Malayan Nature Journal 1993 46 : 243 — 253

The Status of the Hawksbill Eretmochelys imbricata and Green Turtle Chelonia mydas of Melaka and

JEANNE A. MORTIMER 1 , ZAID AHMAD 2 & SAFEE KASLAN2 Abstract : In this paper we present our assessment of the importance of the sea turtl e nesting and foraging habitats of the states of Melaka and Negeri Sembilan . Our studies done in 1990 and 1991 revealed that the population of the highly endangered hawksbil l turtle Eretmochelys imbricata nesting in the state of Melaka is in fact the largest i n Peninsular . The duration of the breeding season was also established for the first time : it extends from February through September, and peaks during May, Jun e and July . In 1990, the Department of Fisheries and the state of Melaka, with assistanc e from WWF Malaysia, established a hatchery near Pengkalan Balak to which collector s sold their eggs during part of the 1990 and all of the 1991 nesting seasons . Of the 324 egg clutches recorded in 1991 (certainly an underestimate of the total actually laid) , 69% were deposited on mainland beaches between the northern border of Melaka an d Kem Terendak, 26% on Pulau Upeh, and 5% near Tanjung Kling . Further surveys are needed to confirm reports of important nesting activity on islands adjacent to Pula u Besar, especially Pulau Nangka. Our surveys and interviews indicate that significan t numbers of juvenile and adult hawksbill and green turtles Chelonia mydas inhabit foraging grounds in the Straits of Melaka . Conservation efforts must focus on preservation o f critical nesting and foraging habitat, complete protection of turtle eggs, and preventio n of accidental captures of turtles in fishing gear. We suggest that Pulau Upeh be designated a turtle nesting sanctuary .

INTRODUCTION During the past four decades, scientists and resource managers in Malaysia have focused attention on the turtle populations of , Saba h and with emphasis on the leatherback Dermochelys coriacea and to a lesser degree on the green turtle Chelonia mydas (see review by Chan, 1991). Although hawksbill Eretmochelys imbricata populations throughout the country received little attention, we now know that the hawksbill i s one of the most endangered species of marine turtle in the world toda y (Carr & Meylan, 1980) .

1 Consultant, World Wide Fund for Nature (WWF) and Courtesy Assistant Professor, Zoology Department, University of Florida, Gainesville, Florida 32611, U .S.A. 2Jabatan Perikanan Negeri Sembilan/Melaka, Wisrna Persekutuan, Tingkat 9 , Jalan Hang Tuah, 75300 Melaka, Malaysia . (Accepted for publication 28 March 1993)

243

In recent years, through the efforts of the Malaysian Department o f Fisheries, the state governments, scientists at Universiti Pertanian Malaysi a and Universiti Malaya, and the World Wide Fund for Nature Malaysia (WWF Malaysia) we know significantly more about the status of turtles throughou t Malaysia, particularly the hawksbill . Current estimates of the numbers o f hawksbill egg clutches laid annually in each state are presented in Table 1 . More hawksbills nest in the state of Melaka than any-where else i n the Peninsula .

Table IL Current estimates the numbers of hawksbill egg clutches lai d annually in each Malaysia e ihe, u are known to occur.

Numbers o f Location Clutche s Source Laid Annually

Turtle Islands Park, 350—400 Sabah Parks, unpubl . data ; (especially Pulau Gulisan) Phillipps, 198 8 Terengganu (especially 20—200 Fisheries Statistics, unpubl . ; Pulau Redang and Pulau Perhentian Mortimer, 1991c ; Chan, 199 1 (offshore islands) 100 Mortimer, 1991 a (offshore islands) 100—200 Fisheries Statistics, unpubl . ; Mortimer, 1991b ; Chan, 199 1 < 25 Sukarno, 199 1 Pulau Pinang < 25 Mortimer, 1991 d Perak (Pasir Panjang and < 25 Mortimer, 1990 ; Sembilan Islands) Fisheries Statistics, unpubl . Melaka > 350 This paper

Kiew (1975) first recognized the need to protect the endangered hawksbills of Melaka, and identified Tanjung Kling, Pulau Upeh and Pulau Besar as important nesting sites. Chua (1979) reported the success of th e first artificial hatchery established in 1978 at . Tanjung Kling, Melaka . In July 1987, the Department of Fisheries of Melaka/Negeri Sembilan and th e state government of Melaka jointly established a hatchery on the island o f Pulau Besar located several kilometres offshore the town of Melak a (Mortimer, 1988) (Fig . 1) . There, 1320 eggs were incubated in 1987, 509 1 in 1988, and 2595 in 1989 . Unfortunately, eggs in the hatchery suffered a very low hatch rate, probably due to mortality incurred during transporta- tion of the eggs from the mainland nesting beaches to the island (Mortimer , 1989). In 1990, the Department of Fisheries and the state government o f Melaka, with partial funding from WWF Malaysia, established a new hatcher y on the mainland at Padang Kemunting near Pengkalan Balak, Melaka (Fig . 1) .

244

TG . DAHA N KG . HILI R • * 0 KUALA SUNOS' BAR U 0 *0 0 • • 0 TELO D BALANGA 0* 0 0 0 ••!••• T OK GON G * . NGEI TUAN G .0 *0 2'24'N - •• : PENGKALAN BALA K 00 KG . PADANG KEMUNTING (HATCHERY )

Figure 1 . Map showing locations of the turtle hatchery and major nesting areas of Melaka . Closed circles indicate the localities from which hawksbill turtle egg clutches wer e reportedly collected during the 1991 nesting season, Each closed circle represents on e egg clutch, Question mark (?) indicates areas in need of further surveys .

Beginning in early June 1990, eggs collected on the mainland were plante d at Padang Kemum ing . Following is an account of the status and distribution of the marin e turtles in the states of Melaka and Negeri Sembilan based on informatio n gathered during operation of the hatchery in 1990 and 1991 and also fro m surveys conducted by personnel of the Department of Fisheries and WW F Malaysia.

245 METHOD S Compilation of Information on Turtle Nestin g All egg collectors were requested to sell the eggs they collected to th e Department of Fisheries for incubation in the hatcheries . During 1991 , the Department paid M$0 .50 per hawksbill egg (up from M$0 .30 per egg i n 1989) . For each egg clutch brought to the hatchery, the following record s were kept : the name of the egg collector, the date and time the eggs were removed from the natural nest, the location of the natural nest, and th e time the eggs were planted in the hatchery . (We also recorded : the number of eggs in the clutch, the incubation methods employed at the hatchery , the numbers of hat (tidings produced and the exact stages at which eg g mortality occurred in each nest . 'f hese data are discussed by Mortimer an d Zaid (1991, 1992), Mortimer et at, (1992) and Mortimer, Zaid & Safe e (MS in prep .) . ) In both 1990 and 1991, the nesting season was already under way when the hatchery began operation (in early June 1990, and in mid-Marc h 1991) . To determine hove any egg clutches had been laid during the firs t part of the 1991 season before the hatchery opened, personnel of th e Department of Fisheries extensively interviewed egg collectors in bot h Melaka and Negeri Sembilan .

Turtles in the Offshore Waters of Melaka and Negeri Sembila n To determine the abundance of sea turtles in offshore waters, and th e extent to which they were purposefully or accidentally captured in fishin g gear, we interviewed fishermen and coastal residents .

RESULTS AND DISCUSSION The Nesting Seaso n The data we gathered during 1991 are the first to define accurately the duration of the hawksbill nesting season in Melaka, and they demon- strate that the turtles nest during the months of February through Septembe r with a peak during the months of May through July (see Fig . 2b). Our records from the 1990 season are incomplete because data collection di d not commence until late in the season (see Fig. 2a) (Mortimer & Zaid, 1991 , 1992) . Earlier studies based largely on interviews with coastal residents ha d underestimated the length of the nesting season (Kiew, 1975 ; Chua, 1979).

Geographic Distribution of Turtle Nesting In constrast to the well developed beaches of the east coast o f , mainland beaches of Melaka have narrow platform s composed of relatively fine-textured pyrogenic sand . The sand of the islan d beaches of Melaka ranges from igneous (e .g. on Pulau Upeh) to calcium

246

MELAKA HAWKSBILL NESTIN G

20 y- ‘:) )UGHT TO HATCHERY 1 a

0-111 71TII - 11 n 111 n Lli L i ll 1 T1 1 111111411111,11 ) JAN FE MAR APR MAY JUN JUL AUG SEP OCT 1990

AN FEB MAR A'R MTh' Jul JUL AU G

1 991

Figure 2 . Seasonal distribution of hawksbill turtle nestings recorded in 1990 (2a) an d 1991 (2b) . Note that during the 1990 season, no data were collected before 3 June an d after 28 August.

247 carbonate (e.g. on Pulau Besar) . Hawksbills typically lay their eggs at the rear of the beach under vegetation, often in a substrate comprising a mixture of sand and mud that is high in organic matter . Turtle nesting habitat at one time extended from the town of Melak a north to the state border . In recent years, however, much of the coastlin e between the town of Melaka and Tanjung Kling has been intensely developed and is no longer suitable for nesting turtles . South of the town of Melak a there is only mangrove . Table 2 shows the localities from which hawksbill egg clutches wer e reportedly collected during part of the 1990 (Mortimer & :aid, 1991, 1992 ) and all of the 1991 nesting seasons . The 324 clutches reported in 199 1 represent only the minimum number of clutches laid. Our data for th e 1991 nesting season are plotted on the map in Fig . 1 and indicate that along the mainland coast, hawksbills nested most abundantly from Kent Terendak northward to the state border, and in relatively smaller number s in the vicinity of Tanjung Kling. Although we make no attempt here t o estimate the total number of clutches laid, information gathered in our interviews suggests that the distribution and intensity of nesting effor t along the mainland beaches is proportional to that shown in Fig . 1 .

Table 2 . The numbers of egg clutches collected from each of 17 beach site s (arranged in order from north to south) in Melaka during the 1990 and 199 1 nesting seasons.

1990 Season 1991 Seaso n

No, of Egg % of Total No. of Egg % of Total Location Clutches Clutches Clutches Clutche s

Pantai Kuala Ifinggi 3 2.3 38 11 .7 Tg . Dahan 2 1 .5 3 0.9 Kg . Mir 1 0.8 3 0.9 Kuala Sg . Baru 9 6.8 10 3. 1 Telok Belanga 3 2.3 18 5.6 Telok Gong 16 12 .1 20 6.2 Sg . Tuareg 5 3 .8 8 2.5 Pengkalan Balak 1 0 .8 6 1 .9 Kg. flail am 2 1 .5 2 0.6 Padang Kemunting 22 16 .7 30 9 .3 Kg. Pasir Gembur 4 3 .0 16 4 .9 Batu, Tg . Bidara 4 3 .0 7 2 .2 Tg. Bidara 11 8 .3 19 5 .9 Kern Terendak 14 10 .6 44 13 .6 Tg. Kling 3 2 .3 15 4 .6 Pulau Upeh 32 24.2 84 25 .9 Pulau Burung 0 0 1 0 . 3

Total 132 100 .0 324 100 .0

248

More surveys are needed to quantify nesting activity on the islands . During both 1990 and 1991, approximately 25% of all reported hawksbil l nestie occurred on less than 150 m of beach at Pulau Upeh, makin g

that ,L the site of the densest nesting known for the state . We were unable to document the number of nesting') that occurred on the islands in the vicinity of Pulau Besar. Egg collectors reported that nesting activit y declined at Pulau Besar after the island was developed in 1988, but clai m that the undeveloped adjacent island of Pulau Nangka remains a particularl y important nesting area . We found no evidence that green turtles Chelonia mydas nested in Melaka during either 1990 or 1991, although reportedly they do nest ther e on occasion (Kim, 1975 ; Siow & Moll, 1981 ; S. Aikanathan, pers . comm . based on interviews). Nor did we find evidence of any marine turtle nestin g in the state of Negeri Sembilan . The River Terrapin or funtung Sunga i Batagur baska nests occasionally in Melaka and more abundantly in Neger i Sembilan (Moll, 1990 ; Laid & Mortimer, MS . in prep .) .

Turtles in Offshore Waters The following compilation of published and unpublished observation s indicates that both adult and juvenile green turtles and hawksbills ar e regularly encountered, apparently while foraging, in Malaysian waters i n the Straits of Melaka . Cantor (1847, cited by Siow 8- 981) observed that green turtles were "at all seasons plentifully tal n thing stakes i n the straits of " . Recent reports from fishermen (Including Kapte n Nathan, Seaview Fishing Centre, pers. comm.) and our own personal field observations confirm the presence of both green turtles and hawksbill s near coral reefs in the vicinity of , Negeri Sembilan . In the mid-1970's, Mr. Ken Scriven photographed two live hawksbil l turtles brought ashore at Port Dickson by a fisherman who had caugh t them in a fine-meshed drift net (pukat hanyut) . The fisherman release d both animals unharmed after showing them to his children . The Director o f Fisheries in Melaka (Mr . Lim Chai Hock, pers . comm . to TAM) reporte d that a young green turtle -Lc °1g 60 cm in carapace length had bee n captured alive in a drift net 'tar Kampung Pulai on 15 October 1986. The turtle was photographed and released. We found no indication that fishermen w-re purposefully harvestin g turtles . However, our interviews provided am- - 21 vidence that accidental drowning of turtles in nets occurs with some a laiity . Documented case s of turtle mortality also exist . On 23 March 1990, two juvenile turtles, a 6.1 kg hawksbill turtle and a 16 .6 kg green turtle, were killed in a ray ne t (pukat pari) set near Kampung Balik Bukit, Tanjung Kling, Melaka (Hiew , 1990) . At Pulau Pangkor, , a dead subadult green turtle measurin g 80 cm curved carapace length washed ashore dead, and abrasions on it s throat suggested that it had been caught in a net (Mortimer, 1990) .

249

The Problem of Conserving Sea Turtles in the Straits of Melaka Marine turtles on the west coast of Peninsular Malaysia are seriousl y threatened by a number of factors associated with human activity . The following is a discussion of the problems and the action needed for thei r solution.

1) For decades, people have harvested most of the eggs laid by the turtles . Only since the relatively recent establishment of the hatchery hav e the turtles been allowed to produce significant numbers of offspring . It is critical that the hatchery program continue, and that a specia l effort be made to ensure that offspring of both sexes are produce d in the hatchery. During the past three years, most of the egg clutche s were incubated in the beach hatchery and the remainder in styrofoa m boxes . Measurements of nest temperatures taken in 1991 indicate tha t eggs incubated in the beach hatchery (mean daily temperature rang e 31 .2 — 32 .4'C) may have produced all female offspring and thos e incubated in the styrofoam boxes (mean daily temperature rang e 26 .5 28 .6°C) may have produced all male offspring (Mortimer , ;laid & Safee, MS in prep.). (Note that for hawksbill eggs from Antigu a Island in the Caribbean, Mrosovsky et aL, 1992 determined the pivota l temperature (i.e . the incubation temperature that yields an equa l sex ratio in the offspring) to be 29 .2°C).

2) Rapid coastal development has already destroyed much of Melaka' s turtle nesting habitat . The placement of artificial lights and sea wall s along the nesting beaches is especially detrimental to breeding turtles . Important nesting areas need to be identified and set aside as turtl e sanctuaries. Within these protected areas, guidelines concerning place- ment of lights and location of setback lines are necessary to ensur e that coastal development is compatible with the needs of the nestin g turtles.

3) Artificial light visible at a turtle rookery disorients hatchling turtle s making their way from the beach out to sea, and also discourage s breeding female turtles from coming ashore . We strongly recommen d that light sources associated with coastal development near importan t turtle nesting habitat be modified according to the following guide - lines : a) Insofar as possible, all external lighting should be shaded o r extinguished so that it is not visible either from the nesting beach or from the sea. b) In those cases where it is absolutely essential to place artificial lights where they are visible from the beach or from the sea, thes e

250

lights should be low-pressure sodium vapor (LPS) luminaires . LPS luminaires emit only yellow light . Studies testing the impac t of various types of luminaires have shown LPS luminaires to b e the least disruptive to both hatchling turtles (Witherington & Bjorndal, 1991) and nesting females (Witherington, 1992) .

1) The Department of Fisheries has proposed that the coastline in the immediate vicinity of the hatchery at Padang Kemunting nea r Pengkalan Balak be designated a protected area . nesting habitat at Pulau Upeh also warrants special protection. Surveys need to be conducted at Pulau Nangka and adjacent islands to assess whethe r sanctuary status is warranted for them.

5) Accidental capture of turtles in fishing nets is a common occurrenc e g nsng the west coast of the Peninsu l - . The use of the ray net (puka t ') should be prohibited . Fisherr - should be educated not to c finer meshed drift nets unati -1 for long periods of tim e

.ing which trapped turtles might T Tn . In the vicinity of turtl e nesting beaches, the law prohibit operation of trawling nets (pukat tunda) within five nautical u if the shoreline needs to b e rigorously enforced .

6) Pollution of the marine 'ot in the Straits of Melaka is a seriou s threat to both turtle pu t s a :- Lions and commercial fisheries . Oil spills, improper disposal of sewage and rubbish, and siltation caused by poorly planned coastal development all contribute to the destructio n of coral reefs, sea grass beds and other marine ecosystems .

7) Stuffed young sea turtles (-specially hawksbills) are occasionally offered for sale in Kuala I our and elsewhere in the country . Pro- hibitions the sale of t items should be enforced . This matter should ha ;a:other inves for example by the newly established TRAFFIC Southeast P. ice in Kuala I...,umpur .

8) In 1991, a Turtle In :.Lion Centre was established at the site of th e hatchery at Padang tinting through the joint efforts of the Depart- ment of Fisheries, the state of Melaka and WWF Malaysia . The photo- graphic displays, exhibits, and the turtle egg hatchery together provid e a tourist attraction easily accessible from either or th e city of Melaka. These efforts should be zr~aintained.

CONCLUSION S In Peninsular Malaysia, the greatest nesting concentration of the highl y endangered hawksbill turtle is found in the state of Melaka . Important

251 foraging habitat for both hawksbills and green turtles also occurs alon g coastline of Melaka and Negeri Sembilan . Efforts to conserve the turtl e populations of these states must focus on preservation of critical nesting and foraging habitat, complete protection of turtle eggs, and prevention o f the accidental capture of both juvenile and adult turtles in fishing gear .

ACKNOWLEDGEMENT S

This study was made possible by the cooperation, assistance, and financial support of the state government of Melaka, the Melaka/Negeri Sembilan and Federal Fisherie s Departments, and WWF Malaysia (under WWF Malaysia Project No . 180/90 and WW F Project 3868) . Special thanks are due En. Maz1an bin Jusoh (Deputy) Director o f Fisheries), Mr. Kevin Hiew (Director of Fisheries for Melaka/Negeri Sembilan), En . Brahim bin Salleh (Federal Fisheries), and Dr . Mikaail Kavanagh (WWF Malaysia) . We are grateful to the Fisheries staff who worked at the hatchery throughout the seasons : Mr. Yeo Cheng Loon, En . Hamzah bin Abu Bakar, En . Harun bin Majid, En, Ibrahim bi n Zakaria, Mr . Robert Leong Ho Fook, En. Samsi bin Ideris, En. Shamsuri bin Ahmad, En . Zulkifli bin Ali, and to all the staff of WWF Malaysia . For assistance in the field, JAM is grateful to Mr . Sugawara Arase, Miss Lim Mel Fong and Kapten Nathan . I 'or logistica l support while preparing the manuscript we thank the Archie Carr Center for Sea Turtl e Research, the Caribbean Conservation Corporation, WWF International, Dian a Matthiesen, and Daryl Harrison . Ms. Sarah. Aikanathan provided helpful comments o n a draft of the manuscript .

REFERENCE S

Cantor, T . 1847 . Catalogue of Reptiles Inhabiting the and Islands . Journal of the Asiatic Society of Bengal, XVI, Reprinted 1966 Amsterdam : A. Asher and Company . [not seen, cited by Slow and Moll, 1981] . Can, A. & Meylan, A .B. 1980 . Extinction or rescue for the hawksbill? Oryx 15 : 449-450 . Chan, E .H. 1991 . Sea turtles, Pp . 120434 in Kiew, R . (ed.) . The State of Nature Con- servation in Malaysia. Malayan Nature Society, Kuala Lumpur . Chua, 'LK 1979. Conservation of the hawksbill turtle in Malacca. Can it be a reality? Malayan Naturalist, Sept ., 1979 : 15.17 . Hiew, W.P. 1990 . Laporan Penyu Terkena Pukat Pari di Kampong Balik Bukit, Tanjun g Kling, Melaka. Jabatan Perikanan Negeri Sembilan/Melaka . 8 pp . Kiew, B.H. 1975 . Report on the turtle beach of Tanjung Kling, Melaka . Malayan Natur e journal 29 : 59-69. Moll, E.O. 1990 . Status and management of the river terrapin Batagur baska in tropical Asia. Final report for WWF Project No . 3901 . October 1990 . 44 pp . Mortimer, J .A. 1988 . Recommendations for a National Strategy on Sea Turtle Con- servation in Malaysia—with suggestions for management of the nesting beach a t Abang, Terengganu and of the turtle hatchery at Pulau Besar, Melaka . Report to WWF/Malaysia and WWF/US. 11 pages . Mortimer, J.A. 1989 . Recommendations for management of the turtle nesting popula- tions in the state of Melaka. Report to Department of Fisheries Malaysia an d WWF Malaysia. August 1989 . 9 pp. Mortimer, J,A . 1990. The status of marine turtle populations in the vicinity of Pangko r Island in the state of Perak and recommendations for their management . Repor t to WWF Malaysia and Department of Fisheries of Malaysia. July 1990. 13 pp .

252 Mortimer, 1991a . A report on the turtle populations of the islands of Pahang an d suggestions for their management . Report to WWF Malaysia and Department o f Fisheries of Malaysia . July 1991 . 15 pp. Mortimer, J .A. 1991b . A report on the turtle populations of the islands of the east coast of Johor and suggestions for their management . Report to WWF Malaysia and Department of Fisheries of Malaysia . January 1990 (revised July 1991) . 13 pp. Mortimer, J .A. 1991c . Marine turtle populations of Pulau Red g : their status an d recommendations for their management . A report submitted to the Turtl e Sanctuary Advisory Council of Terengganu and WWF Malaysia . September 1991 . 31 pp. Mortimer, J .A. 1991d . Recommendations for the management of the sea turtles of Pulau Pinang, Pinang. Report to WWF Malaysia and Department of Fisheries o f Malaysia. January 1990 (revised July 1991) . 17 pp. Mortimer, J .A. & Zaid Ahmad, 1991 . The turtle egg hatchery at Pengkalan Balak, Melaka : 1990 Report. Report to WWF Malaysia and Department of Fisheries of Malaysia . February 1991 . 27 pp . Mortimer, & Zaid Ahmad . 1992. The turtle egg hatchery at Pengkalan Ratak, Melaka : 1990 Report. Buletin Perikanan. No, 76, Department of Fisheries, Ministry o f Agriculture, Malaysia. 24 pp , Mortimer, J .A., Zaid Ahmad, Safee b . Kaslan, Mohd, Dzuhari b . Mohd, Daud, D . Sharma, & S. Aikanathan, 1992, Evaluation of the practice of splitting sea turtle egg clutches under hatchery conditions . A report submitted to the Turtle Sanctuary Advisory Council of Terengganu and WWF Malaysia . March 1992, 12 pp . Mrosovsky, N,, A . Bass, LA . Corliss, Richardson & T.H. Richardson. 1992. Pivotal and beach temperatures for hawksbill turtles nesting in Antigua . Can, J. Zook 70 : 1920-1925 . Phillipps, A. 1988, A Guide to the Parks of Sabah, Sabah Parks Publication No, 9 . Sabah Parks Trustees, , Sabah . 63 pp . Siow, K .T. & Moll, E.O. 1981 . Status and conservation of estuarine and sea turtles in West Malaysian waters . Pp. 339-347 in K.A. Bjorndal (ed.), Biology and Conserva- tion of Sea Turtles. Smithsonian Institution Press, Washington, D .C. Sukarno, W . 1991 . Bancian Pendaratan Penyu Negeri Kedah Dam .). Amain Laporan kepada Pejabat Perikanan Kedah/ untuk Kerajaan Negeri Kedah Darul Amain Pusat Penyelidikan Sumber Ikan Maxim . 15 pp . Witherington, 13,E , 1992 . Behavioral responses of nesting sea turtles to artificial lighting . Herpetologica 48 : 31-39 . Witherington, B .E. & Bjorndal, K .A. 1991 . Influences of artificial lighting on the seawar d orientation of hatchling loggerhead turtles (Caretta caretta). Biological Conserva- tion 55 : 139-149 .

253