Summary
This is a map of locations where the water quality of Vembanad lake is monitored by local communities once in a month, with the support of Ashoka Trust for Research in Ecology and the Environment (ATREE). The attached data contains status of 25 water quality parameters, sampled once in a month.
Description
Vembanad wetland, which is the largest wetland system on the west-coast of India, is facing a grave environmental threat due to the pollution from various human activities. Industrial and agro-chemical residues, municipal sewage, domestic wastes, effluents from motor boats, lake tourism and coir retting to open water bodies are the major sources of pollution. ATREE, a conservation organization, through its participatory water watch program known as Jaladarpanam, has been training and supporting local communities that depend on Vembanad lake for their livelihoods, to monitor regularly the water qualtiy of the lake.
The communities sample and analyse the water quality at fixed Basin Stations once in a month. This participatory monitoring is expected to create public awareness on pollution problems, play a major role in monitoring the health of Vembanad Lake and help identify and resolve pollution issues. The prgram intends to provide baseline information on (1) quality of surface waters; (2) temporal changes of surface water quality conditions;(3) areas where water quality conditions are insufficient to support livelihood and domestic activities;(4) areas where the water quality conditions do not support aquatic life.
Methods
Basin stations were set up at 14 locations south of Thanneermukkom bund and community volunteer groups were trained in monitoring the water quality using field testing kits. Field kits were calibrated at certified professional laboratories. Higher order parameters and bacteriological parameters were screened at laboratories. The results are displayed in public places around the lake.
Factors Affecting Lake Water Quality
Effluents from house boats are a major threat to lake ecology
D.R.Priyadarsanan, ATREE
Like any other water body, Vembanad Lake is a common property resource, whose appropriation was guided by social norms and customs. But as the pressure from growing population increased, new stakeholders emerged and the allocation and use of its resources have been dominated by private interests. As a result of largely uncontrolled resource use, the water quality of the lake is consistently deteriorating and consequently, the well being of the people and habitat needs of other life forms are being severely affected.
Vembanad Lake serves as a sink for effluents of several industrial and manufacturing units and domestic sewage from a string of small towns.
Major pollutants of Vembanad Lake:
Inorganic
1. Effluents from nearby factories
2. Emissions and oil leakage from the engines of motor boats
3. Plastic and other inorganic waste dumped from the house boats
4. Fertilizers and pesticide run-off from the paddy fields of Kuttanad
5. Chemical dyes used in the coir industry
6. Chemical pollution from up-stream tea plantations through the rivers
Organic
7. Sewage emptied into the canals from the nearby towns and habitations
8. Sewage and other organic waste from house boats
9. Invasive (Eichhornia crassipes, Salvinia molesta etc.) and other aquatic weeds (water lillies & grasses)
The construction of a salt-water barrier at Thanneermukkom across the lake in 1976, resulted in sudden cessation of natural flushing out of pollutants from southern parts. This has led to a decline in the water quality, which has adversely affected the prevailing aquatic environment. To add to this, water borne diseases are widespread along the coast and become acute during the monsoon months.
External Links
References
Abbasi, S.A. and Remani, K.N., 1985. Environmental Pollution due to Retting of Coconut Husk and Preliminary Studies on Closed System Retting. Proc. Workshop on Coir Research. Coir Board, pp 121-131
Abdul Aziz P.K and Nair, N.B., 1981. Certain Aspects of Pollution in the Aquatic Ecosystems of the south-west Coast of India. Proceedings of Seminar on Status of Environmental Studies in India: pp 345 – 356
Batcha A.S.M. 2002. Studies on Distribution of Surface and Bottom Water Dissolved Oxygen Content of Vembanad Lake in Different Seasonal Periods. Journal of nature environment and pollution technology 1(4): pp 347-349.
Bijoy Nandan, S., 1991. Effect of Coconut Husk Retting on the water Quality and Biota of an Aquatic Biotope in Kerala. Ph.D Thesis. University of Kerala, Trivandrum, Kerala.
Bijoy Nandan, S., 1994 b. Retting of Coconut Husk – The Problem of Pollution in the Estuaries of Kerala Proc. 1994 Environmental Modelling Seminar, 17-19 August 1994, Trondheim, Norway, pp 380-389.
Bijoy Nandan, S., 1994a. Retting of Coconut Husk – The problem of Pollution in the Estuaries of Kerala. Proc. Sixth International Congress of Ecology, 21- 26 August 1994, Manchester, U.K. John H Tallis, Hazel Norman and Robert A. Benton (ed), pp 376(Abs.).
Bijoy Nandan, S., and Abdul Aziz, P.K., 1994d. Pollution Indicators of Coconut Husk Retting Areas in the Kayals of Kerala. International Journal of Environmental Studies, 47: 19- 25.
Bijoy Nandan, S., and Abdul Aziz, P.K., 1995a. Fish Mortality from Anoxia and Sulphide Pollution. J. Hum. Ecol., 6:97-104.
Bijoy Nandan, S., and Abdul Aziz, P.K., 1995b. Pollution Indicators of Coconut Husk Retting Areas in the Kayals of Kerala. Intern. J. Environ. Studies 47: 19-25.
Bijoy Nandan, S., and Abdul Aziz, P.K., 1996 b. Water Quality and Benthic Faunal Diversity of a Polluted Estuary on the South-West Coast of India. Indian J. Environ. Protection, 16: 12-22.
Bijoy Nandan, S., Aziz, P.K.A. and Natarajan, P., 1989. Water Quality and Faunal Depletion in the Retting Zones of the Backwaters of Kerala, Proc. First Kerala Science Congress, Cochin, State Committee on Science Tech. & Environ., Government of Kerala, Trivandrum, pp 167-175.
CWRDM, 1989. Assessment of Pollution due to Retting of Coconut Husk and Development of Alternative Retting Technology. Final Project Report Submitted to State Committee on Science, Technology and Environment, Govt. of Kerala, Trivandrum, 30pp.
Gore, P.S., Raveendran. O and Unnithan, R.V., 1979. Pollution in Cochin Backwaters with Reference to Indicator Bacteria. Indian J.Mar. Sci., 8: 43-46.
Haridas, P., Madhu Pratap, M. and Rao, T. S. S., 1973. Salinity, Temperature, Oxygen and Zooplankton Biomass of the Backwaters from Cochin to Aleppey. Indian J. Mar. Sci., 2: 94-102.
Jacob, V. C., G. Balasubramanyam and K. Rajagopalan. 1987. Some Hydro Chemical Aspects of the Pamba Estuary in Kerala.
James, E. J., 1984 b. Estuarine Mechanics with Special Reference to Circulation, Mixing and Pollution Dispersion. Proc. Natn. Workshop on the State of the Art on Water Resources Development and Management. October 1984, Warangal.
Josanto V. 1971. The Bottom Salinity Characteristics and the Factors that Influence the Salt Water Penetration in the Vembanad Lake, Bull. Dept. Mar. Biol. Oceanogr 5: pp 1-16
Joseph, C. A., 1987. Management of Paddy in Relation to Environment Pollution with Special Reference to Kuttanad. Proc. Sem. Environmental pollution and Conservation of Nature. Department of Zoology, Marthoma College, Thiruvalla, Kerala.
Mathew, T. B., Visalakshi, A and Das, N. M., 1998. Insecticide Residues in Irrigation Water in Rice Fields Sprayed with Different Volumes of Carbaryl Suspension. In: Reghupathy. A et al (Ed)., Pesticides and Environment. Tamil Nadu Agricultural University Coimbatore, Tamil Nadu.
Paul, A.C and Pillai, K.C., 1976. Studies on Pollution Aspects of Periyar River. Bhabha Atomic Research Centre, Report No. BARC- 1-419. Bombay. 93pp.
Pillai, K.C., 1983. Heavy Metals in Aquatic Environment In: Varshney, C.K (Ed.), Water Pollution and Management. Wiley Eastern Ltd., India, pp 74-93.
Pradeep, R and Samy, P.L., 1986. Distribution of Faecal Indicator Bacteria in Cochin Backwaters. Indian J. Mar. Sci., 15: 99-101.
Prasad, M.K., 1983. State of Environment of Cochin. Proc. Natn. Sem. Environmental Management, Trichur, Kerala, pp 79-92.
Promod, K.C., 1985. Studies of Phosphobacteria in the Vembanad Lake, M.Sc. Thesis. Cochin University of Science and Technology, Cochin, Kerala. 53pp.
Rajendran, N., Kurian.C.V and George, V., 1987. Mercury Concentrations in Crassostrea madrasensis (Preston) from Cochin Backwater. J, Mar. Biol. Assn. India. 29: 237-243.
Remani, K.N., Nirmala, E and S.R., 1989 a. Effect of Coir Retting on Water Quality, Fauna and Flora of backwaters of Kerala. 3rd Intern. J. Conf. Environmental Contamination, 26-29 September 1989. Venice.
Remani, K.N., Nirmala, E and S.R., 1989 b. Pollution due to Coir Retting and its Effect on Estuarine Flora and Fauna. Intern. J. Environ. Studies, 32: 285-295.
Remani, K.N., Nirmala, E and S.R., 1989 c. Prediction and Assessment of the Biological Characteristics in the Retting Yards of Kerala. Natn. Sem. Aquatic Pollution and Management, 18-23 December 1989, Trivandrum, Kerala.
Remani, K.N., Venugopal, P., Saraladevi, K and Unnithan, R. V., 1980. Studies on the Sediments of the Cochin Backwaters in Relation to Pollution. Indian J. Mar. Sci., 9: 111-114.
Remani, K.N., Venugopal, P., Saraladevi, K and Unnithan, R. V., 1983. Indicator Organisms of Pollution in Cochin Backwaters, Mahasagar. 16: 199-207.
Saraladevi, K., 1989. Temporal and Spatial Variations in Particulate Matter, Particulate Organic Carbon and Attenuation Coefficient in Cochin backwaters. Indian J. Mar. Sci., 18: 242-245.
Unnithan, R. V., Vijayan, M., Ramakrishnan, E. V and Remani, K. N., 1977. Incidence of Fish Mortality from Industrial Pollution in Cochin Backwaters. Indian J. Mar. Sci., 6: 81-83.
Unnithan, R.V., Vijayan, M and Remani, K. N., 1975. Organic Pollution in Cochin Backwaters. Indian J. Mar. Sci., 4: 39-42.