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STATUS OF MARINE TURTLES IN THAILAND·

Supot Chantrapornsyl Phuket Marine Biological Center, P.D. Box 60 Phuket 83000, Thailand

ABSTRACT

Conservation attempts are being made for the four remain species of sea turtles in Thai waters, which are green turtle (Chelonia mydas), hawksbill turtle . (Eretmochelys imbricata), olive ridley turtle (Lepidochlys olivacea) and leatherback turtle (Dermochelys coriacea). Green and hawsbill turtles are abundant in the Gulf of Thailand, nesting activities occurs all year round with a peak from May to July. Olive ridley and leatherback turtles are found at the Andaman Sea coast of Thailand, their nesting season is a short period between October and .March. Populations of the green and hawksbill turtles have not been found to drastically declined. While the populations of olive ridley and leatherback declined significantly. The declination caused by several factors. In the past. sea turtles were harvested for commercial. Tourism development creates high demand and raise the value of sea turtle eggs, and even causes invasion of nesting habitat. Only a few areas remain suitable for nesting of the turtles, and most of these areas are now under the jurisdiction of the National Parks and Thai Navy. Laws and regulations have been registered in order to conserve sea turtle. A public information campaign on sea turtle biology and conservation have been conducted to increase public awareness. Biology researches are being conducted to improve conservation efforts.

STATUS AND DISTRIBUTION Annual number of nesting green and

Five species of sea turtles have .been hawksbill are shown in Table 1. The recorded in Thai waters: leatherback turtle number of green turtle nests fluctuated from (Dermochely coreacea), green turtle 933 to 215 during 1985-1995 (Table I). The (Chelonia mydas), hawksbill turtle highest frequency of green turtle nesting (Erethmochelys imbricata) olive ridley turtle occurs in June and July. Nesting peak of (Lepidochelys oltvaceay and loggerhead hawksbill turtle is between May and turtle (Caretta caretta) (Phasuk and August, The highest annual nest numbers Rongmaungsart, 1973). was 126 and the lowest was 27 during same

period (Phasuk,1992 and Mananunsup & There are two main areas for nesting sea Charuchinda, 1994). The populations of turtles in Thailand which are difference in green and hawksbill turtles in this area have geographical and sea turtle species: declined significantly, even though their

nesting areas are controlled by the Thai 1) In the Gulf of Thailand, at Khram Navy since long time ago. As the area is

island, located at the inner Gulf of Thailand, completely protected, very few fishermen or Chonburi Province, is the important nesting poachers can enter the island. Thus the area for green and hawksbill turtles (Fig.1).. reduction of the number of seaturtle nests No other specie has been recorded in this caused by heavy fishing activities in the area. Gulf areas.

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I ~ S i m il a n l. .r. I ~

1-11) 0

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Fig. 1. Map of coastline of Thailand shows sea turtle nesting areas, in the Gulf of Thailand at Kh ram Island , and in the Andaman Sea at Phrathong island, Thaimuang beach, Phuket island, Surin island and Sim ilan island .

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Table 1. Number of nesting sea turtles in main nesting areas of Thailand.

Year Andaman Gulfof Thailand Total Green Hawksbill Total

1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995

360 235 255 192 87 92 . .

123 58 36

390 933 251 904 289 259 411 295 478 215 255

119 123 90 126 69 69 27 64 78 39 51

509 1056 341 1030 358 328 439 359 556 254 306

2) The Andaman sea coast of Thailand, five species of sea turtles had been recorded along the west coast line of Thailand and adjacent islands.

The important areas for nesting olive ridley and leatherback are: 1) along the west coast of Phrathong islands, 2) Thaimuang beach and 3) west coast of Phuket Island (Fig. 1). Green and hawksbill turtles are rarely found in this areas, however they were recorded nesting along Surin and Similan Islands.

The loggerhead turtle is believed being extinct from Thai waters.

According to many long distance beaches, the data records is not complete in scientific way. The records of number of nests was not separated to species. Number of sea turtle nests shows only the total number of each year. Number of.nesting sea turtles in the coast line of southern Thailand, the Andaman Sea was declined from 360 nests in 1985 to 36 nests in 1995 (Table 1) (the record was collected by the local peoples, mainly olive ridley and leatherback turtles). And it was same amount were recorded along Surin island, Similan island and Tarutao isalnd (personal interviewing).

Nesting season are differs among the species and geographical conditions. In the Gulf of Thailand, green and hawksbill

turtles lays their eggs throughout the year with a peak from May to August (Fig. 3).

1000 T ~Andaman i...

II} 800 ~~ QI

....= 600e ...

.8 400 S Z= 200

o -+~_.+-_.--+-

~ ~ ~ Year

Fig. 2. Graph shows fluctuation of sea turtle nesting numbers, green and hawksbill turtle were from the Gulf of Thailand.

100 ,

- !i 80 t '0 60 -'­... J:l 40 +e :I z

Jan. Mar may JuL

Month

Figure 3. Nesting season and the peakofgreen and hawksbill turtles observed at Khram Island, number of nests were average number from 1979-1990 (adaptedfrom Phasuk,1992).

Sep Nov.

so

II 40

~ '; 30

.8 20 E.. Z, 10

o _¥'__

Jun, Aug Oct Dec. Feb Apr

Month

Figure 5. Nesting season and the peak of olive ridley turtle observed at Phathong beach and Phuket Province (Average number from 1979-1990).

In the Andarnan Sea coast, nesting season of sea turtles occurs from October to March with the peak from mid-November to mid­

January (FigA). The· green turtle are abundance at Soon and Similan islands, nesting season occurs from April to November with a peak. from July to October (Captain Winai Klorn-in, personal recorded).

The clutch size of sea turtles have been recorded in various locations. The results are shown in Table 2. The average clutch size of green and hawksbill turtles from Khram Isalnd have been recorded from 1988-1993. The average clutch size of green

and hawksbill turtles eggs at Khram Island were recorded from 1988-1993 by Mananunsup & Charuchinda, 1994. The average clutch size of green turtle eggs at Khram Island (93.61±7.73) is smaller than from Similan Island (112.19±16.78, Table 2). The clutch size of hawksbill turtle at the Andaman sea side have not been reported yet. The number of eggs per nest of olive ridley turtle at the Andaman sea coast have been recorded from 1980-1990, total number of nests were 1120 and number of eggs per clutch varies from 67-133.

Table 2. Average clutch size of sea turtles from Thailand, olive ridley turtle recorded from the Andaman sea from 1980-1990, green turtle from Similan island recorded in 1996, green and hawksbill turtles from Khram island were recorded from 1988-1993.

Species and lications Average Standard Number of clutch size deviation nests

Olive ridley (Andaman sea) 111.89 9.59 1112 Green (Similan island) 112.19 16.78 36 Green (Khram island) 93.61 7.73 2636 Hawksbill (Khram island) 103.55 13.81 442

EXPLOITATION

In the past, sea turtles meat and eggs were consumed in every where. Sea turtle eggs have been used as a protein source in many areas. The price of sea turtle eggs go higher especially it is favorite among tourists. In 1992, the price of sea turtle egg in local market was 25 Baht for leatherback and 16 Baht for the other sea turtles. The price is twice as high in Phuket restaurants.

Hawksbill and green turtles are exploited heavily for their shell and skins. Olive ridley exploitation resulted from high demand of their skin for export. The direct exploitation of leatherback turtle is certainly less than of other species. Leatherback are not consumed by people and their shells can not be used for any product.

In 1964, some heavy fishing gears such as trawling and drift gill nets were introduced to Thailand, a lot of sea turtles were exploited continuously. This gears threaten the turtles population.

Years before legislation has been operated, a lot of sea turtle shell and their products were exported mainly to Hong Kong and Taiwan and some to Singapore, Korea and Japan. The amount of exported sea turtle increased from 14,500 kg in 1973, to 908,000 kg in 1983 (Phasuk, 1992).

In order to control sea turtle population in nature, regulations have been used for sea turtles harvesting. The sea turtle nesting beaches were declared tobe concession areas. The eggs were harvested for commercial purpose, so as to 20-30% of the harvested eggs were incubated under

. human care. The young sea turtles were released to the sea according to an

agreement between government and the concessionaires in order to keep natural populations (Chantrapornsyl, 1992)..But however the number of sea turtles still markedly decline.

Today, the concession of sea turtle eggs is no longer existed. In generally the eggs and turtles are fully protected, but according to the economic problem of the local people, they still looking for the turtle eggs in every where.

THREATS (Management concern)

In the Gulf of Thailand, sea turtle nesting areas are concentrated only along several beaches of Khram Island. Only green and hawksbill turtles are found here. The whole island is occupied by Thai Navy, no one can enter the island without permission. Nesting sea turtles are protected by the Navy, poacher is not serious problem in this area. Natutal predator are mainly some lizards and ghost crabs.

The main problem affected to sea turtle populations in the Gulf of Thailand are the heavy fisheries activities. The main fishing gears threaten to sea turtles are trawling, drift gill nets and long-line hooks.

In the Andaman sea side, number of nesting sea turtles are drastically declined, caused by many factors. The nesting areas along the Andaman sea of Thailand are separated to 4 major nesting sites.

1) Phrathong island, located at the northwest of Phang-nga Province (Fig.l.). There are comprise of three islands; Ra island, Phrathong island and Khorkhao island, Olive ridley and leatherback turtles are found and occasionally green and hawksbill visits this area. There are small villages on the islands, no electricity uses. It was a sea

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turtle concession beach in former time. After give up the concession, many people tried to collect the eggs. The nature predator is only the beach crabs. The main threats to sea turtles in this area is also the heavy fishing activities, trawling and gill nets are the major causes of accidental drowning sea turtles. Housing and hotel development are not getting problem to this area.

2) Thaimuang beach,which is located along the western coast of Phang-nga Province. This area is about twenty kilometers long. The nesting area of olive ridley and leatherback turtles. The Northern half of sea turtle nesting beach is belonging to the National Parks. Where it is fully protected. At the southern part, there is human habitat. Here, eggs poaching is the biggest problem and very difficult to control. The incidental catches of turtles in gill nets is also the big problem here. Other threat to nesting beach is the development of prawn hatchery. The hatcheries are building close to the beach. The light and sound from the farms might be affected to the nesting sea turtles.

3) Phuket island: Sea turtle nesting area is the beach along the west coast of Phuket island. It is the nesting ground of olive ridley and leatherback turtles. The beach at northern part of Phuket have been declared as National Park since 1983. There are many people ·1ive along this area. The middle coastline up to the southern end is now highly developed. The number of tourist has continuously increased which results in disturbance of sea turtle nesting, Turtles are no longer encountered on this area. Therefore, the only national park area is still suitable for nesting sea turtle. According to many people live along this area, eggs poacher is the big problem. And also fJ

incidental catch in gill nets and longline hooks are occasional seen, No other

:·1

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natural predator threats to sea turtle here.

4) Surin and Similan islands: Western off Phang-nga Province, there are green and hawksbill comes for laying eggs in this areas. The island is very far from mainland. Most areas are belonging to National Park. At Surin island, there is a village of sea gypsy settle on the island. Most eggs were collected by the sea gypsy, At Similan island, there are comprise of 9 small island, only two island number 1 and number 4 have a long beaches for nesting sea turtle. The eggs were mostly collected by fishermen. Natural predators are mainly by lizards, birds and shore crabs. Few accidental catch have been reported.

LEGISLATION

Awareness of declination of sea turtle population in Thailand lead to raise serious attempts to conserve sea turtles. The sea turtle conservation· project has been conducted at Phuket Marine Biological Center since 1971, follow by establishment of sea turtle conservation station at Man­Nai Island in the Gulf of Thailand. Since then, biology of sea turtle have been studied and many nesting sites were protected. Some of these areas have been declared as National Park in order to better. protect the animals and their habitats. Laws and regulations have been registered including educational and campaign are provided to public.

Many laws and regulations have been conducted and strictly enforced by Government authorities and many NGO groups.

The protection of sea turtles was officially implemented as follow:

• Ministry of Agriculture and cooperative Enactment 1947: An announcement of

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the protected animals, sea turtles have been listed as protected animal. Kill of the turtle and eggs collecting are prohibited.

• Fisheries Act 1972: commercial fishing within 3 kilometers of the coastline was prohibited. The legislation resulted from the finding that most sea turtles in Thailand are caught from shallow water trawling boats.

• Ministry of Commerce Enactment 1980: The export of sea turtle was prohibited.

• Conservation and protected of living resources Enactment 1992, Act No. 19: Collecting of sea turtles, their products and carcasses are prohibited. The legislation resulted in control of collecting and trading of sea turtles and their products.

• Thailand has been signed up to CITES member (in 1983), the export of sea turtle are prohibited.

• The use of Turtle Excluder Device (TED) in shrimp trawling fisheries have been enforced in 1996.

Present conservation institute and management strategies. There are many agencies responsible for implementation and enforcement of sea turtle conservation including:

1) Sea turtle conservation station, Man-Nai Island, in the Gulf of Thailand. The station belongs to the Department of Fisheries. The activities are mainly to protect green and hawksbill turtles. Sea turtle eggs were collected from Khram Island and incubated in styrofoam boxes. Hatchlings are reared at the

. station before releasing to the sea. _Breeding biology of sea turtles has been

studied with an attempt to establish a sea turtle conservation fann.

2) Sea turtle conservation programme at Khram Island. The sea turtle conservation project here is conducted by the Thai Navy, the aim is protect

hawksbill and green turtles. Sea turtle eggs are collected from several beaches around the island, the eggs are removed to a hatchery. About 50 % of the hatchlings crawled out to the sea naturally, another half were kept and rearing for 3-6 months before release to the sea for the purpose of conservation campaign.

3) Phuket Marine Biological Center (PMBC): This research center belongs to the Department of Fisheries. Sea turtle conservation programme is emphasis on the olive ridley and leatherback turtles. The eggs are collected from various nesting beaches along the west coast of Thailand. As it is mention above, the nesting areas out side the National Park where eggs poaching is the main problem. It is impossible to leave the "eggs in nature. Therefore, in the nesting season some local families are employed for patrolling the beach, the eggs will be collected and transport to the PMBC for incubation. Eggs are moved for incubating at the PMBC. The hatchlings are reared for three to six months and released to the sea. In order to propagate and conservation campaign, The PMBC invited people to have chance to release young turtle by themselves. This impressive act created enthusiastic feeling of saving turtle in nature according to the custom and religion of Thai people.

For the newly hatch leatherback turtle, it is unsuccessful to keep them in captivity, therefore they are released immediately after hatched.

4) Kao Lumpee - Thaimuang Beach National Park: Located at west coast of Phang-nga Province. Sea turtle has been protected by the National Park authority. The beach is strictly patrolled,eggs are removed to a safe place. The hatchlings are allowed to crawl to the sea naturally.

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5) Sirinarth National Park, Phuket Island (formerly called Niyang National Park): The National Park authority together with Phuket NOO group try to protect the leatherback and olive ridley turtles. The beach is patrolled and the eggs are moved to a safe place for incubation and the hatchlings are released immediately to the sea.

6) Soon and Similan National Parks: At Sirin Island, sea turtle are protected by the National Park authority, the eggs will be left in natural conditions. And at Similan Island, the National Park official with cooperation of the Thai navy to protect sea turtle. The beaches are patrolled against the poacher, eggs are collected and incubated in a hatchery. The young turtles were reared for 3-6 months before released to the sea.

7) Other non-governmental organizations: There are some NGO groups concerning sea turtle conservation in Thailand. Phuket NGO provides sea turtle conservation programme at Sirinarth National Park, Phuket. Some private company and hotels groups provides the advertise and campaigns including donation of money for the activities of PMBC conservation programme.

Further actions needed to conserve marine turtles

Education programme Information about sea turtle biology and conservation management has been provided to public. Local educational campaigns on the plight of sea turtle have been done in order to motivate local people into stopping sea turtle egg consumption. T-shirts, articles, newspaper, slide shows, radio and television announcements, posters and exhibition of life history of sea turtle were distributed for public knowledge. The most effective idea tum out to be that of Department of Fisheries

.' ..... ~j !

which invites people to have a chance to sea turtles. The trawling fisheries, push nets release young sea turtle by themselves. are totally prohibited. This impressive act created enthusiastic feelings of saving turtles in nature Future research plan and conservation according to the custom and religion of activities.Thai people. The Department ofFisheries is presently

conducting research on sea turtles as the Law enforcement following: Sea turtle in Thailand are now better * Long-term monitoring survey; data protected than in the past. Commercial collecting in order to assess the harvest and consumption of sea turtle are populations and enhance hatch rate and prohibited. Laws and regulations in sex ratio ofhatchling. Thailand has been documented as * Study on tagging of nesting female sea international strategies. But according to turtles and tag releasing turtles to the economical problems especially for the determine nesting and internesting local people, the turtle eggs poaching still habitats. occurs in various areas. To solve this * Study on internesting hehaviour feeding problem the Department of Fisheries ground and migration routes using provides more authorities patrolling the satellite tagging technique. beach against the poacher. * Study on DNA analysis of sea turtle to

identify the turtle populations within Habitat protection the country and in the region. Many sea turtle nesting areas including the * Laws and regulations for conserve sea off shore islands have been declared to be turtles are strictly enforced. National Parks in order to control the front * Conservation awareness campaign are beach development and fisheries activities. provided to public, cooperative with In addition, sea grass beds and coral reef conservation officers, NGOs and areas are importance foraging habitat for students for effectively results.

ACKNOWLEDGEMENTS

I gratefully thank the Chief of the Kao Lumpee-Thaimaung National Park for cooperation on collected sea turtle surveying data. Thank to Captain Winai Klom-in who has halped in provide the data from Khram island and Similan Island. Thank to Ms. Suwanna Phanutrakul for read and corrected.the manuscript.

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Chantrapornsyl, S. 1992. Artificial incubation and embryonic development of olive ridley turtle eggs (Lepidochelys olivacea). - Phuket mar. biol, Cent. Res. Bull., 57: 41-50 (1992).

Chantrapomsyl, S. 1992. Biology and conservation of olive ridley turtle (Lepidochelys olivacea Eschscholtz) in the Andaman Sea, Southern Thailand. - Phuket Mar. Biol. Bull., 57: 51- 66.

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Chantrapornsyl, S. and O. Bhatiyasevi, 1993. Nesting behaviour and some biological aspects of olive ridley turtles (Lepidochelys olivaceay in breeding captivity. - Proceedings of Sea turtle Conservation Symposium-Workshop, Manila, Philippines. 6-10 December 1993. pp. 193-198.

Kanjanamawin, P. and S. Rongmaungsart (Thai) 1987. Embryonic development of hawksbill turtle eggs comparing in situ and artificial incubation. - Proceeding of The Department ofFisheries Scientific Seminar. 1987 : pp. 194 -204.

Kanjanamawin, P., K. saithanu, S. Rongmuangsart and S. Mananunsub. (Thai). 1988. Diseases of young green turtle in captivity. - Proceeding of The Department of Fisheries Scientific Seminar, 1988 : 174 -185.

Kanjanamawin, P., C. Limsuwan, N. Arrichon, P. Tabthipawan and P. Wutthisin. 1992. (Thai) Diseases of baby green turtle, (Chelonia mydas) and antibiotics sensitivity test. - Thai Fisheries Gazette. 45(5): 1015-1024.

Kanjanamawin, P., P. Wutthisin, S. Mananunsab, and S. Saelim. 1993. Experiment on nursing of baby green turtles (Chelonia mydas) with different diets. - ThaiFisheries Gazette. 46(1): 33-39.

Mananunsub, S. and S. Rongmaungsart. 1987 (Thai). Study on food consumption and growth of green and hawksbill turtles. - Proceeding of The Department of Fisheries Scientific Seminar 1987:221-226.

Mananunsub, S. and S. Rongmaungsart 1987 (Thai). Study on growth of baby green turtles rearing in floating cages. - Proceeding of The Department of Fisheries Scientific Seminar. 1987: pp. 243-255.

Mananunsub, S. and S. Rongmaungsart. 1988 (Thai). Nesting biology and egg incubation of sea turtle at Khram Island. - Proceeding of The Department of Fisheries Scientific Seminar. 1988: pp. 167-173.

Penyapol, A. 1957. A preliminary study of the sea turtle in the Gulf of Thailand. - Royal Thai Navy, Bangkok. 12 pp.

Phasuk, B. and S. Rongmuangsart. 1973. Growth studies on the ridley turtle (Lepidichelys olivacea Eschschz) in captivity and the effect of food preference on growth. - Phuket Mar. BioI. Bull. No.1: 13pp.

Phasuk, B. 1981. (Thai) Sea turtle and conservation. - Thai Fisheries Gazette. 24(3): 253-267. Phusuk, B. 1982.(Eng.) Sea turtle conservation in Thailand. - Tai Fisheries Gazette. 35(2):

171-177. Phasuk, B. 1992. (Thai) Biology, culture technique and conservation of sea turtle in Thailand.

- Phuket Marine Biological Center Technical Paper. No. 1/1992: 114 pp. Sukwong, S. 1991. (Thai) Culture technique of sea turtle. - Proceedings of The Department of

Fisheries Scientific Senimar. 1991: 84-91.