Lake Ogawara
Encyclopedia
is Japan
's eleventh largest lake (by area) and the largest in Aomori Prefecture
. It spans the boundaries of the city of Misawa
and the town of Tohoku
and the village of Rokkasho
in Kamikita District
.
, and the sand bar guarding its mouth has been breached numerous times by storms or typhoons, thus accounting for the brackish water
of the lake. There are four inflowing rivers, all coming from Hakkoda Mountain Range. The only outflow is the Takase River.
. A variety of marimo
occurs naturally in the lake. It is a commercial source of cultivated Japanese smelt, icefish
, goby
and shijimi
, and was previously home to the critically endangered Hucho perryi
, which was last spotted in 1943. Migratory birds include the whooper swan
and tundra swan, among others.
remains and shell middens have been discovered.
The Japanese government initiated a project beginning in the 1970s to convert the lake from brackish to fresh water to serve as a source of drinking, industrial and irrigation water despite the adverse environmental impact.
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
's eleventh largest lake (by area) and the largest in Aomori Prefecture
Aomori Prefecture
is a prefecture of Japan located in the Tōhoku Region. The capital is the city of Aomori.- History :Until the Meiji Restoration, the area of Aomori prefecture was known as Mutsu Province....
. It spans the boundaries of the city of Misawa
Misawa, Aomori
is a city located in eastern Aomori Prefecture in the Tōhoku region of Japan. As of 2009, the city had an estimated population of 42,399 and a density of 353 persons per km²...
and the town of Tohoku
Tohoku, Aomori
is a town located in the Kamikita District of northeastern Aomori Prefecture in the Tōhoku region of Japan. As of 2009, the village had an estimated population of 19,051 and a density of 58.3 persons per km². Its total area was 326.71 km².-Geography:...
and the village of Rokkasho
Rokkasho, Aomori
is a village located in the Kamikita District of northeastern Aomori Prefecture in the Tōhoku region of Japan. As of 2009, the village had an estimated population of 10,890 and a density of 43 persons per km². Its total area was 253.01 km².-Geography:...
in Kamikita District
Kamikita District, Aomori
is a district located in Aomori Prefecture, Japan. It occupies the east-central portion of the prefecture, south of Shimokita Peninsula.As of 2010, the district has an estimated population of 100,526 and a density of 78.5 persons per km². The total area was 1281.05 km².- Towns and villages...
.
Data
The lake has an area of 63.2 km² and holds 0.714 km³ of water. Its circumference is 67.4 kilometers. At its deepest point, the water is 25 meters deep, with an average depth of 11 meters. The surface is at sea level. The lake is shallow (under 2 meters) from the shoreline to a distance of approximately 200 meters, whereupon the depth drops off precipitously. The edge of Lake Ogawara is very near the coast of the Pacific OceanPacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
, and the sand bar guarding its mouth has been breached numerous times by storms or typhoons, thus accounting for the brackish water
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
of the lake. There are four inflowing rivers, all coming from Hakkoda Mountain Range. The only outflow is the Takase River.
Economic activity
Lake Ogawara is an abundant habitat for fish and birds, and is recognized as such by the Japanese Ministry of the EnvironmentMinistry of the Environment (Japan)
The ' of Japan was formed in 2001 from the sub-cabinet level Environmental Agency established in 1971. The minister is a member of the Cabinet and is chosen by the Prime Minister, usually from the Diet., the current is Goshi Hosono...
. A variety of marimo
Marimo
, also known as Cladophora ball, Lake ball, or Moss Balls in English, is a species of filamentous green algae found in a number of lakes in the northern hemisphere. A marimo is a rare growth form of the species where the algae grow into large green balls with a velvety appearance...
occurs naturally in the lake. It is a commercial source of cultivated Japanese smelt, icefish
Salangidae
Icefishes or noodlefishes are a family, the Salangidae, of osmeriform fish, related to the smelts. They are found in freshwater environments in Southeast Asia, although a few species are anadromous, spending most of their life in coastal waters, and only visiting fresh water to spawn.They have...
, goby
Goby
The gobies form the family Gobiidae, which is one of the largest families of fish, with more than 2,000 species in more than 200 genera. Most are relatively small, typically less than 10 cm in length...
and shijimi
Corbicula
Corbicula is a genus of freshwater and brackish water clams, aquatic bivalve mollusks in the family Corbiculidae, the basket clams.The genus name is derived from Latin corbis "basket", referring to the shape and ribs of the shell....
, and was previously home to the critically endangered Hucho perryi
Hucho perryi
The Sakhalin taimen , also called the Sea-run taimen, Stringfish, Japanese huchen, or Ito, is a species of fish in the salmon family of order Salmoniformes.-Description:...
, which was last spotted in 1943. Migratory birds include the whooper swan
Whooper Swan
The Whooper Swan , Cygnus cygnus, is a large Northern Hemisphere swan. It is the Eurasian counterpart of the North American Trumpeter Swan. An old name for the Whooper Swan is Elk; it is so called in Francis Willughby and John Ray's Ornithology of 1676.-Description:The Whooper Swan is similar in...
and tundra swan, among others.
History
Lake Ogawara was originally a marine bay, which became a lake approximately 3,000 years ago by the formation of a sand bar at its mouth. The shoreline around Lake Ogawara has been settled since prehistoric times, and numerous Jomon periodJomon period
The is the time in Japanese prehistory from about 14,000 BC to 300 BC.The term jōmon means "cord-patterned" in Japanese. This refers to the pottery style characteristic of the Jōmon culture, and which has markings made using sticks with cords wrapped around them...
remains and shell middens have been discovered.
The Japanese government initiated a project beginning in the 1970s to convert the lake from brackish to fresh water to serve as a source of drinking, industrial and irrigation water despite the adverse environmental impact.