The are wetlands in the center of Ikema Island, Miyahojima, Okinawa,

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

. It is also called Yunimui or Īnubū in the local dialect. The wetland area extends for and is the largest in

Okinawa Prefecture is a prefecture of Japan. Okinawa Prefecture is the southernmost and westernmost prefecture of Japan, has a population of 1,457,162 (as of 2 February 2020) and a geographic area of 2,281 km2 (880 sq mi). Naha is the capital and largest city o ...

. The "Wetlands and Coral Reefs of Ikema-jima" have been selected by the Ministry of the Environment as one of the and the entire island, totaling . It was designated a Wildlife Protection Area on November 1, 2011.

History

The island of Ikema-jima was formerly divided into an eastern and a western island, with a water lane between. The king of the four islands built a bridge between the two. Eventually, the two islands were connected. The northern water lane was called Īnubū with an opening in the south which was about . For the purposes of land reclamation, the water lane was interrupted between 1924 and 1934. Two area of land became reclaimed, one of , the other of . The wetland area outside the dike, combining both freshwater and seawater, was called Yunimui ("sand elevated area"). Between 1963 and 1982, Ikema Fishing Port was built and the wetland area was completely separated from the sea.

Observation Platform

A wooden observation platform was replaced in 2009 with a steel platform. A road and parking lots were constructed. A problem in the 21st century is that the wetland is shrinking with the growth of weeds.

Biota

Fauna

Birds

The wetland is visited by Eurasian wigeon,

mallard The mallard () or wild duck (''Anas platyrhynchos'') is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa, and has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Arge ...

eastern spot-billed duck The eastern spot-billed duck or Chinese spot-billed duck (''Anas zonorhyncha'') is a species of dabbling duck that breeds in East and Southeast Asia. This species was formerly considered a subspecies of the Indian spot-billed duck and both were ...

, northern shoveler, garganey, Eurasian coot, , and Eurasian bittern. Purple heron and bean goose are rare visitors.

Fish and crustacean

CoconutCrabDictionnaireDHistoireNaturelle1849

Tilapia and guppy of foreign origin are found.

Discoplax ''Discoplax'' is a genus of terrestrial crabs. It is very closely related to the genus ''Cardisoma''. Five species are currently recognised: *''Discoplax celeste'' 2012 *'' Discoplax gracilipes'' Ng & Guinot, 2001 *'' Discoplax longipes'' A. Mi ...

or cross the road for reproduction every June.

Coconut crabs The coconut crab (''Birgus latro'') is a species of terrestrial hermit crab, also known as the robber crab or palm thief. It is the largest terrestrial arthropod in the world, with a weight of up to . It can grow to up to in width from the tip ...

are also found.

Insects

Ceriagrion latericium ryukyuuanum, Cercion sexlineatum, Ictingomphus pertinax, Brachydiplax chalybea flavovittat, Tholymis tillarga are found. Other insects include Gerridae and Hydrophilidae.

Flora

In 1983 the previous wetland was found to have become partly grassland with Panicum repens L. and Miscanthus sinensis.Higa 983:156/ref> In the wetland were Panicum paludosum Roxb., Cyperus tenuispica Streud, Cyoerus pillosus Vahl,

Cyperus difformis ''Cyperus difformis'' is a species of sedge known by several common names, including variable flatsedge, smallflower umbrella-sedge and rice sedge. This plant is native to southern Europe, most of Africa and Asia, and Australia, and it is natural ...

, Eleocharis geniculata,

Fimbristylis miliacea ''Fimbristylis miliacea'', the grasslike fimbry or hoorahgrass, is a species of fimbry that probably originated in coastal tropical Asia but has since spread to most continents as an introduced species. It is a widespread weed in some areas and ...

and Aeschynomene indica. As a reminder of the Bay vegetation was Exoecaria agallocha L. as of 1978. At the frontline of water surface was Typha domingensis, toward the shore were Scirpus tabemaemontanic Gmelin, Paspalum vaginatum Schwarz and Cladium chinense Nees; they were seen in line. At the periphery of the Ikema Island were trees of Pandanus tectorius, while in the eastern muddy area was Clerodendrum inerme.

References

*Kei Higa, ''Okinawa Encyclopedia jou'' 1983, Okinawa Times. {{coord, 24.931944, N, 125.243056, E, display=title, format=dms, type:landmark_region:JP_scale:10000, name=Ikema Shitsugen

External links

Photographs of Ikema Wetland

Footnotes

Miyakojima, Okinawa Protected areas of Japan Environment of Japan