|
|
|
|
|
|
|
Aquatic ecosystems perform numerous valuable environmental functions. They recycle nutrients, purify water, recharge ground water, augment and maintain stream flow, and provide habitat for a variety of flora and fauna and recreation of people. A rapid population increase accompanied by unplanned developmental activities has led to the pollution of surface waters by residential, agricultural, commercial and industrial wastes / effluents and decline in the number of waterbodies. Increased demands for drainage of wetlands have been accommodated by channelisation, resulting in further loss of stream habitat, which has led to aquatic organisms becoming extinct or imperiled in increasing numbers and to the impairment of many beneficial uses of water, including drinking, swimming and fishing. Various anthropogenic activities have altered the physical, chemical and biological processes within aquatic ecosystems. An integrated and accelerated effort toward environmental restoration and preservation is needed to stop further degradation of these fragile ecosystems. Failure to restore these ecosystems will result in sharp increase in environmental costs, extinction of species or ecosystem types, and permanent ecological damage.
Restoration means returning an ecosystem to a close approximation of its condition prior to disturbance. This ensures that the ecosystem structure and function are recreated or restored, and that natural dynamic ecosystem processes operate effectively again. The physical, chemical and biological integrity of surface water is achieved by-
The most widespread problems that lakes and wetlands face are sewage from domestic sector, effluents from industrial sector (point sources), and agricultural non-point runoff of silt and associated nutrients and pesticides. This has led to eutrophication, due to excessive inputs of nutrients and organic matter. Hydrologic and physical changes and siltation from catchment activities have resulted in spatial decline. Lakes are sinks for incoming contaminants that recycle and maintain the impaired conditions. Therefore, there is an urgent need to take up the restoration of lakes and wetlands. In this regard, lake restoration is viewed in watershed context. When inputs are controlled, abatement of eutrophication, siltation and contaminant problems are more effective. Reduction of inputs enhances the long-term effectiveness of in-lake approaches. The watershed is the natural scale for restorations and would be self sustaining. The major barrier for watershed restoration is institutional and educational. Effective restoration can be achieved through collaboration among all stakeholders - scientists, economists, administrators, policy makers, students and local people. The main objective of the symposium was to bring out the current trends in lakes and wetlands restoration including the hydrological and the biophysical aspects, peoples participation and the role of non-governmental, educational and the governmental organisations and future research needs for the restoration, conservation and management of wetlands and to provide a forum for researchers, technologists, economists, sociologists and others to meet and discuss water related issues. The symposium on restoration of lakes and wetlands has enabled planners, scientists, administrators and NGO's concerned with watershed development programme in the region and provided a forum to discuss the various aspects involved in the management of wetlands. This helped in better understanding of the hydrology, development of water and land resource programmes and monitoring their performance for sustainable development.
Selected papers from researchers, planners, development managers, students, economists and social scientists on the following themes were presented and discussed during the symposium.
Capabilities of children are the most intriguing and stimulating in all creation. When these children come forward to represent the cause of Mother Nature, you can well understand the impact they can make on everybody. Students from various schools and colleges actively participated in Lake 2000, presenting posters, delivering talks and designing models of lake ecosystems, and made a deep impact on the audience. Lake 2000 motivated the students by instituting awards for the best poster and paper presentation. Students took efforts to prepare excellent posters and papers, exhibiting their commitment for the restoration of lakes and wetlands. Their team spirit and leadership abilities came to the fore during the symposium. Students can easily impact their families and the society, and in this respect, their enthusiastic efforts during and after the symposium have achieved a great measure of support for environmental protection and ecological sustenance. Papers such as sustainable water resource management policy (by Bhavana of Poornaprajna Education Centre High School, Bangalore), Restoration of lakes and Wetlands (by Parul of Kendriya Vidyalaya, DRDO, Bangalore), Act now before it is too late (by Divya of Poornaprajna Education Centre High School, Bangalore), Conserve nature (Arun Kumar and Jithendra of K.K. High School, Bangalore) and Not just preaching but also practicing (by Bharath, Poornaprajna Education Centre High School, Bangalore) were instances of the potential of our children, which needs to be nurtured and guided properly to ensure they contribute as they grow toward the sustainable development of nature. These presentations effectively conveyed the objectives of the symposium and received wide scale appreciation by symposium participants and local news media. Papers presented and discussed during the symposium are included in this proceedings. Following sections provide brief overview of the papers that were selected for inclusion by the panel of experts and organizing committee members. Ramachandra and Rajasekara Murthy discuss restoration, post-restoration and management strategies through an integrated watershed approach based on the findings of pilot studies in Bangalore city, Karnataka State, India. The pilot studies cover spatio-temporal analysis, status of wetlands, bathymetric analyses, impact of urbanisation on wetlands, restoration and conservation plans, socio-economic evaluation, community's perception of lake restoration program and the role of the various agencies and departments. Dilip Kumar analyses the lake restoration efforts and possible effects of large-scale interventions (such as desilting, creation of jogging paths, etc.) on natural wetland ecosystems, especially in the interest of water birds. In this context some modifications are suggested. As part of the lake restoration efforts, a project is being implemented to convert Madivala lake into a "Wetland System" of sewage treatment, using aquatic plants and their associated microorganisms to cleanse the water. This project includes considerable movement of silt and building of pathways, bunds and islands. Kramer et.al., deal with a 100 ha wetland in an estuary of the capital area of Finland which has gone through major changes in the last decades due to land based and river borne nutrient loads, resulting in unfavourable living conditions for aquatic birds. To fulfill the ecological criteria of dam construction, this paper presents the results of planning scenarios, where alternative pond and brook channels have been designed and controlled by dams with various crest heights. Numerical models are used to assess the impacts of the dredging work on water exchange and level in the wetland. The hydrodynamic model calculates the wetting and drying as well as water exchange due to the sea level variations. A simplified water balance model estimates the long-term impacts of rainfall-runoff, evapotranspiration and infiltration. Saibal De and Cherylann Lobo provide the rehabilitation and ecological restoration package (for Mansagar lake, Jaipur) encompassing sustainable management strategies. Sridar et.al., discuss the need for conservation strategies for sustainable management of lakes in Karnataka. According to the authors, there is a need to quantify and demonstrate the importance of wetlands to halt further degradation and restore them, which require comprehensive policy decisions, management efforts and a strong political will. Jana and Datta-Saha's endeavour on biomanipulation highlight the use of herbivorous fishes in controlling algal bloom (it disturbs oxygen balance, secretes toxins of low molecular weight harmful to many aquatic animals and causes gill clogging of some surface feeding fishes). This paper concludes that silver carp is suitable for cleaning Microcystis in the long term, whereas Tilapia may be used for short-term clearance of Microcystis from small ponds. Kar et.al., discuss the Ichthyospecies diversity in the lotic systems (the rivers in Barak drainage, Mizoram and Tripura) along with their management and conservation aspects. The north and south tributaries of river Barak (North tributaries - Jiri, Chiri, Madhura and Jatinga and south tributaries - Sonai, Rukni, Ghagra, Dhaleswari and Katakahal) field investigations revealed the occurrence of 47 fish species (belonging to 39 genera, 14 families and 6 orders) and 44 species (belonging to 34 genera, 14 families and 6 orders) respectively. While, in the river Surma (a tributary of river Barak after its bifurcation) 21 fish species (belonging to 18 genera, 7 families and 4 orders) were noted. The ichthyological survey in rivers in Tripura (Manu, Khowai, Howrah and Gomati) revealed the occurrence of 20 fish species (belonging to 18 genera, 9 families and 4 orders) and in rivers of Mizoram (Tuirial, Tuirini, Tuivai and Tlawang) 18 species of fish (belonging to 17 genera, 18 families and 3 orders) were noticed. Gopal compares the data on the morphology of the water fern Azolla pinnata R.Br. collected in different seasons from the Kukkarahalli lake (Manasagangotri, University of Mysore campus), with the published morphological accounts on the plant and conclude that parameters such as humidity (85-95% RH), temperature (20-40°C) and pH (5-5.7) influence the growth of the plant. The study highlights the management and usage of this plant in a lake agro-ecosystem for better production of fertiliser, increase in efficiency and productivity, aquaculture, nitrogen fixation, food for poultry, use as antifungal agent and as water purifier. Kar and Barbhuiya discuss the species composition of Aquatic macrophytes (AM), their succession, and phytosociological status in four wetlands of the Barak valley, viz., Barak Nadi Salchapra Anua Beel, Satkarakandi Anua Beel, Ram Nagar Anua Beel and the Chatla Haor. Twenty seven different species of AM were recorded from these wetlands which include five free floating, six rooted floating, three submerged and thirteen emergent species. Chandrashekar et al investigate the two thermal springs - Bendre Thirtha (near Puttur) and Panekal (near Uppinangady) of Dakshina Kannada district, by monitoring parameters such as temperature, pH, dissolved oxygen, sulphur content and aquatic hyphomycetes. The investigation of the effect of temperature and sulphide content on sporulation and growth of fungi revealed the adverse effect of temperature on mycoflora. Studies on the actinomycetes of Panekal spring revealed the presence of facultative sulphur oxidising species. These natural thermal springs form a special ecological niche and emphasise the need for conservation. Madhyastha et.al., highlight the importance of conservation of estuaries and list its functions. Based on field survey results, the problems and need for protection of fragile estuarine ecosystems of Malpe and Gangolli are discussed. The monitoring of these wetlands included phyto and zooplankton along with benthic invertebrate community. Ramakrishna investigates cause for degradation of mangroves in Krishna wetlands and links it to the poor pattern of tidal flushing (in the mangroves) due to the formation of topographically elevated areas (may be due to monsoon floods). In this regard, tidal variation is measured in the creeks adjoining the restoration areas of Sorlagundi and Nakshatranagar. Salinity and temperature variation of the estuarine waters are measured in the area along with the tide for both post monsoon and summer seasons. Krishna talks of removal of nutrients from water entering lakes and tanks to prevent eutrophication by a turnover of floating and emergent vegetation. Krishna also discusses aspects such as necessity for periodic removal and possibility of decomposing aquatic and semi-aquatic vegetation, which return nutrients into the water (in absence of periodic removal). Suggestion includes substituting soft tissue plants with woody vegetation (trees) such as trees from tropical inter tidal and adjacent communities for afforesting inundated and foreshore areas of lakes. Shindikar et.al., quantify solid wastes in Thane creek of Mumbai and discuss impact of non-biodegradable wastes such as plastics, polystyrene, rubber, etc. on mangrove ecosystems. Sathiskumar and Ramachandra review current solid waste management strategies and consequences of improper management in the catchment area. In order to improve the present practice and to avoid environmental degradation, an effort is made to arrive at optimal solid waste management strategy with the help of spatial analysis tools (Geographic Information System). Optimal management of all kinds of wastes is proposed with the attribute information and various layers of spatial information. The proposed management strategy could be replicated in an urban set up of any population size. Mohan and Shreshta's distributed hydrological model with SCS (Soil Conservation Service) and curve number method (CN) assess the hydrological changes due to land use modification (Case study: Kathmandu valley basin, Nepal). Inayathulla et.al. provide one-dimensional finite difference model for transport of contaminants in unsaturated soil medium. This helps in making quantitative predictions on the possible contamination of groundwater supplies resulting from seepage of high salt concentrations in drainage ditches, canals and streams and from groundwater movement through buried wastes. It is also useful for verifying the numerical accuracy of more comprehensive finite element solutions and finite volume solution to the transport equations as well as for investigating some aspect of the transport process in porous media, which has a distance dependent dispersion function of the described form. Ramada et.al., highlight the effect of desilting on fluorosis concentration in Bagepalli taluk of Kolar district, Karnataka. The decreased concentration of flouride and also increase in the groundwater table were noticed after desiltation of the tank near Pathapalaya village. Hosmani and Vasanth Kumar report on the pollution load of Kukkarahalli and Dalvoi lakes of Mysore city based on physico-chemical and biochemical analyses. Both the lakes were productive, in terms of biochemical products (Kukkarahalli lake) and plankton productivity (Dalvoi lake). These lakes have comparatively high electrolytes, low dissolved oxygen, while phosphate and nitrogen content are relatively high and show a quantitative abundance of plankton blooms turning the water highly eutrophic. Exploitation of polluted waters rich in algal biomass for biotechnological products. Yamuna and Balasubramanian's study highlights the quality of water analysed with reference to various physico-chemical parameters in selected lakes of Mysore District, Karnataka. The lakes are found to be under the influence of nitrate, pH, chloride, Total dissolved solids (TDS), calcium and magnesium. In many samples, two or more parameters have been reported above the permissible limit of drinking water. The conservation measures for maintaining the quality of water in these lakes have been discussed. Sudhira and Kumar analyse the uptake of heavy metals in water hyacinth in Kukkarahalli lake in Mysore city. They emphasise on some characteristic parameters as well as the need for sensitising citizens about these activities. The influence of initial metal concentration on growth of plants for all metals reached a saturation concentration at 12 mg/l. Of all the heavy metals, nickel was found to be more toxic. The mature plants were highly resistant to increased metal concentrations than young plants. The young plants could not sustain the increased metal concentrations. The study demonstrates the possible use of water hyacinth for removal of heavy metals from wastewater. Madhyastha, et al. discuss the importance of temporary ponds. Despite their temporary nature, they support diverse biota both during wet and dry seasons. They cater immensely to the village population by meeting their immediate water demands. These small ponds are utilized for a variety of human activities like drinking, irrigation, recreation, and fishing and for dumping agricultural and domestic wastes. The study discusses the need for conserving these ecosystems. Rajinikanth and Ramachandra identify and analyse the qualitative and quantitative impact of urbanization on wetlands based on investigations of various physico-chemical and biological parameters and socio-economic aspects in Rachenahalli and Amruthalli lakes catchment. Geographical Information System (GIS) was used for spatial and temporal assessment, which helped in identifying and monitoring the impacts due to point and non-point pollutant sources. Integration of water quality and quantity with socio-economic information has aided in prediction and appropriate conservation of these two lakes. Shreekantha and Narayana present an impact of anthropogenic activities in the watershed area of Bellandur tank, Bangalore. Based on levels of various physico chemical parameters, Bellandur lake was considered eutrophic. Authors have given feasible suggestions for the restoration of the lake. Ranjani and Ramachandra propose best management practices for conservation and management of lakes based on detailed investigations undertaken in Hebbal catchment to assess its characteristics, bathymetric and physico-chemical aspects. Chakrapani's paper attempts to bring out aspects regarding the Madivala lake's ecological status, and changes observed over time and lists suggestions to improve this habitat, progression of events/efforts on this count including action initiated/ongoing etc. Rathore and Pattusamy report the status of Ulsoor lake based on the water quality (various physico-chemical parameters) investigations carried out during 12 months and provide suitable suggestions. Mohan and Ramani Bai list different techniques for estimating the groundwater potential and their suitability considering practical utility. Mahadeshwara et. al., discuss the chemical analysis of groundwater collected from the region surrounding Yelandur tank of Chamrajnagar district, Karnataka. This study links the deterioration of groundwater quality due to tank's poor status on account of anthropogenic stress. Suraj Kumar and Manoj Kumar show the variation of nitrates and total dissolved solids in the tail reach drain area of an agricultural field (near Mandakalli lake in Mysore district) and also discuss the quality of groundwater near these fields. Prasanna Kumar and Nagaraju discuss the quality of groundwater in and around Pandavapura town, Mandya district, Karnataka. Amitha Kommadath reviews various methods of estimating natural ground water recharge with regard to their limitations and associated uncertainties. Sivaramakrishnan lists rapid bioassessment protocols as practical technical references for conducting cost-effective yet scientifically valid biological monitoring programme. Reports based on these protocols can easily be translated to management employing environmentally benign procedures. Several biological communities including plankton, periphyton, microphytobenthos, macrozoobenthos, aquatic macrophytes and fish have been considered in assessment of stream and river water quality. Kar et.al., discuss about Epizootic Ulcerative Syndrome (EUS), which has contributed to large-scale fish mortality since 1988 affecting four species of fishes initially. The histopathological studies revealed focal areas of fatty degeneration of hepatocytes surrounding the portal triads in the liver. According to this study, sick fishes show low haemoglobin and polymorph, but high ESR and lymphocytes. Bacterial culture revealed occurrence of haemolytic E. Coli, Aeromonas hydrophila, Pseudomonas aeruginosa, Klebsiella sp., and Staphylococcus epidermitis in the surface lesions as well as in the gut, liver, gills, heart, kidney and gonads of sick fishes, all of which are sensitive to Chloramphenicol, Septran, Gentamycin, etc Venkataramaiah Jagannatha compiles Environmental Sound Technologies (ESTs) for the conservation and management of a lake, having the potential for significantly improved environmental performances relative to other technologies. Meenambal et al., list various lake restoration methods. They suggest that diverting the effluents and subsequent treatment, as an effective reclamation technique. This water can be used for various purposes. Jayanthi et al., compile practical ways of approaching accounting and reporting for sustainability. Practical options at every stage are proposed so that any organization could adopt and apply a reporting system for sustainability. We thank all active participants for their views, suggestions, ideas, dialogues, and arguments, which contributed to the success of Lake 2000. Posters and papers presented by the participants will go a long way in establishing a better future for these fragile ecosystems and their sustainable management. Lake 2000 was a platform for all stakeholders especially researchers, scientists, government agencies, teachers, students, planners and decision makers who interacted and shared experiences and knowledge on wetlands and lakes. We firmly believe recommendations by this august body will lay a strong foundation for watershed restoration efforts in the days to come.
All efforts have been taken to ensure this proceedings free of any error. Editors are responsible for all errors and omissions that remain.
Ramachandra ,
Raj Murthy and Ahalya
|
