Training Workshop on Marine Turtle Research and Conservation /7/2001 Vung Tau & Con Dao

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1 Training Workshop on Marine Turtle Research and Conservation 2428/7/2001 Vung Tau & Con Dao 121

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3 D. V. Vu: Opening speech OPENING SPEECH: TRAINING WORKSHOP ON MARINE TURTLE RESEARCH AND CONSERVATION IN VIETNAM Vu Van Dai Director, Fisheries Department, Ministry of Fisheries, Hanoi, Vietnam Dear Representatives of the People s Committee of Ba Ria Vung Tau Province and Vung Tau Town, Representatives of Branches and Offices related to Scientific Research, International Experts, and Colleagues, On behalf of MoFi, I would like to welcome all representatives, scientists and managers who are attending the Training Workshop on Marine Turtle Research and Conservation in Vietnam, organized in Ba Ria Vung Tau. The east coast of Vietnam has a tropical, monsoon climate. Back from the coast there are two large deltas, one in the North and the other in the South. In the middle there is a narrow delta and an enormous mountain range runs parallel with the coast. For many decades our lives have been linked with the sea; and the coastal areas of Vietnam play an important role in our country s political, economic, diplomatic and security sectors. Vietnam also presides over a huge area of ocean. Its seas encompass many natural ecosystems and play a very important role in our economy, and the livelihoods of many people. Vietnam is a country endowed with abundant and diverse ecosystems, and a high diversity of species and gene generated resources. In general, we call these things biodiversity. According to research studies, there are about 12,000 plant species, 275 species of mammal, 800 species of birds, 180 species of reptiles, and 5,500 species of insect present in our country. Additionally, Vietnam has great potential in fisheries, with about 2040 species of sea fish, 225 species of shrimp and more than 653 species of seaweed, 35 species of squid, 12 species of sea snake, 5 species of marine turtle and 170 species of sea birds. Therefore, the Vietnamese Government has been very interested in developing the fisheries sector. Moreover, we are all trying our best to develop the available natural resources in a sustainable manner. Marine turtles have been used as food in the past (fat and protein) and to make many products (from bone, skin, fat and turtle shells). Thousands of years ago, the trading value of marine turtles was discovered. Now, however, selling marine live marine turtles, turtle meat, fat of turtles and turtle shells is illegal. Recently, marine turtles have been used for nonconsumptive purposes such as tourism, study, scientific research, and activities related to finding jobs, gaining information, and producing incomes. The value of marine turtles is not always easy to understand, but they cannot be replaced because of their role in marine ecosystems. This kind of reptile is a unique part of a complicated ecosystem; its life cycle is related to other marine products (including fish and mangrove forests) as well as service of ecosystem (example: coastal zone). Due to the fact that turtles migrate thousands of kilometres and take more than ten years to grow up, they are a symbol of marine and coastal environmental health at the global level and at the regional level. Apart from the material value of sea turtles, these marine species also have a cultural significance that we cannot easily put a value on. Each society has its own tradition of considering turtles as a symbol of belief and knowledge. In industrial society, this kind of reptile has a special function with an attractive appearance and an intriguing life cycle that creates much curiosity, they are ideal for education and research purposes. For all these reasons, marine turtles have become a symbol of conservation locally, as well as at an international level. To protect these species and ensure the rehabilitation of their populations, large areas of the world have to be considered and managed effectively. In short, marine turtle conservation means marine and coastal area protection. It also requires that we should work Training Workshop on Marine Turtle Research and Conservation 123

4 hard and use strong enforcement to protect them and their natural environment as it is the same world that human beings rely on. It should be highlighted that for sea turtles, and many other kinds of animals, it takes a lot of generations before population sizes can be restored after declines. Moreover, when they migrate, animals like sea turtles have to pass over the borders from this country to another. Therefore, we all share the responsibility to protect sea turtles, other animals, and their habitats as natural heritage. Dear colleagues, It is clear that our scientific achievements in biodiversity should have to link with other achievements of the country. The modest results that we have gained so far are a great improvement over the situation in past decades, and this success reflects the close, serious and untiring cooperation not only of scientists but also of supporting groups from government and international organisations. Recognizing the important role of biodiversity in economy and culture, Vietnam has been implementing some steps to protect natural resources for some decades now. Biodiversity conservation is a big challenge for Vietnam, and protecting natural ecosystems and the species that depend on them is not only a job for Vietnam; the rest of the world faces the same challenge. I do hope that the kind attention and encouragement of the Government in combination with the value support of international organisations in general (and of UNDP (CMSUNEP), DANIDA, and IUCN in particular) will help those of us who are researchers, managers and policy makers in continuing to protect Vietnam s natural resources in a sustainable way. And that they will assist us in planning and implementing the biodiversity development action plan for the longterm benefit of the country, as well as encouraging us to display our roles as part of the international community that aims to protect natural heritage. We wish the training workshop the best success, and our guests good health. 124

5 T. H. Nguyen: IUCN welcoming address IUCN STATEMENT AND WELCOME Nguyen Minh Thong Country Representative, IUCN Vietnam, Hanoi, Vietnam It is my pleasure to be here today and to deliver a short statement on behalf of IUCN The World Conservation Union at this important Training Workshop on Marine Turtle Research and Conservation in Vietnam. As you all know, Vietnam, a State Member of IUCN, ratified the Convention on Biological Diversity in November This shows the strong interest and commitment of Vietnam to the cause of environmental protection and nature conservation. IUCN therefore, over the past years, has been in close cooperation with the Government of Vietnam, particularly the Ministry of Environment, Science and Technology/ National Environment Agency (MOSTE/NEA), in a number of activities. Special focus has been on biodiversity conservation through, for example, our collaboration with the Ministry of Fisheries/Research Institute of Marine Products (MOFI/RIMP) in the implementation of the Pilot Hon Mun Marine Protected Area. The National Training Workshop on Marine Turtle Research and Conservation in Vietnam will provide support to the implementation of the Convention on Migratory Species Memorandum of Understanding (CMS/MoU) on Marine Turtle Conservation and Management in the Indian Ocean/SouthEast Asia in Vietnam. This workshop will build on existing national marine turtle research programs to raise awareness of the CMS MoU in Vietnam, particularly amongst senior officials in the Ministry of Fisheries, the Forest Protection Department (terrestrial national parks), and the Provincial Governments. The workshop has been designed to provide a comprehensive introduction to the CMS MoU as well as an introduction to the technical skills (including field observations in Con Dao) required for officials to develop an understanding of conservation and management issues. Additionally, the workshop will identify key stakeholders for participation in the development of a National Marine Turtle Action Plan for Vietnam (under the MoU), and will assess an initial set of issues for incorporation into the National Action Plan. Furthermore, on recommendation of the CMS Secretariat and IUCN Asia, the workshop has provided for limited participation by representatives of Cambodia. The reasons for this are twofold: (1) the workshop will provide an opportunity to increase scientific exchange and cooperation between Vietnam and Cambodia. This is of particular importance given the proximity of known marine turtles distributions to the Cambodia/Vietnam border. (2) Given the absence of a Cambodian national workshop, the present workshop will provide stimulus for Cambodian participation in the MoU. This training workshop will serve as a kickoff activity within the framework of the process to develop a draft National Action Plan for Marine Turtle Conservation and Management in Vietnam, and will support Vietnam s involvement in the CMS and regional marine turtle conservation forums. The workshop has been developed jointly by the Ministry of Fisheries (Research Institute for Marine Products), the Convention on Migratory Species Secretariat, Dr Pilcher of the University of Malaysia in Sarawak, and the IUCN Vietnam Marine Program. I would like to take this opportunity, on behalf of IUCN, to express sincere thanks all those who have contributed to the development the workshop, especially RIMP, Prof. Dr. Pham Thuoc and his staff the Ministry of Fisheries and others for their great support, international expert Dr. Nicholas Pilcher (University Malaysia Sarawak), Mr. Douglas Hykle (Deputy Executive Secretary of CMS UNEP), marine turtle specialist Dr. Jeff Miller, and Dr. Chan Eng Heng. Our special appreciation goes also to the CMS UNEP, the Danish International Development Agency (Danida), the US National Marine Fisheries Service (NMFS), the US National Fish and Training Workshop on Marine Turtle Research and Conservation 125

6 Wildlife Foundation (NFWF), and the members of the IUCN SSC for their cooperation and generous provision of grants to this first national training workshop in Vietnam. Thank you, and I wish you all good health. 126

7 D. Hykle: CMS welcoming address CMS WELCOMING ADDRESS Douglas Hykle Deputy Executive Secretary Convention on Migratory Species Director Vu Van Dai, Distinguished Speakers, Ladies and Gentlemen, I am pleased to be with you today on this, my third or fourth visit to Vietnam, but the first to this splendid southern coast. In February, I had the pleasure of visiting the Research Institute for Marine Products (RIMP) and the Ministry of Fisheries (MoFi), to become familiar with their work and to share information about the organisation that I represent, the Convention on Migratory Species (CMS). I would like to begin my remarks by paying tribute to Prof. Pham Thuoc, who had the vision two or three years ago to organize a national training workshop in Vietnam, as well a the persistence to bring it to fruition with the support of the RIMP and MoFi. I would also like to acknowledge the IUCNVietnam office for all its work in helping to organize the meeting, and Dr Nicholas Pilcher of the University of Malaysia for his efforts to raise funds for the meeting. I would like to complement the eloquent explanation of Dr Vu Van Dai of the rational for this workshop. I was reminded of a similar meeting that CMS organized in Africa some years ago, where some newspaper journalists were present. I remember speaking to an assistant to one of the journalists, who found it very amusing that we had organized a conference on marine turtle conservation. He simply couldn t understand why 50 people from various African countries had gathered to talk about an animal, which his compatriots consumed for food. It drove home to me the realization that we have to make a big effort to convince the general public of the rationale and importance of our work. Marine turtles are remarkable creatures, and we will certainly learn about their characteristics today and during the rest of the week. They are found throughout the world, and they are valued by different peoples and cultures for many purposes. They range from consumption for meat, eggs and shell to nonconsumptive uses, such as helping to generate income for local communities through tourism. We know that turtles are declining in number in many parts of the world, some critically. Their highly migratory nature means that countries need to collaborate in order to achieve effective conservation. In Manila, last June, a first step was in this direction was made with the conclusion of a Memorandum of Understanding on regional collaboration among Indian Ocean and Southeast Asian countries. I am happy to announce that a representative of the Government of Vietnam will sign the MoU on this auspicious occasion, making Vietnam the ninth signatory to the MoU, which will take effect on 1 September In closing, I regret very much that I will not be in a position to join you in Con Dao later in the week, because of other pressing commitments in Bonn, but I am sure that the team of eminent experts who have been assembled here will do a fine job of leading the discussions. I look forward to working with you in the next days and I wish you well in your remaining deliberations. Training Workshop on Marine Turtle Research and Conservation 127

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9 N. Pilcher: General biology GENERAL BIOLOGY OF MARINE TURTLES Nicolas J. Pilcher Institute of Biodiversity and Environmental Conservation Universiti Malaysia Sarawak, Kota Samarahan, Sarawak, Malaysia History and General Biology Marine turtles have survived on earth for centuries. Mankind s actions though, in particular in the 19th and 20th centuries, have brought many populations to the brink of extinction. Awakened in biologists minds by the late Archie Carr (Carr 1942; Carr & Giovannoli 1957; Carr et al. 1966; Carr 1967; Carr 1975; Carr & Stancyk 1975; Carr 1986a; Carr 1986b), sea turtles have come to symbolise conservation efforts in a marine context, and through a far reaching and migratory group of animals such as these, widespread international cooperation. Turtles probably appeared in the late Triassic ca. 200 million years ago (Pritchard 1997). When dinosaurs became extinct ca. 100 million years later, turtles survived through their adaptation to marine environments, and do so today, relatively unchanged. There are several key physiological features that are common to all sea turtle species and which set them apart from other Testudines, such as nonretractile limbs, extensively roofed skulls, limbs converted to paddlelike flippers, and salt glands to excrete excess salt. As is the case with other reptiles, the sex of hatchlings is dependent on temperature during incubation, particularly during the third and fourth weeks (Miller & Limpus 1981; Miller 1985). Today, there are seven or eight (depending on one s point of view) extant species of sea turtles: the Leatherback Dermochelys coriacea (Family Dermochelydae), the Loggerhead Caretta caretta, the Hawksbill Eretmochelys imbricata, the Olive ridley Lepidochelys olivacea, the Kemp s ridley Lepidochelys kempi, the Green Chelonia mydas and the Flatback Natator depressus (all in the Family Cheloniidae). An eighth species, the black turtle Chelonia agassizii is currently the subject of debate among biologists, having first been described by Bocourt (1868) but later disputed by Bowen et al. (1993). The Convention on International Trade in Endangered Species of Flora and Fauna (CITES) lists Chelonia mydas and Caretta caretta as Threatened and the remainder are listed as Endangered, save for Natator, whose status is as yet unknown. Why Conserve Sea Turtles? Sea turtles have been used for as long as man can remember for food and other commodities. Their importance in trade dates back millennia, either for their shell, meat, oils or leather. Recently turtles have become important for nonconsumptive uses such as tourism, education and research activities, employment and other gains. A less apparent, but irreplaceable value is as an ecological resource. Turtles are unique components of complex ecological systems, the viability of which is linked to exploitable products (such as fish and shells). Turtles have immeasurable value as cultural assets as well as being important indicators of coastal and marine environments. They are model flagships for both local and regional conservation, and by conserving turtles and their habitats vast marine areas have to be taken into consideration, protecting the complex, interconnected world on which human societies depend. General Reproductive Biology In general, turtles migrate from distant feeding grounds to different nesting areas and once the males and females arrive, they mate during a period of 1 2 months. After mating, females take 2 4 weeks to emerge on the beach and lay the first clutch of eggs. After this, they may return 4 Training Workshop on Marine Turtle Research and Conservation 129

10 8 more times to lay again in the same season. The actual nesting process can be described in seven basic steps: Emerging when the turtles leave the ocean and crawl up the beach; Digging when the large body pit is excavated using the front flippers; Chambering when the egg chamber is excavated using the rear flippers; Laying actual egg deposition; Filling covering the nest with sand back to the original beach level; Returning crawling back down the beach to the ocean; and Wandering crawling over the beach between nesting attempts. Each nest contains around 100 eggs, which measure 4 5 cm and weigh 2030 g. The eggs take ca. 60 days to incubate, and invariably hatch after dark, when the sand surface cools. The hatchlings excavate through the sand for two or three days before emerging, and weigh g and measure 4 5 cm in length. Hatchlings crawl down the beach and head directly offshore using light, wave direction and the earth s magnetic field for guidance. They swim for 1 2 days in what is known as a swimming frenzy to get as far offshore as possible. After this, they generally float as part of the ocean s plankton for several years until they migrate from oceanic waters onshore to shallow feeding areas. After five to ten years they may grow to juveniles cm in length. They remain at their feeding grounds for 5 10 or more years until they reach sexual maturity, and undertake their first migration to the mating and nesting areas, whereupon the cycle is repeated (Fig. 1). Fig. 1: Generalised life cycle of marine turtles (after Lanyon et al. 1989). Individual adult female green turtles nest after 2 4 year intervals (remigration period), while adult males may remigrate after 1 2 years (Balazs 1983). Hatchlings are believed to have a survival probability of < 0.01, but the probability of turtle survival increases exponentially with size, where adults have the highest survival rate due to size and restricted number of predators (Crouse et al. 1987). Growth is fast (5 10 cm yr 1 ) in hatchlings and juveniles (2 4 cm yr 1 ) but very slow (0.2 cm yr 1 ) or nonexistent in adults (Bjorndal & Bolton 1988). Sea turtles do not tend to become reproductively mature until they reach at least years of age (Frazer & Ehrhart 1985). 130

11 N. Pilcher: General biology By understanding the reproductive output of a population we may draw inferences on its potential growth or decline. Although many reproductive characteristics vary from population to population, it is important to distinguish between evolutionary adaptations and poor nesting success. For example, adult populations across the globe vary in average size and weight, and the turtles in the Middle East region tend to be among the smallest on a global scale, with turtles from the Atlantic Ocean being generally larger. Within the IndoPacific region, the Arabian Gulf population was found to be at the lower end of the scale, while the Red Sea population was found to be at the upper end. Across regions, the Saudi Arabian turtles were smaller and lighter than turtles from the Atlantic Ocean region. It is believed that the longterm feeding history of turtles in the Arabian Gulf, with its associated environmental extremes, may have resulted in the lower overall body size. In contrast, the smaller number of turtles in the Red Sea competing for seagrass that is distributed along the extensive coast, and the lack of migrations in and out of the Red Sea, may be responsible for their larger body size. These physiological differences need not necessarily be an indication of health; they could be simple geographical variations within individual species. Critical Biological Adaptations The physiological design and biological adaptations of sea turtles have remained unchanged for millions of years. There are certain aspects of their natural history set them apart from most marine inhabitants that, when combined with modernera technology and population pressures, may prove detrimental to their longterm survival. Migrations A characteristic that has fascinated biologists through time is the marine turtle s periodic migration to and from nesting and foraging sites, sometimes over vast distances. Chelonia mydas can sustain swimming speeds of 44 km day 1 (Limpus et al. 1992) and have been recorded as migrating distances of up to 3410 km from Gielop (Micronesia) to Majuro (Marshall Islands) (Hirth & U.S. Fish and Wildlife Service 1997). Adult females do not necessarily nest at the closest rookery to the feeding area, as noted with green and hawksbill populations along the Great Barrier Reef (Limpus et al. 1983). Through the results of tagging projects and extensive fieldwork throughout the Caribbean (see Carr 1986b), no turtle tagged in Tortuguero, Costa Rica, was found nesting elsewhere during 22 years of monitoring (Carr et al. 1978), suggesting those turtles nested only at the one site. Green turtles make very deliberate journeys to specific geographical targets with females showing high site fidelity after remigrations, generally of 2 4 years (Limpus et al. 1992). Carr et al. (1978) reported remigration cycles of 2 years (21 %), 3 years (49 %) and 4 years (18 %) for female greens in Tortuguero. Male green turtles possibly have shorter remigration periods (Limpus 1993), and Clifton (1983) described a oneyear breeding cycle for the black turtle in Mexico (in Figueroa et al. 1992). Interestingly, many turtles nest only once in a lifetime (Carr et al. 1978), and are never recorded to remigrate to their nesting ground during subsequent years. With saturation field research projects around the globe, and given most tags last at least four or five years (Limpus 1992), it is doubtful this segment of the population would go unnoticed if they were to nest at other rookeries. Remigrant turtles have been found to nest more frequently in a season and lay more eggs than recruits (Carr et al. 1978), suggesting some sort of adaptive mechanism / learning process related to the first nesting experience. Whereas natural mortality may explain a significant proportion of turtles that nest only once, it is suggested that a bad nesting experience, whereby an adult turtle is disturbed as she nests or attacked while at sea in the vicinity of the nesting beaches may also contribute to this phenomenon. Training Workshop on Marine Turtle Research and Conservation 131

12 Age at Maturity Marine turtles are estimated to live long lives, even up to 100 years. They are known to reach sexual maturity only after 15 to 40 years, depending on species, presenting unique management requirements. Turtle hatchlings emerging today might only return to nest after 20 to 30 years, by which time few, if any, of our present scientists and managers will be following their progress. Additionally, their long absence from known feeding or foraging sites masks any changes to population sizes. For this reason, effects on longterm survival such as egg collection or adult harvesting might not be noted for a number of years, if at all (Fig. 2). Fig. 2: In a simple hypothetical case, if 100% of turtles were harvested each year before laying eggs, there would reach a point at which no further breeding females would be available. However, this would not become apparent for another 25 years (after Mortimer 1995). Additionally, and more importantly, is that their long maturation period means that they face an everincreasing number of mortality pressures during a long period of time, which prevents population restocking. Habitat Requirements and Degradation Sea turtles need a number of different habitats to complete their natural life cycle. From when eggs are deposited on clean sandy beaches, to hatchling migrations through unpolluted waters, and shallow foraging sites such as seagrass beds, rocky reefs and coral reefs, to deep oceans teeming with life, turtles depend on habitats that circumscribe the tropics and even extend to far northern and southern latitudes. On small beaches there is a risk of density dependent nesting mortality as the population size grows exponentially (see Balazs 1980), where nests face higher risks of being disinterred by other nesting adults with high nesting densities. Lighting on beaches is hazardous to emerging hatchlings as the lights attract hatchlings away from the shoreline (Witherington & Bjorndal 1991), and in many developed coastal areas may be responsible for a large percentage of hatchling loss. In Florida, legislation exists that controls light use close to turtle beaches (Lutcavage et al. 1997), but this sort of regulation is not applied nor enforced in most turtle rookeries in other locations. Nesting habitats are threatened by the disappearance of beaches through sea level rise and erosion processes (Ackerman 1997), beach nourishment, armouring and sand mining, and through residential development (Lutcavage et al. 1997). On the open sea, turtles face the risk of fishery mortality (Poiner & Harris 1994), and a number of other threats, such as oil pollution. Hutchinson & Simmonds (1992) discuss the increased threats to turtles from oil as they migrate across vast expanses of ocean. At foraging sites, turtles are threatened by marine debris (Balazs 1985), destructive fishing practices such as blast and cyanide fishing (Bjorndal 1996; Pilcher & Oakley 1997), anchors and propellers, siltation and the use of bottom trawls in seagrass ecosystems (Bjorndal 1996). 132

13 N. Pilcher: General biology References Ackerman RA The nest environment and the embryonic development of sea turtles. In: Lutz PL & Musick JA, eds. The biology of sea turtles. CRC Publishing, Boca Raton, pp Balazs GH Synopsis of the biological data on the green turtle in the Hawaiian Islands. NMFSSWFC7 NOAA, Honolulu. Balazs GH Recovery records of adult green turtles observed or originally tagged at French frigate Shoals, northwestern Hawaiian Islands. Tech. Memo. NMFSSWFC36 NOAA, Honolulu. Balazs GH Impact of ocean debris on marine turtles: Entanglement and ingestion. In: Proceedings of a workshop on the fate and impact of marine debris. NOAA, NOAA TMNMFSSWFC54, Honolulu, pp Bjorndal KA Foraging ecology and nutrition of sea turtles. In: Lutz PL & Musick JA, eds. The biology of the sea turtles. CRC Press, Boca Raton, pp Bjorndal KA & Bolton AB Growth rates of immature green turtles, Chelonia mydas, on feeding grounds in the southern Bahamas. Copeia 1988: Bocourt MM Description de quelques cheloniens nouveau appartenent a la faune mexicaine. Ann. Sci. Nat. Ser. 5: Bowen BW, Nelson WS & Avise JC A Molecular Phylogeny for Marine Turtles Trait Mapping, Rate Assessment, and Conservation Relevance. Proceedings of the National Academy of Sciences of the United States of America 90: Carr A Imperilled gift of the sea. National Geographic 1967: Carr A The Ascention Island green turtle colony. Copeia : Carr A. 1986a. Rips, FADS, and little loggerheads. BioScience 36: Carr A. 1986b. The sea turtle: So excellent a fishe. University of Texas Press, Austin. Carr A & Stancyk S Observations on the ecology and survival outlook of the hawksbill turtle. Biological Conservation 8: Carr A, Hirth A & Ogren L The ecology and migrations of sea turtles. 6. The hawksbill turtle in the Caribbean Sea. American Museum Novitiates 162: 146. Carr A, Carr MH & Meylan AB The ecology and migrations of sea turtles. 7. The west Caribbean Sea. Bulletin of the American Museum of Natural History 162: 146. Carr AE Notes on sea turtles. New England Zoological Club 21: 116. Carr AE & Giovannoli L The ecology and migrations of sea turtles. 2: Results of field work in Costa Rica, American Museum Novitiates 1835: 132. Clifton K The ecological recovery of Chelonia agassizzi, the East Pacific turtle of Mexico. WWFUS, Mexico City. Crouse DT, Crowder LB & Caswell H A stagebased population model for loggerhead sea turtles and implications for conservation. Ecology 68: Figueroa A, Alvarado J, Hernandez F, Rodriguez G & Robles J Population recovery of the sea turtles of Michoacan, Mexico: An integrated conservation approach. WWF, USFWS, Mexico City. Frazer NB & Ehrhart LM Preliminary growth models for green, Chelonia mydas, and loggerhead, Caretta caretta, turtles in the wild. Copeia 1985: 73. Training Workshop on Marine Turtle Research and Conservation 133

14 Hirth HF & U.S. Fish and Wildlife Service Synopsis of the biological data on the green turtle Chelonia mydas (Linnaeus 1758). Fish and Wildlife Service U.S. Dept. of the Interior, Washington, D.C. Hutchinson J & Simmonds M Escalation of threats to marine turtles. Oryx 26: Lanyon JM, Limpus CJ & Marsh H Dugongs and turtles: Graziers in the seagrass system. In: Larkum AD, McComb A & Shepherd SA, eds. Biology of Seagrasses, A treatise on the biology of seagrasses with special reference to the Australian region. Elsevier, Amsterdam, pp Limpus CJ Estimation of tag loss in marine turtle research. Wildlife Research 19: Limpus CJ The green turtle, Chelonia mydas, in Queensland: Breeding males in the southern Great Barrier Reef. Wildlife Research 20: Limpus CJ, Reed P & Miller JD Islands and turtles: The influence of choice of nesting beach on sex ratio. In: Proceedings of the inaugural Great Barrier Reef conference. JCU Press, Townsville, pp Limpus CJ, Miller JD, Parmenter CJ, Reimer D, McLachlan N & Webb R Migration of green (Chelonia mydas) and loggerhead (Caretta caretta) turtles to and from eastern Australian rookeries. Wildlife Research 19: Lutcavage ME, Plotkin P, Witherington BE & Lutz PL Human impacts on sea turtle survival. In: Lutz PL & Musick JA, eds. The biology of sea turtles. Boca Raton, pp Miller JD Embryology of marine turtles. In: Gans C, Billett F & Maderson PFA, eds. Biology of the Reptilia. John Wiley & Sons, New York, pp Miller JD & Limpus CJ Incubation period and sexual differentiation in the green turtle Chelonia mydas L. In: Proceedings of the Melbourne Herpetological Symposium. Zoological Board of Victoria, Melbourne, Victoria, Australia, pp Mortimer JA Teaching critical concepts for the conservation of sea turtles. Marine Turtle Newsletter 71: 14. Pilcher NJ & Oakley SG Unsustainable fishing practices: Crisis in coral reef ecosystems of Southeast Asia. In: Proceedings of the Oceanology International 1997, Pacific Rim May 1997, Singapore, pp Poiner I & Harris ANM The incidental capture and mortality of sea turtles in Australia's northern prawn fishery. In: Proceedings of the Marine Turtle Conservation Workshop. Australian National Parks and Wildlife Service, Canberra, pp Pritchard PCH Evolution, phylogeny, and current status. In: Lutz PL & Musick JA, eds. The biology of sea turtles. CRC Press, Boca Raton, pp Witherington BE & Bjorndal KA Influences of artificial lighting on the seaward orientation of hatchling loggerhead turtles Caretta caretta. Biological Conservation 55:

15 B. O Callaghan: Threats to turtles THREATS TO TURTLES Bernard O Callaghan Chief Technical Advisor, Hon Mun MPA Pilot Project for Vietnam. Marine turtles are severely threatened. Globally the numbers of turtles are decreasing. This is causing great concern worldwide. Thus, the aim of this paper is to consider the main threats to marine turtles and to describe in some detail these threats. Introduction In a natural environment, there are a number of factors that have limited the total numbers of turtles. These include cyclones, predators and diseases. In the natural system these deaths are replaced by the annual breeding and reproduction patterns of the species. However, when recent human activities have caused a dramatic decrease in the total number of turtles through the deaths of many turtles. This is threatening the survival of many turtle populations primarily due to these human activities. These threats can be classified into three categories. They are: Nesting threats Threats from human marine activities Disease threats These threats will be described and discussed in more detail below. Nesting threats All species of marine turtle lay eggs on sandy beaches. Eggs are deposited into holes dug on these beaches and the adult female turtles then return to the sea. However, while adult turtles are agile in the oceans, on land they move very slowly and are vulnerable. In addition, the young turtles are at the most susceptible stage of their lives as they move from the nest to the sea. An important point to note is that it is believed that marine turtles have an extremely high affinity for their nesting beaches, and therefore the loss or reduction of even a single nesting beach can have serious effects. Some of the key threats turtles face during their breeding and nesting are described below. Increased Human Presence Residential and tourist use of beaches can result in disturbance to nesting turtles. The most serious threat is cause by increased human presence on beaches, especially at night. This results in nesting females shifting their nesting sites, sometimes being forced to use less suitable beaches. Egg laying can be aborted or delayed. Recreational equipment The equipment associated with recreation use of beaches discourages nesting activity on beaches that have been used by turtles for millennia. The introduction of recreational equipment such as lounge chairs, umbrellas, small boats, and beach cycles reduces the usefulness of a beach for nesting, and can seriously damage or destroy any existing nests. In addition, female turtles can become trapped in this equipment. Beach replenishment Beach replenishment is where sand is added to the beach, often through offshore dredging. Also, heavy equipment on beaches can pack the sand, making it impossible for turtles to dig proper nests. This alters egg and hatchling survivorship. Beach armouring Beach armouring is the construction of infrastructure such as sea walls, rock walls, sandbag installations, groins and jetties. These practices in the shortterm protect Training Workshop on Marine Turtle Research and Conservation 135

16 investments, but ultimately result in environmental damage and loss of a dry nesting beach. Beach erosion Erosion can be the result of human activities on the coastal environment. Erosion can result in the loss of nesting habitat. Erosion also prompts the development of beach armouring as described above. Changing beach temperature In turtles, the sexes of the young are determined by the sand temperature in which the eggs are incubated. Changes in beach temperature through the construction of highrise buildings close to the shore can alter sex ratios by shading nesting beaches and creating a cooler incubation environment that will produce more male hatchlings Lighting and costal developments Lighting of streets, pathways and developments, e.g. houses and restaurants, can disorient marine turtle hatchlings and nesting females by altering natural lighting and topography horizons which are used as guidance mechanisms by turtles. Predators The opening up of coastal beaches, and the introduction of predatory species onto islands, is having a detrimental impact on young turtles. This unnatural predation, together with natural predation, has dramatically decreased the survival rate of newly hatched turtles. Poaching The eggs of sea turtles are considered by many people as highly desirable for a number of reasons. This results in the theft of turtle eggs and continues to be a serious problem everywhere turtles nest. Threats from human marine activities If young turtles are to survive their entry into the world, they must escape the threats described on the beach areas. They are increasingly threatened by the marine related activities of humans. With the exception of the leatherback, marine turtles live most of their lives in fairly shallow coastal waters, making them very vulnerable to our activities. The number of turtles killed by these activities is not accurately known, but the annual mortality is expected to be in the many thousands. A description of these threats is provided below. Commercial turtle fisheries The most serious marine environment threat to turtles is commercial fishing. In some parts of the world, turtles are still hunted, both for food and for their shells. In places where turtle hunting is banned, the incidental taking of turtles during other fishing operations remains a major threat. Bycatch in fishing activities Many commercial fishing activities catch turtles. Some examples include shrimp trawlers that trap and drown sea turtles. Gill nets also snare turtles, and frequently are not pulled soon enough to free the turtles before they drown. Although turtles can remain underwater for long periods, they need to breathe. In recent years, trawl fishers and scientists have developed and introduced Turtle Exclusion Devices (TEDs) in trawl nets to exclude turtles from the catch. Boat Strikes Many millions of boats operate through our oceans. Any vessel, including commercial ships, fishing vessels, and recreational craft can strike marine turtles. Turtles, especially 136

17 B. O Callaghan: Threats to turtles green turtles, are known to bask at the water's surface. Turtles may be struck when they are unaware of, or fail to avoid, an oncoming vessel, or when the driver of the vessel is not aware of, or cannot avoid, the animal. The increasing number of highspeed vessels operating increases the risk of such collisions. In Australia, on average, 14% of the marine turtles that strand on the Queensland coast show evidence of being struck by boats and/or propellers. Defence Activity Potential impacts arising from Defence activities include detonations of explosives, the use of live munitions and the use of active sonar and other acoustic devices. Shock waves from explosives can kill or injure marine turtles, or cause displacement of animals from areas. Pollution and Marine Debris The dumping of garbage is prohibited in many places, but increasing amounts of debris, such as plastic objects, enter the marine environment every year. The feeding strategies of turtles mean they associate with areas where oceanic debris concentrates. Some of this debris, such as discarded lines, can entangle marine turtles, while other kinds of debris, such as plastic bags, may be mistaken for food and ingested. Debris on nesting beaches can interfere with a turtle's ability to dig an egg chamber. Oil and gas exploration The exploitation of offshore oil and gas reserves leads to oil spills and the presence of tar in the water. Both of these pollutants have serious effects on marine turtles. Oil on the skin and shell of a marine turtle can affect respiration and salt gland functions, as well as the turtle's blood chemistry. The ingestion of tar pellets is also a major concern. Disease Although diseases kill turtles, identifying a specific disease can be difficult. Often carcasses of marine turtles wash ashore on beaches but are too decomposed for an accurate determination of the cause of death. There is particular concern about fibropapilloma (FP) tumours, these are lobeshaped tumours that can infect all soft portions of a turtle's body. Tumours grow primarily on the skin, but they can also appear between scutes, in the mouth, on the eyes, and on internal organs. These tumours often increase in size and number until the turtle is seriously debilitated. Death is a common outcome. While there have been isolated reports of FP in turtles that date back as far as the 1930s, it was only in the early 80s that the disease began to reach epidemic proportions. For unknown reasons, FP began infecting green turtles in large numbers simultaneously in several geographically discrete areas, such as Hawaii, Florida, and Australia. By the mid90s, the single greatest threat to the green turtle was FP. Conclusions The purpose of this paper is to provide an overview of the issues that are being faced by the dwindling populations of marine turtles. It aims to provide an introduction to the discussions that will be held over the next few days. References, sources and further reading Sources of further information on the threats to marine turtles are listed below: Threats to marine turtles Great Barrier Reef Marine Park Authority: Threats to marine turtles Training Workshop on Marine Turtle Research and Conservation 137

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19 J. D. Miller: Identification of species IDENTIFICATION OF MARINE TURTLES IN SOUTHEAST ASIA Jeff D. Miller Queensland Parks and Wildlife Service, PO Box 2066, Cairns, Queensland, Australia There are five species of marine turtles found in the waters of Southeast Asia: the leatherback turtle, the green turtle, the loggerhead turtle, the hawksbill turtle, and the olive ridley turtle (Table 1). The species can be easily identified by counting the scales on the carapace (shell) and head, counting inframarginal scales (between the carapace and plastron), and examining them for pores, and counting the claws on the front flipper (see Pritchard & Mortimer 1999, for greater detail). Although turtle species can often be identified by simply looking at the size, shape and colour, these characteristics can be misleading. Hatchling, juvenile and adult turtles differ in size and shape. Moreover, coloration and pattern varies among individuals and populations. The essential characteristics necessary to identify marine turtles are illustrated in Fig. 1. Table 1. Classification of turtles occurring in Southeast Asian waters. Family Genus Species English Name Vietnamese Name Dermochelyidae Dermochelys D. coriacea leatherback turtle Rùa Da Cheloniidae Chelonia C. mydas green turtle Vích Cheloniidae Caretta Car. caretta loggerhead turtle Quản Ðống Cheloniidae Eretmochelys E. imbricata hawksbill turtle Ðối Mối Thường Cheloniidae Lepidochelys L. olivacea olive ridley turtle Ðối Mối Dứa To use the key, examine the turtle and decide if the carapace is black with several white ridges running from the front to the back of the shell or not. If so, it is a leatherback turtle. If not, count the costal scales (shaded on the diagram). If there are 4 coastal scales, count the scales on the head (shaded on the diagram). If not, then it must have either 5 or 6 (or more) costal scales. If it has 5 costal scales, it is a loggerhead and, if it has 6 or more, it is an olive ridley turtle. To confirm the identification examine the inframarginal scales for the presence or absence of pores and count the number of claws on one front flipper (Table 2). Following this procedure in sequence allows the turtle to be identified regardless of its size or coloration. Using other characters or not following the sequence can lead to misidentification. For example, occasionally a turtle will have an odd number of scales and not be easily identified. These odd scales may or may not reach from the marginal scales to the vertebral scales. If a scale does not touch the four scales around it, do not count it. If the turtle presents a confusing pattern of characteristics, use Table 2 to evaluate the best fit of the most characters. Account for each of the characters listed in the table on the specimen, and be sure to photograph or draw the shell pattern as well as the pattern of the scales on the head. Hybridisation does occur, but only rarely. If you suspect that the turtle you have is a hybrid, collect a small piece of skin and place it in a labelled vial of plain salt for later DNA analysis. Training Workshop on Marine Turtle Research and Conservation 139

20 Fig. 1. The essential characteristics necessary to identify marine turtles. Pictorial key to the identification of marine turtles in South East Asia (modified from an original key by C. J. Limpus) (also see Table 2). Table 2. Synopsis of the characteristics used to identify the marine turtles in Southeast Asia. (See also Fig. 1) GENUS HEAD CARAPACE FLIPPER PLASTRON Number of Prefrontal Scales Number of Coastal Scales Number of Claws on Front Flipper Number of Inframarginal Scales Dermochelys None None, 5 None in adults None longitudinal ridges Chelonia , without pores Caretta 4 (sometimes 5) 5 (rarely 6) 2 3, without pores Eretmochelys , without pores Lepidochelys 4 6 or more 1 4, with pores References Pritchard PCH & Mortimer JA Taxonomy, external morphology and species identification. In: Eckert KL, Bjorndal KA, AbreuGrobois FA & Donnelly M, eds. Research and management techniques for the conservation of sea turtles. IUCN Marine Turtle Specialist Group Publication No. 4., pp

21 J. D. Miller: General beach methods GENERAL BEACH METHODS FOR STUDYING MARINE TURTLES Jeff D. Miller Queensland Parks and Wildlife Service, Northern Region, PO Box 2066 Cairns, Queensland 4870, Australia Introduction The following comments provide a brief outline to the general methods used by researchers around the world and are based on the IUCN SSC Marine Turtle Specialist Group recommended methods (Eckert et al. 1999). These comments are meant to serve as a brief guide and a reminder, rather than a detailed protocol of research methods. There are three distinct phases to conducting a field study of the nesting biology of marine turtles: Preparation, Fieldwork, and Reporting. The ultimate goal of helping marine turtles to survive cannot be achieved unless each phase is completed: without proper preparation (setting of goals, selecting methods), the study never really begins; without field work (including training), the necessary data will not be gathered; without a report, the knowledge gained through the study will not be available to influence the decisions. Preparation The first step in a research project is the identification the problem(s) or issue(s) to be addressed. The identification of issues must be based on experience and local information. Once identified these should be ranked from the most critical to the least and a search of the published literature to find out how others have addressed the issues and what methods were used. Based on the combined input of local experience and published information, a set of goals (both short term and long term) can be formulated. Only after the goals have been set can appropriate methods be selected. Fieldwork Fieldwork is not simply going out and collecting data. The first step in fieldwork is training to ensure that each person is using the same the techniques in the same manner; this builds confidence in each person and helps build a team. Training is also important in ensuring safety of staff and the animals with which they are working. Following training, the actual fieldwork involves the logistical support of the field team as well as their safety. All of the support assists in obtaining the goals by providing a context in which the data are collected. All field data need to be checked in the field. This involves daily record keeping so that discrepancies can be identified and checked before the end of the field period. Sometime it is possible to enter the data into a computerised database in the field and sometimes this is accomplished after the fieldwork has finished. Reporting Like the other two phases of beach work, reporting of the data is important and contains several steps. The field data must be computerised to support analysis, but before being analysed it must be checked for accuracy. The actual analysis of the data must be appropriate to the data; most data recorded during beach work can be displayed using histograms and scatterplots. In future years of the study, the data collected during each season may be compared across seasons using ttest (two seasons) and ANOVAs (multiple seasons), as well as to published information. The analysis of the data is not the end point; appropriate management actions need to be recommended so that managers have a basis for making decisions and committing funds for turtle conservation. This means that a written report is essential at the completion of the project. For projects that span several years, annual reports that keep the managers informed of the progress and findings are very important. It is the job of the researcher to organise and conduct Training Workshop on Marine Turtle Research and Conservation 141

22 scientific research that addresses the important management and biological issues impinging on the longterm survival of the turtles; it is also the job of the researcher to present the result to the managers in an understandable manner. Without both of these tasks being completed, the turtles are still at risk. General methods The methods selected depend on the issues being addressed. If the primary need is to determine the distribution of nesting sites and the relative species distribution, aerial surveys may be the most cost effective means by which to provide the needed information. If this information is already known and the need is for more detailed information then an assessment of the biological characteristics of the turtles may be the most appropriate action. Assessment on the nesting beach might include tagging, measuring, and/or weighing of the females and their eggs. If the emphasis is on evaluating incubation and hatching success, then counting eggs at oviposition, putting a marker in the nest, and counting hatchlings would be relevant actions. Details of how to measure and weigh sea turtles, how to handle their eggs, and how to evaluate the contents of emerged nests, as well as many other how to directions, can be found in the Marine Turtle Specialist Group research and management techniques manual (Eckert et al. 1999). References Eckert KL, Bjorndal KA, AbreuGrobois FA & Donnelly M eds Research and management techniques for the conservation of sea turtles. IUCN/SSC Marine Turtle Specialist Group. 142