Shasthamkotta lake
Encyclopedia
Sasathamkotta Lake, also categorized as a wetland, is the largest fresh water lake in Kerala
Kerala
or Keralam is an Indian state located on the Malabar coast of south-west India. It was created on 1 November 1956 by the States Reorganisation Act by combining various Malayalam speaking regions....

, a state of India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

 on the south of the West Coast. The lake is named after the ancient Sastha temple (a pilgrimage centre) located on its bank. It meets the drinking water needs of half million people of the Quilon
Kollam
Kollam , often anglicized as ', is a city in the Indian state of Kerala. The city lies on the banks of Ashtamudi Lake on the Arabian sea coast and is situated about north of the state capital, Thiruvananthapuram...

 district and also provides fishing resources. The purity of the lake water for drinking use is attributed to the presence of large population of larva called cavaborus that consumes bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 in the lake water. The lake is a designated wetland of international importance
Ramsar list of wetlands of international importance
This is the list of wetlands of international importance as defined by the Ramsar Convention for the conservation and sustainable utilization of wetlands, recognizing the fundamental ecological functions of wetlands and their economic, cultural, scientific, and recreational value.The Convention...

 under the Ramsar Convention
Ramsar Convention
The Ramsar Convention is an international treaty for the conservation and sustainable utilization of wetlands, i.e., to stem the progressive encroachment on and loss of wetlands now and in the future, recognizing the fundamental ecological functions of wetlands and their economic, cultural,...

 since November 2002.

Access

The Lake is located at a distance of 25 km from Quilon
Kollam
Kollam , often anglicized as ', is a city in the Indian state of Kerala. The city lies on the banks of Ashtamudi Lake on the Arabian sea coast and is situated about north of the state capital, Thiruvananthapuram...

 city, which is on the northern side of Ashtamudi Lake
Ashtamudi Lake
Ashtamudi Lake in the Kollam District of Kerala, India, is the second largest and deepest wetland ecosystem, a palm-shaped large water body, next only to the Vembanad estuary ecosystem of the state. Ashtamudi means 'eight coned' in the local language of Malayalam...

. Thiruvanantapuram International Airport, at 105 km, is the nearest airport to Kollam. Karunagapally, at a distance of 8 km, is the closest town to the lake. A ferry service across the lake transports people between West Kallada
Kallada
Kallada is a village in Kollam district of the Indian state of Kerala. Maharajah Marthanda Varma of the Kingdom of Travancore was born here.*The famous Chittumala Sree Durga Devi temple is situated here....

 and Sasthamkotta.

Topography and geology

Except for an earthen embankment of 1.5 km length which separates the lake from the paddy fields on its southern side, bordering the alluvial plains of the Kallada River
Kallada River
The Kallada River is one of two major rivers that flow through the Kollam District of Kerala, India. It originates on the Kulathupuzha hills near Ponmudi and travels for 121 km, flowing through Punalur, Pathanapuram, Kunnathur, Kottarakkara and Kollam before ending at Ashtamudi Lake...

, all other sides of the lake are surrounded by hills which are steep and form narrow valleys. In the south and southwestern parts of the Lake there are a number of smaller water bodies and waterlogged areas.
The present area of the lake is 375 ha since large part of the lake is reported to have been occupied for agriculture.
Rock formation of mainly archaean origin are recorded with intrusions of charnockite
Charnockite
Charnockite is applied to any orthopyroxene-bearing granite, composed mainly of quartz, perthite or antiperthite and orthopyroxene , as an end-member of the charnockite series.-Charnockite series:...

, biotite gneiss
Gneiss
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.-Etymology:...

 and dolerite dyke rocks. The Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...

 Varkala formations are observed along the coastal beds. In the valley portion, sand and silt deposits are recorded. Geomorphological divisions of the basin area of the lake comprise a) the undulating uplands which have fairly thick vegetation of mixed crops and plantations, b) the valley fills of laterite
Laterite
Laterites are soil types rich in iron and aluminium, formed in hot and wet tropical areas. Nearly all laterites are rusty-red because of iron oxides. They develop by intensive and long-lasting weathering of the underlying parent rock...

 alluvium
Alluvium
Alluvium is loose, unconsolidated soil or sediments, eroded, deposited, and reshaped by water in some form in a non-marine setting. Alluvium is typically made up of a variety of materials, including fine particles of silt and clay and larger particles of sand and gravel...

 and colluvial deposits with low level areas which are intensely cultivated and thickly populated and c) the Flood Plains/Alluvial plains of the Kallada River
Kallada River
The Kallada River is one of two major rivers that flow through the Kollam District of Kerala, India. It originates on the Kulathupuzha hills near Ponmudi and travels for 121 km, flowing through Punalur, Pathanapuram, Kunnathur, Kottarakkara and Kollam before ending at Ashtamudi Lake...

 on the south that are mostly cultivated.

Hydrology

There are no visible tributaries feeding the lake but springs at the bottom of the lake are stated to be one of the source which supply water throughout the year; volume of water in the lake is estimated to be of the order of 22.4 million cum.
A thick 10–20 m mantle of Kaolinite
Kaolinite
Kaolinite is a clay mineral, part of the group of industrial minerals, with the chemical composition Al2Si2O54. It is a layered silicate mineral, with one tetrahedral sheet linked through oxygen atoms to one octahedral sheet of alumina octahedra...

 rich (derivative of laterite) soil around the lake is stated to check flow into the lake and the theory is now that the Lake is also rain fed; the lake water level is recorded to be higher at the end of the monsoon season. The average annual rainfall in the area is 2398 mm and mean annual temperature varies between 26.70 C and 29.160 C.
Ground Water table in the area is reported at depth of 3.89 m. After accounting for estimated evaporation loss of 5 Mm3 and water utilized for domestic use of 8 Mm3 (at a pumpage rate of 22 MLD), the two together account for about two-thirds of the inflow.

Water quality

The Lake water is reported to be free of common salt or other minerals and metals. The quality for surface water
Surface water
Surface water is water collecting on the ground or in a stream, river, lake, wetland, or ocean; it is related to water collecting as groundwater or atmospheric water....

, interstitial water and sediments studied by World Wildlife Fund (WWF), India are briefly as noted below.

Quality for Surface Water (average values):
  • Surface water: pH 7.25; EC 63.00 Millimhos/cm; PO4 – P 4.93 Micro gm. / l ; Ca 7.01Micro gm. / l; Na 4.33 Micro gm. / l; Fe 41.57 Micro gm. / l and Mn 12.11 Micro gm. / l.

  • Interstitial water: pH 7.20; PO4 – P 1.11 Micro gm. / l; Fe 59.1Micro gm. / l and Mn49.00 Micro gm. / l

  • Sediments: Organic C 8.95 %; PO4 – P 1690.00 Micro gm. / l; Fe 17724.27 Micro gm. / l and Mn 86.36 Micro gm. /l


Water quality test results indicate that the lake water conforms to standards of drinking water prescribed by regulatory bodies.

Flora

Eastern shore of the lake has the insectivorous plant Drosera Sp. Vegetation is negligible and rooted plants and floating plants are unimportant and insignificant. The crops grown on the banks of the lake, apart from paddy
Rice
Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...

, are the plantation crops such as cashewnut, tapioca
Tapioca
Tapioca is a starch extracted Manihot esculenta. This species, native to the Amazon, Brazil, Colombia, Venezuela, Cuba, Puerto Rico, Haiti, the Dominican Republic, Honduras, and most of the West Indies, is now cultivated worldwide and has many names, including cassava, manioc, aipim,...

 and plantain
Plantain
Plantain is the common name for herbaceous plants of the genus Musa. The fruit they produce is generally used for cooking, in contrast to the soft, sweet banana...

.

Aqua fauna

The aqua fauna noted in the lake are:
  • 27 species of freshwater fishes include pearl spot (Etroplus suratensis
    Etroplus suratensis
    The green chromide is a species of cichlid fish from freshwater and brackish water in southern India and Sri Lanka...

    ) and catfish
    Catfish
    Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

    , two genera of prawns, 21 species of herring
    Herring
    Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...

    s and sardines of the family Clupeidae
    Clupeidae
    Clupeidae is the family of the herrings, shads, sardines, hilsa and menhadens. It includes many of the most important food fishes in the world.-Description and biology:...


  • Common fish
    Fish
    Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

     such as Calichrous bimaculatus and Wallago attu
    Wallago attu
    Wallago attu is a species of catfish in the family Siluridae, or "sheatfishes". The fish is commonly known by its genus name, wallago. Found in large rivers and lakes, it can reach 2.4 m total length...

     These varieties of fish generally have whisker like barbells set round the mouth.


The Common Teal
Common Teal
The Eurasian Teal or Common Teal is a common and widespread duck which breeds in temperate Eurasia and migrates south in winter. The Eurasian Teal is often called simply the Teal due to being the only one of these small dabbling ducks in much of its range...

 or dabbling duck is the smallest migartory bird found in the lake.

Some of the vulnerable, endangered and critically endangered species reported by WWF in the lake area are:
  • Critically Endangered: Puntius ticto punctatus (Day)
  • Endangered: Horabagrus
    Horabagrus
    Horabagrus is a small genus of catfishes . It comprises two species, H. brachysoma and H. nigricollaris. H. brachysoma is an important food fish, and both species are available as aquarium fish.-Common names:...

     brachysoma (Gunther)
  • Vulnerable: Parambassis
    Parambassis
    Parambassis, is a genus of freshwater fish in the Asiatic glassfish family of order Perciformes. The type species is the iridescent glassy perchlet Parambassis, is a genus of freshwater fish in the Asiatic glassfish family (Ambassidae) of order Perciformes. The type species is the iridescent...

     thomassi (Day)

Fauna

Resident troupes of Monkeys are sighted on the banks in large numbers, which are part of the Sasthamkotta temple environment on the bank of the Lake.
13 species of insects have also been identified; 9 are butterflies, 2 odonates and 2 hymenopterans.

Deterioration in lake environment

The quality of the lake environment is affected due the following factors.
  • Increasing anthropogenic
    Anthropogenic
    Human impact on the environment or anthropogenic impact on the environment includes impacts on biophysical environments, biodiversity and other resources. The term anthropogenic designates an effect or object resulting from human activity. The term was first used in the technical sense by Russian...

     pressure
  • Encroachment of parts of lake for agriculture
  • Cultivation of tapioca has increased the soil loss by erosion
    Erosion
    Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

     and runoff into the lake basin
  • Domestic and agrochemical wastes from surrounding areas disposed into the lake
  • Soil erosion of the banks from the encroached land
  • Effluents from domestic sewage
  • Reduction of ground water recharge to the lake due to increase in agriculture
    Agriculture
    Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

     in the area around the lake.
  • Soaking of dry leaves of coconut palm before matting which used for thatching huts

Conservation and management

The Kerala State Government prepared a Conservation and Management Action Plan (MAP) in 1999 for the Lake’s sustainable utilization and conservation and to address the threats faced by the lake. Financial support was sought from the Central Government under the National Lake Conservation Plan (NLCP) for implementation of MAP based on the specific problems identified in the wetland.

The MAP envisages the following activities:
  • Agro-forestry in the catchment,
  • sanitation
    Sanitation
    Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems are human and animal feces, solid wastes, domestic...

     and drainage,
  • pollution
    Pollution
    Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...

     abatement
    Abatement
    Abatement may refer to:*Abatement of debts and legacies, a common law doctrine of wills*Abatement in pleading, a legal defense to civil and criminal actions based purely on procedural and technical issues involving the death of parties...

    ,
  • limited desilting,
  • weed
    Weed
    A weed in a general sense is a plant that is considered by the user of the term to be a nuisance, and normally applied to unwanted plants in human-controlled settings, especially farm fields and gardens, but also lawns, parks, woods, and other areas. More specifically, the term is often used to...

     control,
  • conservation of flora
    Flora
    Flora is the plant life occurring in a particular region or time, generally the naturally occurring or indigenous—native plant life. The corresponding term for animals is fauna.-Etymology:...

     and fauna
    Fauna
    Fauna or faunæ is all of the animal life of any particular region or time. The corresponding term for plants is flora.Zoologists and paleontologists use fauna to refer to a typical collection of animals found in a specific time or place, e.g. the "Sonoran Desert fauna" or the "Burgess shale fauna"...

    ,
  • fishery
    Fishery
    Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...

     development, and
  • awareness campaigns among the local inhabitants.


The above activities were planned to be implemented through the Kerala Water Authority (KWA), Department of Forests and Wild Life, Department of Fisheries, State Fisheries Resource Management Society (FIRMA), District Rural Development Agency (DRDA), CWRDM, etc. Kerala State Council for Science Technology and Environment of Govt. of Kerala provided the support and overall supervision.

See also

  • Kollam
    Kollam
    Kollam , often anglicized as ', is a city in the Indian state of Kerala. The city lies on the banks of Ashtamudi Lake on the Arabian sea coast and is situated about north of the state capital, Thiruvananthapuram...

  • Kallada River
    Kallada River
    The Kallada River is one of two major rivers that flow through the Kollam District of Kerala, India. It originates on the Kulathupuzha hills near Ponmudi and travels for 121 km, flowing through Punalur, Pathanapuram, Kunnathur, Kottarakkara and Kollam before ending at Ashtamudi Lake...

  • Munroethuruth
  • Sasthamcotta Sree Dharma Sastha Temple
    Sasthamcotta Sree Dharma Sastha Temple
    Shri Dharma Sastha temple is a Hindu temple located at the village Sasthamcotta, Kerala, India. It is surrounded three sides by the largest fresh water lake of Kerala, Sasthamkotta lake....


External links

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