Value of Lake Ecosystem in the context of. Bangalore

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1 Value of Lake Ecosystem in the context of avian biodiversity in the lakes of North Bangalore Harish R. Bhat #$, Manjunath P *, Pramod Subbarao $ # Centre for Ecological Sciences, Indian Institute of Science, Bangalore 12, harishrbhat@gmail.com Green Cross #173 4th Cross 4th Main NGEF Layout RMV II Stage Bangalore - Green Cross, #173, 4th Cross, 4th Main, NGEF Layout, RMV II Stage, Bangalore - 94 $ Asima Prathishtana, # 2863, 'Srinrukesari', Officers' Model Colony, S M Road, T Dasarahalli, Bangalore 57

2 Introduction Lakes are often regarded as the most important component of a wetland ecosystem. Though in the past these areas were considered unproductive and unhealthy wastelands They are not only a source of food and water to the numerous communities dependent on them for subsistence but are also of immense importance by rendering several goods and services Over the years, they have gradually depleted, leading to a number of problems in urban areas such as flooding, water scarcity and water logging Bangalore had 272 lakes but their rapid degradation over the last three decades has left only 119 lakes, of which only 70 are in good condition In spite of these, there are quite good number of winged visitors arriving ing to most of these tanks during winter

3 Method Eleven lakes of North Bangalore had been identified for study and monitored since 2001 Census was being conducted one time of a year (in January) at the respective lakes between 7 am and 10 am using block count method The numbers of these birds were documented to understand the population dynamics Questionnaire based interview and group discussion with the stake holders residing at the peripheral areas of the lake to understand the value of the ecosystem

4 Eleven Lakes of North Bangalore Doddatumkur, Hebbal, Hesaraghatta, Jakkur, Kolathur, Madhurekere, Doddatumkur, Hebbal, Hesaraghatta, Jakkur, Kolathur, Madhurekere, Nagavara, Puttenahalli, Singanayanahalli and Yelahanka

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7 Hesarghatta Lake

8 Water Birds id Bar-headed Goose Greater Flamingoes

9 Water birds Sandpipers Little Egret Pond Heron River Tern Purple Heron Open-billed Stork Cattle Egret

10 Result and Discussion 2001 the water birds were in good number in all the lakes as they were with sufficient water and good fish population Hesaraghatta lake-more than 2000 water birds belonging to 29 sp. Totally more than 5000 birds of 42 species were documented each Totally more than 5000 birds of 42 species were documented each year from all the 11 tanks of north Bangalore

11 Result and Discussion 2004, due to acute drought, 7 of these 11 lakes were totally dried up The winged visitors had to be dependent on the remaining 4 tanks (Puttenahalli, Nagavara, Madhure Kere and Hebbal) Nagavara Tank was dry owing to the desiltation programme f Hesaraghatta Tank, which was having good amount of water in 2003 housing a lot of birds was completely dry

12 Result and Discussion 2005 was fair enough for the birds as the tank condition was better with sufficient water, and thus getting back most of the birds but Kolathur and Singanayakanahalli lakes had fully dried up 59 species birds totaling to 2331 number from the nine lakes of North Bangalore Hebbal and Nagavara lake privatised to Oberoi and Lumbini

13 Result and Discussion 2006 proved much better with respect to avian diversity totaling to 50 species of birds with 4533 individuals, but 3 lakes were completely dry 2007, the survey reveals that, 49 species of birds totaling to 1068 individuals were documented. Most of the lakes had little water except one lake (Budigere Lake) which had totally dried up 2008 proved quite better as all the sampled lakes had water and 1506 individuals of 44 species birds were documented Among all the lakes, Jakkur, Hesaraghatta, Puttenahalli, Madhurekere proved to be the haven for water birds - water level and other important components of the ecosystem were not much disturbed - harbouring many migrants and also providing space for many endangered birds (Darter) to breed

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15 Result and Discussion Spot-billed Pelicans roosting and preying is being observed at Hebbal Lake since a year But the pelican-contractor conflict arises Thus the contractor chases away the pelicans to safe guard his investment, depriving food for pelicans. These large birds depending only on fish travel several distance for food and shelter rarely come across good habitat in the urban areas

16 pelican-contractor conflict

17 Result and Discussion Stake holders depending on the lake ecosystem (farmers, seasonal fishermen, and village residents at the vicinity, shepherds, cattle owners and weed collectors) well aware of the ecosystem value Resident villagers - water table around the lake was greatly dependent on the condition of the lake Fishermen - high values for lakes as fish was their main source of income Shepherds, cattle owners and weed collectors - partial source of income Farmers were mostly dependent on the lakes once upon a time for irrigating their fields, have shifted to other source of water due to the shrinking of lakes and very poor water quantity

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19 Result and Discussion values ascribed by all stake holders were in terms of the ecosystem services apart from their livelihood, which could be quantified in terms of the loss incurred after the status of lakes deteriorated Unfortunately many of the lakes, though appears good is Unfortunately many of the lakes, though appears good is not qualifying in terms of the ecosystem services rendered due to anthropogenic problems such as encroachments, landscape transformation, alteration of the catchment area, pollution due to sewage inundation

20 Problems All the major ecosystems like rivers, lakes, agro-ecosystems facing tremendous anthropogenic pressure resulting in lake ecosystem erosion This erosion is due to the following environmental problems, namely: (a) Non-sustainable (uncontrolled and depleting method) harvests of living resources (b) Habitat destruction, transformation and fragmentation (c) Rapid Urbanization (d) Impacts of pollutants (e) Competition with colonizing, often exotic, invasive species

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26 Recommendations: Sustainable periodical de-weeding of water hyacinth (only at the central portion of the lake) to be carried on war-footing basis in avian rich lakes, providing nesting grounds by retaining aquatic weeds at the peripheral region of the lake Constant patrolling by forest department in all the lakes to regulate the poaching of birds and provide protection. Eg: Hesaraghatta, Puttenahalli, Madhurekere, etc Clear all encroachments in and around the lakes. Protect the lake and its vicinity from further encroachment by fencing

27 Recommendations: Clear the encroached areas by providing the alternatives and make the water draining gpoints free from disturbance Re-trace the water draining pathways, map them and integrate the lost links Alternative measures to check the inflow of effluents and set up a sewage treatment plant after estimating the exact inflow and also planning for long term

28 Recommendations: Afforestation programme to be taken by planting native species such as Tamarind, Pongamia, Neem, Figs, Mango, Jamoon etc at the lake boundaries and also on the lost lake beds to restore temporary water charging areas Regulate boating hours and the area covered by the boats during monsoon and winter at all lakes as most of the birds breed during this season Respective department(s) to compensate the investment of the fishermen/contractor in order to provide food source for Pelicans, Ex, Hebbal Lake

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30 Some of the migratory and resident birds Bar-headed Goose (Anser indicus) Brahminy Shelduck (Tadorna ferruginea) Northern Shoveller (Anas clypeata) Northern Pintail (Anas acuta) Garganey (Anas querquedula) Common Pochard (Aythya ferina) Marsh Sandpiper (Tringa stagnatilis) Common Greenshank (Tringa nebularia) Wood Sandpiper (Tringa glareola) Common Sandpiper (Actitis hypoleucos) Darter (Anhinga melanogaster) Great Cormorant (Phalacrocorax carbo) Spot-billed Pelican (Pelecanus philippensis) i Painted Stork (Mycteria leucocephala) Asian Openbill Stork (Anastomus oscitans) White-necked Stork (Ciconia episcopus) p