is a

caldera lake A volcanic crater lake is a lake in a crater that was formed by explosive activity or a collapse during a volcanic eruption. Formation Lakes in calderas fill large craters formed by the collapse of a volcano during an eruption. Lakes in maars ...

located 40 km south of

Kagoshima , abbreviated to , is the capital city of Kagoshima Prefecture, Japan. Located at the southwestern tip of the island of Kyushu, Kagoshima is the largest city in the prefecture by some margin. It has been nicknamed the "Naples of the Eastern wor ...

city;

Kyūshū is the third-largest island of Japan's five main islands and the most southerly of the four largest islands ( i.e. excluding Okinawa). In the past, it has been known as , and . The historical regional name referred to Kyushu and its surround ...

island,

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 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 with a surface area of 11 km² and a shoreline length of 15 km.

Deterioration

The development of the areas surrounding Lake Ikeda has caused the quality of the water to decline since 1955. 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. The irrigation system has been in operation since 1982, resulting in a considerable improvement of the water quality although since the 1950s the transparency of the lake, though still ranked No. 7 in the world, has decreased from 26.8 m to approximately 5m.

Animals

Lake Ikeda is known to harbour large

eels Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage ...

, some six feet in length. In 1998, a benthological survey was conducted in the lake, which found that there were no

zoobenthos Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.oligochaetes Oligochaeta () is a subclass of animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadrile earthworms ...

and a

chironomid The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species ...

were found. The lake was already considered

oligotroph An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates of ...

ic 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 In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

Geology

It is within the

Ikeda Caldera , is a volcanic caldera filled now with Lake Ikeda and associated with the older Ata Caldera on the Satsuma Peninsula. Geology The Ikeda volcano produced about 20,000 years before present the Iwamoto tephra layer found right around the region o ...

and surrounded by its rim and associated volcanic domes.

Mythology

Lake Ikeda is important in the local

Shinto Shinto () is a religion from Japan. Classified as an East Asian religion by scholars of religion, its practitioners often regard it as Japan's indigenous religion and as a nature religion. Scholars sometimes call its practitioners ''Shintois ...

folklore of the surrounding regions. Local religious tradition originally held the lake as the origin of humankind.

Issie

is a Japanese

lake monster A lake monster is a lake-dwelling entity in folklore. The most famous example is the Loch Ness Monster. Depictions of lake monsters are often similar to those of sea monsters. In the ''Motif-Index of Folk-Literature'', entities classified as "lak ...

said to lurk in Lake Ikeda. It is described as being

saurian Sauria is the clade containing the most recent common ancestor of archosaurs (such as crocodilians, dinosaurs, etc.) and lepidosaurs ( lizards and kin), and all its descendants. Since most molecular phylogenies recover turtles as more closel ...

in appearance. The naming convention is analogous to "Nessie" (the

Loch Ness Monster The Loch Ness Monster ( gd, Uilebheist Loch Nis), affectionately known as Nessie, is a creature in Scottish folklore that is said to inhabit Loch Ness in the Scottish Highlands. It is often described as large, long-necked, and with one or mor ...

). 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 were the hereditary military nobility and officer caste of medieval and early-modern Japan from the late 12th century until their abolition in 1876. They were the well-paid retainers of the '' daimyo'' (the great feudal landholders). They h ...

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.''

Metropolis A metropolis () is a large city or conurbation which is a significant economic, political, and cultural center for a country or region, and an important hub for regional or international connections, commerce, and communications. A big c ...

'', "Fortean Japan", 27 June 2008, p. 12. 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.

References

External links

Ikeda and Yamagawa: National catalogue of the active volcanoes in Japan
- Japan Meteorological Agency

- Geological Survey of Japan

Ikeda Ikeda may refer to: * Ikeda (surname), a Japanese surname * Ikeda (comics), a character in ''Usagi Yojimbo'' * Ikeda clan, a Japanese clan * Ikeda map, chaotic attractor * Ikeda (annelid), ''Ikeda'' (annelid) a genus of the family Ikedidae Places< ...

Landforms of Kagoshima Prefecture Ibusuki, Kagoshima {{Kagoshima-geo-stub