Sasthamcotta Lake or Sasthamkotta Lake, also categorized as a wetland, is the largest fresh water lake in

Kerala Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South C ...

, a state of

India India, officially the Republic of India ( Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the ...

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 (), also known by its List of renamed Indian cities and states, former name Quilon , is an ancient seaport and city on the Malabar Coast of India bordering the Laccadive Sea, which is a part of the Arabian Sea. It is north of the sta ...

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 in the lake water. The lake is a designated wetland of international importance under the

Ramsar Convention The Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat is an international treaty for the conservation and sustainable use of Ramsar sites ( wetlands). It is also known as the Convention on Wetlands. It ...

since November 2002.

Access

The lake is located at a distance of 25 km from

city, which is on the northern side of

Ashtamudi Lake Ashtamudi Lake (''Ashtamudi Kayal''), in the Kollam District of the Indian state of Kerala, is the most visited backwater and lake in the state. It possesses a unique wetland ecosystem and a large palm-shaped (also described as octopus-shaped) ...

Thiruvananthapuram Thiruvananthapuram (; ), also known by its former name Trivandrum (), is the capital of the Indian state of Kerala. It is the most populous city in Kerala with a population of 957,730 as of 2011. The encompassing urban agglomeration populat ...

International Airport, at 105 km, is the nearest airport to Kollam.

Karunagapally Karunagappally is a municipality in the Kollam district of Kerala, India. It is 24 km north of Kollam and south of Alappuzha. Karunagappally taluk consists of Alappad, Ochira, Adinad, Karunagappally, Thazhava, Pavumba, Thodiyoor, Ka ...

, at a distance of 8 km, is the closest town to the lake. A ferry service across the lake transports people between West Kallada 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/Kulathupuzha " Puzha "means River.Its's the longest river in Kollam District, Kerala, India.The river originates in Kulathupuzha,a part of Western Ghats and flows west reaching Arabian Sea after travelling a distance of 120km. R ...

, 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 () is any orthopyroxene-bearing quartz-feldspar rock formed at high temperature and pressure, commonly found in granulite facies metamorphic regions, ''sensu stricto'' as an endmember of the charnockite series. Charnockite series ...

, biotite

gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures an ...

and

dolerite Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained ...

dyke rocks. The

Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

Varkala formations are observed along the coastal beds. In the valley portion, sand and silt deposits are recorded.

Geomorphological Geomorphology (from Ancient Greek: , ', "earth"; , ', "form"; and , ', "study") is the scientific study of the origin and evolution of topographic and bathymetric features created by physical, chemical or biological processes operating at or ...

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 is both a soil and a rock type rich in iron and aluminium and is commonly considered to have formed in hot and wet tropical areas. Nearly all laterites are of rusty-red coloration, because of high iron oxide content. They develop by ...

alluvium Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. ...

and colluvial deposits with low level areas which are intensely cultivated and thickly populated and c) the flood plains/alluvial plains of the

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 ( ) is a clay mineral, with the chemical composition Al2 Si2 O5( OH)4. It is an important industrial mineral. It is a layered silicate mineral, with one tetrahedral sheet of silica () linked through oxygen atoms to one octahedral s ...

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 26.7 °C and 29.16 °C. Ground water table in the area is reported at depth of 3.89 m. After accounting for estimated evaporation loss of 5 MCM ( million cubic metres) and water utilized for domestic use of 8 MCM (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 Salt is a mineral composed primarily of sodium chloride (NaCl), a chemical compound belonging to the larger class of salts; salt in the form of a natural crystalline mineral is known as rock salt or halite. Salt is present in vast quantit ...

or other

minerals In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...

and

metals A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...

. The quality for

surface water Surface water is water located on top of land forming terrestrial (inland) waterbodies, and may also be referred to as ''blue water'', opposed to the seawater and waterbodies like the ocean. The vast majority of surface water is produced by pr ...

, interstitial water and

sediments Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand a ...

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 ''Drosera'', which is commonly known as the sundews, is one of the largest genera of carnivorous plants, with at least 194 species. 2 volumes. These members of the family Droseraceae lure, capture, and digest insects using stalked mucilaginou ...

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, are the plantation crops such as

cashewnut The cashew tree (''Anacardium occidentale'') is a tropical evergreen tree native to South America in the genus ''Anacardium'' that produces the cashew seed and the cashew apple accessory fruit. The tree can grow as tall as , but the dwarf cult ...

tapioca Tapioca (; ) is a starch extracted from the storage roots of the cassava plant (''Manihot esculenta,'' also known as manioc), a species native to the North and Northeast regions of Brazil, but whose use is now spread throughout South America ...

and

plantain Plantain may refer to: Plants and fruits * Cooking banana, banana cultivars in the genus ''Musa'' whose fruits are generally used in cooking ** True plantains, a group of cultivars of the genus ''Musa'' * ''Plantaginaceae'', a family of floweri ...

Aqua fauna

The aqua fauna noted in the lake are: * 27 species of freshwater fishes include pearl spot ( Etroplus suratensis) and

catfish Catfish (or catfishes; order Siluriformes or Nematognathi) 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 three largest species alive ...

, two genera of

prawns Prawn is a common name for small aquatic crustaceans with an exoskeleton and ten legs (which is a member of the order decapoda), some of which can be eaten. The term "prawn"Mortenson, Philip B (2010''This is not a weasel: a close look at nature' ...

, 21 species of

herring Herring are forage fish, mostly belonging to the family of Clupeidae. Herring often move in large schools around fishing banks and near the coast, found particularly in shallow, temperate waters of the North Pacific and North Atlantic Oceans, ...

s and

sardines "Sardine" and "pilchard" are common names for various species of small, oily forage fish in the herring family Clupeidae. The term "sardine" was first used in English during the early 15th century, a folk etymology says it comes from the It ...

of the family

Clupeidae Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeoids include many of the most important food fishes in the world, and are also commonly caught for producti ...

* Common

fish Fish are aquatic, craniate, gill-bearing 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. Approximately 95% of liv ...

such as ''Calichrous bimaculatus'' and ''

Wallago attu ''Wallago attu'' is a freshwater catfish of the family Siluridae, native to South and Southeast Asia. It is commonly known as helicopter catfish or wallago catfish. It has known by various names in different regions and languages, such as Borali(� ...

'' These varieties of fish generally have whisker-like barbells set around their mouths. The

common teal The Eurasian teal (''Anas crecca''), common teal, or Eurasian green-winged teal is a common and widespread duck that breeds in temperate Eurosiberia and migrates south in winter. The Eurasian teal is often called simply the teal due to being th ...

dabbling duck The Anatinae are a subfamily of the family Anatidae (swans, geese and ducks). Its surviving members are the dabbling ducks, which feed mainly at the surface rather than by diving. The other members of the Anatinae are the extinct moa-nalo, a yo ...

is the smallest migratory 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 brachysoma'' (Gunther) * Vulnerable: '' Parambassis thomassi'' (Day)

Fauna

Resident troupes of

monkeys Monkey is a common name that may refer to most mammals of the infraorder Simiiformes, also known as the simians. Traditionally, all animals in the group now known as simians are counted as monkeys except the apes, which constitutes an incomple ...

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 Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises ...

, 2 odonates and 2

hymenopteran Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typica ...

Deterioration in lake environment

The quality of the lake environment is affected by the following factors. * Increasing

anthropogenic Anthropogenic ("human" + "generating") is an adjective that may refer to: * Anthropogeny, the study of the origins of humanity Counterintuitively, anthropogenic may also refer to things that have been generated by humans, as follows: * Human im ...

pressure * Encroachment on parts of the lake for agriculture * Cultivation of tapioca has increased the soil loss by

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is di ...

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 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 polluta ...

from domestic sewage * Reduction of ground water recharge to the lake due to increase in

agriculture Agriculture or farming is the practice of cultivating plants and livestock. Agriculture was the key development in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that enabled people t ...

in the area around the lake. * Soaking of dry leaves of

coconut palm The coconut tree (''Cocos nucifera'') is a member of the palm tree family (Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, the seed, or the f ...

before matting, which are then 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 refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation system ...

and drainage, *

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

abatement, * limited desilting, *

weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...

control, * conservation of

flora Flora is all the plant life present in a particular region or time, generally the naturally occurring ( indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms '' gut flora'' or ''skin flora''. ...

and

fauna Fauna is all of the animal life present in a particular region or time. The corresponding term for plants is ''flora'', and for fungi, it is '' funga''. Flora, fauna, funga and other forms of life are collectively referred to as '' biota''. Z ...

, *

fishery Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, ...

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.

Gallery

File:Sasthamcotta Lake 1 by ArunElectra.jpg, Sasthamkotta Lake File:Sasthamcotta Lake 2 by ArunElectra.jpg, Sasthamkotta Lake File:Sasthamcotta Lake Sunset by ArunElectra.jpg, An Evening view of Sasthamkotta Lake File:Keralaback (15).jpg, Village on bank of the lake

References

External links

* {{Ramsar sites in India Lakes of Kollam Ramsar sites in India Tourist attractions in Kollam district Geography of Kollam district