Wetlands

South Chennai

Bio-Diversity

Flora

Wetland plants being Hydrophytes are very well adapted to changing water conditions, high salt and low oxygen environment. This leads to a unique range of adaptations to survive and exploit this wetland environment.  The most obvious being structural, concerned especially with the problem of supplying oxygen to the roots growing in the anaerobic (oxygen-deficient) soil sediments.  Most aquatic plants such as water lilies (pontederiacceae family) are extremely porus and contain special tissue, called aerenchyma, which has large, air filled inter circular spaces.  Oxygen diffuses thousand of times faster in air compared to water, and so the aerenchyma are thought to facilitate the movement of oxygen from the leaves to the root like rhizomes.  Roots are partly or wholly submerged in water and are poorly or not at all branched.  In some cases, they are altogether absent (ceratophyllum).  The floating leaves bear stomata on the upper surface only, which has a waxy coating that prevents wetting and clogging of stomata.

These adaptable plants are categorised into three sections. a. Emergent Plants b. Hygrophytes. c. Surface Floaters and Submerged Plants

Fauna

 Compared to flora, the bio-diversity of fauna is very low. This is due to its extinction from high pollution levels.  Low Faunal presence indicates that advanced stages of wetland degradation.  Some species are exterminated, some others mutate while others just migrate. Avian Fauna: Wetlands all over the worlds act as a wintering spot for many migratory fowls.  Much of our knowledge of wetlands as habitat has been derived from the study of birds (Daniel. R.J.R., 1998).  In all 63 species of birds were found in and around the wetland area.  The number of the birds is expected to rise following the monsoons. The most dominant species is the Indian Moorhen (Gallinula Chloropsus).  This bird is found only in small number in Vedanthangal, a bird sanctuary situated about 50 km from Chennai.  These wetlands serves as an ideal habitat for this species because of the Typha, a type of tall grass which provides it with the food required and material to build its nest.

Socio-Economic Layer

The study area shows a distinct composite environment of the rural and urban confluence. The Velachery, which was a village in 1964, is today a bustling urban suburb with all the basic amenities of the metropolis and more, while the others are still in the same mould. Of the total ten villages in the study area, Velachery and Taramani are total urban locales today, while Perungudi is a town Panchayat with both Perungudi and Seevaram villages within its fold and Medavakkam is also another progressive village that is almost a town toady with its proximity to Tambaram. Pallikaranai, Jalladempettai and Okkiyam Thoraipakkam continue to be in the rural flavour. Inference: That we are losing the wetland would be an understatement.  Over the years, the data collected shows that the region has seen widespread changes with the development of Industries and Educational Institutions

Urban Sprawl

The region has seen rapid growth in the recent past as is evident from the satellite imagery and the latest maps. In all the villages, the field visits proved that the people have shifted from the traditional mode of life to the newer forms of urban life as is evident from the house types and the standard of living of the people. The regions bordering the wetland are inhabited now in sharp contrast to the 1960s or the 1970s maps where most of these areas had scattered settlements. Today the settlements are linear along the arterial roads and all around the water bodies. There are two reasons for this trend:

1. The Government’s initiative of rehabilitation of the slum dwellers of the city as is evident in the case of the Mylai-Balaji Nagar (Slum dwellers from Mylapore evicted in the course of the MRTS construction) and the slum relocation drives by the Corporation and the Govt. in the Okkiyam Thoraipakkam region.

2. Lack of initiative on part of the Government and cohesive action among the authorities.

The study attained a startling information after field visits that due to the sustained encroachments of these wetlands almost a total of 273.560ha had been taken up for various pseudo Developmental work till May 2002.

Save the Wetlands

Solid Waste / Remote Sensing & GIS Analysis