Ecologically sensitive areas and environmental management in Tamilnadu coast

Indian Coastline

The Indian coastline stretches about 5700 km on the mainland and about 7500 km including the two island territories and exhibits most of the known geomorphological features of coastal zones. Presently, Indian coastline is facing increasing human pressures e.g., overexploitation of marine resources, dumping of industrial and toxic wastes, oil spills and leaks which have resulted in substantial damage to its ecosystems. India has been identified as one amongst 27 countries which are most vulnerable to the impacts of global warming related accelerated sea level rise (UNEP, 1989).

The high degree of vulnerability of Indian coasts can be mainly attributed to extensive low-lying coastal area, high population density, frequent occurrence of cyclones and storms, high rate of coastal environmental degradation on account of pollution and non-sustainable development. Most of the people residing in coastal zones are directly dependent on natural resource bases of coastal ecosystems. Any change in frequency, intensity or tracks of cyclones, sea level rise and/ or natural hazards may aggravate the potential risks to coastal zones. Therefore an in-depth investigation and analysis will be made to assess the vulnerability of various sectors of coastal zones of Tamil Nadu to the impacts of natural hazards such as tsunami, cyclones, floods and suggestions on strategies and adaptation measures will be provided.


Coastline of Tamil Nadu

Tamil Nadu, the southernmost state of the Indian peninsula , is spread over 130,058 km2; it lies between 8° 5" to 13° 35" N and 76° 15" to 80° 20" E, accounts for about 4% of the total area of the country. The coastal environment plays a vital role in nation's economy by virtue of the resources, productive habitats and rich biodiversity. India has a coastline of about 7,500 km. The coastline of Tamil Nadu has a length of about 1076 km constitutes about 15% of the total coastal length of India and stretches along the Bay of Bengal, Indian Ocean and Arabian Sea. The Tamil Nadu coast is straight and narrow without many indentations except at Vedaranyam. Fringing and patch reefs are present near Rameswaram and Gulf of Mannar, Pitchavaram, Vedaranyam and Point Calimere have well developed mangrove systems.

In Tamil Nadu about 46 rivers drain into Bay of Bengal forming several estuaries adjoining coastal lagoons. The Cauvery River and its tributaries form a large delta supporting extensive agriculture. The other landforms of the Tamil Nadu coast are rock outcrops of Kanyakumari, mudflats, beaches, spits, coastal dunes and strand features. Deposition is observed at Point Calimere, Nagapattinam, South Madras, etc., while erosion is reported at Ovari Paravarnattam, Mahabalipuram and North Madras near Ennore. Rich deposits of heavy minerals are available in Muttam- Manavalakuruchi coast. The southern tip is also known for the Tera sands.

The areas that are ecologically sensitive and the geomorphological features which play a role in the maintaining the integrity of the coast,

·        Mangroves, in case mangrove area is more than 1000 sq mts, a buffer area of 50meters shall be provided

·        Corals and coral reefs and associated biodiversity

·        Sand Dunes

·        Mudflats which are biologically active

·        National parks, marine parks, sanctuaries, reserve forests, wildlife habitats and other protected areas under the provisions of Wild Life (Protection) Act, 1972 (53 of 1972), the Forest (Conservation) Act, 1980 (69 of 1980) or Environment (Protection) Act, 1986 (29 of 1986); including Biosphere Reserves

·        Salt Marshes

·        Turtle nesting grounds

·        Horse shoe crabs habitats

·        Sea grass beds

·        Nesting grounds of birds

·        Areas or structures of archaeological importance and heritage sites.


Satellite view of Tamilnadu





Aim of the project

To develop comprehensive coastal information for ecologically sensitive areas, identify the vulnerabilities and to suggest coastal protection measures for the State of Tamil Nadu.

Objectives of the project

The primary objectives of the project include to:


·        Identify the ecologically sensitive areas and environmental hotspots along the Tamil Nadu coast

·        Apply and develop methods that reflect changes in value resulting from uses of marine and coastal areas, including pollution, marine erosion, loss of resources and habitat destruction;

·        Provide for an integrated policy and decision-making process to promote compatibility and a balance of uses

·              Identify existing and projected uses of coastal areas and their interactions


 Pichavaram Mangrove Ecosystem Mapping

            The Pichavaram mangrove (Lat. 11º 26’ N; 79º 48’ E) near Parangipettai, is situated on the Southeast coast of the peninsular India and represents a heterogenous mixture of mangrove plants. It lies between the Northern Vellar and Southern Coleroon estuarine systems and along with Killai lagoon, is referred to as the Vellar Coleroon estuarine complex. The mangrove region covering an area of approximately 12km2, represented by 51 islets, waterways, channels, gullies and rivulets and account for 40% of the total area of the mangrove, of this 50% is forest and the remaining consists of mud flats and sandy plains. This ecosystem is well known for its luxuriant growth of mangrove plants with high productivity and diversity of fauna and provided with rich detritus, nutrient salts, trace elements etc.




Mangrove Area in Sq.Km

Dense Mangrove


Sparse Mangrove


Open Mangrove


Total Area






The Muthupet mangroves are located (10°25’N and 79°30’E) in the southernmost end of the Cauvery delta in the districts of Nagapattinam, Thiruvarur and Thanjavur.  Muthupet mangroves cover an area of about 13,000 ha of which 1,200 ha is forest cover (Forest Survey of India, 1999).  It is part of a large coastal wetland complex called the Great Vedaranyam Swamp.  These mangroves are subjected to a variety of anthropogenic inputs including aquaculture (shrimp farming effluent) and more diffuse and seasonal agricultural runoff. The quantity and duration of the freshwater inflow into the Muthupet mangrove wetland has reduced over the years due to the construction of dams and barriers in the upstream area, resulting in increased annual average salinity of both water and soil.  Currently, the Muthupet mangrove wetland is managed by the Tamil Nadu Forest Department under the supervision of the Wildlife Warden, Nagapattinam. 





Mangrove Area in Sq.Km


Dense Mangrove


Sparse Mangrove


Open Mangrove


Degraded Mangrove


Total Area








The district of Thoothukudi is situated in the extreme south-eastern corner of Tamil Nadu state. It is bounded on the north by the districts of Tirunelveli, Virudhunagar and Ramanathapuram, on the east and south-east by Gulf of Mannar and on the west and south-west by the district of Tirunelveli.  Total area of this district is 4621 sq. km. and the administrative headquarters is an urban agglomeration and also one of the taluk headquarters within the district.


The Reclamation for the construction of major harbours, the stretches of mangrove swamps and the Isthmus connecting Pandian tivu have been lost. With this, the entire flora of Pandian tivu, sizeable community of variety of crabs, air breathing fishes, Pechia sp., and other related sedentary coelenterates, polychaetes, nudibranchs, solen, anadara, arca, cardium, meretrix, onchidium and the land mammals like hares and deer have been lost. The local Scylla crab fishing too has been reduced to oblivion because of the loss of breeding ground. The Pandian tivu had also been the breeding ground for the Indian tern Chlidnoias hybrida, Kadal kuruvi and Kentish plover (Charadrius alexandrinus, Kottan).

The mangroves once present in the stuaries of Vaipar and Vembar have been lost. The mangal present in the estuaries of Tambiraparani river too had been replaced extensively by salt pans.The traditional shore seine, stake net, cast net and trap fishermen who earlier used to get good catch of fishes now harvest only small catches, in size and quantity. Therefore many jhave abandoned the vocation. Therefore it is advised that a moratorium on new existing salt pans be imposed. This will enable conservation of the remaining mangal and coastal vegetation associated with flora and fauna.

Tuticorin Group of Islands

The Tuticorin group consists of four islands, one of, which is submerged. Reef patches exist all around the islands. The islands have sparse vegetation. Twenty three species of corals, 11 species of seagrass and 3 species of mangroves and associated species are found in the Tuticorin group of islands.Live corals are found beyond 0.5 m depth. Maximum number of live coral points around Karaichalli Island. Corals reef are around the islands is about 10 Sq. Km and seagrass covers an area of about 10 Sq. Km.



Mangrove Area in Sq.Km

Dense Mangrove


Sparse Mangrove










 Coral Reef in Gulf of Mannar

Reefs in the Gulf of Mannar are found around a string of 21 islands, 8 km off the southeast coast of India. The 3 island groups (Mandapam, Keelakari and Tuticorin) form the ‘Pamban to Tuticorin barrier reef’, which contains fringing, platform, patch and barrier reefs. Narrow fringing reefs surround the islands extending 100 m from the shore. Patch reefs are also found and are typically 1-2 km long, 50 m wide and 2 to 9 m deep. Reef flats are extensive on all islands. The total area includes approximately 65 km of reef flat and 14km of algal growth. The major economic activities are fishing, coral mining for construction, harvesting of sacred chanks (Turbinella pyrum), sea cucumber, pipefishes, sea horses and seaweeds.

            Average live coral cover around the 21 islands in the Gulf of Mannar is 35%, a slight increase over the past 5 years. The highest coral cover occurs in the Keezhakkarai island group (44%) and the lowest in the Tuticorin Group (29%): 117 coral species were recorded in the area in 2005, including 13 new records. Habitat structures, in particular live corals, play a major role in enhancing fish diversity and 50 reef-associated fish species in 27 families were observed in 2005.


Classification of  Corals

Area in Sq.Kms









Gulf of Mannar – Coral Reefs





Future plans

 We plan to create the environmental planning for the ecologically sensitive area, such as Sand Dunes, Mudflats, National parks, marine parks, sanctuaries, reserve forests, wildlife habitats and other protected areas including Biosphere Reserves, Salt Marshes, Turtle nesting grounds, Horse shoe crabs habitats, Sea grass beds, nesting grounds of birds Areas and structures of archaeological importance and heritage sites.

  • To prepare a report on the status of existing land use and land capability assessment for the coast
  • To prepare an inter-sectoral environmental study report with coastal vulnerability maps in 1:5000 scale
  • Preparation of special area management plan
  • Suggest coastal protection measures for the entire coast of Tamil Nadu.