WHAT REMAINS: The remnant of Koyembedu wetland. â€” Photo: K. Pichumani
CHENNAI : Chennai and its suburbs once boasted of over 100 small and big waterbodies. A majority of them have been gradually destroyed due to a combination of hectic urbanisation and anthropogenic interferences.
The city's important waterbodies include the Adyar Estuary, Adambakkam lake, Ambattur lake, Chitlapakkam lake, Ennore creek, Korattur swamp, Koyambedu marshland, Madhavaram and Manali jheels, Pulicat lake and Vyasarpadi Lake besides Buckingham Canal, Cooum and Adyar Rivers and Otteri Nullah.
The wetlands played important roles as groundwater recharging units, natural drain-off mechanisms during monsoon and natural habitat for fish, birds and other aquatic life, said K. V. Sudhakar, secretary, Madras Naturalists Society.
The wetlands are also a haven for bird-watchers and ornithologists. For instance, the Adyar estuary once attracted more than 100 species of birds. Even the doyen of Indian Ornithology, the late Dr. Salim Ali, had stressed the need for protecting the creek not only for the sake of birds but also for the benefit of human beings. Sadly, only a small portion survives today and inlet and outlet channels for seawater have been clogged, Mr. Sudhakar said.
Another classic example is the slow disappearance of Manali jheel ecosystem on the northern fringes of the city. V.Guruswamy, a naturalist overseeing winged visitors at both Madhavaram and Manali jheels, said activities such as release of untreated effluents, drainage water, poaching and illegal creation of a graveyard had reduced the actual jheel area to a great extent.
In Madhavaram jheel, effluents from a nearby government dairy unit are being systematically released into the southern end, unleashing chaos on the aquatic life. The situation is no better in the northern portions of the jheel, laments Mr. Guruswamy. A tomb erected illegally some time ago for a union leader has set a bad precedent with more and more people using the place to bury or burn dead bodies. Now a compound wall has been constructed around the burial site.
In Mr Guruswamy's assessment, failing drastic salvage efforts, the chances of the Manali jheel surviving are slim. He suggests strengthening the embankment, controlling poaching, suspending the release of drainage and prohibiting cattle grazing. Enlisting local support through awareness initiatives was also imperative for any conservation effort to succeed, he said.
The cascading effect of man-made devastation has had an impact of the avifauna population. With the jheels reeling under severe disturbances, the bird population at the Simpsons factory in Sembium has come down drastically. A total of 53 species of wetland and wetland-oriented birds were reported at the jheels until recently, he said.
Naturalists pointed out that the last wetland that died on the pedestal of development was the Koyambedu marshland. About 15 years ago the area used to have a lot of wild growth attracting a large number of birds. During monsoon, rainwater used to get stored in the marsh and it helped in maintaining the groundwater table in the western parts of the city. A few years ago, the marshland was taken over by the Government for housing the vegetable and fruit markets and bus terminus.