is the second-largest lake in

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 ...

, located 60 km to the north-east of

Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...

In a narrower sense and officially, Lake Kasumigaura refers to a waterbody with an area of 167.63 km². In a wider sense, Lake Kasumigaura can also refer to a group of contiguous

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s, which includes Lake Kasumigaura proper, hereby referred to as Nishiura (西浦), and two smaller lakes, Kitaura (北浦; 35.16 km²) and Sotonasakaura (外浪逆浦; 5.85 km²), and also encompasses the rivers connecting them. In this case the total area is 220 km². About 45% of the land surrounding the lake is natural landscape and 43.5% is agricultural land.

History

Lake Kasumigaura originally was a brackish-water

lagoon A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') a ...

, with indirect connections to the Pacific Ocean via the Hitachigawa and Tone Rivers. In 1963, the construction of a gate near the confluence of these rivers disconnected the lake from its sources of ocean water. As a result, the salinity of Lake Kasumigaura declined, and today the lake contains fresh water. This lake was famous for its traditional fishery during the

Edo period The or is the period between 1603 and 1867 in the history of Japan, when Japan was under the rule of the Tokugawa shogunate and the country's 300 regional '' daimyo''. Emerging from the chaos of the Sengoku period, the Edo period was characteriz ...

. But today, fishing production has drastically decreased due to

water quality Water quality refers to the chemical, physical, and biological characteristics of water based on the standards of its usage. It is most frequently used by reference to a set of standards against which compliance, generally achieved through tr ...

deterioration Deterioration may refer to: * Worsening of health * Physical wear See also * Decadence (disambiguation) * Degeneracy (disambiguation) * ''Deteriorata'', a parody of ''Desiderata'' * Decay * Decline Decline may refer to: *Decadence, involves a ...

that was partially caused by the closure of the tide gate in 1963 for purposes of desalination.Havens, K.E., P. Xie, T. Iwakuma, R.T. James, N. Takamura, T. Hanazato, and T. Yamamoto (2001). "Nutrient dynamics and the

eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...

of shallow lakes Kasumigaura (Japan), Donghu (PR China), and Okeechobee (USA)". ''Environmental Pollution''. 111(2):263–272.

Use

Today, Lake Kasumigaura is used for

fishing Fishing is the activity of trying to catch fish. Fish are often caught as wildlife from the natural environment, but may also be caught from stocked bodies of water such as ponds, canals, park wetlands and reservoirs. Fishing techniques inclu ...

irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...

tourism Tourism is travel for pleasure or business; also the theory and practice of touring (disambiguation), touring, the business of attracting, accommodating, and entertaining tourists, and the business of operating tour (disambiguation), tours. Th ...

recreation Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasur ...

, and for

consumption Consumption may refer to: *Resource consumption *Tuberculosis, an infectious disease, historically * Consumption (ecology), receipt of energy by consuming other organisms * Consumption (economics), the purchasing of newly produced goods for curren ...

by the surrounding public and local industry. A variety of fish can be caught from the waters of Lake Kasumigaura, including

smelt Smelt may refer to: * Smelting, chemical process * The common name of various fish: ** Smelt (fish), a family of small fish, Osmeridae ** Australian smelt in the family Retropinnidae and species ''Retropinna semoni'' ** Big-scale sand smelt ''Ath ...

, Japanese icefish,

crucian carp The crucian carp (''Carassius carassius'') is a medium-sized member of the common carp family Cyprinidae. It occurs widely in northern European regions. Its name derives from the Low German ''karusse'' or ''karutze'', possibly from Medieval Lat ...

goby Goby is a common name for many species of small to medium sized ray-finned fish, normally with large heads and tapered bodies, which are found in marine, brackish and freshwater environments. Traditionally most of the species called gobies have b ...

Japanese eel The Japanese eel (''Anguilla japonica''; Japanese: 日本鰻 ''nihon'unagi'') is a species of anguillid eel found in Japan, Korea, China, and Vietnam, as well as the northern Philippines. There are three main species under the Anguilla genus, and ...

and river prawn. The most popular catch is cultivated carp, followed by smelt and goby. Another cultivated treasure from Lake Kasumigaura is the beautiful Kasumi freshwater

pearl A pearl is a hard, glistening object produced within the soft tissue (specifically the mantle) of a living shelled mollusk or another animal, such as fossil conulariids. Just like the shell of a mollusk, a pearl is composed of calcium carb ...

s. They were known for their high luster and rosy hues, which is the result of a four-year cultivation period. However, in 2006, cultivation was discontinued as cheap freshwater pearls from China proved too difficult to compete against. The water from Lake Kasumigaura has long been used for the irrigation of

paddy field A paddy field is a flooded field (agriculture), field of arable land used for growing Aquatic plant, semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in sout ...

s in the surrounding

alluvial plain An alluvial plain is a largely flat landform created by the deposition of sediment over a long period of time by one or more rivers coming from highland regions, from which alluvial soil forms. A floodplain is part of the process, being the sma ...

and upland fields on diluvial terraces covered by thick deposits of

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...

. The primary crops are

rice Rice is the seed of the grass species ''Oryza sativa'' (Asian rice) or less commonly ''Oryza glaberrima ''Oryza glaberrima'', commonly known as African rice, is one of the two domesticated rice species. It was first domesticated and grown i ...

and

lotus root ''Nelumbo nucifera'', also known as sacred lotus, Laxmi lotus, Indian lotus, or simply lotus, is one of two extant species of aquatic plant in the family Nelumbonaceae. It is sometimes colloquially called a water lily, though this more often re ...

(a local speciality). Other crops include

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

cucumber Cucumber (''Cucumis sativus'') is a widely-cultivated Vine#Horticultural climbing plants, creeping vine plant in the Cucurbitaceae family that bears usually cylindrical Fruit, fruits, which are used as culinary vegetables.

eggplant Eggplant ( US, Canada), aubergine ( UK, Ireland) or brinjal (Indian subcontinent, Singapore, Malaysia, South Africa) is a plant species in the nightshade family Solanaceae. ''Solanum melongena'' is grown worldwide for its edible fruit. Mos ...

watermelon Watermelon (''Citrullus lanatus'') is a flowering plant species of the Cucurbitaceae family and the name of its edible fruit. A scrambling and trailing vine-like plant, it is a highly cultivated fruit worldwide, with more than 1,000 varieti ...

corn Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. Th ...

edamame is a preparation of immature soybeans in the pod, found in cuisines with origins in East Asia. The pods are boiled or steamed and may be served with salt or other condiments. In Japan, they are usually blanched in 4% salt water for 5 minut ...

sweet potato The sweet potato or sweetpotato (''Ipomoea batatas'') is a dicotyledonous plant that belongs to the Convolvulus, bindweed or morning glory family (biology), family, Convolvulaceae. Its large, starchy, sweet-tasting tuberous roots are used as a r ...

kabocha Kabocha (; from Japanese カボチャ, 南瓜) is a type of winter squash, a Japanese variety of the species ''Cucurbita maxima.'' It is also called kabocha squash or Japanese pumpkin in North America. In Japan, "''kabocha''" may refer to eithe ...

daikon Daikon or mooli, ''Radish, Raphanus sativus'' Variety (botany), var. ''longipinnatus,'' is a mild-flavored winter radish usually characterized by fast-growing leaves and a long, white, root. Originally native to continental East Asia, daikon ...

and

peanut The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible Seed, seeds. It is widely grown in the tropics and subtropics, important to both small ...

. Many tourists come to the lake in the summer to view the ''Hobikibune'' (帆引き船)

sail A sail is a tensile structure—which is made from fabric or other membrane materials—that uses wind power to propel sailing craft, including sailing ships, sailboats, windsurfers, ice boats, and even sail-powered land vehicles. Sails may ...

fishing boat A fishing vessel is a boat or ship used to catch fish in the sea, or on a lake or river. Many different kinds of vessels are used in commercial, artisanal and recreational fishing. The total number of fishing vessels in the world in 2016 was ...

s which are unique to Lake Kasumigaura. The Suigo

aquapark A water park (or waterpark, water world) is an amusement park that features water play areas such as swimming pools, water slides, splash pads, water playgrounds, and lazy rivers, as well as areas for floating, bathing, swimming, and other ba ...

, located in

Tsuchiura is a Cities of Japan, city located in Ibaraki Prefecture, Japan. , the city had an estimated population of 138,033 in 60,069 households and a population density of 1123 persons per km2. The percentage of the population aged over 65 was 29.7%. Th ...

, is popular during the hottest months. The

windmill A windmill is a structure that converts wind power into rotational energy using vanes called windmill sail, sails or blades, specifically to mill (grinding), mill grain (gristmills), but the term is also extended to windpumps, wind turbines, and ...

of Kasumigaura comprehensive park is a popular site along the shores throughout the year and especially in the spring when the

tulip Tulips (''Tulipa'') are a genus of spring-blooming perennial herbaceous bulbiferous geophytes (having bulbs as storage organs). The flowers are usually large, showy and brightly coloured, generally red, pink, yellow, or white (usually in warm ...

s are flowering. The lake is a recreation hotspot.

Sport fishing Recreational fishing, also called sport fishing or game fishing, is fishing for leisure, exercise or competition. It can be contrasted with commercial fishing, which is professional fishing for profit; or subsistence fishing, which is fishing ...

enthusiasts and anglers can be found close to shore and around the river mouths surrounding the lake.

Recreational boat Boating is the leisurely activity of travelling by boat, or the recreational use of a boat whether powerboats, sailboats, or man-powered vessels (such as rowing and paddle boats), focused on the travel itself, as well as sports activities, s ...

s, such as

yachts A yacht is a sailing or power vessel used for pleasure, cruising, or racing. There is no standard definition, though the term generally applies to vessels with a cabin intended for overnight use. To be termed a , as opposed to a , such a pleasu ...

power boat A motorboat, speedboat or powerboat is a boat that is exclusively powered by an engine. Some motorboats are fitted with inboard engines, others have an outboard motor installed on the rear, containing the internal combustion engine, the ge ...

sail boat A sailboat or sailing boat is a boat propelled partly or entirely by sails and is smaller than a sailing ship. Distinctions in what constitutes a sailing boat and ship vary by region and maritime culture. Types Although sailboat terminology ...

s and

personal watercraft A personal watercraft (PWC), also called water scooter or jet ski, is a recreational watercraft that a rider sits or stands on, not within, as in a boat. PWCs have two style categories, first and most popular being a runabout or "sit down" whe ...

, are regularly enjoyed on warm weekends. The wide surrounding

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

s are wonderful for

birdwatching Birdwatching, or birding, is the observing of birds, either as a recreational activity or as a form of citizen science. A birdwatcher may observe by using their naked eye, by using a visual enhancement device like binoculars or a telescope, b ...

, as large numbers of

water fowl The Anatidae are the biological family of water birds that includes ducks, geese, and swans. The family has a cosmopolitan distribution, occurring on all the world's continents except Antarctica. These birds are adapted for swimming, floating on ...

can be observed, primarily during the wintering period.

Japanese cormorant The Japanese cormorant (''Phalacrocorax capillatus''), also known as Temminck's cormorant, is a cormorant native to the east Palearctic. It lives from Taiwan, north through Korea and Japan, to the Russian Far East. The Japanese cormorant has a b ...

, Bewick’s swan, little egret,

grey heron The grey heron (''Ardea cinerea'') is a long-legged wading bird of the heron family, Ardeidae, native throughout temperate Europe and Asia and also parts of Africa. It is resident in much of its range, but some populations from the more northern ...

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 ...

Eurasian wigeon The Eurasian wigeon or European wigeon (''Mareca penelope''), also known as the widgeon or the wigeon, is one of three species of wigeon in the dabbling duck genus ''Mareca''. It is common and widespread within its Palearctic range. Taxonomy Th ...

striated heron The striated heron (''Butorides striata'') also known as mangrove heron, little green heron or green-backed heron, is a small heron, about 44 cm tall. Striated herons are mostly sedentary and noted for some interesting behavioral traits. The ...

sharp-tailed sandpiper The sharp-tailed sandpiper (''Calidris acuminata'') (but see below) is a small wader. Taxonomy A review of data has indicated that this bird should perhaps better be placed into the genus ''Philomachus'' – as ''P. acuminatus'' – which now ...

bush warbler Bush-warblers (or bush warblers) are small insectivorous songbirds of the genera ''Cettia'', ''Horornis'', and ''Bradypterus''. They were formerly placed in the "wastebin" Old World warbler family. None of the genera as traditionally delimited a ...

wood sandpiper The wood sandpiper (''Tringa glareola'') is a small wader. This Eurasian species is the smallest of the shanks, which are mid-sized long-legged waders of the family Scolopacidae. The genus name ''Tringa'' is the New Latin name given to the gree ...

, marsh grassbird,

Japanese reed bunting The Japanese reed bunting or ochre-rumped bunting (''Emberiza yessoensis'') is a bird in the family Emberizidae. The species was first described by Robert Swinhoe in 1863. It is found in Manchuria, Korea and Japan. Its natural habitats are tem ...

, and the

Eurasian coot The Eurasian coot (''Fulica atra''), also known as the common coot, or Australian coot, is a member of the rail and crake bird family, the Rallidae. It is found in Europe, Asia, Australia, New Zealand and parts of North Africa. It has a slaty-bla ...

are a few of the birds seen around the lake. Lake Kasumigaura provides over 60 tons of water per second; most goes to agriculture (83%). The rest is provided to local industry (13%) and public (4%) in the

prefectures A prefecture (from the Latin ''Praefectura'') is an administrative jurisdiction traditionally governed by an appointed prefect. This can be a regional or local government subdivision in various countries, or a subdivision in certain international ...

of Ibaraki,

Chiba Chiba may refer to: Places China * (), town in Jianli County, Jingzhou, Hubei Japan * Chiba (city), capital of Chiba Prefecture ** Chiba Station, a train station * Chiba Prefecture, a sub-national jurisdiction in the Greater Tokyo Area on ...

and

Challenges

Eutrophication Eutrophication is the process by which an entire body of water, or parts of it, becomes progressively enriched with minerals and nutrients, particularly nitrogen and phosphorus. It has also been defined as "nutrient-induced increase in phytopla ...

is a serious problem for Lake Kasumigaura. Legislation was enacted in 1982 to help prevent it, including a ban on the use and sale of phosphate-containing synthetic

detergent A detergent is a surfactant or a mixture of surfactants with cleansing properties when in dilute solutions. There are a large variety of detergents, a common family being the alkylbenzene sulfonates, which are soap-like compounds that are more ...

s, and the control of nitrogen and phosphorus contents in the

effluent Effluent is wastewater from sewers or industrial outfalls that flows directly into surface waters either untreated or after being treated at a facility. The term has slightly different meanings in certain contexts, and may contain various pollut ...

from factories. In order to help maintain the lake, dredging work is being carried out around the lake and at the estuaries of main inflowing rivers, such as Sakura River (桜川).

References

External links

Page on Hobikisen

{{Authority control Kasumigaura Landforms of Ibaraki Prefecture Kasumigaura