Lake BIJU DHARMAPALAN

All pictures by Biju Dharmapalan RTICLE A

Vellayani Lake, the

EATURE only freshwater

F reservoir in the district of , is under serious threat due to several anthropogenic factors

Biodiversity of the Lake The region is also rich in fl oral The lake and the adjoining Punchakkari biodiversity typical of a wetland wet lands are an abode of fl oral as well ecosystem. Many members of Poaceae as faunal biodiversity. Many types of and Cyperaceae dominate the wetlands, birds visit the wetlands adjoining the even though members of Malvaceae, lake. According to the reports of Euphorbiaceae, Passifl oraceae are also State Council for Science Technology and noticed along the fringes. According Environment the lake is home to nearly 92 to local people, different types of ELLAYANI lake or Vellayani kayal species of wetland birds and 37 species of mushrooms including fairy rings were Vas known in local language is one fi shes. common in this locality. But now with the of the three rain-fed freshwater lakes in Some of the birds that have been dwindling ecosystem these mushrooms Kerala, the other two being Sasthamcotta reported from the area are the Black have vanished. lake in Kollam and in headed bunting, Marsh harrier, Osprey, Earlier, the biodiversity of the Wayanad. Water cock, Pied Crested cuckoo, Indian area supported the livelihood of the is the largest fresh coot, Common Stone chat, Pied kingfi sher, local people. Screwpine matt making water lake in Thiruvananthapuram Cormorants, Little egret, pond heron, and Kora matt making industry were district of Kerala. This very vast purple moorhen etc. The area harbors a common in the region. But now one can picturesque lake surrounded by lush good population of butterfl ies like tawny hardly fi nd these small-scale industries greenery is located about 9 km away from coster. because of declining population of Thiruvananthapuram city. The lake is a rich repository of fl ora and fauna, and the Lotus rearing – a livelihood for the local people biodiversity supports the livelihood of people around the lake. About hundred species of wetland birds frequent the lake, including migratory ones. Till 1953, the lake was solely used for the cultivation of lotus fl owers for the famous Sri PadmanabhaswamyTemple. But later the water from the lake was extensively used for drinking and irrigational purposes. The Vellayani fresh water lake is the major source of drinking water for the people of Kalliyoor, Venganoor, and Vizhinjam grama panchayats. SCIENCE REPORTER, JUNE 2014 2222 FEATURE ARTICLE

From left: Pied kingfi sher; Cormorant; Little egret; Indian Pond heron; Tawny coster

Screwpines (Pandanus spp.) and Kora most productive areas in vegetable The exploitation of water is rampant grass (Rhynchospora spp.), due to large cultivation. This is being heralded as an in the locality. The water from the lake scale reclamation of lake and adjoining achievement, but this also brings havoc to as well as from the wells bored near the wetlands for cultivation and construction the environment of the lake. lake is drawn unscrupulously for sale. purposes. Most of these wetlands are slowly In addition, sand mining is also affecting being converted for developmental the ecosystem of the lake. The leaching of Threats to the Lake activities both by private parties and the agricultural residues and domestic waste Various anthropogenic activities have government. During the early 1980s one has led to the growth of Eichhornia in adversely affected the water quality and of the bund roads connecting the two ends some parts of the lake. the environment of the lake. The initial of the lake was converted into a tarred The introduction of many exotic destruction of the lake was done by road, which is now a major bye-pass road varieties of fi sh as part of the government an unscientifi c approach of cultivation connecting Trivandrum and Kaliyakkavilai initiative to empower the local people has locally known as “Puncha Krishi”, in Tamil Nadu. Many parts of the lake are also adversely affected the ecosystem. launched during the early 1950s. In in the process of transforming into modern According to locals this has led to genetic this pattern of cultivation the lake was roads utilizing funds from the Pradhan erosion of many local species. dewatered for paddy cultivation. Since Mantri Gram Sadak Yojana. Since the times of the Travancore the lake is about a metre above the sea Many regions of wetlands kings the Vellayani Lake has been a level, the dewatering is carried out easily encroached by private parties are also centre of attraction for tourists. In recent through the Madhupalam spillway, slowly being converted for building times, irresponsible tourism activities near Thiruvallam. This practice over the houses. This conversion takes place in have badly affected the ecosystem. Plastic period has resulted in drastic depletion of a slow manner. In the fi rst phase the water bottles and liquor bottles are ground water. paddy plant is replaced by vegetables like littered in the lake. Installation of street In many houses in Kalliyoor Cucumber, Amaranthus, Momordica, lamps near the lake may also affect the panchayat the average depth of wells is etc. In the next phase the fi elds are fi lled biological rhythm of the fl ora and fauna above 100 feet. The usage of manures, with soil and banana plants and coconut present in the lake. fertilizers and pesticides for cultivation palms are grown. By the end of three or Even though the Kerala State Council has deteriorated the quality of water and fi ve years buildings are constructed there. for Science, Technology and Environment drastically reduced the water spread area. The region also faces threat due to (KCSTE) has initiated steps to protect the The lake is encroached partly introduction of exotic plants that are not Vellayani lake and the wetlands in the area by a college and by private parties suitable to the habitat like Bamboos and by including them in the National Lake for cultivation purpose, which goes Acacia. This is done purposefully with Conservation Plan (NLCP) formulated unnoticed by the authorities. The villages the aim of destroying the ecosystem so by the ministry of environment and surrounding this lake like Palaparru that it could be utilized for developmental forests, not much has been done by any and Kalliyoor are considered to be the activities. of the government agencies to protect Pumping station of Kerala Water Authority Pandanus population

23 SCIENCE REPORTER, JUNE 2014 FEATURE ARTICLE

Above: Eichhornia menace Left: Pumping out water by tankers Below: Irresponsible tourism affects the biota

The usage of manures, fertilizers and pesticides for cultivation has deteriorated the quality of water and drastically reduced the water spread A new road in the making area.

the ecosystem from depleting. The lake, potable water. Microbiological analysis Lake. Birds like Pied cuckoo, Buntings which was spread over 750 hectares in carried out by different agencies has and the Brahminy starlings that prefer a 1926, has undergone an alarming rate of shown that the water from the lake is drier weather visited the area indicating depletion in area, now covering hardly not suitable for drinking. Yet in most the change in the temperature pattern in 450 hectares. Environmentalists have been cases the water is pumped directly into the wetlands of this area. demanding to recommend the lake for the lane without any proper treatment It also signals a warning bell to getting Ramsar tag so that international mechanism. human beings to take urgent steps to attention will help prevent the remaining This is the only fresh water reservoir prevent the degradation of this unique part of the lake from further decline. in the entire Thiruvananthapuram district ecosystem. The dictum, “water, water of Kerala but people are not bothered to everywhere, nor any drop to drink” is notice the changes that are happening highly appropriate for the people living in their living stream. Last year, bird Dr Biju Dharmapalan is Assistant Professor, near to the lake. The water table in the watchers observed unusual migratory School of Biosciences, Mar Athanasios College for adjoining areas of the lake is receding pattern of birds visiting the Punchakkari Advanced Studies, Tiruvalla-689101; Email: biju@ every day; even bore wells cannot gather wetlands surrounding the Vellayani macfast.org/[email protected]

SCIENCE REPORTER, JUNE 2014 24