands)
Native Name:大東諸島
Daitō Shotō
Sobriquet:Ufuagari
Pushpin Map:Japan Ryukyu Islands
Waterbody:Philippine Sea
Total Islands:3
Area Km2:44.427
Country:Japan
Country Admin Divisions Title:Region
Country Admin Divisions:Ryukyu Islands
Country Admin Divisions Title 1:Prefecture
Country Admin Divisions 1:Okinawa
Country Admin Divisions Title 2:District
Country Admin Divisions 2:Shimajiri
Population:2,107
Population As Of:2010
Density Km2:45.83
Ethnic Groups:Japanese

The are an archipelago consisting of three isolated coral islands in the Philippine Sea southeast of Okinawa. The islands have a total area of 44.427sqkm and a population of 2,107.

Administratively, the whole group belongs to Shimajiri District of Okinawa Prefecture, and is divided between the villages of Minamidaitō and Kitadaitō, with uninhabited Okidaitōjima island administered as part of Kitadaitō municipality, although physically located closer to Minamidaitōjima.

Etymology

Kita, minami, and oki means, respectively, "north", "south", and "offshore" while daitō means "great east".

History

These islands have long been known in Okinawa as Ufuagari (“the Great East”). Okidaitōjima was first sighted by the Spanish explorer Bernardo de la Torre on 25 September 1543 during a failed attempt to find a northern route back to Mexico from the Philippines. Minamidaitōjima and Kitadaitōjima were recorded a few days later.[1] They were visited later by European explorers of various nations, and were commonly known as the Borodino Islands after a Russian vessel surveyed them in 1820.

The islands remained uninhabited until formally claimed by the Empire of Japan in 1885. In 1900, a team of pioneers from Hachijōjima, one of the Izu Islands located 287km (178miles) south of Tokyo led by Tamaoki Han'emon (1838  - 1910), started a settlement on Minamidaitōjima, and began cultivating sugar cane. He subsequently led colonization efforts on Kitadaitōjima and Okidaitōjima. Those two islands had substantial deposits of guano, which was mined for phosphate-based fertilizer and gunpowder. By 1919, the population was more than 4000 people.

Kitadaitōjima is built of limestone from an ancient coral reef. In 1934, a team of Japanese scientists visited it in order to bore cores through the limestone, in an attempt to discover the nature of the rock upon which the limestone sits. In 1936, the bore hole reached a final depth of 431.67 meters. However, the scientists discovered nothing beyond fossil corals and ancient foraminiferous sands.[2]

During World War II, Minamidaitōjima was repeatedly attacked by the United States Navy. After World War II all of the islands were occupied by the United States and administered as part of the United States Civil Administration of the Ryukyu Islands from 1950. The islands were returned to Japan in 1972.

Islands

Photo Name Kanji Area
[km<sup>2</sup>]
Population
2004
highest point
[m]
Peak Coordinates
Minamidaitōjima fee ufuagarijimaJapanese: 南大東島30.571,44278
Kitadaitōjimanishi ufuagarijimaJapanese: 北大東島11.9466575
Okidaitōjimauchi ufuagarijimaJapanese: 沖大東島1.15

Ecology

Being separated by more than 300 km from Ryukyu Islands, the nearest landmass, a unique and isolated ecosystem holding endemic species was established on Daitō Islands which doesn't include habu vipers naturally unlike many of Ryukyu Islands.[3] Lack of snakes caused introduced and invasive toads to flourish and run rampant.[4] Three main islands of Kita, Minami, and Oki were originally covered by virgin forests, however human activities including military exercise severely damaged and resulted in disappearing of forests and extinction of endemic species most notably on Okidaitōjima.[5] Aside from eels, any fresh water fish and amphibians had not been recorded in pre-exploration periods. Entire archipelago excluding Okidaitōjima and smaller islands is listed as a Wildlife Protection Areas in Japan extending for 4,251 hectare with a special protection zone of 234 hectare.

Many of flora and fauna were named after the islands including Daito fruit bat, Daito buzzard, Daito Neolitsea, Daito scops owl (listed in the natural monument of Japan),[6] Daito Stag Beetle,[7] Daito Figulus binodulus (stag beetle), Daito Euterpnosia (cicada), Daito Little grebe, Daito Bulbul, Daito Mejiro, Daito Livistona,[8] Daito Excoecaria,[9] and Daito Crepidiastrum.[10] Several of these such as Daito bush warbler, Daito varied tit, and Daito wren became extinct. The island group has been recognised as an Important Bird Area (IBA) by BirdLife International.[11]

Migratory and oceanic species that breed on the islands include such as Laysan albatross, Black-winged stilt,[12] tuna, skipjack tuna, Japanese Spanish mackerel, marlin, manta rays, Japanese spiny lobster, sea turtles, dolphins and Humpback whales.[13] Among Ryukyu Islands, green pheasant is only present on Daitō Islands followed by corals and coral fish that are rare in the rest of the archipelago most notably Chaetodon auripes which is occasionally regarded as endemic to the islands[14] and Hemitaurichthys thompsoni was only previously recorded in Bonin Islands.[15] Black Jacks and knifejaws that have become rarer in Japanese waters still occur as well.[16]

European sightings of the Daitō Islands

Further reading

Notes and References

  1. .
  2. Hanzawa . Shôshirô . 1938 . Studies on the Foraminifera Fauna Found in the Bore Cores from the Deep Well in Kita-Daitô-Zima (North Borodino Island) . Proceedings of the Imperial Academy . 14 . 10 . 384–390 . 10.2183/pjab1912.14.384. free .
  3. Web site: 南大東でヘビ初確認/荷物に紛れ来島"か " . 2017-01-27 . https://web.archive.org/web/20160704224504/http://ryukyushimpo.jp/news/prentry-106306.html . 2016-07-04 . dead .
  4. http://www.okinawa-kaeru.net/frog/frog-okinawa.html 沖縄に生息するカエル達の写真・鳴き声
  5. http://haiena-factory.com/link.html 大東諸島の生物生態について
  6. https://www.sci.hokudai.ac.jp/~m_takagi/m_takagi/Study_group_for_conservartion_of_the_Daito_Scops_Owl.html Study Group for Conservation of the Daito Scops Owl
  7. http://www.sci.osaka-cu.ac.jp/biol/asoci/pages11/photo/daitobirds.html 大東島の鳥たち
  8. http://koma33.web.fc2.com/daitoubirou.html ダイトウビロウ(大東尾籠)
  9. http://koma33.web.fc2.com/daitouseisi.html ダイトウセイシボク(大東青紫木)
  10. http://hanamist.sakura.ne.jp/flower/gouben/kiku/daito.html ダイトウワダン(大東わだん)- Crepidiastrum lanceolatum var. daitoense
  11. Web site: Daito Islands. . 2021. BirdLife Data Zone. BirdLife International. 25 January 2021.
  12. http://vill.kitadaito.okinawa.jp/nature/nature2.html 島の暮し - 島の動物
  13. [琉球新報]
  14. http://vill.kitadaito.okinawa.jp/nature/nature4.html 島の暮し - 島の生物
  15. https://www.env.go.jp/nature/biodic/coralreefs/reference/mokuji/060105j.pdf 6-1-5 大東諸島
  16. http://jpsatobunka.net/meisan/okinawa/okinawa-11.html 南大東島の伝統行事 南大東島の豊年祭 - 日本の郷文化 - 南大東島名物 スキューバダイビング・透明度100mの海