59. Present Status of Sea Turtles
and their Conservation in India
M. Rajagopalan
Madras Research Centre, Central Marine
Fisheries, Research Institute, 68/1, Greams Road, Chennai-600
006
Introduction
Sea turtles represent an ancient and distinctive
part of the world's biological diversity. They are a group of
harmless reptiles which coexisted with the dinosaurs and were
most common during the Cretaceous, 130 million years ago. Though
the fossil record extends back to 200 million years, all the present
day genera and species originated in the period from the early
Eocene to the Pleistocene, between 60 and 10 million year ago.
Turtles, aptly termed as living fossils, not only have a long
evolutionary history but also surpass all other vertebrates in
longevity. On one hand we have a very fragmentary information
on their biology in the marine environment where they spend nearly
their entire life. On the other hand, we have a much better understanding
of the very brief but critical period in their life history when
they are obligated to use the beach.
Sea Turtle Fauna of India
Five species of sea turtles are known to inhabit Indian coastal waters and Bay Islands. In the order of abundance they are the olive ridley Lepidochelys olivacea, the green turtle Chelonia mydas, the hawksbill Eretmochelys imbricata, the loggerhead Caretta caretta and the leatherback Dermochelys coriacea.
Lepidochelys olivacea (Olive ridley turtle)
This is the most common sea turtle in
Indian waters. Very heavy concentration of this species occurs
in Orissa coast. Mass nesting occurs in a stretch of 15 km Gahirmatha
beach during January-March every year. This species nests both
in the east and west coasts of India, as well as in the Bay Islands.
Chelonia mydas (Green turtle)
This is the largest species found in the
Indian waters. It occurs in the west and east coasts of India,
Lakshadweep and Andaman & Nicobar Islands. The name Green
turtle indicates the green colour of the fat. It is predominantly
herbivorous and feeds on sea grass. This species was highly priced
and there was a directed fishery for the green turtle in the 1970s
in the Gulf of Mannar area.
Eretmochelys imbricata (Hawksbill turtle)
It is comparatively a small sized turtle
and numerically less abundant in the Indian waters than the other
species. It is reported from Lakshadweep, southwest coast, Tamil
Nadu and Andaman & Nicobar Islands. It feeds mainly on sponges,
crabs and molluscs. As it frequently feeds on poisonous marine
animals, the flesh of this species is often reported to be poisonous.
Caretta caretta (Loggerhead turtle)
This species is reddish brown in colour
and is characterized by a large head in relation to the body size.
In India, it is recorded only from the Gulf of Mannar. It is a
carnivore, feeding on crabs, fish and other benthic animals.
Dermochelys coriacea (Leatherback turtle)
Individuals of this species attain a weight
of 500 kg. A thick leathery tissue covers the bones of the shells
and hence the common name. Indiscriminate poaching of eggs in
the 1970s caused the disappearance of this species in the mainland
coastal waters. However, they occur in pristine beaches and adjacent
waters of Little Andamans and Nicobar Islands.
Turtle fishery in the past
Turtle fishing was practiced in the Gulf of Mannar and Palk Bay in Tamil Nadu for ages mainly by non-Hindu fishermen. In the sixties it was estimated that on an average about 3000 to 4000 turtles were landed every year between Pamban and Cape Comorin. In the Palk Bay the fishery was of a much lower level and about 1000 turtles were landed annually between Rameswaram and Mimisal. The main fishing centres in the Gulf of Mannar were Pamban, Kilakarai, Tuticorin, Ovari, Kuttankuli, Periathalai and Cape Comorin while along the Palk Bay the centres were Rameswaram, Tondi, Tirupalakudi and Devipatnam. The green turtle constituted about three-fourth of the total catch. Olive ridley and loggerhead formed about 20% of the catch. The catch was mainly sent to Tuticorin from different assembling centres where special pens were constructed in the sea close to shore for keeping the turtles alive.
Turtles were caught by special type of
wall nets made of fibres of Acacia planifrons or of cotton
yarn. Two type of nets known as pachu valai and kattu valai were
used, requiring 5 to 8 men each for operation. The pachu valai
was usually cast out during night at the entrance of two parallel
coral reefs and hauled after a lapse of 12 to 18 hours. Kattu
valai fishing was also conducted between two coral reefs but in
much shallower water and six fisherman usually operate the net.
The net was usually laid on fullmoon nights and fishing was generally
conducted for two hours.
Status of export
Prior to the enforcement of Wildlife Act,
there was a regular trade in turtles between India and Sri Lanka.
Live turtles were transported in sailing boats from Pamban to
Jaffna. Chelonian products have been exported under the category
as turtle meat, turtle shell, turtles, tortoise shell, living
tortoise, tortoise belly and tortoise skin. Between 1963 and 1974
about 102 tonnes of sea turtle products valued $ 1,00,800 were
exported from India. The price of 1 kg of tortoise shell increased
from Rs.1 in 1967 to Rs.200 in 1969 and to Rs. 500 in 1985. Turtle
flesh as calipash, the light greenish fat-like meat found as irregular
patches inside the carapace immediately below the scutes and calipee
the light yellowish meat found in patches attached to the plastron
were exported.
Present Status
At present all the five species of turtles occurring in Indian seas are protected as they are placed in Schedule I of the Indian Wildlife (Protection) Act 1972 as per the Amendments made to the Schedule in September 1977. India abides by the Convention of International Trade in Endangered Species of Wild Fauna and Flora (CITES) which prohibits the trade in turtle products by party countries. In June 1981, India became a party to the Bonn Convention on the Conservation of Migratory Species of Wild Animals. To protect the sea turtles, Bhitarkanika and Gahirmatha (65,000 ha) in Orissa were declared as wildlife sanctuary in 1975. In addition, India has four coastal mainland national parks and 17 protected areas. There are 94 sanctuaries in the Andaman and Nicobar Islands.
All the five species are highly migratory and visits parts of our coast and the Bay Islands of Lakshadweep and Andaman and Nicobars for nesting during certain months. Some of the marine habitat such as coral reef areas in the Gulf of Mannar, Andaman and Nicobar Islands and Lakshadweep form the feeding grounds for turtles. None of the five species are endemic and may undertake long migration to feeding and breeding grounds often across international boundaries.
The explosive trade which sprung up for the olive ridley in the late seventies and early eighties despite the Indian Wildlife (Protection) Act, created considerable concern at the national level. During the 1981-82 season it was estimated that 15 fishing units each unit comprising of a motor launch with six country boats were deployed from Digha, West Bengal. Each unit captured about 6000 turtles during the season from November to January off Orissa coast. During the 1982-83 season, the scale of poaching was reduced to a great extent.
In the Andaman Islands all the species except the leatherback was hunted for meat. In the Nicobar, cooked turtle meat is consumed regularly but sometimes taken raw when it is minced and mixed with coconut. The green turtle and hawksbill are the species usually eaten. The green turtle meat was sold at Rs. 3 to 5 per kg as late as seventies in Port Blair markets.
In the Lakshadweep the turtle meat is rarely eaten by the Islanders but a handful have acquired the habit from turtle eating mainlanders. In some areas turtle meat was used as shark bait. Turtle fat was used to waterproof the boats in Amindivi and other islands. There was no systematic effort made to dig out eggs for consumption.
A `Recovery Program' for the olive ridley was started by the Central Marine Fisheries Research Institute along the Madras coast as a conservation measure due to the heavy predation on eggs by man as well as wild animals. The need for developing a sea turtle hatchery for the transplantation of egg from the clutches of natural nests as soon as they are laid to a safer location closer to sea shore for incubation and the release of hatchlings was keenly felt. Under the `Recovery program' 60,410 olive ridley hatchlings which hatched out a the CMFRI field Laboratory, Kovalam have been successfully released from 1977 to 1987. The work of the sea turtle project of CMFRI has created awareness in Tamil Nadu and adjacent maritime states in developing and enlarging similar conservation program for sea turtles.
One of the most spectacular activities
of the sea turtle is the mass nesting (also called `arribada',
a Spanish word meaning arrival) of the olive ridley Lepidochelys
olivacea along north Orissa coast more specifically along
Gahirmatha beach. This is the largest rookery of the olive ridley,
and for that matter, of any species of nesting turtles in the
world. Arribada normally occurs in two seasons in a year the first
one during December-January and the second during March-April.
It is estimated that on an average about 2.5 lakhs of female olive
ridleys nest every year.
Incidental catch
A major threat which still persists is the incidental catch of sea turtles in fishing gears like trawl net and gill net. In India the total number of mechanized craft has increased from 19,210 in 1980 to 47,706 in 1994. Almost the entire fishing fleet exploit the inshore area < 50 m depth exerting enormous pressure on the living resources.
The Central Marine Fisheries Research Institute besides its headquarters has 12 research centres and 30 field centres along the coast of India from where data on exploited marine fishery resources from artisanal and industrial sectors are being collected and evaluated. The National Marine Living Resources Data Centre (NMLRDC) also collects data on the incidental catch of sea turtles in all the fish landing centres by designating code numbers for the five species of sea turtles.
From the data thus collected on the incidental catch in all the maritime states in India during 1985-95, it could be observed that 335 sea turtles were incidentally caught all over the Indian coasts (barring Gahirmatha, Orissa coast). It is estimated that 17.8% of the incidental catch was by the trawlers and 76.5% by the gill netters.
The incidental catch appears to have sharply
decreased considering the large scale capture in earlier years
prior to enforcement of Wildlife Protection Act. The reasons for
the decline despite increase in the number and efficiency of fishing
craft are: awareness of the fishermen to release the sea turtles;
lack of demand for turtle meat even if brought to the shore due
to vigilance by different agencies and; implementation of a 3
km inshore fishing ban on mechanized trawlers to prevent massive
annual incidental take.
Incidental catch in the mass nesting area
Observations on the stranded sea turtles
in a stretch of 10 km at Gahirmatha beach, Orissa revealed that
7500 olive ridley carcasses were washed ashore during 1983. The
turtles were washed ashore due to entangling in fishing operations
conducted off Paradip and adjacent fishing areas, the carcasses
drifting northwards and reaching the Gahirmatha beach. Due to
the stringent protective measures taken by the Wildlife officials
of Orissa and West Bengal state governments and with the ban on
fishing activities during mass nesting, the mortality of sea turtles
declined in the subsequent years. The mortality was maximum during
December-February and 87.5% of the annual strandings was during
this period.
Management Strategies
The Centre Marine Fishery Research Institute (ICAR) in 1984 organized Workshop jointly with the Department of Environment, Government of India, Madras Crocodile Bank and Marine Biological Association of India at Madras and a number of suggestions were made for effective conservation and management of sea turtles in India.
They are habitat preservation of the present
critical areas, already identified vulnerable areas, new areas
and the national sea shore; system species preservation through
recovery programs, translocation of nests and setting up of hatcheries;
legislation and enforcement of prevalent laws and regulations
and future requirements; research pertaining to biology, ecology,
reproductive physiology and endocrinology; behaviour and education,
training and extension especially among public and children on
the importance of turtles and need for their conservation and
of the supervisory personnel.
Habitat preservation
Elevation of the Bhitarkanika Sanctuary
in Orissa to the status of a National Park. Extension of the
Konark Sanctuary on the sea face by 10 km north to include the
sand pit at the Devi River mouth which is another mass nesting
beach for the olive ridley. Evaluation of the Point Calimere
Sanctuary for its extension on the seaward side and ways and means
of conservation of turtle resource in the region. Evaluation
of the status of Bhaidar Island near Okha, Gujarat as a nesting
site of the green turtle Chelonia mydas. Establishment
of the Gulf of Mannar National Marine Park. Protection from human
and non-human interference in Andaman and Lakshadweep. Development
of a National sea shore system/and integrated system of coastal
zone management including social forestry program and exclusive
reservation of certain segments of beaches for turtle nesting.
Species preservation
Standard technologies be developed for
collection of data relating to turtle nests, nesting season, clutch
size, transportation of eggs, transplanting, incubation and emergence
of hatchings and release of young turtles. Detailed data be collected
on recovery/rehabilitation program on the four most threatened
species in the region, hawks bill, the loggerhead, the green and
leathery turtle for different regions of the coasts with a view
to improving the resource. Attractive incentives be provided
for the services rendered for egg collection for the recovery
program and species preservation.
Legislation and enforcement
A critical appraisal of the existing legislation
relevant to conservation and management of sea turtles resource
is made and interpretations of CITES article III (5) is reviewed
for regulating capture of sea turtles from the EEZ of the country
or their introduction through the EEZ. Effective coordination
be developed between the Forest an Wildlife Department with the
Fisheries Department of the maritime states. The sea patrol is
effectively activated and surveillance strengthened for strict
enforcement of the Acts and Legislation. Suitable regulations
be formulated to arm the Executive Officers with appropriate powers
to confiscate powered, non-powered and any other vessels or vehicles
used or engaged in poaching, illegal exploitation or transportation
of sea turtles. Appropriate legislation be formulated to prohibit
use of mechanical or manual means, tools or any destructive instruments
to kill sea turtles from the EEZ of the country.
Research
Directed research be undertaken of sea turtles. A planned survey be launched along the Indian coast to identify nesting beaches. Investigations on beach erosion and accretions particularly at the important nesting beaches be intensified. The unique phenomenon of congregation of world's largest population of sea turtles at the Gahirmatha and adjacent regions be immediately studied.
Turtle hatchery programs be encouraged
with adequate financial support. Trials with turtle excluder device
in trawl nets may be initiated and the gear modified to suit Indian
waters. For future conservation practices it is necessary to explore
options of sustained exploitation. A coordinated and centralized
mark recovery program for sea turtles may be initiated. A centralized
data bank to facilitate collection, collation and dissemination
of information is needed. Research committee for sea turtles in
India may be established by the Department of Environment, Government
of India. A coordination committee be established for the maritime
states to facilitate formulation of coordinated action plan and
its implementation for the conservation and management of the
sea turtle resources.
Education, Training and Extension
Concerted efforts be made on mass education of the public, fisherman and school children. Organized training courses be offered to field officers and extension officers who are involved with sea turtle conservation program. Extension programs relating to turtle conservation be strengthened and intensified.
References
James, P.S.B.R., M.Rajagopalan,
S.S.Dan, A.Bastian Fernando and V.Selvaraj, 1988. Observations
on the arribadas of the olive ridley Lepidochelys olivacea
at Gahirmatha, Orissa during the 1987 season. Proc. Symp. on
Tropical Marine Living Resources, Cochin.
James, P.S.B.R., M. Rajagopalan,
S.S. Dan, A. Bastian Fernando and V. Selvaraj 1988. On the mortality
and stranding of marine mammals and turtles observed at Gahirmatha,
Orissa during 1983-1987. J. Mar.biol. Ass. India 31 (1
& 2) : 2835.
Rajagopalan, M. 1984, Studies on
the growth of olive ridley Lepidochelys olivacea in captivity.
Bull Cent mar. Fish. Inst. 35 : 49-54.
Silas, E.G., M. Rajagopalan and
A. Bastian Fernando, 1983. Sea turtles of India - Need for a crash
programme on conservation and effective management of the resources.
Mar. Fish. Infor. Ser., T & E. Ser., 50 : 1-12.
Silas, E.G., M.Rajagopalan and A.Bastian
Fernando, and S.S. Dan 1983. Marine turtle conservation and management.
A survey of the situation in Orissa 1981/82 and 1982/83 Mar.
Fish. Infor. Serv. T & E. Ser., 50 : 13-23.
Silas, E.G., M. Rajagopalan and
S.S. Dan, 1983. Marine turtle conservation and management. A survey
of the situation in West Bengal 1981/82 and 1982/83. Mar. Fish.
Infor. T & E Serv., 50 : 24-32.
Silas, E.G., and M. Rajagopalan,
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(Eschscholtz, 1829)along Madras Coast. Bull. Cent. Mar. Fish.
Res. Inst. 35 : 9-21.
Silas, E.G.(Ed.) 1984. Proceedings
of the workshop on sea turtle conservation, Madras, India. CMFRI
special publication No. 18, 110 pp.
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