Indian Turtles, Its status and Conservation

Kiran Rasal; Avinash Rasal,Prabhakar Nikumbe, Sachin Khairnar*, Amod Salgaokar,Trivesh Mayekar, Pankaj patil**, Roshan Akhade**

Central Institute of Fisheries Education, Mumbai 400 061

*Fishery Survey of India, Mumbai

**College of fisheries, Shirgaon, Ratnagiri, Maharashtra.

Correponding Author- kirancife@gmail.com

 

 

Introduction

Indian turtle, along with tortoise and terrapin, belongs to the Testudines order of reptiles and the Chelonia crown group. The body of a turtle is covered with special bony or cartilaginous shell, which is developed from its ribs. One of the oldest reptile groups, the turtle of India was in existence even before lizards and snakes. Some of the species of the Indian turtles have become extinct, while a number of others have become highly endangered. Turtles are cold-blooded creatures i.e., their body temperature changes with their surroundings. The size of an Indian turtle tends to vary a lot, with marine turtles being bigger than land and freshwater.

 

Kingdom:	Animalia
Class :	Sauropsida
Order :	Testudines
Suborders :	Cryptodira and Pleurodira

 

Types of Indian Turtles

• Olive Ridley Turtle (Lepidochelys olivacea)
• Green Sea Turtle (Chelonia mydas)
• Hawksbill Turtle (Eretmochelys imbricate)
• Leathery Turtle (Dermochelys coriacea)
• Eastern Mud turtle (Kinosternun subrubum subrubum)

Life history

Although many turtles spend large amounts of their lives underwater, all turtles and tortoises breathe air, and must surface at regular intervals to refill their lungs. They can also spend much of their lives on dry land. Aquatic respiration in Australian freshwater turtles is currently being studied. Some species have large cloacal cavities that are lined with many finger-like projections. These projections, called "papillae", have a rich blood supply, and increase the surface area of the cloaca. The turtles can take up dissolved oxygen from the water using these papillae, in much the same way that fish use gills to respire.

Turtles lay eggs, like other reptiles, which are slightly soft and leathery. The eggs of the largest species are spherical, while the eggs of the rest are elongated. Their albumen is white and contains a different protein than bird eggs, such that it will not coagulate when cooked. Turtle eggs prepared to eat consist mainly of yolk. In some species, temperature determines whether an egg develops into a male or a female: a higher temperature causes a female; a lower temperature causes a male. Large numbers of eggs are deposited in holes dug into mud or sand. They are then covered and left to incubate by themselves. When the turtles hatch, they squirm their way to the surface and head toward the water. There are no known species in which the mother cares for the young.

Sea turtles lay their eggs on dry, sandy beaches. Immature sea turtles are not cared for by the adults. Most are endangered largely as a result of beach development and over harvesting. Turtles can take many years to reach breeding age, and in many cases breed every few years rather than annually.

            Researchers have recently discovered a turtle's organs do not gradually break down or become less efficient over time, unlike most other animals. It was found that the liver, lungs and kidneys of a centenarian turtle are virtually indistinguishable from those of its immature counterpart. This has inspired genetic researchers to begin examining the turtle genome for longevity genes.

 

Current Status of turtle species in India

Although legal protection given to all sea turtle species in India, in recent years the populations migrating to Indian waters are on the decline. Several thousand adult breeding individuals die every year along the Indian coastline, and have become a major concern of national and international community (Pandav et al. 1997, Pandav & Choudhury 1999). The repercussions of such large scale mortality of a globally migratory species group has had its reflection at the WTO, where India contested a ban that was imposed by the USA on the export of marine products caught with gear that did not address sea turtle mortality.

Location	Species Recorded	Confirmed Nesting	Known nesting beaches
West Coast (Gujarat,  Maharashtra, Goa, Karnataka and Kerala	Green, Olive ridley and Leatherback	Olive ridley and Green	Gujarat: Mandvi in Kutch, Sea beach between Okay and Okha Madhi, Bhaidar, Beyt, Nora and Chank Islands. Maharashtra: Olive ridley nest near Gorai, Kihim, Manowrie and Versova.
East Coast (West Bengal, Orissa, Andhra Pradesh and Tamil Nadu)	Olive ridley, Green, Hawksbill, Leatherback and Loggerhead	Olive ridley	Tamil Nadu: Nest in Gulf of Mannar, Point Calimere, and 50 km coastline south of Madras. Andhra Pradesh: Kakinada coast, sea beach near the mouth of Godavari and Krishna and near Visakhapattanam. Orissa: All along the coast south of Dhamra river mouth. Two mass nesting beaches at Gahirmatha and Rushikulya. West Bengal: In the sandy beaches of Sunderbans.
Islands (Andaman & Nicobar Islands and Lakshadweep)	Olive ridley, Green Leatherback, Hawksbill and Loggerhead	Olive ridley, Green, Hawksbill and Leatherback	Great Nicobar, Little Andaman, Rutland, Middle Andaman, Katchal, South Sentinel, south Reef and Teris Islands

Table I: Nesting sites for sea turtles in India

 

The small-scale research, conservation and management of sea turtles in India, which dates back to the mid 1970's, culminated in the mid 1980's with the active participation of the Indian Coast Guard and Navy in sea turtle protection. However, sea turtles, which spend almost six months each year along the Indian coastline, face a multitude of problems in need of address. The major problems that sea turtles face in Indian coastline include:

1. Non-human predation: A significant proportion of nests are subjected to heavy predation. Studies on the population dynamics of the Olive ridley at Gahirmatha rookery, along northern Orissa coast, have indicated that a large percentage of eggs laid during each nesting season are destroyed (Dash & Kar 1990). This results from destruction of nests by other females during an arribada, nest destruction by wild pigs, jackals, and feral dogs, and by beach erosion (Pandav et al. 1994). Feral dogs and wild pigs cause considerable damage to the nests of Leatherback, Green and Hawksbill turtles in Andaman (Bhaskar 1993).

2 .Incidental capture in fishing nets: Near-shore mechanized fishing within 5 km from the shoreline results in the mortality of large numbers of sea turtles along the Indian coast every year. More than 5,000 dead Olive ridley sea turtles were counted along 480 km of the Orissa coast during a six month survey in 1994 (Pandav et al. 1994). The ongoing research programme of the Wildlife Institute of India (WII) documents a three-fold increase in this number during 1997-98 along the same stretch. These deaths were due to accidental capture in trawl nets, although details of the incidental capture of marine turtles in fishing nets along rest part of Indian coast are yet to be documented.

3 Loss of nesting habitats: Development activities close to the coast such as construction of roads, tourist resorts and aquaculture projects result in the loss of nesting habitats. Besides this, plantations of Casuarina close to some of the major sea turtle nesting beaches has resulted in a drastic decline of the nesting population. The plantations reduce the space available for sea turtles to nest, and once the Casuarina grows it changes the beach topography with its lifter deposition and root growth, rendering the beach unsuitable for turtles nesting (Pandav et al. 1994). Further, legislation which is supposed to protect nesting sites of turtles and other marine life does not include sites presently and historically known as breeding grounds. There are no legal guidelines for discussion among concerned authorities and local villagers to develop a more suitable non- forested coastal area protection program.

4      Artificial illumination: Many of the major sea turtle nesting beaches are now subjected to bright illumination. Artificial illumination from development activities near nesting beaches has resulted in disorienting adult nesting sea turtles as well as hatchlings, leading to heavy hatchling mortality (Pandav et al 1998).

Olive ridley turtle

The olive ridley sea turtle nests at several sites in the western Indian Ocean, Indian subcontinent and Southeast Asia. The single most important breeding area for olive ridleys in the Indian Ocean along the Bay of Bengal is Orissa. The Olive ridley is the most numerous among the sea turtles found in India and is well known for its arribadas, or annual mass nestings when thousands of turtles migrate to the breeding ground to nest simultaneously. Of the few such mass nesting beaches left in the world today where arribadas occur, India has three. A significant proportion of world's Olive ridley population migrate every winter to the Indian coastal waters to nest on these beaches in Orissa, as well as along other parts of Indian coast

In 1993, biologists from the Orissa Forest Department and the Wildlife Institute of India learned that large scale nesting of olive ridley turtles was taking place near the mouth of the Rushikulya river. This area is the location of one of the largest mass nesting (arribada) sites of olive ridley sea turtles in India.

 

The conservation agenda of Project Sea Turtle, Government of India

The 8129 km coastline of India, with its high human population density and their utilization of the diverse marine and coastal resources makes it difficult to develop a conservation management strategy for sea turtles. The Indian Wild Life Protection Act (1972), Amendment 2002, has a provision of declaring certain wildlife areas as Community Reserve (CR). However, in light of the fact that the Indian coastal environment harbors almost 30-40 % of world's Olive ridley sea turtle population, the Government of India has launched PROJECT SEA TURTLE at a national level. The main objectives of the project are to:

1. Prepare an inventory map of breeding sites, both verified and others to be surveyed along the Indian coasts. These areas would be placed under CRZ-I categories, accordingly in State and UT Government's CRZ plans and maps.
2. Identify areas along the coast, both on landward side and seaward side, to be protected and managed as the nesting and breeding habitats along the shore line.
3. To establish guidelines for developing infrastructure facilities, so as to safeguard and minimize the large scale mortality of breeding sea turtles both on- and off-shore.
4. Identify the migratory routes taken by sea turtles in Indian territorial waters and beyond (if necessary with other organizations active in this field). Annual migration charts are to be developed and sent each year to all coastal management authorities and other agencies involved in coastal resource use.
5. Network and develop national and international inter-agency co-operative and collaborative action for sea turtle conservation.
6. Develop infrastructure and human resources for sea turtle conservation that will also take care of other coastal biodiversity.
7. Priorities areas, agencies and action (both short-term and long-term) for a sustained sea turtle conservation program.
8. Carry out extensive and exhaustive 5-year surveys of the coastal area at the appropriate nesting times to verify potential sites of turtle breeding.

Develop guidelines for tourism in sea turtle areas, indicating the permissible and prohibited activities (most of these can be given legal protection from existing laws and regulations).

 

To meet the project objectives the following strategy is planned to be adopted.

1.    To train and dedicate staff of the wildlife wing of nine coastal States and the Bay Islands to take up a survey and demarcation of nesting beaches within their geographic locality, which could be carried out by the WII in association with select agencies. Thereafter, protection and monitoring of the nesting beaches could be taken by individual State wildlife wings with technical support from an expert group. Based on this a system of annual population monitoring and analysis plans would be developed. Research centres to study breeding, feeding and migration biology of these species could be initiated. Migration routes of the turtles would be charted and monitored in a systematic manner so that future management strategies evolve through them but based on them.

2.    To enhance effective off-shore patrols and protection of sea turtles through (a) wildlife wings of coastal States and Bay islands, (b) State maritime fisheries departments and (c) Indian Coast Guard, by providing them with adequate infrastructure. For this purpose the Ministry of Environment and Forests (MoEF) is to organize a consultative meeting to assess requirements.

3.    To enforce the use of Turtle Excluder Devices (TEDs) in trawl nets to minimize fishery-related sea turtle mortality. The Ministry of Environment and Fisheries MoEF, Commerce and Agriculture ministries will develop an advertisement and extension programme for TED demonstration and subsidised supply of TEDs to trawl operators.

4.    To initiate and upgrade sea turtle research and monitoring and develop a suitable database, the MoEF will lease with the Department of Ocean Development, University Grants Commission and Commerce Ministry to support agencies such as the WII, the Central Marine Fisheries Research Institute (CMFRI), the National Institute of Oceanography (NIO) and coastal Universities, to set-up a suitable research programs. Additionally, the MoEF will also priorities management-related research topics in consultation with WII, CMFRI, NIO, wildlife wings of coastal States and Islands and select universities.

5.     To develop a national sea turtle conservation education and awareness campaign. In consultation with Centre for Environmental Education (CEE), WII and select media group, a national level long-term sea turtle conservation education awareness campaign will be developed. Local NGO's will be encouraged to initiate action on this issue.

6.    Revive and strengthen the Indian sea turtle expert group for technical advice and evaluation of projects.

7.    Develop a participatory nesting beach protection and management programme with people participation, and where benefits will reach the local people. A suggested protocol for this is to bring adjoining villages together and create a Turtle Protection and Village Development fund through development of a seasonal eco-tourism activity. Benefits of such tourism should go directly to the human residents of these sites where planned tourism is involved.

8.    Collaborate with Regional and International Agencies in developing sea turtle Conservation programs. The MoEF plans to initiate dialogue with organizations such as the Convention of Migratory Species (CMS), United Nations Development Programme (UNDP), and South Asia Association for Regional Co-operation (SAARC) and ASEAN for developing a cross-sectional and integrated Coastal Resource management program, where sea turtles feature in a significant manner.

 

Reference:-

1.    Bhaskar, S., 1993. The Status and ecology of sea turtles in the Andaman and Nicobar Islands. Centre for Herpetology Publication No.ST1193: 1-37.

2.    Dash, MC. & CS. Kar, 1990. The turtle paradise - Gahirmatha. Interprint, New Delhi: 295pp.

    Kar, CS. & S. Bhaskar, 1982. The status of Sea turtles in the eastern Indian Ocean. In The Biology and Conservation of Sea Turtles (K. Bjorndal, ed.) Smithsonian Press, Washington DC: 365-372.

4.    Rieppel, O., and DeBraga, M. (1996). "Turtles as diapsid reptiles." Nature, 384: 453-455

5.    David Alderton (1986). An Interpret Guide to Reptiles & Amphibians, Salamander Books Ltd., London & New York.

6.    The Sea Turtle Conservation Agenda of India by B.C. Choudhury, S.C. Sharma, S.K. Mukherjee.

7.    Pandav, B., B.C. Choudhury & CS. Kar, 1994. Olive ridley sea turtles (Lepidochelys olivacea) and its nesting habitats along the Orissa coast, India - A status Survey. Wildlife Institute of India, Dehra Dun, July 1994.

8.    Pandav, B., B.C. Choudhury & CS. Kar, 1997. Mortality of Olive ridley turtles (Lepidochelys olivacea) due to incidental capture in fishing nets along the Orissa coast, India. Oryx 3 1(1): 32-36.

9.    Pandav, B., B.C. Choudhury & CS. Kar, 1997. Mortality of Olive ridley turtles (Lepidochelys olivacea) due to incidental capture in fishing nets along the Orissa coast, India. Oryx 3 1(1): 32-36.

10.    Pandav, B., & B.C. Choudhury, 1999. An update on the mortality of Olive ridley sea turtles in Orissa, India. Marine Turtle Newsletter, 83: 10-12.

11.    Pandav, B., B.C. Choudhury & K. Shankar, 1995. The Olive ridley sea turtle (Lepidochelys olivacea) in Orissa : An urgent call to be on an intensive and integrated conservation program. Current Science, 75(12): 1323-1328.