{{Short description|Caldera on the island of Kyushu, Japan}} {{Infobox body of water | name = Lake Ikeda | image = Lake Ikeda (152624734).jpg | caption = Lake Ikeda with Mount Kaimon | image_bathymetry = | caption_bathymetry = | location = Kyūshū island | coords = {{coord|31|14|N|130|34|E|region:JP-46_type:waterbody|display=inline,title}} | type = caldera lake | inflow = | outflow = | catchment = {{convert|41|km2|abbr=on}} | basin_countries = Japan | length = | width = | area = {{convert|11|km2|abbr=on}} | depth = {{convert|135|m|abbr=on}} | max-depth = {{convert|233|m|abbr=on}} | volume = {{convert|1.47|km3|acre.ft|abbr=on}} | residence_time = 1.7 years | shore = {{convert|15.1|km|abbr=on}} | elevation = {{convert|63|m|ft|abbr=on}} | islands = | cities = <!-- Map --> | pushpin_map = Japan | pushpin_label_position = | pushpin_map_alt = Location of Lake Ikeda in Japan. | pushpin_map_caption = <!-- Below --> | website = | reference = }} {{nihongo|'''Lake Ikeda'''|池田湖湖|Ikeda-ko}} is in Ikeda Caldera located {{convert|40|km|abbr=on}} south of Kagoshima city; Kyūshū island, Japan. It is perhaps best known to tourists as the location of the purported sightings of a monster named Issie, and as the largest lake on Kyūshū island<ref name="Jnto">{{cite web |url=http://www.jnto.go.jp/eng/ttp/sg/10-MajorDestinations/MediumIndex/09-Kyushu.html |title=Major Destinations in Japan - Kyushu Island |publisher=www.jnto.go.jp |accessdate=2008-05-21 |url-status=dead |archiveurl=https://web.archive.org/web/20080108133817/http://www.jnto.go.jp/eng/ttp/sg/10-MajorDestinations/MediumIndex/09-Kyushu.html |archivedate=2008-01-08 }}</ref> with a surface area of {{convert|11|sqkm|abbr=on}} and a shoreline length of {{convert|15|km|abbr=on}}.<ref name="ILEC"/>
==Deterioration== The development of the areas surrounding Lake Ikeda has caused the quality of the water to decline since 1955.<ref name="ILEC">{{cite web |url=http://www.ilec.or.jp/database/asi/asi-30.html |title=International Lake Environment Committee article on Lake Ikeda |publisher=International Lake Environment Committee |accessdate=2008-05-21 |archive-url=https://web.archive.org/web/20070715074328/http://www.ilec.or.jp/database/asi/asi-30.html |archive-date=2007-07-15 |url-status=dead }}</ref> Other causes include an irrigation project, developed for agricultural field and households in the area, which was initiated in 1965, for it the courses of three nearby rivers were diverted into the lake.<ref name="ILEC"/> The irrigation system has been in operation since 1982, resulting in a considerable improvement of the water quality<ref name="ILEC"/> although since the 1950s the transparency of the lake, though still ranked No. 7 in the world,<ref name="Jnto"/> has decreased from {{convert|26.8|m|abbr=on}} to approximately {{convert|5|m|abbr=on}}.<ref name="ILEC"/>
==Animals== Lake Ikeda is known to harbour large eels, some six feet in length.<ref name="Jnto"/> In 1998, a benthological survey was conducted in the lake, which found that there were no zoobenthos, although two tubificid oligochaetes and a chironomid were found.<ref name="Ingenta Connect">{{cite web |url=http://www.ingentaconnect.com/content/klu/10201/2006/00000007/00000003/00000180 |title=Disappearance of deep profundal zoobenthos in Lake Ikeda, southern Kyushu, Japan, with relation to recent environmental changes in the lake |publisher=Ingenta Connect.com |date=December 2006 |accessdate=2008-05-21}}</ref> The lake was already considered oligotrophic until the 1940s, but one theory for the further drop in underwater life is that the existing life in Lake Ikeda has been affected by global warming.<ref name="Ingenta Connect"/>
==Geology==
{{main|Ikeda Caldera}}
It is within the Ikeda Caldera and surrounded by its rim and associated volcanic domes.
==Mythology== Lake Ikeda is important in the local Shinto folklore of the surrounding regions. Local religious tradition originally held the lake as the origin of humankind.
===Issie=== {{nihongo|'''Issie'''|イッシー|Isshī}} is a Japanese lake monster said to lurk in Lake Ikeda.<ref>{{cite book |last1=Radford |first1=Benjamin |title=Lake Monster Mysteries: Investigating the World's Most Elusive Creatures |date=May 5, 2006 |publisher=University Press of Kentucky |isbn=9780813171302 |pages=145–146}}</ref> It is described as being saurian in appearance. The naming convention is analogous to "Nessie" (the Loch Ness Monster).
According to mythology, Issie was a white mare who lived together with her foal on the shore of Lake Ikeda. However, when the foal was kidnapped by a samurai and Issie was unable to find it, she jumped into the lake and her despair transformed her into a giant, saurian beast, which since then frequently surfaces, trying to find her lost child.<ref name="Metro">''Metropolis'', "Fortean Japan", 27 June 2008, p. 12.</ref> The creature was reportedly photographed in 1978 by a man who went by the name "Mr. Matsubara". Twenty other people reportedly also saw the creature swimming in the lake in 1978; they described it as black and having two humps, each about 5 meters (16 feet) long.<ref name="Metro"/><ref>{{cite book |last1=Welfare |first1=Simon |last2=Fairley |first2=John |date=1980|url=https://archive.org/details/arthurcclarkesmy00welf/page/106/mode/2up?view=theater |url-access=registration |title=Arthur C. Clarke's Mysterious World |page=107 |publisher=A & W Publishers |isbn=0-89479-075-7}}</ref>
==See also== *List of lakes in japan *List of volcanoes in Japan
==References== {{reflist}}
== External links == * [https://www.data.jma.go.jp/svd/vois/data/tokyo/STOCK/souran_eng/volcanoes/091_ikeda_and_yamagawa.pdf Ikeda and Yamagawa: National catalogue of the active volcanoes in Japan] - Japan Meteorological Agency * [https://gbank.gsj.jp/volcano/Quat_Vol/volcano_data/K26.html Ikeda] - Geological Survey of Japan
{{Lakes of Japan}}
Ikeda Ikeda Category:Geography of Ibusuki